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1. The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters

Author

Mathew S. Madhavacheril, Frank J. Qu, Blake D. Sherwin, Niall MacCrann, Yaqiong Li, Irene Abril-Cabezas, Peter A. R. Ade, Simone Aiola, Tommy Alford, Mandana Amiri, Stefania Amodeo, Rui An, Zachary Atkins, Jason E. Austermann, Nicholas Battaglia, Elia Stefano Battistelli, James A. Beall, Rachel Bean, Benjamin Beringue, Tanay Bhandarkar, Emily Biermann, Boris Bolliet, J Richard Bond, Hongbo Cai, Erminia Calabrese, Victoria Calafut, Valentina Capalbo, Felipe Carrero, Anthony Challinor, Grace E. Chesmore, Hsiao-mei Cho, Steve K. Choi, Susan E. Clark, Rodrigo Córdova Rosado, Nicholas F. Cothard, Kevin Coughlin, William Coulton, Kevin T. Crowley, Roohi Dalal, Omar Darwish, Mark J. Devlin, Simon Dicker, Peter Doze, Cody J. Duell, Shannon M. Duff, Adriaan J. Duivenvoorden, Jo Dunkley, Rolando Dünner, Valentina Fanfani, Max Fankhanel, Gerrit Farren, Simone Ferraro, Rodrigo Freundt, Brittany Fuzia, Patricio A. Gallardo, Xavier Garrido, Jahmour Givans, Vera Gluscevic, Joseph E. Golec, Yilun Guan, Kirsten R. Hall, Mark Halpern, Dongwon Han, Ian Harrison, Matthew Hasselfield, Erin Healy, Shawn Henderson, Brandon Hensley, Carlos Hervías-Caimapo, J. Colin Hill, Gene C. Hilton, Matt Hilton, Adam D. Hincks, Renée Hložek, Shuay-Pwu Patty Ho, Zachary B. Huber, Johannes Hubmayr, Kevin M. Huffenberger, John P. Hughes, Kent Irwin, Giovanni Isopi, Hidde T. Jense, Ben Keller, Joshua Kim, Kenda Knowles, Brian J. Koopman, Arthur Kosowsky, Darby Kramer, Aleksandra Kusiak, Adrien La Posta, Alex Lague, Victoria Lakey, Eunseong Lee, Zack Li, Michele Limon, Martine Lokken, Thibaut Louis, Marius Lungu, Amanda MacInnis, Diego Maldonado, Felipe Maldonado, Maya Mallaby-Kay, Gabriela A. Marques, Jeff McMahon, Yogesh Mehta, Felipe Menanteau, Kavilan Moodley, Thomas W. Morris, Tony Mroczkowski, Sigurd Naess, Toshiya Namikawa, Federico Nati, Laura Newburgh, Andrina Nicola, Michael D. Niemack, Michael R. Nolta, John Orlowski-Scherer, Lyman A. Page, Shivam Pandey, Bruce Partridge, Heather Prince, Roberto Puddu, Federico Radiconi, Naomi Robertson, Felipe Rojas, Tai Sakuma, Maria Salatino, Emmanuel Schaan, Benjamin L. Schmitt, Neelima Sehgal, Shabbir Shaikh, Carlos Sierra, Jon Sievers, Cristóbal Sifón, Sara Simon, Rita Sonka, David N. Spergel, Suzanne T. Staggs, Emilie Storer, Eric R. Switzer, Niklas Tampier, Robert Thornton, Hy Trac, Jesse Treu, Carole Tucker, Joel Ullom, Leila R. Vale, Alexander Van Engelen, Jeff Van Lanen, Joshiwa van Marrewijk, Cristian Vargas, Eve M. Vavagiakis, Kasey Wagoner, Yuhan Wang, Lukas Wenzl, Edward J. Wollack, Zhilei Xu, Fernando Zago, and Kaiwen Zheng

Subjects
Cosmology, Observational cosmology, Cosmic microwave background radiation, Large-scale structure of the universe, Cosmological neutrinos, Particle astrophysics, Astrophysics, QB460-466
Abstract

We present cosmological constraints from a gravitational lensing mass map covering 9400 deg ^2 reconstructed from measurements of the cosmic microwave background (CMB) made by the Atacama Cosmology Telescope (ACT) from 2017 to 2021. In combination with measurements of baryon acoustic oscillations and big bang nucleosynthesis, we obtain the clustering amplitude σ _8 = 0.819 ± 0.015 at 1.8% precision, ${S}_{8}\equiv {\sigma }_{8}{({{\rm{\Omega }}}_{{\rm{m}}}/0.3)}^{0.5}=0.840\pm 0.028$ , and the Hubble constant H _0 = (68.3 ± 1.1) km s ^−1 Mpc ^−1 at 1.6% precision. A joint constraint with Planck CMB lensing yields σ _8 = 0.812 ± 0.013, ${S}_{8}\equiv {\sigma }_{8}{({{\rm{\Omega }}}_{{\rm{m}}}/0.3)}^{0.5}=0.831\pm 0.023$ , and H _0 = (68.1 ± 1.0) km s ^−1 Mpc ^−1 . These measurements agree with ΛCDM extrapolations from the CMB anisotropies measured by Planck. We revisit constraints from the KiDS, DES, and HSC galaxy surveys with a uniform set of assumptions and find that S _8 from all three are lower than that from ACT+Planck lensing by levels ranging from 1.7 σ to 2.1 σ . This motivates further measurements and comparison, not just between the CMB anisotropies and galaxy lensing but also between CMB lensing probing z ∼ 0.5–5 on mostly linear scales and galaxy lensing at z ∼ 0.5 on smaller scales. We combine with CMB anisotropies to constrain extensions of ΛCDM, limiting neutrino masses to ∑ m _ν < 0.13 eV (95% c.l.), for example. We describe the mass map and related data products that will enable a wide array of cross-correlation science. Our results provide independent confirmation that the universe is spatially flat, conforms with general relativity, and is described remarkably well by the ΛCDM model, while paving a promising path for neutrino physics with lensing from upcoming ground-based CMB surveys.

Published
2024
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2. The Atacama Cosmology Telescope: A Measurement of the DR6 CMB Lensing Power Spectrum and Its Implications for Structure Growth

Author

Frank J. Qu, Blake D. Sherwin, Mathew S. Madhavacheril, Dongwon Han, Kevin T. Crowley, Irene Abril-Cabezas, Peter A. R. Ade, Simone Aiola, Tommy Alford, Mandana Amiri, Stefania Amodeo, Rui An, Zachary Atkins, Jason E. Austermann, Nicholas Battaglia, Elia Stefano Battistelli, James A. Beall, Rachel Bean, Benjamin Beringue, Tanay Bhandarkar, Emily Biermann, Boris Bolliet, J Richard Bond, Hongbo Cai, Erminia Calabrese, Victoria Calafut, Valentina Capalbo, Felipe Carrero, Julien Carron, Anthony Challinor, Grace E. Chesmore, Hsiao-mei Cho, Steve K. Choi, Susan E. Clark, Rodrigo Córdova Rosado, Nicholas F. Cothard, Kevin Coughlin, William Coulton, Roohi Dalal, Omar Darwish, Mark J. Devlin, Simon Dicker, Peter Doze, Cody J. Duell, Shannon M. Duff, Adriaan J. Duivenvoorden, Jo Dunkley, Rolando Dünner, Valentina Fanfani, Max Fankhanel, Gerrit Farren, Simone Ferraro, Rodrigo Freundt, Brittany Fuzia, Patricio A. Gallardo, Xavier Garrido, Vera Gluscevic, Joseph E. Golec, Yilun Guan, Mark Halpern, Ian Harrison, Matthew Hasselfield, Erin Healy, Shawn Henderson, Brandon Hensley, Carlos Hervías-Caimapo, J. Colin Hill, Gene C. Hilton, Matt Hilton, Adam D. Hincks, Renée Hložek, Shuay-Pwu Patty Ho, Zachary B. Huber, Johannes Hubmayr, Kevin M. Huffenberger, John P. Hughes, Kent Irwin, Giovanni Isopi, Hidde T. Jense, Ben Keller, Joshua Kim, Kenda Knowles, Brian J. Koopman, Arthur Kosowsky, Darby Kramer, Aleksandra Kusiak, Adrien La Posta, Alex Lague, Victoria Lakey, Eunseong Lee, Zack Li, Yaqiong Li, Michele Limon, Martine Lokken, Thibaut Louis, Marius Lungu, Niall MacCrann, Amanda MacInnis, Diego Maldonado, Felipe Maldonado, Maya Mallaby-Kay, Gabriela A. Marques, Jeff McMahon, Yogesh Mehta, Felipe Menanteau, Kavilan Moodley, Thomas W. Morris, Tony Mroczkowski, Sigurd Naess, Toshiya Namikawa, Federico Nati, Laura Newburgh, Andrina Nicola, Michael D. Niemack, Michael R. Nolta, John Orlowski-Scherer, Lyman A. Page, Shivam Pandey, Bruce Partridge, Heather Prince, Roberto Puddu, Federico Radiconi, Naomi Robertson, Felipe Rojas, Tai Sakuma, Maria Salatino, Emmanuel Schaan, Benjamin L. Schmitt, Neelima Sehgal, Shabbir Shaikh, Carlos Sierra, Jon Sievers, Cristóbal Sifón, Sara Simon, Rita Sonka, David N. Spergel, Suzanne T. Staggs, Emilie Storer, Eric R. Switzer, Niklas Tampier, Robert Thornton, Hy Trac, Jesse Treu, Carole Tucker, Joel Ullom, Leila R. Vale, Alexander Van Engelen, Jeff Van Lanen, Joshiwa van Marrewijk, Cristian Vargas, Eve M. Vavagiakis, Kasey Wagoner, Yuhan Wang, Lukas Wenzl, Edward J. Wollack, Zhilei Xu, Fernando Zago, and Kaiwen Zheng

Subjects
Cosmological parameters, Cosmological parameters from large-scale structure, Astrophysics, QB460-466
Abstract

We present new measurements of cosmic microwave background (CMB) lensing over 9400 deg ^2 of the sky. These lensing measurements are derived from the Atacama Cosmology Telescope (ACT) Data Release 6 (DR6) CMB data set, which consists of five seasons of ACT CMB temperature and polarization observations. We determine the amplitude of the CMB lensing power spectrum at 2.3% precision (43 σ significance) using a novel pipeline that minimizes sensitivity to foregrounds and to noise properties. To ensure that our results are robust, we analyze an extensive set of null tests, consistency tests, and systematic error estimates and employ a blinded analysis framework. Our CMB lensing power spectrum measurement provides constraints on the amplitude of cosmic structure that do not depend on Planck or galaxy survey data, thus giving independent information about large-scale structure growth and potential tensions in structure measurements. The baseline spectrum is well fit by a lensing amplitude of A _lens = 1.013 ± 0.023 relative to the Planck 2018 CMB power spectra best-fit ΛCDM model and A _lens = 1.005 ± 0.023 relative to the ACT DR4 + WMAP best-fit model. From our lensing power spectrum measurement, we derive constraints on the parameter combination ${S}_{8}^{\mathrm{CMBL}}\equiv {\sigma }_{8}{\left({{\rm{\Omega }}}_{m}/0.3\right)}^{0.25}$ of ${S}_{8}^{\mathrm{CMBL}}=0.818\pm 0.022$ from ACT DR6 CMB lensing alone and ${S}_{8}^{\mathrm{CMBL}}=0.813\pm 0.018$ when combining ACT DR6 and Planck NPIPE CMB lensing power spectra. These results are in excellent agreement with ΛCDM model constraints from Planck or ACT DR4 + WMAP CMB power spectrum measurements. Our lensing measurements from redshifts z ∼ 0.5–5 are thus fully consistent with ΛCDM structure growth predictions based on CMB anisotropies probing primarily z ∼ 1100. We find no evidence for a suppression of the amplitude of cosmic structure at low redshifts.

Published
2024
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3. The Simons Observatory: Beam Characterization for the Small Aperture Telescopes

Author

Nadia Dachlythra, Adriaan J. Duivenvoorden, Jon E. Gudmundsson, Matthew Hasselfield, Gabriele Coppi, Alexandre E. Adler, David Alonso, Susanna Azzoni, Grace E. Chesmore, Giulio Fabbian, Ken Ganga, Remington G. Gerras, Andrew H. Jaffe, Bradley R. Johnson, Brian Keating, Reijo Keskitalo, Theodore S. Kisner, Nicoletta Krachmalnicoff, Marius Lungu, Frederick Matsuda, Sigurd Naess, Lyman Page, Roberto Puddu, Giuseppe Puglisi, Sara M. Simon, Grant Teply, Tran Tsan, Edward J. Wollack, Kevin Wolz, and Zhilei Xu

Subjects
Cosmic microwave background radiation, Calibration, Cosmology, Ground telescopes, Astronomical detectors, Astronomical instrumentation, Astrophysics, QB460-466
Abstract

We use time-domain simulations of Jupiter observations to test and develop a beam reconstruction pipeline for the Simons Observatory Small Aperture Telescopes. The method relies on a mapmaker that estimates and subtracts correlated atmospheric noise and a beam fitting code designed to compensate for the bias caused by the mapmaker. We test our reconstruction performance for four different frequency bands against various algorithmic parameters, atmospheric conditions, and input beams. We additionally show the reconstruction quality as a function of the number of available observations and investigate how different calibration strategies affect the beam uncertainty. For all of the cases considered, we find good agreement between the fitted results and the input beam model within an ∼1.5% error for a multipole range ℓ = 30–700 and an ∼0.5% error for a multipole range ℓ = 50–200. We conclude by using a harmonic-domain component separation algorithm to verify that the beam reconstruction errors and biases observed in our analysis do not significantly bias the Simons Observatory r -measurement

Published
2024
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4. Simons Observatory: Characterizing the Large Aperture Telescope Receiver with Radio Holography

Author

Grace. E. Chesmore, Kathleen Harrington, Carlos E. Sierra, Patricio A. Gallardo, Shreya Sutariya, Tommy Alford, Alexandre E. Adler, Tanay Bhandarkar, Gabriele Coppi, Nadia Dachlythra, Joseph Golec, Jon Gudmundsson, Saianeesh K. Haridas, Bradley R. Johnson, Anna M. Kofman, Jeffrey Iuliano, Jeff McMahon, Michael D. Niemack, John Orlowski-Scherer, Karen Perez Sarmiento, Roberto Puddu, Max Silva-Feaver, Sara M. Simon, Julia Robe, Edward J. Wollack, and Zhilei Xu

Subjects
Optics, Instrumentation and Photography
Abstract

We present near-field radio holography measurements of the Simons Observatory Large Aperture Telescope Receiver optics. These measurements demonstrate that radio holography of complex millimeter-wave optical systems comprising cryogenic lenses, filters, and feed horns can provide detailed characterization of wave propagation before deployment. We used the measured amplitude and phase, at 4 K, of the receiver near-field beam pattern to predict two key performance parameters: 1) the amount of scattered light that will spill past the telescope to 300 K and 2) the beam pattern expected from the receiver when fielded on the telescope. These cryogenic measurements informed the removal of a filter, which led to improved optical efficiency and reduced sidelobes at the exit of the receiver. Holography measurements of this system suggest that the spilled power past the telescope mirrors will be less than 1%, and the main beam with its near sidelobes are consistent with the nominal telescope design. This is the first time such parameters have been confirmed in the lab prior to deployment of a new receiver. This approach is broadly applicable to millimeter and submillimeter instruments.

Published
2022
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6. The Atacama Cosmology Telescope: DR4 maps and cosmological parameters

Author

Simone Aiola, Erminia Calabrese, Loic Maurin, Sigurd Naess, Benjamin L. Schmitt, Maximilian H. Abitbol, Graeme E. Addison, Peter A. R. Ade, David Alonso, Mandana Amiri, Stefania Amodeo, Elio Angile, Jason E. Austermann, Taylor Baildon, Nick Battaglia, James A. Beall, Rachel Bean, Daniel T. Becker, J Richard Bond, Sarah Marie Bruno, Victoria Calafut, Luis E. Campusano, Felipe Carrero, Grace E. Chesmore, Hsiao-mei Cho, Steve K. Choi, Susan E. Clark, Nicholas F. Cothard, Devin Crichton, Kevin T. Crowley, Omar Darwish, Rahul Datta, Edward V. Denison, Mark J. Devlin, Cody J. Duell, Shannon M. Duff, Adriaan J. Duivenvoorden, Jo Dunkley, Rolando Dunner, Thomas Essinger-Hileman, Max Fankhanel, Simone Ferraro, Anna E. Fox, Brittany Fuzia, Patricio A. Gallardo, Vera Gluscevic, Joseph E. Golec, Emily Grace, Megan Gralla, Yilun Guan, 8 Mark Halpern, Dongwon Han, Peter Hargrave, Matthew Hasselfield, Jakob M. Helton, Shawn Henderson, Brandon Hensley, J. Colin Hill, Gene C. Hilton, Matt Hilton, Adam D. Hincks, Renee Hlozek, Shuay-Pwu Patty Ho, Johannes Hubmayr, Kevin M. Huffenberger, John P. Hughes, Leopoldo Infante, Kent Irwin, Rebecca Jackson, Jeff Klein, Kenda Knowles, Brian Koopman, Arthur Kosowsky, Vincent Lakey, Dale Li, Yaqiong Li, Zack Li, Martine Lokken, Thibaut Louis, Marius Lungu, Amanda MacInnis, Mathew Madhavacheril, Felipe Maldonado, Maya Mallaby-Kay, Danica Marsden, Jeff McMahon, Felipe Menanteau, Kavilan Moodley, Tim Morton, Toshiya Namikawa, Federico Nati, Laura Newburgh, John P. Nibarger, Andrina Nicola, Michael D. Niemack, Michael R. Nolta, John Orlowski-Sherer, Lyman A. Page, Christine G. Pappas, Bruce Partridge, Phumlani Phakathi, Giampaolo Pisano, Heather Prince, Roberto Puddu, Frank J. Qu, Jesus Rivera, Naomi Robertson, Felipe Rojas, Maria Salatino, Emmanuel Schaan, Alessandro Schillaci, Neelima Sehgal, Blake D. Sherwin, Carlos Sierra, Jon Sievers, Cristobal Sifon, Precious Sikhosana, Sara Simon, David N. Spergel, Suzanne T. Staggs, Jason Stevens, Emilie Storer, Dhaneshwar D. Sunder, Eric R. Switzer, Ben Thorne, Robert Thornton, Hy Trac, Jesse Treu, Carole Tucker, Leila R. Vale, Alexander Van Engelen, Jeff Van Lanen, Eve M. Vavagiakis, Kasey Wagoner, Yuhan Wang, Jonathan T. Ward, Edward J Wollack, Zhilei Xu, Fernando Zago, and Ningfeng Zhu

Subjects
Astrophysics, Physics Of Elementary Particles And Fields
Abstract

We present new arcminute-resolution maps of the Cosmic Microwave Background temperature and polarization anisotropy from the Atacama Cosmology Telescope, using data taken from 2013{2016 at 98 and 150 GHz. The maps cover more than 17,000 deg(^2), the deepest 600 deg(^2) with noise levels below 10µK-arcmin. We use the power spectrum derived from almost 6,000 deg(^2) of these maps to constrain cosmology. The ACT data enable a measurement of the angular scale of features in both the divergence-like polarization and the temperature anisotropy, tracing both the velocity and density at last-scattering. From these one can derive the distance to the last-scattering surface and thus infer the local expansion rate, H0. By combining ACT data with large-scale information from WMAP we measure H0 = 67:6±1:1 km/s/Mpc, at 68% confidence, in excellent agreement with the independently measured Planck satellite estimate (from ACT alone we find H0 = 67:9± 1:5 km/s/Mpc). The ΛCDM model provides a good fit to the ACT data, and we find no evidence for deviations: both the spatial curvature, and the departure from the standard lensing signal in the spectrum, are zero to within 1σ; the number of relativistic species, the primordial Helium fraction, and the running of the spectral index are consistent with ΛCDM predictions to within 1.5{2.2σ. We compare ACT, WMAP, and Planck at the parameter level and find good consistency; we investigate how the constraints on the correlated spectral index and baryon density parameters readjust when adding CMB large-scale information that ACT does not measure. The DR4 products presented here will be publicly released on the NASA Legacy Archive for Microwave Background Data Analysis.

Published
2020
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7. The Atacama Cosmology Telescope: Constraints on Cosmic Birefringence

Author

Toshiya Namikawa, Yilun Guan, Omar Darwish, Blake D. Sherwin, Simone Aiola, Nicholas Battaglia, James A. Beall, Daniel T. Becker, J. Richard Bond, Erminia Calabrese, Grace E. Chesmore, Steve K.Choi, Mark J. Devlin, Joanna Dunkley, Rolando Dunner, Anna E. Fox, Patricio A. Gallardo, Vera Gluscevic, Dongwon Han, Matthew Hasselfield, Gene C. Hilton, Adam D. Hincks, Renee Hlozek, Johannes Hubmayr, Kevin Huffenberger, John P. Hughes, Brian J. Koopman, Arthur Kosowsky, Thibaut Louis, Marius Lungu, Amanda MacInnis, Mathew S. Madhavacheril, Maya Mallaby-Kay, Loıc Maurin, Jeffrey McMahon, Kavilan Moodley, Sigurd Naess, Federico Nati, Laura B.Newburgh, John P. Nibarger, Michael D. Niemack, Lyman A. Page, Frank J. Qu, Naomi Robertson, Alessandro Schillaci, Neelima Sehgal, Cristobal Sifon, Sara M. Simon, David N. Spergel, Suzanne T.Staggs, Emilie R. Storer, Alexander van Engelen, Jeff van Lanen, and Edward J. Wollack

Subjects
Astrophysics, Space Radiation
Abstract

We present new constraints on anisotropic birefringence of the cosmic microwave background polarization using two seasons of data from the Atacama Cosmology Telescope covering 456 square degrees of sky. The birefringence power spectrum, measured using a curved-sky quadratic estimator, is consistent with zero. Our results provide the tightest current constraint on birefringence over a range of angular scales between 5 arc minutes and 9°. We improve previous upper limits on the amplitude of a scale-invariant birefringence power spectrum by a factor of between 2 and 3. Assuming a nearly massless axion field during inflation, our result is equivalent to a 2σ upper limit on the Chern-Simons coupling constant between axions and photons of g(αγ)< 4.0 × 10(exp -2)/H(I), where H(I) is the inflationary Hubble scale.

Published
2020
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8. Atacama Cosmology Telescope: Constraints on cosmic birefringence

Author

Toshiya Namikawa, Yilun Guan, Omar Darwish, Blake D. Sherwin, Simone Aiola, Nicholas Battaglia, James A. Beall, Daniel T. Becker, J. Richard Bond, Erminia Calabrese, Grace E. Chesmore, Steve K. Choi, Mark J. Devlin, Joanna Dunkley, Rolando Dünner, Anna E. Fox, Patricio A. Gallardo, Vera Gluscevic, Dongwon Han, Matthew Hasselfield, Gene C. Hilton, Adam D. Hincks, Renée Hložek, Johannes Hubmayr, Kevin Huffenberger, John P. Hughes, Brian J. Koopman, Arthur Kosowsky, Thibaut Louis, Marius Lungu, Amanda MacInnis, Mathew S. Madhavacheril, Maya Mallaby-Kay, Loïc Maurin, Jeffrey McMahon, Kavilan Moodley, Sigurd Naess, Federico Nati, Laura B. Newburgh, John P. Nibarger, Michael D. Niemack, Lyman A. Page, Frank J. Qu, Naomi Robertson, Alessandro Schillaci, Neelima Sehgal, Cristóbal Sifón, Sara M. Simon, David N. Spergel, Suzanne T. Staggs, Emilie R. Storer, Alexander van Engelen, Jeff van Lanen, and Edward J. Wollack

Published
2020
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9. The Simons Observatory: Characterizing the Large Aperture Telescope Receiver with Radio Holography

Author

Grace E. Chesmore, Kathleen Harrington, Carlos E. Sierra, Patricio A. Gallardo, Shreya Sutariya, Tommy Alford, Alexandre E. Adler, Tanay Bhandarkar, Gabriele Coppi, Nadia Dachlythra, Joseph Golec, Jon Gudmundsson, Saianeesh K. Haridas, Bradley R. Johnson, Anna M. Kofman, Jeffrey Iuliano, Jeff McMahon, Michael D. Niemack, John Orlowski-Scherer, Karen Perez Sarmiento, Roberto Puddu, Max Silva-Feaver, Sara M. Simon, Julia Robe, Edward J. Wollack, Zhilei Xu, Chesmore, G, Harrington, K, Sierra, C, Gallardo, P, Sutariya, S, Alford, T, Adler, A, Bhandarkar, T, Coppi, G, Dachlythra, N, Golec, J, Gudmundsson, J, Haridas, S, Johnson, B, Kofman, A, Iuliano, J, Mcmahon, J, Niemack, M, Orlowski-Scherer, J, Perez Sarmiento, K, Puddu, R, Silva-Feaver, M, Simon, S, Robe, J, Wollack, E, and Xu, Z

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Electrical and Electronic Engineering, Astrophysics - Instrumentation and Methods for Astrophysics, Engineering (miscellaneous), Instrumentation and Methods for Astrophysics (astro-ph.IM), Atomic and Molecular Physics, and Optics, optics, Astrophysics::Galaxy Astrophysics
Abstract

We present near-field radio holography measurements of the Simons Observatory Large Aperture Telescope Receiver optics. These measurements demonstrate that radio holography of complex millimeter-wave optical systems comprising cryogenic lenses, filters, and feed horns can provide detailed characterization of wave propagation before deployment. We used the measured amplitude and phase, at 4 K, of the receiver near-field beam pattern to predict two key performance parameters: 1) the amount of scattered light that will spill past the telescope to 300 K and 2) the beam pattern expected from the receiver when fielded on the telescope. These cryogenic measurements informed the removal of a filter, which led to improved optical efficiency and reduced sidelobes at the exit of the receiver. Holography measurements of this system suggest that the spilled power past the telescope mirrors will be less than 1%, and the main beam with its near sidelobes are consistent with the nominal telescope design. This is the first time such parameters have been confirmed in the lab prior to deployment of a new receiver. This approach is broadly applicable to millimeter and submillimeter instruments.

Published
2022

10. Simons Observatory: characterizing the Large Aperture Telescope Receiver with radio holography

Author

Chesmore, G, Harrington, K, Sierra, C, Gallardo, P, Sutariya, S, Alford, T, Adler, A, Bhandarkar, T, Coppi, G, Dachlythra, N, Golec, J, Gudmundsson, J, Haridas, S, Johnson, B, Kofman, A, Iuliano, J, Mcmahon, J, Niemack, M, Orlowski-Scherer, J, Perez Sarmiento, K, Puddu, R, Silva-Feaver, M, Simon, S, Robe, J, Wollack, E, Xu, Z, Grace E. Chesmore, Kathleen Harrington, Carlos E. Sierra, Patricio A. Gallardo, Shreya Sutariya, Tommy Alford, Alexandre E. Adler, Tanay Bhandarkar, Gabriele Coppi, Nadia Dachlythra, Joseph Golec, Jon Gudmundsson, Saianeesh K. Haridas, Bradley R. Johnson, Anna M. Kofman, Jeffrey Iuliano, Jeff McMahon, Michael D. Niemack, John Orlowski-Scherer, Karen Perez Sarmiento, Roberto Puddu, Max Silva-Feaver, Sara M. Simon, Julia Robe, Edward J. Wollack, Zhilei Xu, Chesmore, G, Harrington, K, Sierra, C, Gallardo, P, Sutariya, S, Alford, T, Adler, A, Bhandarkar, T, Coppi, G, Dachlythra, N, Golec, J, Gudmundsson, J, Haridas, S, Johnson, B, Kofman, A, Iuliano, J, Mcmahon, J, Niemack, M, Orlowski-Scherer, J, Perez Sarmiento, K, Puddu, R, Silva-Feaver, M, Simon, S, Robe, J, Wollack, E, Xu, Z, Grace E. Chesmore, Kathleen Harrington, Carlos E. Sierra, Patricio A. Gallardo, Shreya Sutariya, Tommy Alford, Alexandre E. Adler, Tanay Bhandarkar, Gabriele Coppi, Nadia Dachlythra, Joseph Golec, Jon Gudmundsson, Saianeesh K. Haridas, Bradley R. Johnson, Anna M. Kofman, Jeffrey Iuliano, Jeff McMahon, Michael D. Niemack, John Orlowski-Scherer, Karen Perez Sarmiento, Roberto Puddu, Max Silva-Feaver, Sara M. Simon, Julia Robe, Edward J. Wollack, and Zhilei Xu

Abstract

We present near-field radio holography measurements of the Simons Observatory Large Aperture Telescope Receiver optics. These measurements demonstrate that radio holography of complex millimeter-wave optical systems comprising cryogenic lenses, filters, and feed horns can provide detailed characterization of wave propagation before deployment. We used the measured amplitude and phase, at 4 K, of the receiver near-field beam pattern to predict two key performance parameters: 1) the amount of scattered light that will spill past the telescope to 300 K and 2) the beam pattern expected from the receiver when fielded on the telescope. These cryogenic measurements informed the removal of a filter, which led to improved optical efficiency and reduced sidelobes at the exit of the receiver. Holography measurements of this system suggest that the spilled power past the telescope mirrors will be less than 1%, and the main beam with its near sidelobes are consistent with the nominal telescope design. This is the first time such parameters have been confirmed in the lab prior to deployment of a new receiver. This approach is broadly applicable to millimeter and submillimeter instruments.

Published
2022

11. The Crisis of US Coal Communities: Strategies for a Just Transition to Renewable Energy

Author

Rachel L. Starr, Grace E. Chesmore, Meredith L. Ward, and Rebecca V. Van Hoeck

Subjects
010504 meteorology & atmospheric sciences, Natural resource economics, business.industry, 0211 other engineering and technologies, Coal, 021108 energy, 02 engineering and technology, Business, 01 natural sciences, 0105 earth and related environmental sciences, Renewable energy
Abstract

Though coal was once a leading source of energy and economic growth, negative health impacts, detrimental environmental effects, and market forces have led to a rapid decline in production. Without nationwide legislation aiding them, coal-dependent communities in the US are suffering from financial downfall during this shift. Here, we propose three policy options to uplift these communities by providing subsidies to renewable energy companies that expand operations in former coal communities, reclaim the land, and provide job retraining. These options, alongside suggested federal funding for direct community aid, work cohesively to provide a lasting source of economic stability, improve environmental and public health in former coal-dependent communities, and mitigate the climate crisis. We call upon the Interagency Working Group on Coal and Power Plant Communities and Economic Revitalization (Interagency Working Group) to ensure the diversion of subsidies away from the coal industry and towards these efforts to promote a just transition for the affected communities.

Published
2021
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12. The Integration and Testing Program for the Simons Observatory Large Aperture Telescope Optics Tubes

Author

Shreya Sutariya, Grace E. Chesmore, Eve M. Vavagiakis, Carlos Sierra, A. M. Kofman, Jeff McMahon, Shuay-Pwu Patty Ho, Brian J. Koopman, Steve K. Choi, Zhilei Xu, Jack Lashner, Kathleen Harrington, Nicholas Galitzki, John Orlowski-Scherer, Max Silva-Feaver, Aamir Ali, Ningfeng Zhu, Simon Dicker, Michael D. Niemack, Nicholas F. Cothard, and Joseph Seibert

Subjects
Physics, Cryostat, business.industry, Physics::Instrumentation and Detectors, Detector, Cosmic microwave background, Bolometer, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Spectral bands, Astrophysics::Cosmology and Extragalactic Astrophysics, Dichroic glass, law.invention, Telescope, Optics, Observatory, law, business, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM)
Abstract

The Simons Observatory (SO) will be a cosmic microwave background (CMB) survey experiment with three small-aperture telescopes and one large-aperture telescope, which will observe from the Atacama Desert in Chile. In total, SO will field over 60,000 transition-edge sensor (TES) bolometers in six spectral bands centered between 27 and 280 GHz in order to achieve the sensitivity necessary to measure or constrain numerous cosmological quantities, as outlined in The Simons Observatory Collaboration et al. (2019). The 6~m Large Aperture Telescope (LAT), which will target the smaller angular scales of the CMB, utilizes a cryogenic receiver (LATR) designed to house up to 13 individual optics tubes. Each optics tube is comprised of three silicon lenses, IR blocking filters, and three dual-polarization, dichroic TES detector wafers. The scientific objectives of the SO project require these optics tubes to achieve high-throughput optical performance while maintaining exquisite control of systematic effects. We describe the integration and testing program for the SO LATR optics tubes that will verify the design and assembly of the optics tubes before they are shipped to the SO site and installed in the LATR cryostat. The program includes a quick turn-around test cryostat that is used to cool single optics tubes and validate the cryogenic performance and detector readout assembly. We discuss the optical design specifications the optics tubes must meet to be deployed on sky and the suite of optical test equipment that is prepared to measure these requirements.

Published
2021

13. The Atacama Cosmology Telescope: Summary of DR4 and DR5 Data Products and Data Access

Author

Joseph E. Golec, Shannon M. Duff, Maya Mallaby-Kay, Thibaut Louis, Lyman A. Page, Erminia Calabrese, E. V. Denison, Yilun Guan, Edward J. Wollack, Kavilan Moodley, Jason E. Austermann, Daniel T. Becker, John P. Hughes, Joel N. Ullom, Leila R. Vale, Simone Aiola, Dongwon Han, C. Sifon, John P. Nibarger, Sara M. Simon, Toshiya Namikawa, Kyra Fichman, Zhilei Xu, Blake D. Sherwin, Jo Dunkley, Maria Salatino, Brian J. Koopman, Emmanuel Schaan, Kevin M. Huffenberger, Johannes Hubmayr, Jeff McMahon, Matt Hilton, Simone Ferraro, Matthew Hasselfield, Laura Newburgh, Mark J. Devlin, Zachary Atkins, Patricio A. Gallardo, James A. Beall, Mathew S. Madhavacheril, Kevin T. Crowley, J. Colin Hill, Steve K. Choi, Suzanne T. Staggs, Amanda MacInnis, Alessandro Schillaci, Adriaan J. Duivenvoorden, Omar Darwish, Grace E. Chesmore, Neelima Sehgal, S. Amodeo, Gene C. Hilton, Emilie R. Storer, Sigurd Naess, Jeff Van Lanen, J. Richard Bond, Alexander van Engelen, Federico Nati, Michael D. Niemack, Renée Hložek, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Mallaby-Kay, M, Atkins, Z, Aiola, S, Amodeo, S, Austermann, J, Beall, J, Becker, D, Bond, J, Calabrese, E, Chesmore, G, Choi, S, Crowley, K, Darwish, O, Denison, E, Devlin, M, Duff, S, Duivenvoorden, A, Dunkley, J, Ferraro, S, Fichman, K, Gallardo, P, Golec, J, Guan, Y, Han, D, Hasselfield, M, Hill, J, Hilton, G, Hilton, M, Hlozek, R, Hubmayr, J, Huffenberger, K, Hughes, J, Koopman, B, Louis, T, Macinnis, A, Madhavacheril, M, Mcmahon, J, Moodley, K, Naess, S, Namikawa, T, Nati, F, Newburgh, L, Nibarger, J, Niemack, M, Page, L, Salatino, M, Schaan, E, Schillaci, A, Sehgal, N, Sherwin, B, Sifon, C, Simon, S, Staggs, S, Storer, E, Ullom, J, Van Engelen, A, Van Lanen, J, Vale, L, Wollack, E, and Xu, Z

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Data products, Art history, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astronomy & Astrophysics, 01 natural sciences, Atomic, Public access, Particle and Plasma Physics, 0103 physical sciences, Nuclear, 010303 astronomy & astrophysics, Order (virtue), Astrophysics::Galaxy Astrophysics, Physics, 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Molecular, Astronomy and Astrophysics, CMB, Cosmology, Space and Planetary Science, Atacama Cosmology Telescope, astro-ph.CO, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astronomical and Space Sciences, Physical Chemistry (incl. Structural), Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

Two recent large data releases for the Atacama Cosmology Telescope (ACT), called DR4 and DR5, are available for public access. These data include temperature and polarization maps that cover nearly half the sky at arcminute resolution in three frequency bands; lensing maps and component-separated maps covering ~ 2,100 deg^2 of sky; derived power spectra and cosmological likelihoods; a catalog of over 4,000 galaxy clusters; and supporting ancillary products including beam functions and masks. The data and products are described in a suite of ACT papers; here we provide a summary. In order to facilitate ease of access to these data we present a set of Jupyter IPython notebooks developed to introduce users to DR4, DR5, and the tools needed to analyze these data. The data products (excluding simulations) and the set of notebooks are publicly available on the NASA Legacy Archive for Microwave Background Data Analysis (LAMBDA); simulation products are available on the National Energy Research Scientific Computing Center (NERSC)., Accepted to ApJS. 21 pages, 8 figures. Data and notebooks available on LAMBDA https://lambda.gsfc.nasa.gov/product/act/

Published
2021
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14. The Simons Observatory: modeling optical systematics in the Large Aperture Telescope

Author

Rolando Dünner, John Orlowski-Scherer, Adrian T. Lee, Kavilan Moodley, Aamir Ali, Philip Daniel Mauskopf, Giuseppe Puglisi, Patricio A. Gallardo, Sara M. Simon, Carlos Sierra, Michael D. Niemack, Grace E. Chesmore, Giulio Fabbian, Alexandre E. Adler, Nicholas F. Cothard, Lyman A. Page, Gabriele Coppi, Ningfeng Zhu, Nicholas Galitzki, Edward J. Wollack, Federico Nati, Shuay-Pwu Patty Ho, Nadia Dachlythra, Bruce Partridge, Michele Limon, Zhilei Xu, Christian L. Reichardt, A. M. Kofman, Jon E. Gudmundsson, Simon Dicker, Peter Charles Hargrave, Joseph E. Golec, Andrew Bazarko, Roberto Puddu, Frederick Matsuda, Carole Tucker, Mark J. Devlin, Grant Teply, Gudmundsson, J, Gallardo, P, Puddu, R, Dicker, S, Adler, A, Ali, A, Bazarko, A, Chesmore, G, Coppi, G, Cothard, N, Dachlythra, N, Devlin, M, Dünner, R, Fabbian, G, Galitzki, N, Golec, J, Patty Ho, S, Hargrave, P, Kofman, A, Lee, A, Limon, M, Matsuda, F, Mauskopf, P, Moodley, K, Nati, F, Niemack, M, Orlowski-Scherer, J, Page, L, Partridge, B, Puglisi, G, Reichardt, C, Sierra, C, Simon, S, Teply, G, Tucker, C, Wollack, E, Xu, Z, and Zhu, N

Subjects
FOS: Physical sciences, 01 natural sciences, law.invention, 010309 optics, Telescope, Optics, Observatory, law, 0103 physical sciences, Light beam, Electrical and Electronic Engineering, Instrumentation and Methods for Astrophysics (astro-ph.IM), Engineering (miscellaneous), Physics, Geometrical optics, business.industry, Stray light, Settore FIS/05, Optical Design, Telescope, Simons Observatory, Detector, Astrophysics::Instrumentation and Methods for Astrophysics, Physical optics, Atomic and Molecular Physics, and Optics, Ray tracing (graphics), Astrophysics - Instrumentation and Methods for Astrophysics, business
Abstract

We present geometrical and physical optics simulation results for the Simons Observatory Large Aperture Telescope. This work was developed as part of the general design process for the telescope; allowing us to evaluate the impact of various design choices on performance metrics and potential systematic effects. The primary goal of the simulations was to evaluate the final design of the reflectors and the cold optics which are now being built. We describe non-sequential ray tracing used to inform the design of the cold optics, including absorbers internal to each optics tube. We discuss ray tracing simulations of the telescope structure that allow us to determine geometries that minimize detector loading and mitigate spurious near-field effects that have not been resolved by the internal baffling. We also describe physical optics simulations, performed over a range of frequencies and field locations, that produce estimates of monochromatic far field beam patterns which in turn are used to gauge general optical performance. Finally, we describe simulations that shed light on beam sidelobes from panel gap diffraction., 15 pages, 13 figures

Published
2021

15. The Simons Observatory Large Aperture Telescope Receiver

Author

Zhu, N, Bhandarkar, T, Coppi, G, Kofman, A, Orlowski-Scherer, J, Xu, Z, Adachi, S, Ade, P, Aiola, S, Austermann, J, Bazarko, A, Beall, J, Bhimani, S, Richard Bond, J, Chesmore, G, Choi, S, Connors, J, Cothard, N, Devlin, M, Dicker, S, Dober, B, Duell, C, Duff, S, Dünner, R, Fabbian, G, Galitzki, N, Gallardo, P, Golec, J, Haridas, S, Harrington, K, Healy, E, Patty Ho, S, Huber, Z, Hubmayr, J, Iuliano, J, Johnson, B, Keatin, B, Kiuchi, K, Koopman, B, Lashner, J, Lee, A, Li, Y, Limon, M, Link, M, J Lucas, T, Mccarrick, H, Moore, J, Nati, F, Newburgh, L, Niemack, M, Pierpaoli, E, Randall, M, Perez Sarmiento, K, Saunders, L, Seibert, J, Sierra, C, Sonka, R, Spisak, J, Sutariya, S, Tajima, O, Teply, G, Thornton, R, Tsan, T, Tucker, C, Ullom, J, Vavagiakis, E, Vissers, M, Walker, S, Westbrook, B, Wollack, E, Zannoni, M, Ningfeng Zhu, Tanay Bhandarkar, Gabriele Coppi, Anna M. Kofman, John L. Orlowski-Scherer, Zhilei Xu, Shunsuke Adachi, Peter Ade, Simone Aiola, Jason Austermann, Andrew O. Bazarko, James A. Beall, Sanah Bhimani, J. Richard Bond, Grace E. Chesmore, Steve K. Choi, Jake Connors, Nicholas F. Cothard, Mark Devlin, Simon Dicker, Bradley Dober, Cody J. Duell, Shannon M. Duff, Rolando Dünner, Giulio Fabbian, Nicholas Galitzki, Patricio A. Gallardo, Joseph E. Golec, Saianeesh K. Haridas, Kathleen Harrington, Erin Healy, Shuay-Pwu Patty Ho, Zachary B. Huber, Johannes Hubmayr, Jeffrey Iuliano, Bradley R. Johnson, Brian Keatin, Kenji Kiuchi, Brian J. Koopman, Jack Lashner, Adrian T. Lee, Yaqiong Li, Michele Limon, Michael Link, Tammy J Lucas, Heather McCarrick, Jenna Moore, Federico Nati, Laura B. Newburgh, Michael D. Niemack, Elena Pierpaoli, Michael J. Randall, Karen Perez Sarmiento, Lauren J. Saunders, Joseph Seibert, Carlos Sierra, Rita Sonka, Jacob Spisak, Shreya Sutariya, Osamu Tajima, Grant P. Teply, Robert J. Thornton, Tran Tsan, Carole Tucker, Joel Ullom, Eve M. Vavagiakis, Michael R. Vissers, Samantha Walker, Benjamin Westbrook, Edward J. Wollack, Mario Zannoni, Zhu, N, Bhandarkar, T, Coppi, G, Kofman, A, Orlowski-Scherer, J, Xu, Z, Adachi, S, Ade, P, Aiola, S, Austermann, J, Bazarko, A, Beall, J, Bhimani, S, Richard Bond, J, Chesmore, G, Choi, S, Connors, J, Cothard, N, Devlin, M, Dicker, S, Dober, B, Duell, C, Duff, S, Dünner, R, Fabbian, G, Galitzki, N, Gallardo, P, Golec, J, Haridas, S, Harrington, K, Healy, E, Patty Ho, S, Huber, Z, Hubmayr, J, Iuliano, J, Johnson, B, Keatin, B, Kiuchi, K, Koopman, B, Lashner, J, Lee, A, Li, Y, Limon, M, Link, M, J Lucas, T, Mccarrick, H, Moore, J, Nati, F, Newburgh, L, Niemack, M, Pierpaoli, E, Randall, M, Perez Sarmiento, K, Saunders, L, Seibert, J, Sierra, C, Sonka, R, Spisak, J, Sutariya, S, Tajima, O, Teply, G, Thornton, R, Tsan, T, Tucker, C, Ullom, J, Vavagiakis, E, Vissers, M, Walker, S, Westbrook, B, Wollack, E, Zannoni, M, Ningfeng Zhu, Tanay Bhandarkar, Gabriele Coppi, Anna M. Kofman, John L. Orlowski-Scherer, Zhilei Xu, Shunsuke Adachi, Peter Ade, Simone Aiola, Jason Austermann, Andrew O. Bazarko, James A. Beall, Sanah Bhimani, J. Richard Bond, Grace E. Chesmore, Steve K. Choi, Jake Connors, Nicholas F. Cothard, Mark Devlin, Simon Dicker, Bradley Dober, Cody J. Duell, Shannon M. Duff, Rolando Dünner, Giulio Fabbian, Nicholas Galitzki, Patricio A. Gallardo, Joseph E. Golec, Saianeesh K. Haridas, Kathleen Harrington, Erin Healy, Shuay-Pwu Patty Ho, Zachary B. Huber, Johannes Hubmayr, Jeffrey Iuliano, Bradley R. Johnson, Brian Keatin, Kenji Kiuchi, Brian J. Koopman, Jack Lashner, Adrian T. Lee, Yaqiong Li, Michele Limon, Michael Link, Tammy J Lucas, Heather McCarrick, Jenna Moore, Federico Nati, Laura B. Newburgh, Michael D. Niemack, Elena Pierpaoli, Michael J. Randall, Karen Perez Sarmiento, Lauren J. Saunders, Joseph Seibert, Carlos Sierra, Rita Sonka, Jacob Spisak, Shreya Sutariya, Osamu Tajima, Grant P. Teply, Robert J. Thornton, Tran Tsan, Carole Tucker, Joel Ullom, Eve M. Vavagiakis, Michael R. Vissers, Samantha Walker, Benjamin Westbrook, Edward J. Wollack, and Mario Zannoni

Abstract

The Simons Observatory is a ground-based cosmic microwave background experiment that consists of three 0.4 m small-aperture telescopes and one 6 m Large Aperture Telescope, located at an elevation of 5300 m on Cerro Toco in Chile. The Simons Observatory Large Aperture Telescope Receiver (LATR) is the cryogenic camera that will be coupled to the Large Aperture Telescope. The resulting instrument will produce arcminute-resolution millimeter-wave maps of half the sky with unprecedented precision. The LATR is the largest cryogenic millimeter-wave camera built to date, with a diameter of 2.4 m and a length of 2.6 m. The coldest stage of the camera is cooled to 100 mK, the operating temperature of the bolometric detectors with bands centered around 27, 39, 93, 145, 225, and 280 GHz. Ultimately, the LATR will accommodate 13 40 cm diameter optics tubes, each with three detector wafers and a total of 62,000 detectors. The LATR design must simultaneously maintain the optical alignment of the system, control stray light, provide cryogenic isolation, limit thermal gradients, and minimize the time to cool the system from room temperature to 100 mK. The interplay between these competing factors poses unique challenges. We discuss the trade studies involved with the design, the final optimization, the construction, and ultimate performance of the system.

Published
2021

16. The Atacama Cosmology Telescope: measurement and analysis of 1D beams for DR4

Author

Marius Lungu, Emilie R. Storer, Matthew Hasselfield, Adriaan J. Duivenvoorden, Erminia Calabrese, Grace E. Chesmore, Steve K. Choi, Jo Dunkley, Rolando Dünner, Patricio A. Gallardo, Joseph E. Golec, Yilun Guan, J. Colin Hill, Adam D. Hincks, Johannes Hubmayr, Mathew S. Madhavacheril, Maya Mallaby-Kay, Jeff McMahon, Kavilan Moodley, Sigurd Naess, Federico Nati, Michael D. Niemack, Lyman A. Page, Bruce Partridge, Roberto Puddu, Alessandro Schillaci, Cristóbal Sifón, Suzanne Staggs, Dhaneshwar D. Sunder, Edward J. Wollack, Zhilei Xu, Lungu, M, Storer, E, Hasselfield, M, Duivenvoorden, A, Calabrese, E, Chesmore, G, Choi, S, Dunkley, J, Dunner, R, Gallardo, P, Golec, J, Guan, Y, Hill, J, Hincks, A, Hubmayr, J, Madhavacheril, M, Mallaby-Kay, M, Mcmahon, J, Moodley, K, Naess, S, Nati, F, Niemack, M, Page, L, Partridge, B, Puddu, R, Schillaci, A, Sifon, C, Staggs, S, Sunder, D, Wollack, E, and Xu, Z

Subjects
Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::Instrumentation and Methods for Astrophysics, Physics::Accelerator Physics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, CMBR experiment, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), CMBR detector, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We describe the measurement and treatment of the telescope beams for the Atacama Cosmology Telescope's fourth data release, DR4. Observations of Uranus are used to measure the central portion (, 32 pages, 21 figures

Published
2022
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17. Amend Pandemic Preparedness Legislation to Prioritize Diagnostic Test Development and Deployment

Author

Lirong Shi, Kelsey Diffley, and Grace E. Chesmore

Subjects
03 medical and health sciences, 0302 clinical medicine, Software deployment, Pandemic preparedness, medicine, Diagnostic test, 030211 gastroenterology & hepatology, Legislation, 030212 general & internal medicine, Business, Medical emergency, medicine.disease
Abstract

As the world becomes increasingly globalized, the propensity of pandemics, such as COVID-19, increases. The United States Pandemic and All-Hazards Preparedness and Advancing Innovation Act of 2019 (PAHPAI) details the federal response to a health crisis including pandemics. The PAHPAI has hindered the nation’s response to COVID-19 due to its lack of emphasis on diagnostic testing (Burr 2019). Rapid testing is critical to slowing the spread of this disease. Ample testing will identify infected populations and will allow communities to take necessary precautions such as staying home and avoiding contact with others. Widespread shelter in place would not be necessary to control the spread of the virus, therefore reducing the economic impact of the pandemic. We propose Congress amends the PAHPAI to institute an improved testing response for future pandemics.

Published
2020
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18. The Atacama Cosmology Telescope: A Measurement of the Cosmic Microwave Background Power Spectra at 98 and 150 GHz

Author

Kavilan Moodley, Emilie R. Storer, Simone Aiola, Phumlani Phakathi, Jeff Van Lanen, E. Grace, Stefania Amodeo, Felipe Rojas, Yaqiong Li, Nick Battaglia, Precious Sikhosana, Suzanne T. Staggs, Vera Gluscevic, Robert Thornton, Benjamin L. Schmitt, Christine G. Pappas, Rolando Dünner, Danica Marsden, Yilun Guan, Felipe Carrero, Blake D. Sherwin, Sigurd Naess, Leopoldo Infante, Adam D. Hincks, Toshiya Namikawa, Zhilei Xu, Brittany Fuzia, Graeme E. Addison, Kasey Wagoner, Daniel T. Becker, J. Richard Bond, Jason E. Austermann, Sarah Marie Bruno, Matthew Hasselfield, Naomi Robertson, Jesse Treu, Vincent Lakey, John P. Nibarger, Timothy D. Morton, Sara M. Simon, David N. Spergel, Jesus Rivera, Michael R. Nolta, Zack Li, Shawn W. Henderson, Max Fankhanel, Martine Lokken, B. Thorne, Mark J. Devlin, Thomas Essinger-Hileman, James A. Beall, Yuhan Wang, Kevin T. Crowley, John Orlowski-Sherer, Bruce Partridge, Adriaan J. Duivenvoorden, Laura Newburgh, Grace E. Chesmore, Alessandro Schillaci, Jon Sievers, Dhaneshwar D. Sunder, Federico Nati, Rahul Datta, Dale Li, Shuay-Pwu Patty Ho, Shannon M. Duff, Edward V. Denison, Peter A. R. Ade, Mathew S. Madhavacheril, Maya Mallaby-Kay, Erminia Calabrese, Roberto Puddu, J. Colin Hill, Elio Angile, Jo Dunkley, Omar Darwish, Kenda Knowles, Marius Lungu, Megan Gralla, Susan E. Clark, Jeff Klein, Fernando Zago, Dongwon Han, Brandon S. Hensley, Devin Crichton, Renée Hložek, Peter Charles Hargrave, Frank J. Qu, Neelima Sehgal, Leila R. Vale, Matt Hilton, Gene C. Hilton, Joseph E. Golec, Heather Prince, Mandana Amiri, Alexander van Engelen, Maria Salatino, Loïc Maurin, Andrina Nicola, Lyman A. Page, Thibaut Louis, Steve K. Choi, Michael D. Niemack, Eve M. Vavagiakis, Nicholas F. Cothard, Victoria Calafut, Jonathan T. Ward, Carole Tucker, Arthur Kosowsky, Kevin M. Huffenberger, Kent D. Irwin, Hsiao-Mei Cho, Edward J. Wollack, Anna E. Fox, Ningfeng Zhu, Amanda MacInnis, Felipe Maldonado, Brian J. Koopman, Jeff McMahon, Cristóbal Sifón, Emmanuel Schaan, Johannes Hubmayr, Mark Halpern, Simone Ferraro, Hy Trac, Patricio A. Gallardo, Maximilian H. Abitbol, Taylor Baildon, Luis E. Campusano, Rebecca Jackson, Carlos Sierra, Felipe Menanteau, Jason R. Stevens, John P. Hughes, Cody J. Duell, Eric R. Switzer, Kirsten Hall, Rachel Bean, David Alonso, Choi, S, Hasselfield, M, Ho, S, Koopman, B, Lungu, M, Abitbol, M, Addison, G, Ade, P, Aiola, S, Alonso, D, Amiri, M, Amodeo, S, Angile, E, Austermann, J, Baildon, T, Battaglia, N, Beall, J, Bean, R, Becker, D, Richard Bond, J, Bruno, S, Calabrese, E, Calafut, V, Campusano, L, Carrero, F, Chesmore, G, Cho, H, Clark, S, Cothard, N, Crichton, D, Crowley, K, Darwish, O, Datta, R, Denison, E, Devlin, M, Duell, C, Duff, S, Duivenvoorden, A, Dunkley, J, Dunner, R, Essinger-Hileman, T, Fankhanel, M, Ferraro, S, Fox, A, Fuzia, B, Gallardo, P, Gluscevic, V, Golec, J, Grace, E, Gralla, M, Guan, Y, Hall, K, Halpern, M, Han, D, Hargrave, P, Henderson, S, Hensley, B, Colin Hill, J, Hilton, G, Hilton, M, Hincks, A, Hlozek, R, Hubmayr, J, Huffenberger, K, Hughes, J, Infante, L, Irwin, K, Jackson, R, Klein, J, Knowles, K, Kosowsky, A, Lakey, V, Li, D, Li, Y, Li, Z, Lokken, M, Louis, T, Macinnis, A, Madhavacheril, M, Maldonado, F, Mallaby-Kay, M, Marsden, D, Maurin, L, Mcmahon, J, Menanteau, F, Moodley, K, Morton, T, Naess, S, Namikawa, T, Nati, F, Newburgh, L, Nibarger, J, Nicola, A, Niemack, M, Nolta, M, Orlowski-Sherer, J, Page, L, Pappas, C, Partridge, B, Phakathi, P, Prince, H, Puddu, R, Qu, F, Rivera, J, Robertson, N, Rojas, F, Salatino, M, Schaan, E, Schillaci, A, Schmitt, B, Sehgal, N, Sherwin, B, Sierra, C, Sievers, J, Sifon, C, Sikhosana, P, Simon, S, Spergel, D, Staggs, S, Stevens, J, Storer, E, Sunder, D, Switzer, E, Thorne, B, Thornton, R, Trac, H, Treu, J, Tucker, C, Vale, L, van Engelen, A, van Lanen, J, Vavagiakis, E, Wagoner, K, Wang, Y, Ward, J, Wollack, E, Xu, Z, Zago, F, Zhu, N, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and ACT

Subjects
Physics, CMBR polarisation, Cosmology and Nongalactic Astrophysics (astro-ph.CO), 010308 nuclear & particles physics, Cosmic microwave background, Library science, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Cosmological parameters from CMBR, 0103 physical sciences, Atacama Cosmology Telescope, CMBR experiment, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

We present the temperature and polarization angular power spectra of the CMB measured by the Atacama Cosmology Telescope (ACT) from 5400 deg$^2$ of the 2013-2016 survey, which covers $>$15000 deg$^2$ at 98 and 150 GHz. For this analysis we adopt a blinding strategy to help avoid confirmation bias and, related to this, show numerous checks for systematic error done before unblinding. Using the likelihood for the cosmological analysis we constrain secondary sources of anisotropy and foreground emission, and derive a "CMB-only" spectrum that extends to $\ell=4000$. At large angular scales, foreground emission at 150 GHz is $\sim$1% of TT and EE within our selected regions and consistent with that found by Planck. Using the same likelihood, we obtain the cosmological parameters for $\Lambda$CDM for the ACT data alone with a prior on the optical depth of $\tau=0.065\pm0.015$. $\Lambda$CDM is a good fit. The best-fit model has a reduced $\chi^2$ of 1.07 (PTE=0.07) with $H_0=67.9\pm1.5$ km/s/Mpc. We show that the lensing BB signal is consistent with $\Lambda$CDM and limit the celestial EB polarization angle to $\psi_P =-0.07^{\circ}\pm0.09^{\circ}$. We directly cross correlate ACT with Planck and observe generally good agreement but with some discrepancies in TE. All data on which this analysis is based will be publicly released., Comment: 44 pages, 27 figures, products available on the NASA LAMBDA website, version accepted for publication in JCAP

Published
2020
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19. Wideband 67−116 GHz receiver development for ALMA Band 2

Author

S. Ricciardi, Magnus Strandberg, H. Gibson, Neil M. Phillips, Igor Lapkin, Gianni Marconi, Grace E. Chesmore, D. Vigano, Victor Belitsky, Axel Murk, C. De Breuck, Jeff McMahon, Keiko Kaneko, Alvaro Gonzalez, Alec Josaitis, J. Ceru, Juan Daniel Gallego, Francesco Cavaliere, Mikko Kotiranta, I. Lopez-Fernandez, V. Tapia, Luca Terenzi, Leonardo Testi, F. Pezzotta, S. Mariotti, Renzo Nesti, Danielle George, D. Cuadrado-Calle, Pavel A. Yagoubov, Niklas Wadefalk, Kevin Coughlin, Fabrizio Villa, Joseph E. Golec, R. Molina, Mathias Fredrixon, Francisca Kemper, B. Thomas, Tony Mroczkowski, Nicolas Reyes, William McGenn, Patricio Mena, Yoshinori Uzawa, M. Sandri, F. Cuttaia, Gary A. Fuller, Maria T. Beltrán, ITA, GBR, DEU, ESP, NLD, RUS, SWE, CHE, and Electromagnetics

Subjects
Physics - Instrumentation and Detectors, Computer science, Local oscillator, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, Radio spectrum, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Wideband, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, business.industry, Amplifier, Bandwidth (signal processing), 620 Ingenieurwissenschaften, Electrical engineering, 020206 networking & telecommunications, Astronomy and Astrophysics, Instrumentation and Detectors (physics.ins-det), Polarization (waves), 530 Physik, Intermediate frequency, Instrumentation: interferometers, Space and Planetary Science, Infrared window, 500 Naturwissenschaften, Astrophysics - Instrumentation and Methods for Astrophysics, business
Abstract

ALMA has been operating since 2011, but has not yet been populated with the full suite of intended frequency bands. In particular, ALMA Band 2 (67-90 GHz) is the final band in the original ALMA band definition to be approved for production. We aim to produce a wideband, tuneable, sideband-separating receiver with 28 GHz of instantaneous bandwidth per polarisation operating in the sky frequency range 67-116 GHz. Our design anticipates new ALMA requirements following the recommendations in the 2030 ALMA Development Roadmap. The cryogenic cartridge is designed to be compatible with the ALMA Band 2 cartridge slot, where the coldest components -- the feedhorns, orthomode transducers, and cryogenic low noise amplifiers -- operate at a temperature of 15 K. We use multiple simulation methods and tools to optimise our designs for both the passive optics and the active components. The cryogenic cartridge interfaces with a room temperature cartridge hosting the local oscillator (LO) and the downconverter module. This warm cartridge is largely based on GaAs semiconductor technology and is optimised to match the cryogenic receiver bandwidth with the required instantaneous LO tuning range. Our collaboration has designed, fabricated, and tested multiple technical solutions for each of the components, producing a state-of-the-art receiver covering the full ALMA Band 2 & 3 atmospheric window. The receiver is suitable for deployment on ALMA in the coming years, and is capable of dual-polarisation, sideband-separating observations in intermediate frequency bands spanning 4-18 GHz, for a total of 28 GHz on-sky bandwidth per polarisation channel. We conclude that the 67-116 GHz wideband implementation for ALMA Band 2 is now feasible, and this receiver is a compelling instrumental upgrade that will enhance observational capabilities and scientific reach., 23 pages, accepted for publication in A&A on 20 Dec 2019. This version corrects the affiliations of 2 co-authors

Published
2020
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20. Atacama Cosmology Telescope: Constraints on cosmic birefringence

Author

Michael D. Niemack, Mathew S. Madhavacheril, Sigurd Naess, J. Richard Bond, Adam D. Hincks, Neelima Sehgal, Kavilan Moodley, Loïc Maurin, Thibaut Louis, Joanna Dunkley, Grace E. Chesmore, Frank J. Qu, Omar Darwish, Johannes Hubmayr, Simone Aiola, Gene C. Hilton, Lyman A. Page, Toshiya Namikawa, Rolando Dünner, Maya Mallaby-Kay, C. Sifon, Mark J. Devlin, Patricio A. Gallardo, Daniel T. Becker, Amanda MacInnis, Alexander van Engelen, Renée Hložek, John P. Nibarger, Sara M. Simon, Emilie R. Storer, Matthew Hasselfield, Blake D. Sherwin, Kevin M. Huffenberger, Yilun Guan, Laura Newburgh, Vera Gluscevic, Arthur Kosowsky, Jeff Van Lanen, Edward J. Wollack, Anna E. Fox, Brian J. Koopman, Erminia Calabrese, Jeff McMahon, James A. Beall, Steve K. Choi, Alessandro Schillaci, Naomi Robertson, Nicholas Battaglia, Marius Lungu, John P. Hughes, Suzanne T. Staggs, David N. Spergel, Federico Nati, Dongwon Han, Namikawa, T, Guan, Y, Darwish, O, Sherwin, B, Aiola, S, Battaglia, N, Beall, J, Becker, D, Bond, J, Calabrese, E, Chesmore, G, Choi, S, Devlin, M, Dunkley, J, Dunner, R, Fox, A, Gallardo, P, Gluscevic, V, Han, D, Hasselfield, M, Hilton, G, Hincks, A, Hlozek, R, Hubmayr, J, Huffenberger, K, Hughes, J, Koopman, B, Kosowsky, A, Louis, T, Lungu, M, Macinnis, A, Madhavacheril, M, Mallaby-Kay, M, Maurin, L, Mcmahon, J, Moodley, K, Naess, S, Nati, F, Newburgh, L, Nibarger, J, Niemack, M, Page, L, Qu, F, Robertson, N, Schillaci, A, Sehgal, N, Sifon, C, Simon, S, Spergel, D, Staggs, S, Storer, E, Van Engelen, A, Van Lanen, J, Wollack, E, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut d'astrophysique spatiale (IAS), and Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
data analysis method, cosmological model, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Cosmic microwave background, cosmic background radiation: polarization, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, power spectrum, 01 natural sciences, 7. Clean energy, Cosmology, High Energy Physics - Experiment, current: constraint, High Energy Physics - Experiment (hep-ex), High Energy Physics - Phenomenology (hep-ph), statistical analysis, 0103 physical sciences, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Cosmic Birefringence, CMB, Cosmology, inflation, 010303 astronomy & astrophysics, Axion, Physics, Birefringence, birefringence, 010308 nuclear & particles physics, Chern-Simons term, photon, coupling constant, Polarization (waves), Massless particle, High Energy Physics - Phenomenology, Amplitude, axion, [PHYS.HPHE]Physics [physics]/High Energy Physics - Phenomenology [hep-ph], Atacama Cosmology Telescope, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Cosmology and Nongalactic Astrophysics, cosmic background radiation: anisotropy
Abstract

We present new constraints on anisotropic birefringence of the cosmic microwave background polarization using two seasons of data from the Atacama Cosmology Telescope covering $456$ square degrees of sky. The birefringence power spectrum, measured using a curved-sky quadratic estimator, is consistent with zero. Our results provide the tightest current constraint on birefringence over a range of angular scales between $5$ arcminutes and $9$ degrees. We improve previous upper limits on the amplitude of a scale-invariant birefringence power spectrum by a factor of between $2$ and $3$. Assuming a nearly-massless axion field during inflation, our result is equivalent to a $2\,\sigma$ upper limit on the Chern-Simons coupling constant between axions and photons of $g_{\alpha\gamma}, Comment: 18 pages, 3 figures, Accepted for publication in PRD

Published
2020
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21. Erratum: 'The Simons Observatory Large Aperture Telescope Receiver' (2021, ApJS, 256, 23)

Author

Ningfeng Zhu, Tanay Bhandarkar, Gabriele Coppi, Anna M. Kofman, John L. Orlowski-Scherer, Zhilei Xu, Shunsuke Adachi, Peter Ade, Simone Aiola, Jason Austermann, Andrew O. Bazarko, James A. Beall, Sanah Bhimani, J. Richard Bond, Grace E. Chesmore, Steve K. Choi, Jake Connors, Nicholas F. Cothard, Mark Devlin, Simon Dicker, Bradley Dober, Cody J. Duell, Shannon M. Duff, Rolando Dünner, Giulio Fabbian, Nicholas Galitzki, Patricio A. Gallardo, Joseph E. Golec, Saianeesh K. Haridas, Kathleen Harrington, Erin Healy, Shuay-Pwu Patty Ho, Zachary B. Huber, Johannes Hubmayr, Jeffrey Iuliano, Bradley R. Johnson, Brian Keating, Kenji Kiuchi, Brian J. Koopman, Jack Lashner, Adrian T. Lee, Yaqiong Li, Michele Limon, Michael Link, Tammy J Lucas, Heather McCarrick, Jenna Moore, Federico Nati, Laura B. Newburgh, Michael D. Niemack, Elena Pierpaoli, Michael J. Randall, Karen Perez Sarmiento, Lauren J. Saunders, Joseph Seibert, Carlos Sierra, Rita Sonka, Jacob Spisak, Shreya Sutariya, Osamu Tajima, Grant P. Teply, Robert J. Thornton, Tran Tsan, Carole Tucker, Joel Ullom, Eve M. Vavagiakis, Michael R. Vissers, Samantha Walker, Benjamin Westbrook, Edward J. Wollack, and Mario Zannoni

Subjects
Space and Planetary Science, Astronomy and Astrophysics
Published
2021
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22. Simons Observatory HoloSim-ML: machine learning applied to the efficient analysis of radio holography measurements of complex optical systems

Author

Grace E. Chesmore, Kevin Wolz, Zhilei Xu, Patricio A. Gallardo, Jeff McMahon, B. R. Johnson, Michele Limon, Edward J. Wollack, S. M. Simon, Alexandre E. Adler, Michael D. Niemack, Ningfeng Zhu, Federico Nati, Jon E. Gudmundsson, Nadia Dachlythra, Nicholas F. Cothard, Giuseppe Puglisi, Chesmore, G, Adler, A, Cothard, N, Dachlythra, N, Gallardo, P, Gudmundsson, J, Johnson, B, Limon, M, Mcmahon, J, Nati, F, Niemack, M, Puglisi, G, Simon, S, Wollack, E, Wolz, K, Xu, Z, and Zhu, N

Subjects
Computer science, Cosmology, Optics, Holography, Holography, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, 02 engineering and technology, Machine learning, computer.software_genre, 01 natural sciences, law.invention, 010309 optics, Telescope, Optics, law, Observatory, Position (vector), 0103 physical sciences, FOS: Electrical engineering, electronic engineering, information engineering, Code (cryptography), Electrical and Electronic Engineering, Instrumentation and Methods for Astrophysics (astro-ph.IM), Engineering (miscellaneous), computer.programming_language, Settore FIS/05, business.industry, Image and Video Processing (eess.IV), Astrophysics::Instrumentation and Methods for Astrophysics, Electrical Engineering and Systems Science - Image and Video Processing, Python (programming language), 021001 nanoscience & nanotechnology, Atomic and Molecular Physics, and Optics, Millimeter, Artificial intelligence, Astrophysics - Instrumentation and Methods for Astrophysics, 0210 nano-technology, business, computer, Beam (structure), Optics (physics.optics), Physics - Optics
Abstract

Near-field radio holography is a common method for measuring and aligning mirror surfaces for millimeter and sub-millimeter telescopes. In instruments with more than a single mirror, degeneracies arise in the holography measurement, requiring multiple measurements and new fitting methods. We present HoloSim-ML, a Python code for beam simulation and analysis of radio holography data from complex optical systems. This code uses machine learning to efficiently determine the position of hundreds of mirror adjusters on multiple mirrors with few micron accuracy. We apply this approach to the example of the Simons Observatory 6m telescope., Software is publicly available at: https://github.com/McMahonCosmologyGroup/holosim-ml

Published
2021
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23. Broadband, millimeter-wave antireflection coatings for large-format, cryogenic aluminum oxide optics

Author

N. Huang, W. L. Holzapfel, W. B. Everett, Jason Gallicchio, Z. Ahmed, A. E. Gambrel, Marion Dierickx, J. A. Sobrin, Jason W. Henning, T. de Haan, S. S. Meyer, A. Suzuki, Joaquin Vieira, D. Dutcher, S. Guns, K. W. Yoon, J. Stephen, Graeme Smecher, K. Vanderlinde, Andrew Nadolski, Aled Jones, Lincoln Bryant, Valentine Novosad, J. C. Groh, D. Howe, C. M. Po sada, H. Nguyen, J. Fu, A. H. Harke-Hosemann, T. Natoli, Faustin Carter, L. Florez, John M Kovac, A. Foster, J. T. Sayre, Thomas Cecil, Erik Shirokoff, A. Lowitz, Antony A. Stark, P. Paschos, S. E. Kuhlmann, Junjia Ding, C. L. Kuo, Kent D. Irwin, J. E. Ruhl, A. M. Kofman, Daniel Michalik, K. R. Ferguson, C. Tucker, J. Cheshire, Adam Anderson, M. R. Young, Grace E. Chesmore, Gensheng Wang, M. Korman, Donna Kubik, V. G. Yefremenko, W. Quan, S. Padin, J. F. Cliche, Jeff McMahon, John E. Pearson, J. Meier, Jessica Avva, A. Cukierman, R. Guyser, Andreas Bender, G. I. Noble, M. Jonas, C. Tandoi, N. W. Halverson, Peter A. R. Ade, R. J. Harris, K. T. Story, Bradford Benson, Nathan Whitehorn, N. L. Harrington, Joshua Montgomery, D. Riebel, K. L. Thompson, Z. Pan, Oliver Jeong, Robert Gardner, John E. Carlstrom, J. Farwick, Adrian T. Lee, Alexandra S. Rahlin, R. Basu Thakur, and Chihway Chang

Subjects
Physics - Instrumentation and Detectors, Materials science, Fabrication, Oxide, FOS: Physical sciences, Dielectric, Substrate (electronics), Lenslet, engineering.material, 01 natural sciences, 010309 optics, chemistry.chemical_compound, Optics, Coating, 0103 physical sciences, Transmittance, Electrical and Electronic Engineering, Engineering (miscellaneous), Instrumentation and Methods for Astrophysics (astro-ph.IM), business.industry, Instrumentation and Detectors (physics.ins-det), Atomic and Molecular Physics, and Optics, chemistry, engineering, Astrophysics - Instrumentation and Methods for Astrophysics, business, Refractive index
Abstract

We present two prescriptions for broadband (~77 - 252 GHz), millimeter-wave antireflection coatings for cryogenic, sintered polycrystalline aluminum oxide optics: one for large-format (700 mm diameter) planar and plano-convex elements, the other for densely packed arrays of quasi-optical elements, in our case 5 mm diameter half-spheres (called "lenslets"). The coatings comprise three layers of commercially-available, polytetrafluoroethylene-based, dielectric sheet material. The lenslet coating is molded to fit the 150 mm diameter arrays directly while the large-diameter lenses are coated using a tiled approach. We review the fabrication processes for both prescriptions then discuss laboratory measurements of their transmittance and reflectance. In addition, we present the inferred refractive indices and loss tangents for the coating materials and the aluminum oxide substrate. We find that at 150 GHz and 300 K the large-format coating sample achieves (97 +/- 2)% transmittance and the lenslet coating sample achieves (94 +/- 3)% transmittance., Comment: 19 pages, 11 figures; submitted 05 Dec 2019, accepted 26 Feb 2020

Published
2019
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24. The Simons Observatory: The Large Aperture Telescope (LAT)

Author

Nicholas Galitzki, Michael R. Vissers, Osamu Tajima, Kevin D. Crowley, Karen Perez Sarmiento, Edward J. Wollack, J. Richard Bond, C. Hervias-Caimapo, Simon Dicker, Frederick Matsuda, Shreya Sutariya, Michele Limon, Brian J. Koopman, Saianeesh K. Haridas, D. Kaneko, Andrea Zonca, Federico Nati, Zachary B. Huber, Zhilei Xu, Ningfeng Zhu, Tomoki Terasaki, A. M. Kofman, Robert Thornton, Gabriele Coppi, Samantha Walker, Peter A. R. Ade, Jack Lashner, Jeffrey Iuliano, Tanay Bhandarkar, Rita Sonka, Maximiliano Silva-Feaver, Zachary Whipps, Carole Tucker, Shunsuke Adachi, Michael J. Link, Grace E. Chesmore, Eve M. Vavagiakis, Bradley Dober, Mario Zannoni, Michael D. Niemack, Steve K. Choi, Tammy J. Lucas, Joel N. Ullom, Shannon M. Duff, Shuay-Pwu Patty Ho, Nicholas F. Cothard, Emmanuel Schaan, Johannes Hubmayr, Kathleen Harrington, Mark J. Devlin, Patricio A. Gallardo, Joseph E. Golec, Lucio Piccirillo, Heather McCarrick, Yuji Chinone, Grant Teply, Jon E. Gudmundsson, Jake Connors, J. A. Beall, and John Orlowski-Scherer

Subjects
Physics, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, Cosmic microwave background, Astrophysics::Instrumentation and Methods for Astrophysics, FOS: Physical sciences, Astronomy, Astrophysics::Cosmology and Extragalactic Astrophysics, General Medicine, Large aperture, Radio spectrum, law.invention, Telescope, Sky, Observatory, law, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics::Galaxy Astrophysics, Microwave, Astrophysics - Cosmology and Nongalactic Astrophysics, media_common
Abstract

The Simons Observatory (SO) is a Cosmic Microwave Background (CMB) experiment to observe the microwave sky in six frequency bands from 30GHz to 290GHz. The Observatory -- at $\sim$5200m altitude -- comprises three Small Aperture Telescopes (SATs) and one Large Aperture Telescope (LAT) at the Atacama Desert, Chile. This research note describes the design and current status of the LAT along with its future timeline., 4 pages, 1 figure

Published
2021
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25. Evaluation of 3D Carbon Nanotube Composite Atomic Force Microscopy Probes Fabricated with Ion Flux Molding

Author

Richard P. Barber, Carrollyn Roque, Grace E. Chesmore, and Kai-Hsiang Hung

Subjects
Kelvin probe force microscope, Materials science, Composite number, Nanotechnology, Mechanical properties of carbon nanotubes, Conductive atomic force microscopy, Molding (process), Carbon nanotube, Ion, law.invention, law, General Materials Science, Composite material, Instrumentation, Photoconductive atomic force microscopy
Published
2016
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26. Structure-function relationships of fullerene esters in polymer solar cells: unexpected structural effects on lifetime and efficiency

Author

Kyle J. Bandaccari, Richard P. Barber, Parisa Tajalli-Tehrani Valverde, Michael Tro, David Oparko, Maxwell J. Giammona, Grace E. Chesmore, Alexis Sarabia, Brian J. McNelis, Justin Isaac, Emma Lewis, and Thorsteinn Adalsteinsson

Subjects
Materials science, Fullerene, Substituent, Energy Engineering and Power Technology, Structural diversity, Device Properties, 02 engineering and technology, 010402 general chemistry, Photochemistry, 01 natural sciences, Polymer solar cell, chemistry.chemical_compound, Photovoltaics, Physics::Atomic and Molecular Clusters, Physics::Chemical Physics, chemistry.chemical_classification, Renewable Energy, Sustainability and the Environment, business.industry, Structure function, Polymer, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Fuel Technology, Nuclear Energy and Engineering, chemistry, 0210 nano-technology, business
Abstract

We report both transport measurements and spectroscopic data of polymer/fullerene blend photovoltaics using a small library of fullerene esters to correlate device properties with a range of functionality and structural diversity of the ester substituent. We observe that minor structural changes can lead to significant differences in device efficiency and lifetime. Surprisingly, we have found that isomeric R-groups in the fullerene ester-based devices we have studied have very different efficiencies. The characteristic lifetimes derived from both transport and spectroscopic measurements are generally comparable, however some more rapid effects in specific fullerene esters are not observed spectroscopically. Our results support using a library approach for optimizing device performance in these systems.

Published
2015
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27. Time-dependent efficiency measurements of polymer solar cells with dye additives: unexpected initial increase of efficiency

Author

Brian J. McNelis, Grace E. Chesmore, Parisa Tajalli-Tehrani Valverde, Kyle J. Bandaccari, Richard P. Barber, and Mitchel Bugaj

Subjects
leakage current, Range (particle radiation), Materials science, Morphology (linguistics), Microscope, Renewable Energy, Sustainability and the Environment, Atomic force microscopy, lcsh:TJ807-830, lcsh:Renewable energy sources, Condensed Matter Physics, dye additives, Polymer solar cell, Electronic, Optical and Magnetic Materials, Characterization (materials science), Active layer, law.invention, Chemical engineering, law, morphology, Electrical and Electronic Engineering, polymer photovoltaic, Layer (electronics)
Abstract

We report the effects of the addition of two azo-dye additives on the time-dependent efficiency of polymer solar cells. Although the maximum efficiencies of devices containing different amounts of dye do not vary greatly over the selected concentration range, the time dependence results reveal a surprising initial increase in efficiency in some samples. We observe this effect to be correlated with a leakage current, although a specific mechanism is not yet identified. We also present the measured lifetimes of these solar cells, and find that variations in dye concentrations produce a small effect at most. Characterization of the bulk heterojunction layer (active layer) morphology using atomic-force microscope (AFM) imaging reveals reordering patterns which suggest that the primary effects of the dyes arise via structural, not absorptive, characteristics.

Published
2018
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