A. Tomás

ORCID: 0000-0001-7231-2562
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About
Contact & Profiles
Research Areas
  • Dark Matter and Cosmic Phenomena
  • Particle Detector Development and Performance
  • Atomic and Subatomic Physics Research
  • Particle physics theoretical and experimental studies
  • Neutrino Physics Research
  • Radiation Detection and Scintillator Technologies
  • Astrophysics and Cosmic Phenomena
  • Nuclear Physics and Applications
  • Cosmology and Gravitation Theories
  • Medical History and Innovations
  • Nuclear and radioactivity studies
  • Muon and positron interactions and applications
  • Solar and Space Plasma Dynamics
  • Catalytic Processes in Materials Science
  • Leaf Properties and Growth Measurement
  • Phase Equilibria and Thermodynamics
  • Age of Information Optimization
  • Plant responses to water stress
  • Plant Water Relations and Carbon Dynamics
  • Cardiac, Anesthesia and Surgical Outcomes
  • Plasma Diagnostics and Applications
  • Silicon Carbide Semiconductor Technologies
  • Gas Dynamics and Kinetic Theory
  • Diversity and Career in Medicine
  • Spectroscopy and Laser Applications

Imperial College London
2013-2023

Moscow Engineering Physics Institute
2017-2019

University of California, Berkeley
2017

Strategic Insight (United States)
2017

IMS Nanofabrication (Austria)
2017

Parc Científic de la Universitat de València
2017

Instituto de Física Corpuscular
2017

Universitat de València
2017

Institute for Basic Science
2017

Royal Holloway University of London
2017

The International Axion Observatory (IAXO) will be a forth generation axion helioscope. As its primary physics goal, IAXO look for axions or axion-like particles (ALPs) originating in the Sun via Primakoff conversion of solar plasma photons. In terms signal-to-noise ratio, about 4–5 orders magnitude more sensitive than CAST, currently most powerful helioscope, reaching sensitivity to axion-photon couplings down few × 10−12 GeV−1 and thus probing large fraction unexplored ALP parameter space....

10.1088/1748-0221/9/05/t05002 article EN cc-by Journal of Instrumentation 2014-05-12

We present the case for a dark matter detector with directional sensitivity. This document was developed at 2009 CYGNUS workshop on detection, and contains contributions from theorists experimental groups in field. describe need sensitivity; each experiment presents their project's status; we close feasibility study scaling up to one ton detector, which would cost around $150M.

10.1142/s0217751x10048172 article EN International Journal of Modern Physics A 2010-01-10

The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using 3He as a buffer gas. At T=1.8 K this allows larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with 4He. With about 1 h of data taking at each 252 different we have scanned the mass range 0.39 eV < m_a 0.64 eV. From absence excess X-rays when magnet was pointing Sun set typical upper limit on axion-photon coupling g_ag 2.3 x 10^{-10} GeV^{-1} 95% CL, exact...

10.1103/physrevlett.107.261302 article EN cc-by Physical Review Letters 2011-12-23

We study the feasibility of a new generation axion helioscope, most ambitious and promising detector solar axions to date. show that large improvements in magnetic field volume, x-ray focusing optics backgrounds are possible beyond those achieved CERN Axion Solar Telescope (CAST). For hadronic models, sensitivity axion-photon coupling gaγ ≳ few × 10−12 GeV−1 is conceivable, 1–1.5 orders magnitude CAST sensitivity. If also couple electrons, Sun produces larger flux for same value Peccei-Quinn...

10.1088/1475-7516/2011/06/013 article EN Journal of Cosmology and Astroparticle Physics 2011-06-10

A new Micromegas manufacturing technique, based on kapton etching technology, has been developed recently, resulting in further improvement of the characteristics detector, such as uniformity and stability. Excellent energy resolution obtained, reaching 11% FWHM for 5.9 keV photon peak the55Fe X-ray source 1.8% (with possible evidence less than 1%) 5.5 MeV alpha 241Am source. The Microbulk detector shows several advantages like flexible structure, low material high radio-purity, opening thus...

10.1088/1748-0221/5/02/p02001 article EN Journal of Instrumentation 2010-02-01

The CERN Axion Solar Telescope has finished its search for solar axions with (3)He buffer gas, covering the range 0.64 eV ≲ ma 1.17 eV. This closes gap to cosmological hot dark matter limit and actually overlaps it. From absence of excess x rays when magnet was pointing Sun we set a typical upper on axion-photon coupling gaγ 3.3 × 10(-10) GeV(-1) at 95% C.L., exact value depending pressure setting. Future direct axion searches will focus increasing sensitivity smaller values gaγ, example by...

10.1103/physrevlett.112.091302 article EN cc-by Physical Review Letters 2014-03-04

In this Technical Design Report (TDR) we describe the LZ detector to be built at Sanford Underground Research Facility (SURF). The dark matter experiment is designed achieve sensitivity a WIMP-nucleon spin-independent cross section of three times ten negative forty-eighth square centimeters.

10.48550/arxiv.1703.09144 preprint EN other-oa arXiv (Cornell University) 2017-01-01

In this Technical Design Report (TDR) we describe the NEXT-100 detector that will search for neutrinoless double beta decay (ββ0ν) in 136XE at Laboratorio Subterráneo de Canfranc (LSC), Spain. The document formalizes design presented our Conceptual (CDR): an electroluminescence time projection chamber, with separate readout planes calorimetry and tracking, located, respectively, behind cathode anode. is designed to hold a maximum of about 150 kg xenon 15 bar, or 100 10 bar. This option...

10.1088/1748-0221/7/06/t06001 article EN Journal of Instrumentation 2012-06-06

NEXT is an experiment dedicated to neutrinoless double beta decay searches in xenon. The detector a TPC, holding 100 kg of high-pressure xenon enriched the 136 Xe isotope. It under construction Laboratorio Subterráneo de Canfranc Spain, and it will begin operations 2015. concept provides energy resolutionbetter than 1% FWHM topological signal that can be used reduce background. Furthermore, technology extrapolated 1 ton-scale experiment.

10.1155/2014/907067 article EN cc-by Advances in High Energy Physics 2014-01-01

The CERN Axion Solar Telescope (CAST) searches for $a\ensuremath{\rightarrow}\ensuremath{\gamma}$ conversion in the 9 T magnetic field of a refurbished LHC test magnet that can be directed toward Sun. Two parallel bores filled with helium adjustable pressure to match x-ray refractive mass ${m}_{\ensuremath{\gamma}}$ axion search ${m}_{a}$. After vacuum phase (2003--2004), which is optimal ${m}_{a}\ensuremath{\lesssim}0.02\text{ }\text{ }\mathrm{eV}$, we used $^{4}\mathrm{He}$ 2005--2007...

10.1103/physrevd.92.021101 article EN cc-by Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D, Particles, fields, gravitation, and cosmology 2015-07-28

NEXT-DEMO is a high-pressure xenon gas TPC which acts as technological test-bed and demonstrator for the NEXT-100 neutrinoless double beta decay experiment. In its current configuration apparatus fully implements design concept. This an asymmetric TPC, with energy plane made of photomultipliers tracking silicon (SiPM) coated TPB. The detector in this new has been used to reconstruct characteristic signature electrons dense gas, demonstrating ability identify MIP ``blob'' regions. Moreover,...

10.1088/1748-0221/8/09/p09011 article EN Journal of Instrumentation 2013-09-20

We propose an EASY (Electroluminescent ApparatuS of high Yield) and SOFT (Separated Optimized FuncTion) time-projection chamber for the NEXT experiment, that will search neutrinoless double beta decay (bb0nu) in Xe-136. Our experiment must be competitive with new generation bb0nu searches already operation or construction. This requires a detector very good energy resolution (&lt;1%), low background con- tamination (1E-4 counts/(keV \bullet kg y)) large target mass. In addition, it needs to...

10.48550/arxiv.1106.3630 preprint EN other-oa arXiv (Cornell University) 2011-01-01

NEXT-DEMO is a large-scale prototype of the NEXT-100 detector, an electroluminescent time projection chamber that will search for neutrinoless double beta decay \XE using 100–150 kg enriched xenon gas. was built to prove expected performance NEXT-100, namely, energy resolution better than 1% FWHM at 2.5 MeV and event topological reconstruction. In this paper we describe its initial results. A 1.75% 511 keV (which extrapolates 0.8% MeV) obtained 10 bar pressure gamma-ray calibration source....

10.1088/1748-0221/8/04/p04002 article EN Journal of Instrumentation 2013-04-03

The Neutrino Experiment with a Xenon TPC (NEXT) is intended to investigate the neutrinoless double beta decay of 136Xe, which requires severe suppression potential backgrounds. An extensive screening and material selection process underway for NEXT since control radiopurity levels materials be used in experimental set-up must rare event searches. First measurements based on Glow Discharge Mass Spectrometry gamma-ray spectroscopy using ultra-low background germanium detectors at Laboratorio...

10.1088/1748-0221/8/01/t01002 article EN Journal of Instrumentation 2013-01-22

We report the performance of a 10 atm Xenon/trimethylamine time projection chamber (TPC) for detection X-rays (30 keV) and γ-rays (0.511–1.275 MeV) in conjunction with accurate tracking associated electrons. When operated at such high pressure ~1%-admixtures, trimethylamine (TMA) endows Xenon an extremely low electron diffusion (1.3±0.13mm-σ (longitudinal), 0.95±0.20mm-σ (transverse) along 1 m drift) besides forming convenient 'Penning-Fluorescent' mixture. The TPC, that houses 1.1 kg gas...

10.1016/j.nima.2015.08.033 article EN cc-by Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 2015-08-28

We propose a novel detection concept for neutrinoless double-beta decay searches. This is based on Time Projection Chamber (TPC) filled with high-pressure gaseous xenon, and separated-function capabilities calorimetry tracking. Thanks to its excellent energy resolution, together powerful background rejection provided by the distinct topological signature, design discussed in this Letter Of Intent promises be competitive possibly out-perform existing proposals next-generation experiments....

10.48550/arxiv.0907.4054 preprint EN other-oa arXiv (Cornell University) 2009-01-01

In this work we present a systematic study of Micromegas detectors in high pressure gaseous Xenon using trimethylamine (TMA) as quencher gas. Gas gains and energy resolutions for 22.1 keV X-rays are measured pressures between 1 10 bar various relative concentrations TMA from 0.3 % to 15 %. We observe stable operation at all pressures, strongly enhanced gas gain, suggestive Penning-like energy-transfer processes. The effect is it strongest ranging 1.5 3 Operating concentration range, the...

10.1088/1748-0221/8/01/p01012 article EN Journal of Instrumentation 2013-01-23

10.1016/j.nima.2009.06.099 article EN Nuclear Instruments and Methods in Physics Research Section A Accelerators Spectrometers Detectors and Associated Equipment 2009-07-12

The International Axion Observatory (IAXO) is a next generation axion helioscope aiming at sensitivity to the axion-photon coupling of few 10^{-12} GeV^{-1}, i.e. 1-1.5 orders magnitude beyond sensitivities achieved by currently most sensitive helioscope, CERN Solar Telescope (CAST). Crucial factors in improving for IAXO are increase magnetic field volume together with extensive use x-ray focusing optics and low background detectors, innovations already successfully tested CAST....

10.48550/arxiv.1302.3273 preprint EN other-oa arXiv (Cornell University) 2013-01-01

Axion helioscopes aim at the detection of solar axions through their conversion into x-rays in laboratory magnetic fields. The use low background x-ray detectors is an essential component contributing to sensitivity these searches. Here we review recent advances on Micromegas used CERN Solar Telescope (CAST) and proposed for future International Observatory (IAXO). most setups CAST have achieved levels 1.5 × 10−6 keV−1 cm−2 s−1, a factor more than 100 lower ones obtained by first generation...

10.1088/1748-0221/9/01/p01001 article EN cc-by Journal of Instrumentation 2014-01-07
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