Al0.52In0.48P avalanche photodiodes for soft X-ray spectroscopy

The performance of Al0.52In0.48P avalanche photodiodes was assessed as soft X-ray detectors at room temperature. The effect of the avalanche gain improved the energy resolution and an energy resolution (FWHM) of 682 eV is reported for 5.9 keV X-rays

Low-diffusion Xe-He gas mixtures for rare-event detection: electroluminescence yield

[EN] High pressure xenon Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification are being proposed for rare event detection such as directional dark matter, double electron capture and double beta decay detection. The discrimination of the rare event through the topological signature of primary ionisation trails is a major asset for this type of TPC when compared to single liquid or double-phase TPCs, limited mainly by the high electron diffusion in pure xenon. Helium admixtures with xenon can be an attractive solution to reduce the electron diffu- sion significantly, improving the discrimination efficiency of these optical TPCs. We have measured the electroluminescence (EL) yield of Xe-He mixtures, in the range of 0 to 30% He and demonstrated the small impact on the EL yield of the addition of helium to pure xenon. For a typical reduced electric field of 2.5 kV/cm/bar in the EL region, the EL yield is lowered by similar to 2%, 3%, 6% and 10% for 10%, 15%, 20% and 30% of helium concentration, respectively. This decrease is less than what has been obtained from the most recent simulation framework in the literature. The impact of the addition of helium on EL statistical fluctuations is negligible, within the experimental uncertainties. The present results are an important benchmark for the simulation tools to be applied to future optical TPCs based on Xe-He mixtures.The NEXT Collaboration acknowledges support from the following agencies and institutions: the European Research Council (ERC) under the Advanced Grant 339787-NEXT; the European Union's Framework Programme for Research and Innovation Horizon 2020 (2014-2020) under the Marie Sklodowska-Curie Grant Agreements No. 674896, 690575 and 740055; the Ministerio de Economa y Competitividad of Spain under grants FIS2014-53371-C04, RTI2018-095979, the Severo Ochoa Program SEV-2014-0398 and the Mara de Maetzu Program MDM-2016-0692; the GVA of Spain under grants PROMETEO/2016/120 and SEJI/2017/011; the Portuguese FCT under project PTDC/FIS-NUC/2525/2014, under project UID/FIS/04559/2013 to fund the activities of LIBPhys, and under grants PD/BD/105921/2014, SFRH/BPD/109180/2015; the U.S. Department of Energy under contracts number DEAC02-06CH11357 (Argonne National Laboratory), DE-AC0207CH11359 (Fermi National Accelerator Laboratory), DE-FG02-13ER42020 (Texas A& M) and DE-SC0019223/DESC0019054 (University of Texas at Arlington); and the University of Texas at Arlington. DGD acknowledges Ramon y Cajal program (Spain) under contract number RYC-2015-18820. We also warmly acknowledge the Laboratori Nazionali del Gran Sasso (LNGS) and the Dark Side collaboration for their help with TPB coating of various parts of the NEXT-White TPC. Finally, we are grateful to the Laboratorio Subterraneo de Canfranc for hosting and supporting the NEXT experiment.Fernandes, A.; Henriques, C.; Mano, R.; González-Díaz, D.; Azevedo, C.; Silva, P.; Gómez-Cadenas, J.... (2020). Low-diffusion Xe-He gas mixtures for rare-event detection: electroluminescence yield. Journal of High Energy Physics (Online). (4):1-18. https://doi.org/10.1007/JHEP04(2020)034S1184D.R. Nygren, Columnar recombination: a tool for nuclear recoil directional sensitivity in a xenon-based direct detection WIMP search, J. Phys. Conf. Ser.460 (2013) 012006 [INSPIRE].G. Mohlabeng et al., Dark matter directionality revisited with a high pressure xenon gas detector, JHEP07 (2015) 092 [arXiv:1503.03937] [INSPIRE].N.S. Phan, R.J. Lauer, E.R. Lee, D. Loomba, J.A.J. Matthews and E.H. Miller, GEM-based TPC with CCD Imaging for Directional Dark Matter Detection, Astropart. Phys.84 (2016) 82 [arXiv:1510.02170] [INSPIRE].J. Martin-Albo et al., Sensitivity of NEXT-100 to neutrinoless double beta decay, JHEP05 (2016) 159 [arXiv:1511.09246] [INSPIRE].K. Nakamura et al., AXEL — a high pressure xenon gas TPC for neutrinoless double beta decay search, Nucl. Instrum. Meth.A 845 (2017) 394 [INSPIRE].D. Yu. Akimov, A.A. Burenkov, V.F. Kuzichev, V.L. Morgunov and V.N. Solovev, Low background experiments with high pressure gas scintillation proportional detector, physics/9704021 [INSPIRE].Yu. M. Gavrilyuk et al., A technique for searching for the 2K capture in124Xe with a copper proportional counter, Phys. Atom. Nucl.78 (2015) 1563 [INSPIRE].Yu. M. Gavrilyuk et al., Results of In-Depth Analysis of Data Obtained in the Experimental Search for 2K (2ν)-Capture in78Kr, Phys. Part. Nucl.49 (2018) 540 [INSPIRE].C.A.N. Conde and A.J.P.L. Policarpo, A Gas Proportional Scintillation Counter, Nucl. Instrum. Meth.53 (1967) 7.A.J.P.L. Policarpo, M.A.F. Alves and C.A.N. Conde, The Argon-Nitrogen Proportional Scintillation Counter, Nucl. Instrum. Meth.55 (1967) 105.J.M.F. dos Santos et al., Development of portable gas proportional scintillation counters for x-ray spectrometry, X-Ray Spectrom.30 (2001) 373.NEXT collaboration, Accurate γ and MeV-electron track reconstruction with an ultra-low diffusion Xenon/TMA TPC at 10 atm, Nucl. Instrum. Meth.A 804 (2015) 8 [arXiv:1504.03678] [INSPIRE].NEXT collaboration, Characterisation of NEXT-DEMO using xenon KαX-rays, 2014 JINST9 P10007 [arXiv:1407.3966] [INSPIRE].NEXT collaboration, Energy calibration of the NEXT-White detector with 1% resolution near Qββof136Xe, JHEP10 (2019) 230 [arXiv:1905.13110] [INSPIRE].R. Lüscher et al., Search for beta beta decay in Xe-136: New results from the Gotthard experiment, Phys. Lett.B 434 (1998) 407 [INSPIRE].NEXT collaboration, First proof of topological signature in the high pressure xenon gas TPC with electroluminescence amplification for the NEXT experiment, JHEP01 (2016) 104 [arXiv:1507.05902] [INSPIRE].NEXT collaboration, Background rejection in NEXT using deep neural networks, 2017 JINST12 T01004 [arXiv:1609.06202] [INSPIRE].NEXT collaboration, The Next White (NEW) Detector, 2018 JINST13 P12010 [arXiv:1804.02409] [INSPIRE].H. Qiao et al., Signal-background discrimination with convolutional neural networks in the PandaX-III experiment using MC simulation, Sci. China Phys. Mech. Astron.61 (2018) 101007 [arXiv:1802.03489] [INSPIRE].NEXT collaboration, Secondary scintillation yield of xenon with sub-percent levels of CO2additive for rare-event detection, Phys. Lett.B 773 (2017) 663 [arXiv:1704.01623] [INSPIRE].C.M.B. Monteiro et al., Secondary Scintillation Yield in Pure Xenon, 2007 JINST2 P05001 [physics/0702142] [INSPIRE].C.M.B. Monteiro, J.A.M. Lopes, J.F. C.A. Veloso and J.M.F. dos Santos, Secondary scintillation yield in pure argon, Phys. Lett.B 668 (2008) 167 [INSPIRE].C.A.B. Oliveira et al., A simulation toolkit for electroluminescence assessment in rare event experiments, Phys. Lett.B 703 (2011) 217 [arXiv:1103.6237] [INSPIRE].E.D.C. Freitas et al., Secondary scintillation yield in high-pressure xenon gas for neutrinoless double beta decay (0νββ) search, Phys. Lett.B 684 (2010) 205 [INSPIRE].C.M.B. Monteiro et al., Secondary scintillation yield from gaseous micropattern electron multipliers in direct dark matter detection, Phys. Lett.B 677 (2009) 133 [INSPIRE].C.M.B. Monteiro, L.M.P. Fernandes, J.F. C.A. Veloso, C.A.B. Oliveira and J.M.F. dos Santos, Secondary scintillation yield from GEM and THGEM gaseous electron multipliers for direct dark matter search, Phys. Lett.B 714 (2012) 18 [INSPIRE].C. Balan et al., MicrOMEGAs operation in high pressure xenon: Charge and scintillation readout, 2011 JINST6 P02006 [arXiv:1009.2960] [INSPIRE].C.M.B. Monteiro, L.M.P. Fernandes, J.F. C.A. Veloso and J.M.F. dos Santos, Secondary scintillation readout from GEM and THGEM with a large area avalanche photodiode, 2012 JINST7 P06012 [INSPIRE].C.D.R. Azevedo et al., An homeopathic cure to pure Xenon large diffusion, 2016 JINST11 C02007 [arXiv:1511.07189] [INSPIRE].C.D.R. Azevedo et al., Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives, Nucl. Intrum. Meth.A 877 (2018) 157 [arXiv:1705.09481] [INSPIRE].NEXT collaboration, Electroluminescence TPCs at the Thermal Diffusion Limit, JHEP01 (2019) 027 [arXiv:1806.05891] [INSPIRE].R.C. Lanza et al., Gas scintillators for imaging of low energy isotopes, IEEE Trans. Nucl. Sci.34 (1987) 406.R. Felkai et al., Helium-Xenon mixtures to improve the topological signature in high pressure gas xenon TPCs, Nucl. Intrum. Meth.A 905 (2018) 82 [arXiv:1710.05600] [INSPIRE].NEXT collaboration, Electron Drift and Longitudinal Diffusion in High Pressure Xenon-Helium Gas Mixtures, 2019 JINST14 P08009 [arXiv:1902.05544] [INSPIRE].J.A.M. Lopes et al., A xenon gas proportional scintillation counter with a UV-sensitive large-area avalanche photodiode, IEEE Trans. Nucl. Sci.48 (2001) 312.C.M.B. Monteiro et al., An argon gas proportional scintillation counter with UV avalanche photodiode scintillation readout, IEEE Trans. Nucl. Sci.48 (2001) 1081.Advanced Photonix, Inc., 1240 Avenida Acaso, Camarillo, CA 93012, U.S.A. .L.M.P. Fernandes et al., Characterization of large area avalanche photodiodes in X-ray and VUV-light detection, 2007 JINST2 P08005 [physics/0702130] [INSPIRE].L.M.P. Fernandes, E.D.C. Freitas, M. Ball, J.J. Gomez-Cadenas, C.M.B. Monteiro, N. Yahlali et al., Primary and secondary scintillation measurements in a xenon Gas Proportional Scintillation Counter, 2010 JINST5 P09006 [Erratum ibid.5 (2010) A12001] [arXiv:1009.2719] [INSPIRE].C.A.B. Oliveira, M. Sorel, J. Martin-Albo, J.J. Gomez-Cadenas, A.L. Ferreira and J.F. C.A. Veloso, Energy Resolution studies for NEXT, 2011 JINST6 P05007 [arXiv:1105.2954] [INSPIRE].D.F. Anderson et al., A large area, gas scintillation proportional counter, Nucl. Instrum. Meth.163 (1979) 125.T.Z. Kowalski et al., Fano factor implications from gas scintillation proportional counter measurements, Nucl. Instrum. Meth.A 279 (1989) 567.T. Doke, Basic properties of high pressure xenon gas as detector medium, in Proceedings of the XeSAT, Tokyo Japan (2005), pg. 92.S.J.C. do Carmo et al., Experimental Study of the ω-Values and Fano Factors of Gaseous Xenon and Ar-Xe Mixtures for X-Rays, IEEE Trans. Nucl. Sci.55 (2008) 2637.A. Buzulutskov, E. Shemyakina, A. Bondar, A. Dolgov, E. Frolov, V. Nosov et al., Revealing neutral bremsstrahlung in two-phase argon electroluminescence, Astropart. Phys.103 (2018) 29 [arXiv:1803.05329] [INSPIRE]

The scintillation and ionization yield of liquid xenon for nuclear recoils

XENON10 is an experiment designed to directly detect particle dark matter. It is a dual phase (liquid/gas) xenon time-projection chamber with 3D position imaging. Particle interactions generate a primary scintillation signal (S1) and ionization signal (S2), which are both functions of the deposited recoil energy and the incident particle type. We present a new precision measurement of the relative scintillation yield \leff and the absolute ionization yield Q_y, for nuclear recoils in xenon. A dark matter particle is expected to deposit energy by scattering from a xenon nucleus. Knowledge of \leff is therefore crucial for establishing the energy threshold of the experiment; this in turn determines the sensitivity to particle dark matter. Our \leff measurement is in agreement with recent theoretical predictions above 15 keV nuclear recoil energy, and the energy threshold of the measurement is 4 keV. A knowledge of the ionization yield \Qy is necessary to establish the trigger threshold of the experiment. The ionization yield \Qy is measured in two ways, both in agreement with previous measurements and with a factor of 10 lower energy threshold.Comment: 8 pages, 9 figures. To be published in Nucl. Instrum. Methods

Design and Performance of the XENON10 Dark Matter Experiment

XENON10 is the first two-phase xenon time projection chamber (TPC) developed within the XENON dark matter search program. The TPC, with an active liquid xenon (LXe) mass of about 14 kg, was installed at the Gran Sasso underground laboratory (LNGS) in Italy, and operated for more than one year, with excellent stability and performance. Results from a dark matter search with XENON10 have been published elsewhere. In this paper, we summarize the design and performance of the detector and its subsystems, based on calibration data using sources of gamma-rays and neutrons as well as background and Monte Carlo simulations data. The results on the detector's energy threshold, energy and position resolution, and overall efficiency show a performance that exceeds design specifications, in view of the very low energy threshold achieved (<10 keVr) and the excellent energy resolution achieved by combining the ionization and scintillation signals, detected simultaneously

Evaluation of turbulent dissipation rate retrievals from Doppler Cloud Radar

Turbulent dissipation rate retrievals from cloud radar Doppler velocity measurements are evaluated using independent, in situ observations in Arctic stratocumulus clouds. In situ validation data sets of dissipation rate are derived using sonic anemometer measurements from a tethered balloon and high frequency pressure variation observations from a research aircraft, both flown in proximity to stationary, ground-based radars. Modest biases are found among the data sets in particularly low- or high-turbulence regimes, but in general the radar-retrieved values correspond well with the in situ measurements. Root mean square differences are typically a factor of 4-6 relative to any given magnitude of dissipation rate. These differences are no larger than those found when comparing dissipation rates computed from tetheredballoon and meteorological tower-mounted sonic anemometer measurements made at spatial distances of a few hundred meters. Temporal lag analyses suggest that approximately half of the observed differences are due to spatial sampling considerations, such that the anticipated radar-based retrieval uncertainty is on the order of a factor of 2-3. Moreover, radar retrievals are clearly able to capture the vertical dissipation rate structure observed by the in situ sensors, while offering substantially more information on the time variability of turbulence profiles. Together these evaluations indicate that radar-based retrievals can, at a minimum, be used to determine the vertical structure of turbulence in Arctic stratocumulus clouds

Low-diffusion Xe-He gas mixtures for rare-event detection: electroluminescence yield

High pressure xenon Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification are being proposed for rare event detection such as directional dark matter, double electron capture and double beta decay detection. The discrimination of the rare event through the topological signature of primary ionisation trails is a major asset for this type of TPC when compared to single liquid or double-phase TPCs, limited mainly by the high electron diffusion in pure xenon. Helium admixtures with xenon can be an attractive solution to reduce the electron diffu- sion significantly, improving the discrimination efficiency of these optical TPCs. We have measured the electroluminescence (EL) yield of Xe–He mixtures, in the range of 0 to 30% He and demonstrated the small impact on the EL yield of the addition of helium to pure xenon. For a typical reduced electric field of 2.5 kV/cm/bar in the EL region, the EL yield is lowered by ∼ 2%, 3%, 6% and 10% for 10%, 15%, 20% and 30% of helium concentration, respectively. This decrease is less than what has been obtained from the most recent simulation framework in the literature. The impact of the addition of helium on EL statistical fluctuations is negligible, within the experimental uncertainties. The present results are an important benchmark for the simulation tools to be applied to future optical TPCs based on Xe-He mixtures. [Figure not available: see fulltext.]

Study of infrared scintillations in gaseous and liquid argon - Part II: light yield and possible applications

We present here a comprehensive study of the light yield of primary and secondary scintillations produced in gaseous and liquid Ar in the near infrared (NIR) and visible region, at cryogenic temperatures. The measurements were performed using Geiger-mode avalanche photodiodes (GAPDs) and pulsed X-ray irradiation. The primary scintillation yield of the fast emission component in gaseous Ar was found to be independent of temperature in the range of 87-160 K; it amounted to 17000+/-3000 photon/MeV in the NIR in the range of 690-1000 nm. In liquid Ar at 87 K, the primary scintillation yield of the fast component was considerably reduced, amounting to 510+/-90 photon/MeV, in the range of 400-1000 nm. Proportional NIR scintillations (electroluminescence) in gaseous Ar were also observed; their amplification parameter at 160 K was measured to be 13 photons per drifting electron per kV. No proportional scintillations were observed in liquid Ar up to the electric fields of 30 kV/cm. The applications of NIR scintillations in dark matter search and coherent neutrino-nucleus scattering experiments and in ion beam radiotherapy are considered.Comment: 20 pages, 11 figures. Submitted to JINS

The Lamb shift in muonic hydrogen and the proton radius

By means of pulsed laser spectroscopy applied to muonic hydrogen (μ− p) we have measured the 2S F = 1 1/2 − 2PF = 2 3/2 transition frequency to be 49881.88(76) GHz. By comparing this measurement with its theoretical prediction based on bound-state QED we have determined a proton radius value of rp = 0.84184 (67) fm. This new value is an order of magnitude preciser than previous results but disagrees by 5 standard deviations from the CODATA and the electronproton scattering values. An overview of the present effort attempting to solve the observed discrepancy is given. Using the measured isotope shift of the 1S-2S transition in regular hydrogen and deuterium also the rms charge radius of the deuteron rd = 2.12809 (31) fm has been determined. Moreover we present here the motivations for the measurements of the μ 4He + and μ 3He + 2S-2P splittings. The alpha and triton charge radii are extracted from these measurements with relative accuracies of few 10 − 4. Measurements could help to solve the observed discrepancy, lead to the best test of hydrogen-like energy levels and provide crucial tests for few-nucleon ab-initio theories and potentials

Erratum to: "XENON" [Nucl. Phys. B (Proc. Suppl.) 173 (2007) 113–116]

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An improved measurement of electron-ion recombination in high-pressure xenon gas

We report on results obtained with the NEXT-DEMO prototype of the NEXT-100 high-pressure xenon gas time projection chamber (TPC), exposed to an alpha decay calibration source. Compared to our previous measurements with alpha particles, an upgraded detector and improved analysis techniques have been used. We measure event-by-event correlated fluctuations between ionization and scintillation due to electron-ion recombination in the gas, with correlation coeffcients between -0.80 and -0.56 depending on the drift field conditions. By combining the two signals, we obtain a 2.8% FWHM energy resolution for 5.49 MeV alpha particles and a measurement of the optical gain of the electroluminescent TPC. The improved energy resolution also allows us to measure the specific activity of the radon in the gas due to natural impurities. Finally, we measure the average ratio of excited to ionized atoms produced in the xenon gas by alpha particles to be 0:561 0:045, translating into an average energy to produce a primary scintillation photon ofWex = (39:2 3:2) eV.This work was supported by the following agencies and institutions: the European Research Council under the Advanced Grant 339787-NEXT; the Ministerio de Economia y Competitividad of Spain under grants CONSOLIDER-Ingenio 2010 CSD2008-0037 (CUP), FPA2009-13697-C04 and FIS2012-37947-C04; the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under contract no. DE-AC02-05CH11231; and the Portuguese FCT and FEDER through the program COMPETE, project PTDC/FIS/103860/2008.Serra, L.; Sorel, M.; Alvarez, V.; Borges, FIG.; Camargo, M.; Carcel, S.; Cebrian, S.... (2015). An improved measurement of electron-ion recombination in high-pressure xenon gas. Journal of Instrumentation. 10:1-19. https://doi.org/10.1088/1748-0221/10/03/P03025S1191