2,108 results on '"Datta, R."'
Search Results
2. Bayesian Inference analysis of jet quenching using inclusive jet and hadron suppression measurements
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Ehlers, R., Chen, Y., Mulligan, J., Ji, Y., Kumar, A., Mak, S., Jacobs, P. M., Majumder, A., Angerami, A., Arora, R., Bass, S. A., Datta, R., Du, L., Elfner, H., Fries, R. J., Gale, C., He, Y., Jacak, B. V., Jeon, S., Jonas, F., Kasper, L., Kordell II, M., Kunnawalkam-Elayavalli, R., Latessa, J., Lee, Y. -J., Lemmon, R., Luzum, M., Mankolli, A., Martin, C., Mehryar, H., Mengel, T., Nattrass, C., Norman, J., Parker, C., Paquet, J. -F., Putschke, J. H., Roch, H., Roland, G., Schenke, B., Schwiebert, L., Sengupta, A., Shen, C., Singh, M., Sirimanna, C., Soeder, D., Soltz, R. A., Soudi, I., Tachibana, Y., Velkovska, J., Vujanovic, G., Wang, X. -N., Wu, X., and Zhao, W.
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High Energy Physics - Phenomenology ,Nuclear Experiment ,Nuclear Theory - Abstract
The JETSCAPE Collaboration reports a new determination of the jet transport parameter $\hat{q}$ in the Quark-Gluon Plasma (QGP) using Bayesian Inference, incorporating all available inclusive hadron and jet yield suppression data measured in heavy-ion collisions at RHIC and the LHC. This multi-observable analysis extends the previously published JETSCAPE Bayesian Inference determination of $\hat{q}$, which was based solely on a selection of inclusive hadron suppression data. JETSCAPE is a modular framework incorporating detailed dynamical models of QGP formation and evolution, and jet propagation and interaction in the QGP. Virtuality-dependent partonic energy loss in the QGP is modeled as a thermalized weakly-coupled plasma, with parameters determined from Bayesian calibration using soft-sector observables. This Bayesian calibration of $\hat{q}$ utilizes Active Learning, a machine--learning approach, for efficient exploitation of computing resources. The experimental data included in this analysis span a broad range in collision energy and centrality, and in transverse momentum. In order to explore the systematic dependence of the extracted parameter posterior distributions, several different calibrations are reported, based on combined jet and hadron data; on jet or hadron data separately; and on restricted kinematic or centrality ranges of the jet and hadron data. Tension is observed in comparison of these variations, providing new insights into the physics of jet transport in the QGP and its theoretical formulation., Comment: 20 pages, 10 figures, 2 tables, submitted to PRC; updated acknowledgements
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- 2024
3. A soft-hard framework with exact four momentum conservation for small systems
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Soudi, I., Zhao, W., Majumder, A., Shen, C., Putschke, J. H., Boudreaux, B., Angerami, A., Arora, R., Bass, S. A., Chen, Y., Datta, R., Du, L., Ehlers, R., Elfner, H., Fries, R. J., Gale, C., He, Y., Jacak, B. V., Jacobs, P. M., Jeon, S., Ji, Y., Kasper, L., Kelsey, M., Kordell II, M., Kumar, A., Kunnawalkam-Elayavalli, R., Latessa, J., Lee, Y. -J., Lemmon, R., Luzum, M., Mak, S., Mankolli, A., Martin, C., Mehryar, H., Mengel, T., Nattrass, C., Norman, J., Parker, C., Paquet, J. -F., Roch, H., Roland, G., Schenke, B., Schwiebert, L., Sengupta, A., Singh, M., Sirimanna, C., Soeder, D., Soltz, R. A., Tachibana, Y., Velkovska, J., Vujanovic, G., Wang, X. -N., and Wu, X.
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High Energy Physics - Phenomenology ,High Energy Physics - Experiment ,High Energy Physics - Theory ,Nuclear Theory - Abstract
A new framework, called x-scape, for the combined study of both hard and soft transverse momentum sectors in high energy proton-proton ($p$-$p$) and proton-nucleus ($p$-$A$) collisions is set up. A dynamical initial state is set up using the 3d-Glauber model with transverse locations of hotspots within each incoming nucleon. A hard scattering that emanates from two colliding hotspots is carried out using the Pythia generator. Initial state radiation from the incoming hard partons is carried out in a new module called I-matter, which includes the longitudinal location of initial splits. The energy-momentum of both the initial hard partons and their associated beam remnants is removed from the hot spots, depleting the energy-momentum available for the formation of the bulk medium. Outgoing showers are simulated using the matter generator, and results are presented for both cases, allowing for and not allowing for energy loss. First comparisons between this hard-soft model and single inclusive hadron and jet data from $p$-$p$ and minimum bias $p$-$Pb$ collisions are presented. Single hadron spectra in $p$-$p$ are used to carry out a limited (in number of parameters) Bayesian calibration of the model. Fair comparisons with data are indicative of the utility of this new framework. Theoretical studies of the correlation between jet $p_T$ and event activity at mid and forward rapidity are carried out., Comment: 18 pages, 15 figures
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- 2024
4. Radiatively Cooled Magnetic Reconnection Experiments Driven by Pulsed Power
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Datta, R, Chandler, K, Myers, C E, Chittenden, J P, Crilly, A J, Aragon, C, Ampleford, D J, Banasek, J T, Edens, A, Fox, W R, Hansen, S B, Harding, E C, Jennings, C A, Ji, H, Kuranz, C C, Lebedev, S V, Looker, Q, Patel, S G, Porwitzky, A J, Shipley, G A, Uzdensky, D A, Yager-Elorriaga, D A, and Hare, J D
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Physics - Plasma Physics - Abstract
We present evidence for strong radiative cooling in a pulsed-power-driven magnetic reconnection experiment. Two aluminum exploding wire arrays, driven by a 20 MA peak current, 300 ns rise time pulse from the Z machine (Sandia National Laboratories), generate strongly-driven plasma flows ($M_A \approx 7$) with anti-parallel magnetic fields, which form a reconnection layer ($S_L \approx 120$) at the mid-plane. The net cooling rate far exceeds the Alfv\'enic transit rate ($\tau_{\text{cool}}^{-1}/\tau_{\text{A}}^{-1} > 100$), leading to strong cooling of the reconnection layer. We determine the advected magnetic field and flow velocity using inductive probes positioned in the inflow to the layer, and inflow ion density and temperature from analysis of visible emission spectroscopy. A sharp decrease in X-ray emission from the reconnection layer, measured using filtered diodes and time-gated X-ray imaging, provides evidence for strong cooling of the reconnection layer after its initial formation. X-ray images also show localized hotspots, regions of strong X-ray emission, with velocities comparable to the expected outflow velocity from the reconnection layer. These hotspots are consistent with plasmoids observed in 3D radiative resistive magnetohydrodynamic simulations of the experiment. X-ray spectroscopy further indicates that the hotspots have a temperature (170 eV) much higher than the bulk layer ($\leq$ 75 eV) and inflow temperatures (about 2 eV), and that these hotspots generate the majority of the high-energy (> 1 keV) emission.
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- 2024
5. Plasmoid formation and strong radiative cooling in a driven magnetic reconnection experiment
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Datta, R., Chandler, K., Myers, C. E., Chittenden, J. P., Crilly, A. J., Aragon, C., Ampleford, D. J., Banasek, J. T., Edens, A., Fox, W. R., Hansen, S. B., Harding, E. C., Jennings, C. A., Ji, H., Kuranz, C. C., Lebedev, S. V., Looker, Q., Patel, S. G., Porwitzky, A., Shipley, G. A., Uzdensky, D. A., Yager-Elorriaga, D. A., and Hare, J. D.
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Physics - Plasma Physics - Abstract
We present results from the first experimental study of strongly radiatively-cooled magnetic reconnection. Two exploding aluminum wire arrays, driven simultaneously by the Z machine ($I_{max} = 20 \, \text{MA}$, $t_{\text{rise}} = 300 \, \text{ns}$), generate a radiatively-cooled reconnection layer ($S_L \approx 120$) in which the total cooling rate exceeds the hydrodynamic transit rate ($\tau_{\text{hydro}}/\tau_{\text{cool}} > 100$). Measurements of X-ray emission from the reconnection layer using a filtered diode ($>1$ keV) show a narrow (50 ns FWHM) burst of emission at 220 ns after current start, consistent with the formation and subsequent rapid cooling of the reconnection layer. Time-gated X-ray images of the reconnection layer show fast-moving (up to 50 km/s) hotspots inside the layer, consistent with the presence of plasmoids observed in 3D resistive magnetohydrodynamic simulations. X-ray spectroscopy shows that these hotspots generate the majority of Al K-shell emission (at around 1.6 keV) prior to the onset of cooling, and exhibit temperatures of 170 eV, much greater than the temperature of the plasma inflows and the rest of the reconnection layer.
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- 2024
6. New Measurement of the Hoyle State Radiative Transition Width
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Rana, T. K., Pandit, Deepak, Manna, S., Kundu, S., Banerjee, K., Sen, A., Pandey, R., Mukherjee, G., Ghosh, T. K., Nayak, S. S., Shil, R., Karmakar, P., Atreya, K., Rani, K., Paul, D., Santra, Rajkumar, Sultana, A., Basu, S., Pal, S., Sadhukhan, S., Mondal, Debasish, Mukhopadhyay, S., Bhattacharya, Srijit, Pal, Surajit, Pant, Pankaj, Roy, Pratap, Ali, Sk M., Mondal, S., De, A., Dey, Balaram, Datta, R., Bhattacharya, S., and Bhattacharya, C.
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Nuclear Experiment - Abstract
The radiative decay of the Hoyle state is the doorway to the production of heavier elements in stellar environment. Here we report, an exclusive measurement of electric quadruple (E$_2$) transitions of the Hoyle state to the ground state of $^{12}$C through the $^{12}$C(p, p$^\prime$$\gamma$$\gamma$)$^{12}$C reaction. Triple coincidence measurement yields a value of radiative branching ratio $\Gamma_{rad}$/$\Gamma$ = 4.01 (30) $\times$ 10$^{-4}$. The result has been corroborated by an independent experiment based on the complete kinematical measurement $via.$ $^{12}$C(p, p$^\prime$)$^{12}$C reaction ($\Gamma_{rad}$/$\Gamma$ = 4.04 (30) $\times$ 10$^{-4}$). Using our results together with the currently adopted values of $\Gamma_{\pi}$(E$_0$)/$\Gamma$ and $\Gamma_{\pi}$($E_0$), the radiative width of the Hoyle state is found to be 3.75 (40) $\times$ 10$^{-3}$ eV. We emphasize here that our result is not in agreement with 34 $\%$ increase in the radiative decay width of the Hoyle state measured recently but consistent with the currently adopted value., Comment: 7 pages, 5 figures Submitted to Phys. Rev. Lett
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- 2023
7. Analysis of Indian foreign exchange markets: A Multifractal Detrended Fluctuation Analysis (MFDFA) approach
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Datta, R. P.
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Quantitative Finance - Statistical Finance - Abstract
The multifractal spectra of daily foreign exchange rates for US dollar (USD), the British Pound (GBP), the Euro (Euro) and the Japanese Yen (Yen) with respect to the Indian Rupee are analysed for the period 6th January 1999 to 24th July 2018. We observe that the time series of logarithmic returns of all the four exchange rates exhibit features of multifractality. Next, we research the source of the observed multifractality. For this, we transform the return series in two ways: a) We randomly shuffle the original time series of logarithmic returns and b) We apply the process of phase randomisation on the unchanged series. Our results indicate in the case of the US dollar the source of multifractality is mainly the fat tail. For the British Pound and the Euro, we see the long-range correlations between the observations and the thick tails of the probability distribution give rise to the observed multifractal features, while in the case of the Japanese Yen, the origin of the multifractal nature of the return series is mostly due to the broad tail.
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- 2023
8. Plasma flows during the ablation stage of an over-massed pulsed-power-driven exploding planar wire array
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Datta, R., Angel, J., Greenly, J. B., Bland, S. N., Chittenden, J. P., Lavine, E. S., Potter, W. M., Robinson, D., Varnish, T. W. O., Wong, E., Hammer, D. A., Kusse, B. R., and Hare, J. D.
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Physics - Plasma Physics - Abstract
We characterize the plasma flows generated during the ablation stage of an over-massed exploding planar wire array, fielded on the COBRA pulsed-power facility (1 MA peak current, 250 ns rise time). The planar wire array is designed to provide a driving magnetic field (80-100 T) and current per wire distribution (about 60 kA), similar to that in a 10 MA cylindrical exploding wire array fielded on the Z machine. Over-massing the arrays enables continuous plasma ablation over the duration of the experiment. The requirement to over-mass on the Z machine necessitates wires with diameters of 75-100 $\mu$m, which are thicker than wires usually fielded on wire array experiments. To test ablation with thicker wires, we perform a parametric study by varying the initial wire diameter between 33-100 $\mu$m. The largest wire diameter (100 $\mu$m) array exhibits early closure of the AK gap, while the gap remains open during the duration of the experiment for wire diameters between 33-75 $\mu$m. Laser plasma interferometry and time-gated XUV imaging are used to probe the plasma flows ablating from the wires. The plasma flows from the wires converge to generate a pinch, which appears as a fast-moving ($V \approx {100}$ kms$^{-1}$) column of increased plasma density ($\bar{n}_e \approx 2 \times 10^{18}$ cm$^{-3}$) and strong XUV emission. Finally, we compare the results with three-dimensional resistive-magnetohydrodynamic (MHD) simulations performed using the code GORGON, the results of which reproduce the dynamics of the experiment reasonably well., Comment: 14 pages; 14 figures
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- 2023
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9. Time-resolved velocity and ion sound speed measurements from simultaneous bow shock imaging and inductive probe measurements
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Datta, R., Russell, D. R., Clayson, T., Chittenden, J. P., Lebedev, S. V., and Hare, J. D.
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Physics - Plasma Physics - Abstract
We present a technique to measure the time-resolved velocity and ion sound speed in magnetized, supersonic high-energy-density plasmas. We place an inductive (`b-dot') probe in a supersonic pulsed-power-driven plasma flow and measure the magnetic field advected by the plasma. As the magnetic Reynolds number is large ($R_M > 10$), the plasma flow advects a magnetic field proportional to the current at the load. This enables us to estimate the plasma flow velocity as a function of time from the delay between the current at the load and the signal at the probe. The supersonic flow also generates a detached hydrodynamic bow shock around the probe, the structure of which depends on the upstream sonic Mach number. By imaging the shock around the probe with a Mach-Zehnder interferometer, we determine the upstream Mach number from the shock Mach angle, which we then use to determine the ion sound speed from the known upstream velocity. We use the measured sound speed to infer the value of $\bar{Z}T_e$, where $\bar{Z}$ is the average ionization, and $T_e$ is the electron temperature. We use this diagnostic to measure the time-resolved velocity and sound speed of a supersonic $(M_S \sim 8)$, super-Alfv\'enic $(M_A \sim 2)$ aluminum plasma generated during the ablation stage of an exploding wire array on the MAGPIE generator (1.4 MA, 250 ns). Velocity and $\bar{Z}T_e$ measured using this technique agree well with optical Thompson scattering measurements reported in literature, and with 3D resistive MHD simulations in GORGON.
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- 2022
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10. Unravelling the oxygen factor - An investigation of transcriptional activation of hypoxia associated placental angiogenesis in recurrent pregnancy loss (RPL) patients from Assam, India
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Kashyap, N., Das, C.R., Datta, R., Begum, A., Islam, M., Bose, S., and Bose, P.D.
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- 2024
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11. Management und Versorgung von Leberverletzungen nach stumpfem Bauchtrauma
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Thomas, M. N., Whaba, R., Datta, R. R., Bunck, A. C., Stippel, D. L., and Bruns, C. J.
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- 2023
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12. Introduction of laparoscopic nephrectomy for autosomal dominant polycystic kidney disease as the standard procedure
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Thomas, M. N., Datta, R. R., Wahba, R., Buchner, D., Chiapponi, C., Kurschat, C., Grundmann, F., Urbanski, A., Tolksdorf, S., Müller, R., Henze, J., Petrescu-Jipa, V.-M., Meyer, F., Bruns, C. J., and Stippel, D. L.
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- 2023
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13. An Optimal (2, 2) Visual Cryptography Schemes For Information Security
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Somwanshi, Datta R., Humbe, Vikas T., Luo, Xun, Editor-in-Chief, Almohammedi, Akram A., Series Editor, Chen, Chi-Hua, Series Editor, Guan, Steven, Series Editor, Pamucar, Dragan, Series Editor, Manza, Ramesh, editor, Gawali, Bharti, editor, Yannawar, Pravin, editor, and Juwono, Filbert, editor
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- 2023
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14. Propagation of Water Waves in the Presence of a Horizontal Plate Submerged in a Two-Layer Fluid
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Naskar, S., Islam, N., Gayen, R., Datta, R., Sharma, Rajesh Kumar, editor, Pareschi, Lorenzo, editor, Atangana, Abdon, editor, Sahoo, Bikash, editor, and Kukreja, Vijay Kumar, editor
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- 2023
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15. Measurement of energy and directional distribution of neutron ambient dose equivalent for the [formula omitted]Li(p,n)[formula omitted]Be reaction
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Roy, A.S., Banerjee, K., Roy, Pratap, Shil, R., Ravishankar, R., Datta, R., Sen, A., Manna, S., Ghosh, T.K., Mukherjee, G., Rana, T.K., Kundu, S., Nayak, S.S., Pandey, R., Paul, D., Atreya, K., Basu, S., Mukhopadhyay, S., Pandit, Deepak, Kulkarni, M.S., and Bhattacharya, C.
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- 2024
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16. An Optimal (2, 2) Visual Cryptography Schemes For Information Security
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Somwanshi, Datta R., primary and Humbe, Vikas T., additional
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- 2023
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17. The Atacama Cosmology Telescope: Arcminute-resolution maps of 18 000 square degrees of the microwave sky from ACT 2008–2018 data combined with Planck
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Naess, S, Aiola, S, Austermann, JE, Battaglia, N, Beall, JA, Becker, DT, Bond, RJ, Calabrese, E, Choi, SK, Cothard, NF, Crowley, KT, Darwish, O, Datta, R, Denison, EV, Devlin, M, Duell, CJ, Duff, SM, Duivenvoorden, AJ, Dunkley, J, Dünner, R, Fox, AE, Gallardo, PA, Halpern, M, Han, D, Hasselfield, M, Colin Hill, J, Hilton, GC, Hilton, M, Hincks, AD, Hložek, R, Ho, SPP, Hubmayr, J, Huffenberger, K, Hughes, JP, Kosowsky, AB, Louis, T, Madhavacheril, MS, McMahon, J, Moodley, K, Nati, F, Nibarger, JP, Niemack, MD, Page, L, Partridge, B, Salatino, M, Schaan, E, Schillaci, A, Schmitt, B, Sherwin, BD, Sehgal, N, Sifón, C, Spergel, D, Staggs, S, Stevens, J, Storer, E, Ullom, JN, Vale, LR, van Engelen, A, van Lanen, J, Vavagiakis, EM, Wollack, EJ, and Xu, Z
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CMBR experiments ,CMBR polarisation ,astro-ph.IM ,astro-ph.CO ,Nuclear & Particles Physics ,Astronomical and Space Sciences ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics - Abstract
This paper presents a maximum-likelihood algorithm for combining sky maps with disparate sky coverage, angular resolution and spatially varying anisotropic noise into a single map of the sky. We use this to merge hundreds of individual maps covering the 2008–2018 ACT observing seasons, resulting in by far the deepest ACT maps released so far. We also combine the maps with the full Planck maps, resulting in maps that have the best features of both Planck and ACT: Planck’s nearly white noise on intermediate and large angular scales and ACT’s high-resolution and sensitivity on small angular scales. The maps cover over 18 000 square degrees, nearly half the full sky, at 100, 150 and 220 GHz. They reveal 4 000 optically-confirmed clusters through the Sunyaev Zel’dovich effect (SZ) and 18 500 point source candidates at > 5σ, the largest single collection of SZ clusters and millimeter wave sources to date. The multi-frequency maps provide millimeter images of nearby galaxies and individual Milky Way nebulae, and even clear detections of several nearby stars. Other anticipated uses of these maps include, for example, thermal SZ and kinematic SZ cluster stacking, CMB cluster lensing and galactic dust science. The method itself has negligible bias. However, due to the preliminary nature of some of the component data sets, we caution that these maps should not be used for precision cosmological analysis. The maps are part of ACT DR5, and will be made available on LAMBDA no later than three months after the journal publication of this article, along with an interactive sky atlas.
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- 2020
18. The Atacama Cosmology Telescope: DR4 maps and cosmological parameters
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Aiola, S, Calabrese, E, Maurin, L, Naess, S, Schmitt, BL, Abitbol, MH, Addison, GE, Ade, PAR, Alonso, D, Amiri, M, Amodeo, S, Angile, E, Austermann, JE, Baildon, T, Battaglia, N, Beall, JA, Bean, R, Becker, DT, Richard Bond, J, Bruno, SM, Calafut, V, Campusano, LE, Carrero, F, Chesmore, GE, Cho, HM, Choi, SK, Clark, SE, Cothard, NF, Crichton, D, Crowley, KT, Darwish, O, Datta, R, Denison, EV, Devlin, MJ, Duell, CJ, Duff, SM, Duivenvoorden, AJ, Dunkley, J, Dünner, R, Essinger-Hileman, T, Fankhanel, M, Ferraro, S, Fox, AE, Fuzia, B, Gallardo, PA, Gluscevic, V, Golec, JE, Grace, E, Gralla, M, Guan, Y, Hall, K, Halpern, M, Han, D, Hargrave, P, Hasselfield, M, Helton, JM, Henderson, S, Hensley, B, Colin Hill, J, Hilton, GC, Hilton, M, Hincks, AD, Hložek, R, Ho, SPP, Hubmayr, J, Huffenberger, KM, Hughes, JP, Infante, L, Irwin, K, Jackson, R, Klein, J, Knowles, K, Koopman, B, Kosowsky, A, Lakey, V, Li, D, Li, Y, Li, Z, Lokken, M, Louis, T, Lungu, M, MacInnis, A, Madhavacheril, M, Maldonado, F, Mallaby-Kay, M, Marsden, D, McMahon, J, Menanteau, F, Moodley, K, Morton, T, Namikawa, T, Nati, F, Newburgh, L, Nibarger, JP, Nicola, A, Niemack, MD, Nolta, MR, Orlowski-Sherer, J, Page, LA, and Pappas, CG
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CMBR experiments ,CMBR polarisation ,cosmological parameters from CMBR ,astro-ph.CO ,Astronomical and Space Sciences ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics ,Nuclear & Particles Physics ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics - 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 deg2, the deepest 600 deg2 with noise levels below 10µK-arcmin. We use the power spectrum derived from almost 6,000 deg2 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.
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- 2020
19. The atacama cosmology telescope: A measurement of the cosmic microwave background power spectra at 98 and 150 GHz
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Choi, SK, Hasselfield, M, Ho, SPP, Koopman, B, Lungu, M, Abitbol, MH, Addison, GE, Ade, PAR, Aiola, S, Alonso, D, Amiri, M, Amodeo, S, Angile, E, Austermann, JE, Baildon, T, Battaglia, N, Beall, JA, Bean, R, Becker, DT, Richard Bond, J, Bruno, SM, Calabrese, E, Calafut, V, Campusano, LE, Carrero, F, Chesmore, GE, Cho, HM, Clark, SE, Cothard, NF, Crichton, D, Crowley, KT, Darwish, O, Datta, R, Denison, EV, Devlin, MJ, Duell, CJ, Duff, SM, Duivenvoorden, AJ, Dunkley, J, Dünner, R, Essinger-Hileman, T, Fankhanel, M, Ferraro, S, Fox, AE, Fuzia, B, Gallardo, PA, Gluscevic, V, Golec, JE, Grace, E, Gralla, M, Guan, Y, Hall, K, Halpern, M, Han, D, Hargrave, P, Henderson, S, Hensley, B, Colin Hill, J, Hilton, GC, Hilton, M, Hincks, AD, Hložek, R, Hubmayr, J, Huffenberger, KM, Hughes, JP, 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, JP, Nicola, A, Niemack, MD, Nolta, MR, Orlowski-Sherer, J, Page, LA, Pappas, CG, Partridge, B, and Phakathi, P
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CMBR experiments ,CMBR polarisation ,cosmological parameters from CMBR ,astro-ph.CO ,Astronomical and Space Sciences ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics ,Nuclear & Particles Physics ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics - Abstract
We present the temperature and polarization angular power spectra of the CMB measured by the Atacama Cosmology Telescope (ACT) from 5400 deg2 of the 2013–2016 survey, which covers >15000 deg2 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 ` = 4000. At large angular scales, foreground emission at 150 GHz is ∼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 ΛCDM for the ACT data alone with a prior on the optical depth of τ = 0.065 ± 0.015. ΛCDM is a good fit. The best-fit model has a reduced χ2 of 1.07 (PTE = 0.07) with H0 = 67.9 ± 1.5 km/s/Mpc. We show that the lensing BB signal is consistent with ΛCDM and limit the celestial EB polarization angle to ψP = −0.07◦ ±0.09◦. 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.
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- 2020
20. 51/m mit rezidivierenden, unspezifischen Oberbauchbeschwerden und Gewichtsverlust: Vorbereitung auf die Facharztprüfung: Fall 17
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Datta, R. R., Bohle, J., and Bruns, C. J.
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- 2022
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21. Sub-Kelvin cooling for two kilopixel bolometer arrays in the PIPER receiver
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Switzer, E. R., Ade, P. A. R., Baildon, T., Benford, D., Bennett, C. L., Chuss, D. T., Datta, R., Eimer, J. R., Fixsen, D. J., Gandilo, N. N., Essinger-Hileman, T. M., Halpern, M., Hilton, G., Irwin, K., Jhabvala, C., Kimball, M., Kogut, A., Lazear, J., Lowe, L. N., McMahon, J. J., Miller, T. M., Mirel, P., Moseley, S. H., Pawlyk, S., Rodriguez, S., Sharp, E., Shirron, P., Staguhn, J. G., Sullivan, D. F., Taraschi, P., Tucker, C. E., Walts, A., and Wollack, E. J.
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Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
The Primordial Inflation Polarization Explorer (PIPER) is a balloon-borne telescope mission to search for inflationary gravitational waves from the early universe. PIPER employs two 32x40 arrays of superconducting transition-edge sensors, which operate at 100 mK. An open bucket dewar of liquid helium maintains the receiver and telescope optics at 1.7 K. We describe the thermal design of the receiver and sub-kelvin cooling with a continuous adiabatic demagnetization refrigerator (CADR). The CADR operates between 70-130 mK and provides ~10 uW cooling power at 100 mK, nearly five times the loading of the two detector assemblies. We describe electronics and software to robustly control the CADR, overall CADR performance in flight-like integrated receiver testing, and practical considerations for implementation in the balloon float environment., Comment: 14 pages, 12 figures
- Published
- 2019
- Full Text
- View/download PDF
22. Rich diversity of crystallographic phase formation in 2D Rex:Mo1-xS2 (x< 0.5) alloy
- Author
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Sharona, H., Vishal, B., Bhat, U., Paul, A., Mukherjee, A., Sarma, S. C., Peter, S. C., and Datta, R.
- Subjects
Condensed Matter - Materials Science - Abstract
We report on the observation of rich variety of crystallographic phase formation in RexMo1-xS2 alloy for x < 0.5. For x < 0.23, no low dimensional super-structural modulation is observed and inter-cation hybridization remains discrete forming dimers to tetramers with increasing Re concentration. For x > 0.23, super-strutural modulaton is observed. Depending on the Re concentrations (x = 0.23, 0.32, 0.38 and 0.45) and its distributions, various types of cation hybridization results in rich variety of low dimensional super-structural modulation as directly revealed by high resolution transmission electron microscopy. These layered alloy system may be useful for various energy and novel device applications.
- Published
- 2019
- Full Text
- View/download PDF
23. Atacama Cosmology Telescope: Component-separated maps of CMB temperature and the thermal Sunyaev-Zel'dovich effect
- Author
-
Madhavacheril, MS, Hill, JC, Næss, S, Addison, GE, Aiola, S, Baildon, T, Battaglia, N, Bean, R, Bond, JR, Calabrese, E, Calafut, V, Choi, SK, Darwish, O, Datta, R, Devlin, MJ, Dunkley, J, Dünner, R, Ferraro, S, Gallardo, PA, Gluscevic, V, Halpern, M, Han, D, Hasselfield, M, Hilton, M, Hincks, AD, HloŽek, R, Ho, SPP, Huffenberger, KM, Hughes, JP, Koopman, BJ, Kosowsky, A, Lokken, M, Louis, T, Lungu, M, Macinnis, A, Maurin, L, McMahon, JJ, Moodley, K, Nati, F, Niemack, MD, Page, LA, Partridge, B, Robertson, N, Sehgal, N, Schaan, E, Schillaci, A, Sherwin, BD, Sifón, C, Simon, SM, Spergel, DN, Staggs, ST, Storer, ER, Van Engelen, A, Vavagiakis, EM, Wollack, EJ, and Xu, Z
- Subjects
astro-ph.CO ,astro-ph.GA - Abstract
Optimal analyses of many signals in the cosmic microwave background (CMB) require map-level extraction of individual components in the microwave sky, rather than measurements at the power spectrum level alone. To date, nearly all map-level component separation in CMB analyses has been performed exclusively using satellite data. In this paper, we implement a component separation method based on the internal linear combination (ILC) approach which we have designed to optimally account for the anisotropic noise (in the 2D Fourier domain) often found in ground-based CMB experiments. Using this method, we combine multifrequency data from the Planck satellite and the Atacama Cosmology Telescope Polarimeter (ACTPol) to construct the first wide-area (≈2100 sq. deg.), arcminute-resolution component-separated maps of the CMB temperature anisotropy and the thermal Sunyaev-Zel'dovich (tSZ) effect sourced by the inverse-Compton scattering of CMB photons off hot, ionized gas. Our ILC pipeline allows for explicit deprojection of various contaminating signals, including a modified blackbody approximation of the cosmic infrared background (CIB) spectral energy distribution. The cleaned CMB maps will be a useful resource for CMB lensing reconstruction, kinematic SZ cross-correlations, and primordial non-Gaussianity studies. The tSZ maps will be used to study the pressure profiles of galaxies, groups, and clusters through cross-correlations with halo catalogs, with dust contamination controlled via CIB deprojection. The data products described in this paper are available on LAMBDA.
- Published
- 2020
24. Growth of epitaxial ReS2 thin film by pulsed laser deposition
- Author
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Vishal, B., Sharona, H., Bhat, U., Paul, A., Sreedhara, M. B., Rajaji, V., Sarma, S. C., Narayana, C., Peter, S. C., and Datta, R.
- Subjects
Condensed Matter - Materials Science - Abstract
We present results on growth of large area epitaxial ReS2 thin film both on c plane sapphire substrate and MoS2 template by pulsed laser deposition (PLD). Films tend to grow with (0001) ReS2 perpendicular to (0001) Al2O3 and (0001) ReS2 perpendicular to (0001) MoS2 parallel to (0001) Al2O3 at deposition temperature below 300 deg C. Films are polycrystalline grown at temperature above 300 deg C. The smoothness and quality of the films are significantly improved when grown on MoS2 template compared to sapphire substrate. The results show that PLD is suitable to grow ReS2 epitaxial thin film over large area for practical device application.
- Published
- 2018
- Full Text
- View/download PDF
25. Radiatively cooled magnetic reconnection experiments driven by pulsed power
- Author
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Datta, R., primary, Chandler, K., additional, Myers, C. E., additional, Chittenden, J. P., additional, Crilly, A. J., additional, Aragon, C., additional, Ampleford, D. J., additional, Banasek, J. T., additional, Edens, A., additional, Fox, W. R., additional, Hansen, S. B., additional, Harding, E. C., additional, Jennings, C. A., additional, Ji, H., additional, Kuranz, C. C., additional, Lebedev, S. V., additional, Looker, Q., additional, Patel, S. G., additional, Porwitzky, A., additional, Shipley, G. A., additional, Uzdensky, D. A., additional, Yager-Elorriaga, D. A., additional, and Hare, J. D., additional
- Published
- 2024
- Full Text
- View/download PDF
26. Plasmoid Formation and Strong Radiative Cooling in a Driven Magnetic Reconnection Experiment
- Author
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Datta, R., primary, Chandler, K., additional, Myers, C. E., additional, Chittenden, J. P., additional, Crilly, A. J., additional, Aragon, C., additional, Ampleford, D. J., additional, Banasek, J. T., additional, Edens, A., additional, Fox, W. R., additional, Hansen, S. B., additional, Harding, E. C., additional, Jennings, C. A., additional, Ji, H., additional, Kuranz, C. C., additional, Lebedev, S. V., additional, Looker, Q., additional, Patel, S. G., additional, Porwitzky, A., additional, Shipley, G. A., additional, Uzdensky, D. A., additional, Yager-Elorriaga, D. A., additional, and Hare, J. D., additional
- Published
- 2024
- Full Text
- View/download PDF
27. Development of Multi-Chroic MKIDs for Next-Generation CMB Polarization Studies
- Author
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Johnson, B. R., Flanigan, D., Abitbol, M. H., Ade, P. A. R., Bryan, S., Cho, H. -M., Datta, R., Day, P., Doyle, S., Irwin, K., Jones, G., Li, D., Mauskopf, P., McCarrick, H., McMahon, J., Miller, A., Pisano, G., Song, Y., Surdi, H., and Tucker, C.
- Subjects
Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
We report on the status of an ongoing effort to develop arrays of horn-coupled, polarization-sensitive microwave kinetic inductance detectors (MKIDs) that are each sensitive to two spectral bands between 125 and 280 GHz. These multi-chroic MKID arrays are tailored for next-generation, large-detector-count experiments that are being designed to simultaneously characterize the polarization properties of both the cosmic microwave background (CMB) and Galactic dust emission. We present our device design and describe laboratory-based measurement results from two 23-element prototype arrays. From dark measurements of our first engineering array we demonstrated a multiplexing factor of 92, showed the resonators respond to bath temperature changes as expected, and found that the fabrication yield was 100%. From our first optically loaded array we found the MKIDs respond to millimeter-wave pulses, additional optical characterization measurements are ongoing. We end by discussing our plans for scaling up this technology to kilo-pixel arrays over the next two years., Comment: LTD-17 paper accepted by Journal of Low Temperature Physics
- Published
- 2017
- Full Text
- View/download PDF
28. Distinct photoluminescence in multilayered van der Waals heterostructures of MoS2/WS2/ReS2 and BN
- Author
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Bhat, U., Singh, R., Vishal, B., Sharma, A., Sharona, H., Sahu, R., and Datta, R.
- Subjects
Condensed Matter - Materials Science - Abstract
Van der Waals heterostructures of (TMDL=1/BNL=1-4/TMDL=1/BNL=1-4), [TMD = MoS2, WS2, and ReS2] are grown on c-plane sapphire substrate by pulsed laser deposition under slow kinetic condition. The heterostructure systems show strong emission around 2.3 eV and subsidiary peaks around 2.8, 1.9, 1.7 and 1.5 eV. BN and TMDs forms type-I heterojunction and the emission peaks observed are explained in terms of various band to band recombination processes and considering relative orientation of Brillouin Zones. The emission peak around 2.3eV is promising for solar and photovoltaic application. The observation is almost similar for three different heterostructure systems., Comment: 24 pages, 10 figures
- Published
- 2017
- Full Text
- View/download PDF
29. Utility-Based Road Space Distribution Model for Vehicles, Pedestrian, Parking and Hawkers
- Author
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Ghosh, Solanki, Datta, R. N., di Prisco, Marco, Series Editor, Chen, Sheng-Hong, Series Editor, Vayas, Ioannis, Series Editor, Kumar Shukla, Sanjay, Series Editor, Sharma, Anuj, Series Editor, Kumar, Nagesh, Series Editor, Wang, Chien Ming, Series Editor, Jana, Arnab, editor, and Banerji, Pradipta, editor
- Published
- 2021
- Full Text
- View/download PDF
30. Study of slamming load using one and two way coupled method
- Author
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Acharya, A., primary and Datta, R., additional
- Published
- 2022
- Full Text
- View/download PDF
31. Surface spin canting in Fe3O4 and CoFe2O4 nanoparticles probed by high resolution electron energy loss spectroscopy
- Author
-
Negi, D. S., Sharona, H., Bhat, U., Palchoudhury, S., Gupta, A., and Datta, R.
- Subjects
Condensed Matter - Materials Science - Abstract
High resolution electron energy loss spectroscopy (HR-EELS) is utilized to probe the surface spin canting in nanoparticles of two technologically important magnetic materials, i.e. Fe3O4 and CoFe2O4 (CFO). A soft experimental technique is developed that is capable of extracting EELS spectra with one atomic plane resolution recorded in a single frame. This yields information at different depth of the nanoparticle from the surface to the core regions with high signal to noise ratio and without beam damage. This enables comparing the fine structures between the surface and core regions of the nanoparticles. The results confirm earlier observations of uniformly oriented spin canting structure for CFO with additional information on atom site-selective spin canting information. In case of Fe3O4 preferred canting orientation forming core and shell structure is deduced. Unlike earlier reports based on polarized spin-flip neutron scattering measurement, it is possible to narrow down the possible canting angles for Fe3O4 (Td, Oh tilts 40{\deg}, 40{\deg}) and CFO (Td, Oh tilts 17{\deg}, 17{\deg}) from the experimental spectra combined with the first principle based calculation considering non-collinear magnetism. In addition, the role of Dzyaloshinskii-Moriya interaction in stabilizing the spin canting at the nanoparticle surface is discussed. The results demonstrate that HREELS can be a powerful technique to probe the magnetic structure in nano-dimensional systems and has advantages over neutron based techniques in terms of superior spatial resolution, site specific information and easy of sample preparation.
- Published
- 2017
- Full Text
- View/download PDF
32. Nature of low dimensional structural modulations and relative phase stability in MoS2/WS2-ReS2 transition metal dichalcogenide alloys
- Author
-
Sahu, R., Bhat, U., Batra, N. M., Sharona, H., Vishal, B., Sarkar, S., Aravindh, S. Assa, Peter, S. C., Roqan, I. S., Costa, P. M. F. J. D., and Datta, R.
- Subjects
Condensed Matter - Materials Science - Abstract
We report on the various types of Peierls like two dimensional structural modulations and relative phase stability of 2H and 1T poly-types in MoS2-ReS2 and WS2-ReS2 alloy system. Theoretical calculation predicts a polytype phase transition cross over at ~50 at.% of Mo and W in ReS2 in both monolayer and bulk form, respectively. Experimentally, two different types of structural modulations at 50% and a modulation corresponding to trimerization at 75% alloy composition is observed for MoS2-ReS2 and only one type of modulation is observed at 50% WS2-ReS2 alloy system. The 50% alloy system is found to be a suitable monolithic candidate for metal semiconductor transition with minute external perturbation. ReS2 is known to be in 2D Peierls distorted 1Td structure and forms a chain like superstructure. Incorporation of Mo and W atoms in the ReS2 lattice modifies the metal-metal hybridization between the cations and influences the structural modulation and electronic property of the system. The results offer yet another effective way to tune the electronic structure and poly-type phases of this class of materials other than intercalation, strain, and vertical stacking arrangement.
- Published
- 2016
33. Navigated laparoscopic microwave ablation of tumour mimics in pig livers: a randomized ex-vivo experimental trial
- Author
-
Thomas, M. N., Dieplinger, G., Datta, R. R., Kleinert, R., Fuchs, H. F., Bunck, A., Peterhans, M., Bruns, C. J., Stippel, D., and Wahba, R.
- Published
- 2021
- Full Text
- View/download PDF
34. Design of Stable Channel in Coherent Soil
- Author
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Datta, R. R.
- Published
- 1957
35. Measurement of energy and directional distribution of neutron ambient dose equivalent for the 7Li(p,n)7Be reaction
- Author
-
Roy, A.S., primary, Banerjee, K., additional, Roy, Pratap, additional, Shil, R., additional, Ravishankar, R., additional, Datta, R., additional, Sen, A., additional, Manna, S., additional, Ghosh, T.K., additional, Mukherjee, G., additional, Rana, T.K., additional, Kundu, S., additional, Nayak, S.S., additional, Pandey, R., additional, Paul, D., additional, Atreya, K., additional, Basu, S., additional, Mukhopadhyay, S., additional, Pandit, Deepak, additional, Kulkarni, M.S., additional, and Bhattacharya, C., additional
- Published
- 2024
- Full Text
- View/download PDF
36. Detection of the pairwise kinematic Sunyaev-Zel'dovich effect with BOSS DR11 and the Atacama Cosmology Telescope
- Author
-
De Bernardis, F., Aiola, S., Vavagiakis, E. M., Battaglia, N., Niemack, M. D., Beall, J., Becker, D. T., Bond, J. R., Calabrese, E., Cho, H., Coughlin, K., Datta, R., Devlin, M., Dunkley, J., Dunner, R., Ferraro, S., Fox, A., Gallardo, P. A., Halpern, M., Hand, N., Hasselfield, M., Henderson, S. W., Hill, J. C., Hilton, G. C., Hilton, M., Hincks, A. D., Hlozek, R., Hubmayr, J., Huffenberger, K., Hughes, J. P., Irwin, K. D., Koopman, B. J., Kosowsky, A., Li, D., Louis, T., Lungu, M., Madhavacheril, M. S., Maurin, L., McMahon, J., Moodley, K., Naess, S., Nati, F., Newburgh, L., Nibarger, J. P., Page, L. A., Partridge, B., Schaan, E., Schmitt, B. L., Sehgal, N., Sievers, J., Simon, S. M., Spergel, D. N., Staggs, S. T., Stevens, J. R., Thornton, R. J., van Engelen, A., Van Lanen, J., and Wollack, E. J.
- Subjects
Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We present a new measurement of the kinematic Sunyaev-Zeldovich effect using data from the Atacama Cosmology Telescope (ACT) and the Baryon Oscillation Spectroscopic Survey (BOSS). Using 600 square degrees of overlapping sky area, we evaluate the mean pairwise baryon momentum associated with the positions of 50,000 bright galaxies in the BOSS DR11 Large Scale Structure catalog. A non-zero signal arises from the large-scale motions of halos containing the sample galaxies. The data fits an analytical signal model well, with the optical depth to microwave photon scattering as a free parameter determining the overall signal amplitude. We estimate the covariance matrix of the mean pairwise momentum as a function of galaxy separation, using microwave sky simulations, jackknife evaluation, and bootstrap estimates. The most conservative simulation-based errors give signal-to-noise estimates between 3.6 and 4.1 for varying galaxy luminosity cuts. We discuss how the other error determinations can lead to higher signal-to-noise values, and consider the impact of several possible systematic errors. Estimates of the optical depth from the average thermal Sunyaev-Zeldovich signal at the sample galaxy positions are broadly consistent with those obtained from the mean pairwise momentum signal., Comment: 15 pages, 8 figures, 2 tables
- Published
- 2016
- Full Text
- View/download PDF
37. The Atacama Cosmology Telescope: The polarization-sensitive ACTPol instrument
- Author
-
Thornton, R. J., Ade, P. A. R., Aiola, S., Angile, F. E., Amiri, M., Beall, J. A., Becker, D. T., Cho, H-M., Choi, S. K., Corlies, P., Coughlin, K. P., Datta, R., Devlin, M. J., Dicker, S. R., Dunner, R., Fowler, J. W., Fox, A. E., Gallardo, P. A., Gao, J., Grace, E., Halpern, M., Hasselfield, M., Henderson, S. W., Hilton, G. C., Hincks, A. D., Ho, S. P., Hubmayr, J., Irwin, K. D., Klein, J., Koopman, B., Li, Dale, Louis, T., Lungu, M., Maurin, L., McMahon, J., Munson, C. D., Naess, S., Nati, F., Newburgh, L., Nibarger, J., Niemack, M. D., Niraula, P., Nolta, M. R., Page, L. A., Pappas, C. G., Schillaci, A., Schmitt, B. L., Sehgal, N., Sievers, J. L., Simon, S. M., Staggs, S. T., Tucker, C., Uehara, M., van Lanen, J., Ward, J. T., and Wollack, E. J.
- Subjects
Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
The Atacama Cosmology Telescope (ACT) is designed to make high angular resolution measurements of anisotropies in the Cosmic Microwave Background (CMB) at millimeter wavelengths. We describe ACTPol, an upgraded receiver for ACT, which uses feedhorn-coupled, polarization-sensitive detector arrays, a 3 degree field of view, 100 mK cryogenics with continuous cooling, and meta material anti-reflection coatings. ACTPol comprises three arrays with separate cryogenic optics: two arrays at a central frequency of 148 GHz and one array operating simultaneously at both 97 GHz and 148 GHz. The combined instrument sensitivity, angular resolution, and sky coverage are optimized for measuring angular power spectra, clusters via the thermal Sunyaev-Zel'dovich and kinetic Sunyaev-Zel'dovich signals, and CMB lensing due to large scale structure. The receiver was commissioned with its first 148 GHz array in 2013, observed with both 148 GHz arrays in 2014, and has recently completed its first full season of operations with the full suite of three arrays. This paper provides an overview of the design and initial performance of the receiver and related systems.
- Published
- 2016
- Full Text
- View/download PDF
38. Meteorological Connectivity from Regions of High Biodiversity within the McMurdo Dry Valleys of Antarctica
- Author
-
Katurji, M., Khan, B., Sprenger, M., Datta, R., Joy, K., Zawar-Reza, P., and Hawes, I.
- Published
- 2019
39. Design and Deployment of a Multichroic Polarimeter Array on the Atacama Cosmology Telescope
- Author
-
Datta, R., Austermann, J., Beall, J. A., Becker, D., Coughlin, K. P., Duff, S. M., Gallardo, P. A., Grace, E., Hasselfield, M., Henderson, S. W., Hilton, G. C., Ho, S. P., Hubmayr, J., Koopman, B. J., Lanen, J. V., Li, D., McMahon, J., Munson, C. D., Nati, F., Niemack, M. D., Page, L., Pappas, C. G., Salatino, M., Schmitt, B. L., Schillaci, A., Simon, S. M., Staggs, S. T., Stevens, J. R., Vavagiakis, E. M., Ward, J. T., and Wollack, E. J.
- Subjects
Astrophysics - Instrumentation and Methods for Astrophysics - Abstract
We present the design and the preliminary on sky performance with respect to beams and pass-bands of a multichroic polarimeter array covering the 90 and 146 GHz Cosmic Microwave Background (CMB) bands and its enabling broadband optical system recently deployed on the Atacama Cosmology Telescope (ACT). The constituent pixels are feedhorn-coupled multichroic polarimeters fabricated at NIST. This array is coupled to the ACT telescope via a set of three silicon lenses incorporating novel broad-band metamaterial anti-reflection coatings. This receiver represents the first multichroic detector array deployed for a CMB experiment and paves the way for the extensive use of multichroic detectors and broadband optical systems in the next generation of CMB experiments.
- Published
- 2015
- Full Text
- View/download PDF
40. Advanced ACTPol Cryogenic Detector Arrays and Readout
- Author
-
Henderson, S. W., Allison, R., Austermann, J., Baildon, T., Battaglia, N., Beall, J. A., Becker, D., De Bernardis, F., Bond, J. R., Calabrese, E., Choi, S. K., Coughlin, K. P., Crowley, K. T., Datta, R., Devlin, M. J., Duff, S. M., Dunner, R., Dunkley, J., van Engelen, A., Gallardo, P. A., Grace, E., Hasselfield, M., Hills, F., Hilton, G. C., Hincks, A. D., Hlozek, R., Ho, S. P., Hubmayr, J., Huffenberger, K., Hughes, J. P., Irwin, K. D., Koopman, B. J., Kosowsky, A. B., Li, D., McMahon, J., Munson, C., Nati, F., Newburgh, L., Niemack, M. D., Niraula, P., Page, L. A., Pappas, C. G., Salatino, M., Schillaci, A., Schmitt, B. L., Sehgal, N., Sherwin, B. D., Sievers, J. L., Simon, S. M., Spergel, D. N., Staggs, S. T., Stevens, J. R., Thornton, R., Van Lanen, J., Vavagiakis, E. M., Ward, J. T., and Wollack, E. J.
- Subjects
Astrophysics - Instrumentation and Methods for Astrophysics ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
Advanced ACTPol is a polarization-sensitive upgrade for the 6 m aperture Atacama Cosmology Telescope (ACT), adding new frequencies and increasing sensitivity over the previous ACTPol receiver. In 2016, Advanced ACTPol will begin to map approximately half the sky in five frequency bands (28-230 GHz). Its maps of primary and secondary cosmic microwave background (CMB) anisotropies -- imaged in intensity and polarization at few arcminute-scale resolution -- will enable precision cosmological constraints and also a wide array of cross-correlation science that probes the expansion history of the universe and the growth of structure via gravitational collapse. To accomplish these scientific goals, the Advanced ACTPol receiver will be a significant upgrade to the ACTPol receiver, including four new multichroic arrays of cryogenic, feedhorn-coupled AlMn transition edge sensor (TES) polarimeters (fabricated on 150 mm diameter wafers); a system of continuously rotating meta-material silicon half-wave plates; and a new multiplexing readout architecture which uses superconducting quantum interference devices (SQUIDs) and time division to achieve a 64-row multiplexing factor. Here we present the status and scientific goals of the Advanced ACTPol instrument, emphasizing the design and implementation of the Advanced ACTPol cryogenic detector arrays., Comment: 9 pages, 3 figures, conference proceedings submitted to Journal of Low Temperature Physics
- Published
- 2015
- Full Text
- View/download PDF
41. The Atacama Cosmology Telescope: Two-season ACTPol spectra and parameters
- Author
-
Louis, T, Grace, E, Hasselfield, M, Lungu, M, Maurin, L, Addison, GE, Ade, PAR, Aiola, S, Allison, R, Amiri, M, Angile, E, Battaglia, N, Beall, JA, De Bernardis, F, Bond, JR, Britton, J, Calabrese, E, Cho, HM, Choi, SK, Coughlin, K, Crichton, D, Crowley, K, Datta, R, Devlin, MJ, Dicker, SR, Dunkley, J, Dünner, R, Ferraro, S, Fox, AE, Gallardo, P, Gralla, M, Halpern, M, Henderson, S, Hill, JC, Hilton, GC, Hilton, M, Hincks, AD, Hlozek, R, Patty Ho, SP, Huang, Z, Hubmayr, J, Huffenberger, KM, Hughes, JP, Infante, L, Irwin, K, Kasanda, SM, Klein, J, Koopman, B, Kosowsky, A, Li, D, Madhavacheril, M, Marriage, TA, McMahon, J, Menanteau, F, Moodley, K, Munson, C, Naess, S, Nati, F, Newburgh, L, Nibarger, J, Niemack, MD, Nolta, MR, Nuñez, C, Page, LA, Pappas, C, Partridge, B, Rojas, F, Schaan, E, Schmitt, BL, Sehgal, N, Sherwin, BD, Sievers, J, Simon, S, Spergel, DN, Staggs, ST, Switzer, ER, Thornton, R, Trac, H, Treu, J, Tucker, C, Engelen, AV, Ward, JT, and Wollack, EJ
- Subjects
CMBR experiments ,CMBR polarisation ,cosmological parameters from CMBR ,astro-ph.CO ,Nuclear & Particles Physics ,Astronomical and Space Sciences ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics - Abstract
We present the temperature and polarization angular power spectra measured by the Atacama Cosmology Telescope Polarimeter (ACTPol). We analyze night-time data collected during 2013-14 using two detector arrays at 149 GHz, from 548 deg2 of sky on the celestial equator. We use these spectra, and the spectra measured with the MBAC camera on ACT from 2008-10, in combination with planck and wmap data to estimate cosmological parameters from the temperature, polarization, and temperature-polarization cross-correlations. We find the new ACTPol data to be consistent with the ΛCDM model. The ACTPol temperature-polarization cross-spectrum now provides stronger constraints on multiple parameters than the ACTPol temperature spectrum, including the baryon density, the acoustic peak angular scale, and the derived Hubble constant. The new ACTPol data provide information on damping tail parameters. The joint uncertainty on the number of neutrino species and the primordial helium fraction is reduced by 20% when adding ACTPol to Planck temperature data alone.
- Published
- 2017
42. Detection of the pairwise kinematic Sunyaev-Zel'dovich effect with BOSS DR11 and the Atacama Cosmology Telescope
- Author
-
Bernardis, FD, Aiola, S, Vavagiakis, EM, Battaglia, N, Niemack, MD, Beall, J, Becker, DT, Bond, JR, Calabrese, E, Cho, H, Coughlin, K, Datta, R, Devlin, M, Dunkley, J, Dunner, R, Ferraro, S, Fox, A, Gallardo, PA, Halpern, M, Hand, N, Hasselfield, M, Henderson, SW, Hill, JC, Hilton, GC, Hilton, M, Hincks, AD, Hlozek, R, Hubmayr, J, Huffenberger, K, Hughes, JP, Irwin, KD, Koopman, BJ, Kosowsky, A, Li, D, Louis, T, Lungu, M, Madhavacheril, MS, Maurin, L, McMahon, J, Moodley, K, Naess, S, Nati, F, Newburgh, L, Nibarger, JP, Page, LA, Partridge, B, Schaan, E, Schmitt, BL, Sehgal, N, Sievers, J, Simon, SM, Spergel, DN, Staggs, ST, Stevens, JR, Thornton, RJ, Engelen, AV, Lanen, JV, and Wollack, EJ
- Subjects
CMBR experiments ,galaxy surveys ,hydrodynamical simulations ,Sunyaev-Zeldovich effect ,astro-ph.CO ,Nuclear & Particles Physics ,Astronomical and Space Sciences ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics - Abstract
We present a new measurement of the kinematic Sunyaev-Zel'dovich effect using data from the Atacama Cosmology Telescope (ACT) and the Baryon Oscillation Spectroscopic Survey (BOSS). Using 600 square degrees of overlapping sky area, we evaluate the mean pairwise baryon momentum associated with the positions of 50,000 bright galaxies in the BOSS DR11 Large Scale Structure catalog. A non-zero signal arises from the large-scale motions of halos containing the sample galaxies. The data fits an analytical signal model well, with the optical depth to microwave photon scattering as a free parameter determining the overall signal amplitude. We estimate the covariance matrix of the mean pairwise momentum as a function of galaxy separation, using microwave sky simulations, jackknife evaluation, and bootstrap estimates. The most conservative simulation-based errors give signal-to-noise estimates between 3.6 and 4.1 for varying galaxy luminosity cuts. We discuss how the other error determinations can lead to higher signal-to-noise values, and consider the impact of several possible systematic errors. Estimates of the optical depth from the average thermal Sunyaev-Zel'dovich signal at the sample galaxy positions are broadly consistent with those obtained from the mean pairwise momentum signal.
- Published
- 2017
43. Detection of the pairwise kinematic Sunyaev-Zel'dovich effect with BOSS DR11 and the Atacama Cosmology Telescope
- Author
-
De Bernardis, F, Aiola, S, Vavagiakis, EM, Battaglia, N, Niemack, MD, Beall, J, Becker, DT, Bond, JR, Calabrese, E, Cho, H, Coughlin, K, Datta, R, Devlin, M, Dunkley, J, Dunner, R, Ferraro, S, Fox, A, Gallardo, PA, Halpern, M, Hand, N, Hasselfield, M, Henderson, SW, Hill, JC, Hilton, GC, Hilton, M, Hincks, AD, Hlozek, R, Hubmayr, J, Huffenberger, K, Hughes, JP, Irwin, KD, Koopman, BJ, Kosowsky, A, Li, D, Louis, T, Lungu, M, Madhavacheril, MS, Maurin, L, McMahon, J, Moodley, K, Naess, S, Nati, F, Newburgh, L, Nibarger, JP, Page, LA, Partridge, B, Schaan, E, Schmitt, BL, Sehgal, N, Sievers, J, Simon, SM, Spergel, DN, Staggs, ST, Stevens, JR, Thornton, RJ, van Engelen, A, Van Lanen, J, and Wollack, EJ
- Subjects
CMBR experiments ,galaxy surveys ,hydrodynamical simulations ,Sunyaev-Zeldovich effect ,astro-ph.CO ,Astronomical and Space Sciences ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics ,Nuclear & Particles Physics - Abstract
We present a new measurement of the kinematic Sunyaev-Zel'dovich effect using data from the Atacama Cosmology Telescope (ACT) and the Baryon Oscillation Spectroscopic Survey (BOSS). Using 600 square degrees of overlapping sky area, we evaluate the mean pairwise baryon momentum associated with the positions of 50,000 bright galaxies in the BOSS DR11 Large Scale Structure catalog. A non-zero signal arises from the large-scale motions of halos containing the sample galaxies. The data fits an analytical signal model well, with the optical depth to microwave photon scattering as a free parameter determining the overall signal amplitude. We estimate the covariance matrix of the mean pairwise momentum as a function of galaxy separation, using microwave sky simulations, jackknife evaluation, and bootstrap estimates. The most conservative simulation-based errors give signal-to-noise estimates between 3.6 and 4.1 for varying galaxy luminosity cuts. We discuss how the other error determinations can lead to higher signal-to-noise values, and consider the impact of several possible systematic errors. Estimates of the optical depth from the average thermal Sunyaev-Zel'dovich signal at the sample galaxy positions are broadly consistent with those obtained from the mean pairwise momentum signal.
- Published
- 2017
44. Microstructural and magnetic properties of epitaxial Ni50Mn37/35Sn13/15 Heusler alloy thin films grown by pulsed laser deposition
- Author
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Vishal, B., Bhat, U., Sharona, H., Mukherjee, A., Roy, S., Peter, S.C., and Datta, R.
- Published
- 2020
- Full Text
- View/download PDF
45. The CLASS 150/220 GHz Polarimeter Array: Design, Assembly, and Characterization
- Author
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Dahal, S., Amiri, M., Appel, J. W., Bennett, C. L., Corbett, L., Datta, R., Denis, K., Essinger-Hileman, T., Halpern, M., Helson, K., Hilton, G., Hubmayr, J., Keller, B., Marriage, T., Nunez, C., Petroff, M., Reintsema, C., Rostem, K., U-Yen, K., and Wollack, E.
- Published
- 2020
- Full Text
- View/download PDF
46. Bougainvillea
- Author
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S.K. Datta, R. Jayanthi & T. Janakiram and S.K. Datta, R. Jayanthi & T. Janakiram
- Published
- 2020
47. Large-aperture wide-bandwidth antireflection-coated silicon lenses for millimeter wavelengths
- Author
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Datta, R., Munson, C. D., Niemack, M. D., McMahon, J. J., Britton, J., Wollack, E. J., Beall, J., Devlin, M. J., Fowler, J., Gallardo, P., Hubmayr, J., Irwin, K., Newburgh, L., Nibarger, J. P., Page, L., Quijada, M. A., Schmitt, B. L., Staggs, S. T., Thornton, R., and Zhang, L.
- Subjects
Astrophysics - Instrumentation and Methods for Astrophysics ,Physics - Optics - Abstract
The increasing scale of cryogenic detector arrays for sub-millimeter and millimeter wavelength astrophysics has led to the need for large aperture, high index of refraction, low loss, cryogenic refracting optics. Silicon with n = 3.4, low loss, and relatively high thermal conductivity is a nearly optimal material for these purposes, but requires an antireflection (AR) coating with broad bandwidth, low loss, low reflectance, and a matched coefficient of thermal expansion. We present an AR coating for curved silicon optics comprised of subwavelength features cut into the lens surface with a custom three axis silicon dicing saw. These features constitute a metamaterial that behaves as a simple dielectric coating. We have fabricated and coated silicon lenses as large as 33.4 cm in diameter with coatings optimized for use between 125-165 GHz. Our design reduces average reflections to a few tenths of a percent for angles of incidence up to 30 degrees with low cross-polarization. We describe the design, tolerance, manufacture, and measurements of these coatings and present measurements of the optical properties of silicon at millimeter wavelengths at cryogenic and room temperatures. This coating and lens fabrication approach is applicable from centimeter to sub-millimeter wavelengths and can be used to fabricate coatings with greater than octave bandwidth., Comment: submitted to Applied Optics
- Published
- 2013
- Full Text
- View/download PDF
48. Numerical Investigation of Heave and Pitch Motion Effects on Green Water Loading for a Floating Body
- Author
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Ravindra Babu, K., Datta, R., and Bhattacharyya, A.
- Published
- 2019
- Full Text
- View/download PDF
49. Non-Invasive Image-Based Assessment of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes
- Author
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Heylman, CM, Datta, R, Kurokawa, Y, Tran, DD, Conklin, BR, Gratton, E, and George, SC
- Subjects
Biomedical Engineering ,Biochemistry and Cell Biology ,Materials Engineering - Published
- 2014
50. Label - free fluorescence lifetime imaging of microfluidic device based cardiac tissue model metabolism
- Author
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Datta, R, Heylman, C, Tran, D, George, SC, and Gratton, E
- Abstract
In this work, we show mapping of metabolic activity and non-invasive monitoring of drug response of a microphysiological tissue system in a PDMS microfluidic device chamber by fluorescence lifetime imaging of NADH, an endogenous fluorophore. © 2014 OSA.
- Published
- 2014
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