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Your search keyword '"dos Santos J. M. F."' showing total 7 results
Start Over Author "dos Santos J. M. F." Publisher american institute of physics
7 results on '"dos Santos J. M. F."'

1. Conclusions from recent pionic—atom experiments.

Author

Gotta, D., Amaro, F., Anagnostopoulos, D. F., Biri, S., Covita, D. S., Gorke, H., Gruber, A., Hennebach, M., Hirtl, A., Ishiwatari, T., Indelicato, P., Jensen, Th., Le Bigot, E.-O., Marton, J., Nekipelov, M., dos Santos, J. M. F., Schlesser, S., Schmid, Ph., Simons, L. M., and Strauch, Th.

Subjects
ATOMS, CYCLOTRONS, CYCLOTRON resonance, ION traps, ENERGY-band theory of solids, QUANTUM electrodynamics, NUCLEAR physics
Abstract

The most recent pionic—hydrogen experiment marks the completion of a whole series of measurements, the main goal of which was to provide conclusive data on pion—nucleon interaction at threshold for comparison with calculations from Chiral perturbation theory. The precision achieved for hadronic shift and broadening of 0.2% and 2%, respectively, became possible by comprehensive studies of cascade effects in hydrogen and other light exotic atoms including results from the last years of LEAR operation. In order to obtain optimum conditions for the Bragg crystal spectrometer, the cyclotron trap II has been used to provide a suitable X—ray source. To characterize the bent crystal spectrometer, the cyclotron trap has been modified to operate as an electron—cyclotron resonance source, which produces with high intensity narrow X-ray transitions in the few keV range originating from highly charged ions. [ABSTRACT FROM AUTHOR]

Published
2008
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2. High Resolution He-like Argon And Sulfur Spectra From The PSI ECRIT.

Author

Trassinelli, M., Biri, S., Boucard, S., Covita, D. S., Gotta, D., Leoni, B., Hirtl, A., Indelicato, P., Le Bigot, E.-O., dos Santos, J. M. F., Simons, L. M., Stingelin, L., Veloso, J. F. C. A., Wasser, A., and Zmeskal, J.

Subjects
SPECTRUM analysis, ELECTRIC equipment, PHYSICS instruments, OPTICS, X-ray spectroscopy, RESONANCE
Abstract

We present new results on the X-ray spectroscopy of multicharged argon, sulfur and chlorine obtained with the Electron Cyclotron Resonance Ion Trap (ECRIT) in operation at the Paul Scherrer Institut (Villigen, Switzerland). We used a Johann-type Bragg spectrometer with a spherically-bent crystal, with an energy resolution of about 0.4 eV. The ECRIT itself is of a hybrid type, with a superconducting split coil magnet, special iron inserts which provides the mirror field, and a permanent magnetic hexapole. The high frequency was provided by a 6.4 GHz microwave emitter. We obtained high intensity X-ray spectra of multicharged F-like to He-like argon, sulfur and chlorine with one 1s hole. In particular, we observed the 1s2s 3S1 → 1s2 1S0 M1 and 1s2p 3P2 → 1s2 1S0 M2 transitions in He-like argon, sulfur and chlorine with unprecedented statistics and resolution. The energies of the observed lines are being determined with good accuracy using the He-like M1 line as a reference. We surveyed the He-like M1 transition intensity as a function of the ECRIT working conditions. In particular we observed the M1 intensity dependency on the coil current and on the injected microwave power. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Published
2005
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3. Towards a Lamb shift measurement in muonic hydrogen.

Author

Kottmann, F., Biraben, F., Conde, C. A. N., Donche-Gay, C., Ha¨nsch, T. W., Hartmann, F. J., Hauser, P., Hughes, V. W., Huot, O., Indelicato, P., Knowles, P., Liu, Y.-W., Markushin, V. E., Mulhauser, F., Nez, F., Pohl, R., Rabinowitz, P., dos Santos, J. M. F., Schaller, L. A., and Schneuwly, H.

Subjects
MUONS, QUANTUM electrodynamics
Abstract

A measurement of the 2S Lamb shift (2S—2P energy difference) in muonic hydrogen (μ[sup -] p) is being prepared at the Paul Scherrer Institute (PSI). The goal of the experiment is to measure the Lamb shift with 30 ppm precision and to deduce the root mean square (rms) proton charge radius with 10[sup -3] relative accuracy, 20 times more precise than presently known. The experiment is based on the availability of long-lived metastable muonic hydrogen atoms in the 2S state which has been investigated in a recent series of experiments at PSI. From the low—energy part of the initial kinetic energy distribution of μp(1S) atoms we determined the fraction of long—lived μp(2S) to be ∼1.5 % for H[sub 2] gas pressures between 1 and 64 hPa. Another analysis involving μp(1S) with a kinetic energy of 0.9 keV originating from quenching of thermalized μp(2S) via the resonant process μp(2S) + H[sub 2] → {[(ppμ)[sup +]]*pee}* → μp(1S) + p + ... + 2 keV gives the same result. This is the first direct observation of long-lived μp(2S) atoms. The realization of the μp Lamb shift experiment involves a new low energy negative muon beam with entrance detectors for keV-muons, a xenon gas-proportionalscintillation-chamber (GPSC) read out by a microstrip-gas-chamber (MSGC) for the detection of 2 keV X-rays, and a randomly triggered 3—stage laser system providing 0.5 m J, 7 ns laser pulses at 6.02 μm wavelength. [ABSTRACT FROM AUTHOR]

Published
2001

4. Accurate miscut angle determination for spherically bent Bragg crystals.

Author

Covita, D. S., Ay, M., Schlesser, S., Gotta, D., Simons, L. M., Le Bigot, E.-O., and dos Santos, J. M. F.

Subjects
CRYSTALLOGRAPHY, CRYSTALS, LABORATORY equipment & supplies, SPECTRUM analysis, OPTICS
Abstract

Spherically bent crystals are used as analyzers in high-resolution spectroscopy, in particular, in low count-rate applications such as exotic-atom research. The focal conditions are determined not only by the bending radius and the Bragg angle but also by the crystal cut angle between its surface and the reflecting crystal planes, along with their orientation with respect to the direction of dispersion. We describe a simple but precise method for measuring the cut angle and its orientation for mounted spherically bent crystals, by combining x-ray diffraction and laser optical alignment, which can be easily performed with standard x-ray laboratory equipment. [ABSTRACT FROM AUTHOR]

Published
2008
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5. The microhole and strip plate gas detector: Initial results.

Author

Veloso, J. F. C. A., Maia, J. M., Morgado, R. E., dos Santos, J. M. F., and Conde, C. A. N

Subjects
MICROSTRUCTURE, ARGON
Abstract

We report the initial performance of an argon gas proportional counter consisting of a microstructure: the microhole and strip plate (MHSP). The MHSP combines desirable features of both a gas electron multiplier (GEM) and a microstrip plate (MSP) into a single integrated microstructure. Like the GEM, the MHSP is fabricated with flexible printed-circuit technology. As implemented, the MHSP provides two charge-amplification stages: slotted holes that function as a GEM, and microstrip anodes that also function as the charge-collection electrode. With two stages of amplification the microstrip can be operated with bias voltages well below the breakdown threshold. Results for the operation of the MHSP in argon are presented. A charge amplification factor of seven was achieved in the microholes with a maximum electron transmission approaching 100%. The measured energy resolution for 5.9 kev x rays was 30%. Future plans include the incorporation of a photocathode into the MHSP for applications as an ultraviolet photosensor. [ABSTRACT FROM AUTHOR]

Published
2002
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6. A proposed new microstructure for gas radiation detectors: The microhole and strip plate.

Author

Veloso, J. F. C. A., dos Santos, J. M. F., and Conde, C. A. N.

Subjects
*NANOSTRUCTURED materials, *CHARGE exchange, *ELECTRONS, *SCIENTIFIC apparatus & instruments
Abstract

A new type of microstructure device for a gas radiation detector is proposed. This microstructure, the microhole and strip plate structure, merges the structures of a gas electron multiplier and a microstrip plate in one single plate. This design allows two-multiplication stages and a separation of the sensitive and the detection regions, with full optical positive feedback suppression. Simulations for gas gain and electron transparency of the microstructure are presented. Different applications are discussed. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2000
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7. Search for inelastic scattering of WIMP dark matter in XENON1T

Author

A. Manfredini, L. Scotto Lavina, Hardy Simgen, A. D. Ferella, R. Budnik, Yuehuan Wei, L. Grandi, G. Koltman, C. Weinheimer, K. Martens, F. Arneodo, M. Messina, Lorne Levinson, F. Joerg, Kaixuan Ni, D. Cichon, N. Kato, C. Macolino, L. Hoetzsch, A. Elykov, T. Wolf, Elena Aprile, João Cardoso, M. Pierre, D. Ramírez García, F. Gao, Keita Mizukoshi, P. Shagin, J. A. M. Lopes, Y. Mosbacher, Y. Ma, Masaki Yamashita, P. Di Gangi, S. Moriyama, T. Zhu, F. D. Amaro, Guillaume Plante, Fabrizio Marignetti, M. Vargas, H. Landsman, M. P. Decowski, April S. Brown, Boris Bauermeister, Jochen Schreiner, D. Masson, T. Marrodán Undagoitia, L. Bellagamba, A. Rocchetti, S. Liang, Manfred Lindner, L. Althueser, K. Odgers, J. Howlett, Katsuki Hiraide, F. Lombardi, M. Alfonsi, S. Andaloro, J.M.F. dos Santos, F. Agostini, R. Di Stefano, V. Pizzella, Giacomo Bruno, J. Naganoma, N. Šarčević, J. Qin, Sebastian Lindemann, G. Sartorelli, J. Pienaar, C. Capelli, N. Rupp, Gian Carlo Trinchero, K. Morå, Michelle Galloway, H. Schulze Eißing, E. Angelino, S. Bruenner, A. Molinario, S. Mastroianni, Jean-Pierre Cussonneau, M. Iacovacci, A. Di Giovanni, Bart Pelssers, C. Tunnell, C. Wittweg, J. P. Zopounidis, D. Coderre, Manuel Gameiro da Silva, M. Scheibelhut, Jelle Aalbers, A. Depoian, M. Selvi, D. Schulte, Kathrin Valerius, A. Kopec, S. Reichard, Qing Lin, J. Qi, J. Palacio, J. Ye, B. Cimmino, M. Clark, Atsushi Takeda, Shingo Kazama, G. Volta, Uwe Oberlack, V. C. Antochi, Ethan Brown, Kentaro Miuchi, C. Therreau, J. Cuenca, Y. Zhang, Julien Masbou, Z. Xu, M. Murra, W. Fulgione, Laura Manenti, C. Hils, Sara Diglio, J. Mahlstedt, G. Zavattini, Laura Baudis, P. Gaemers, F. Toschi, M. L. Benabderrahmane, J. Long, J. R. Angevaare, E. Shockley, Jan Conrad, Masanori Kobayashi, R. Gaior, Yoshitaka Itow, M. Weiss, D. Thers, Marc Schumann, F. Semeria, R. F. Lang, A. P. Colijn, D. Wenz, R. Peres, A. Mancuso, Aprile, E., Aalbers, J., Agostini, F., Alfonsi, M., Althueser, L., Amaro, F. D., Andaloro, S., Angelino, E., Angevaare, J. R., Antochi, V. C., Arneodo, F., Baudis, L., Bauermeister, B., Bellagamba, L., Benabderrahmane, M. L., Brown, A., Brown, E., Bruenner, S., Bruno, G., Budnik, R., Capelli, C., Cardoso, J. M. R., Cichon, D., Cimmino, B., Clark, M., Coderre, D., Colijn, A. P., Conrad, J., Cuenca, J., Cussonneau, J. P., Decowski, M. P., Depoian, A., Di Gangi, P., Di Giovanni, A., Di Stefano, R., Diglio, S., Elykov, A., Ferella, A. D., Fulgione, W., Gaemers, P., Gaior, R., Galloway, M., Gao, F., Grandi, L., Hils, C., Hiraide, K., Hoetzsch, L., Howlett, J., Iacovacci, M., Itow, Y., Joerg, F., Kato, N., Kazama, S., Kobayashi, M., Koltman, G., Kopec, A., Landsman, H., Lang, R. F., Levinson, L., Liang, S., Lin, Q., Lindemann, S., Lindner, M., Lombardi, F., Long, J., Lopes, J. A. M., Ma, Y., Macolino, C., Mahlstedt, J., Mancuso, A., Manenti, L., Manfredini, A., Marignetti, F., Marrodan Undagoitia, T., Martens, K., Masbou, J., Masson, D., Mastroianni, S., Messina, M., Miuchi, K., Mizukoshi, K., Molinario, A., Mora, K., Moriyama, S., Mosbacher, Y., Murra, M., Naganoma, J., Ni, K., Oberlack, U., Odgers, K., Palacio, J., Pelssers, B., Peres, R., Pienaar, J., Pierre, M., Pizzella, V., Plante, G., Qi, J., Qin, J., Ramirez Garcia, D., Reichard, S., Rocchetti, A., Rupp, N., Dos Santos, J. M. F., Sartorelli, G., Sarcevic, N., Scheibelhut, M., Schreiner, J., Schulte, D., Schulze Eissing, H., Schumann, M., Scotto Lavina, L., Selvi, M., Semeria, F., Shagin, P., Shockley, E., Silva, M., Simgen, H., Takeda, A., Therreau, C., Thers, D., Toschi, F., Trinchero, G., Tunnell, C., Valerius, K., Vargas, M., Volta, G., Wei, Y., Weinheimer, C., Weiss, M., Wenz, D., Wittweg, C., Wolf, T., Xu, Z., Yamashita, M., Ye, J., Zavattini, G., Zhang, Y., Zhu, T., Zopounidis, J. P., XENON Collaboration, Columbia University [New York], Oskar Klein Centre [Stockholm], Stockholm University, University of Bologna, Johannes Gutenberg - Universität Mainz (JGU), Westfälische Wilhelms-Universität Münster (WWU), University of Coimbra [Portugal] (UC), Università degli studi di Torino (UNITO), University of Amsterdam [Amsterdam] (UvA), Laboratoire de physique subatomique et des technologies associées (SUBATECH), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire de Physique Nucléaire et de Hautes Énergies (LPNHE (UMR_7585)), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), 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), XENON, IoP (FNWI), and XENON (IHEF, IoP, FNWI)

Subjects
xenon: target, Photon, Physics::Instrumentation and Detectors, Parameter space, 01 natural sciences, WIMP: dark matter, High Energy Physics - Experiment, astro-ph.CO, High Energy Physics - Experiment (hep-ex), XENON, Recoil, WIMP, WIMP nucleus: cross section, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], Dark Matter, parameter space, Nuclear Experiment, ComputingMilieux_MISCELLANEOUS, nucleus: recoil, Physics, Dark Matter, Inelastic scattering, XENON, Direct Dark Matter, photon, Astrophysics::Instrumentation and Methods for Astrophysics, Direct Dark Matter, Weakly interacting massive particles, signature, Astrophysics - Cosmology and Nongalactic Astrophysics, Particle physics, Inelastic scattering, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Dark matter, FOS: Physical sciences, WIMP: mass, Astrophysics::Cosmology and Extragalactic Astrophysics, NO, PE2_2, PE2_1, 0103 physical sciences, ddc:530, 010306 general physics, 010308 nuclear & particles physics, Scattering, WIMP nucleus: interaction, Dark, matter, WIMP: interaction, High Energy Physics::Experiment, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics and astroparticle physics, experimental results
Abstract

We report the results of a search for the inelastic scattering of weakly interacting massive particles (WIMPs) in the XENON1T dark matter experiment. Scattering off $^{129}$Xe is the most sensitive probe of inelastic WIMP interactions, with a signature of a 39.6 keV de-excitation photon detected simultaneously with the nuclear recoil. Using an exposure of 0.89 tonne-years, we find no evidence of inelastic WIMP scattering with a significance of more than 2$\sigma$. A profile-likelihood ratio analysis is used to set upper limits on the cross-section of WIMP-nucleus interactions. We exclude new parameter space for WIMPs heavier than 100 GeV/c${}^2$, with the strongest upper limit of $3.3 \times 10^{-39}$ cm${}^2$ for 130 GeV/c${}^2$ WIMPs at 90\% confidence level., Comment: 9 pages, 4 figures

Published
2021
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