F.P. Santos
A5009797007- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Particle Detector Development and Performance
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Nuclear Physics and Applications
- Particle physics theoretical and experimental studies
- Plasma Diagnostics and Applications
- Mass Spectrometry Techniques and Applications
- Astrophysics and Cosmic Phenomena
- Photocathodes and Microchannel Plates
- X-ray Spectroscopy and Fluorescence Analysis
- Spectroscopy and Laser Applications
- Advanced X-ray and CT Imaging
- Electron and X-Ray Spectroscopy Techniques
- Muon and positron interactions and applications
- Quantum, superfluid, helium dynamics
- Analytical Chemistry and Sensors
- Radiation Therapy and Dosimetry
- Radioactivity and Radon Measurements
- Atomic and Molecular Physics
- Digital Radiography and Breast Imaging
- Analytical chemistry methods development
- Radiation Effects in Electronics
- Radioactive Decay and Measurement Techniques
University of Coimbra
2015-2024
LIP - Laboratory of Instrumentation and Experimental Particle Physics
2011-2024
Universitat Politècnica de València
2023
Universidad de Zaragoza
2023
Instituto de Instrumentación para Imagen Molecular
2023
Weizmann Institute of Science
2023
Universidade de Santiago de Compostela
2023
Ben-Gurion University of the Negev
2023
The University of Texas at Austin
2020
Israel Atomic Energy Commission
2020
NEXT-100 is an electroluminescent high-pressure xenon gas time projection chamber that will search for the neutrinoless double beta (0νββ) decay of 136Xe. The detector possesses two features great value 0νββ searches: energy resolution better than 1% FWHM at Q 136Xe and track reconstruction discrimination signal background events. This combination results in excellent sensitivity, as discussed this paper. Material-screening measurements a detailed Monte Carlo simulation predict rate most 4 ×...
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...
A new method to tag the barium daughter in double-beta decay of ^{136}Xe is reported. Using technique single molecule fluorescent imaging (SMFI), individual dication (Ba^{++}) resolution at a transparent scanning surface demonstrated. single-step photobleach confirms ion interpretation. Individual ions are localized with superresolution (∼2 nm), and detected statistical significance 12.9σ over backgrounds. This lays foundation for potentially background-free neutrinoless technology, based on...
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.
The NEXT experiment aims to observe the neutrinoless double beta decay of 136Xe in a high-pressure xenon gas TPC using electroluminescence (EL) amplify signal from ionization. One main advantages this technology is possibility reconstruct topology events with energies close Q ββ . This paper presents first demonstration that provides extra handles reject background data obtained NEXT-DEMO prototype. Single electrons resulting interactions 22Na 1275 keV gammas and electronpositron pairs...
A bstract The Neutrino Experiment with a Xenon TPC (NEXT) searches for the neutrinoless double-beta (0 νββ ) decay of 136 Xe using high-pressure xenon gas TPCs electroluminescent amplification. scaled-up version this technology about 1 tonne enriched could reach in less than 5 years operation sensitivity to half-life 0 better 10 27 years, improving current limits by at least one order magnitude. This prediction is based on well-understood background model dominated radiogenic sources....
We investigate the potential of using deep learning techniques to reject background events in searches for neutrinoless double beta decay with high pressure xenon time projection chambers capable detailed track reconstruction. The differences topological signatures and signal can be learned by neural networks via training over many thousands events. These then used classify further as or background, providing an additional rejection factor at acceptable loss efficiency. trained this study...
Conceived to host 5 kg of xenon at a pressure 15 bar in the fiducial volume, NEXT- White (NEW) apparatus is currently largest high gas TPC using electroluminescent amplification world. It also 1:2 scale model NEXT-100 detector scheduled start searching for $\beta\beta 0\nu$ decays 136Xe 2019. Both detectors measure energy event plane photomultipliers located behind transparent cathode. They can reconstruct trajectories charged tracks dense with help silicon anode. A sophisticated system,...
A detailed Monte Carlo simulation model has been developed to study the absorption of soft x rays and subsequent behavior resulting electrons under influence an applied electric field in gaseous xenon. All relevant physical processes are included from initial photoionization through decay residual ion scattering drift interactions with background gas. Details provided for cross sections rates employed as well criteria used terminate simulation, depending on information or results required....
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,...
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 (<1%), low background con- tamination (1E-4 counts/(keV \bullet kg y)) large target mass. In addition, it needs to...
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....
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...
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...
The NEXT-White (NEW) detector is currently the largest radio-pure high-pressure xenon gas time projection chamber with electroluminescent readout in world. It has been operating at Laboratorio Subterr'aneo de Canfranc (LSC) since October 2016. This paper describes calibrations performed using 83mKr decays during a long run taken from March to November 2017 (Run II). Krypton are used correct for finite drift-electron lifetime as well dependence of measured energy on event transverse position...
We report a measurement of the half-life 136Xe two-neutrino double-β decay performed with novel direct-background-subtraction technique. The analysis relies on data collected NEXT-White detector operated 136Xe-enriched and 136Xe-depleted xenon, as well topology double-electron tracks. With fiducial mass only 3.5 kg Xe, 2.34+0.80−0.46(stat)+0.30−0.17(sys)×1021yr is derived from background-subtracted energy spectrum. presented technique demonstrates feasibility unique...
The paper presents a set of electroluminescence and other transport parameters calculated using detailed three-dimensional Monte Carlo method, which simulates the drift electrons in gaseous xenon (p=760 Torr, T=293 K) under reduced electric fields E/N 3 to 16 Td range (E/P approximately 1 5 V cm-1 Torr-1), is region for secondary scintillation production filled gas proportional counters. Results are compared with available experimental or theoretical data as well an earlier one-dimensional...
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....
The Neutrino Experiment with a Xenon Time-Projection Chamber (NEXT) is intended to investigate the neutrinoless double beta decay of 136Xe, which requires severe suppression potential backgrounds; therefore, an extensive screening and selection process underway control radiopurity levels materials be used in experimental set-up NEXT. detector design combines measurement topological signature event for background discrimination energy resolution optimization. Separate tracking readout planes...
A bstract Excellent energy resolution is one of the primary advantages electroluminescent high-pressure xenon TPCs. These detectors are promising tools in searching for rare physics events, such as neutrinoless double-beta decay ( ββ 0 ν ), which require precise measurements. Using NEXT-White detector, developed by NEXT (Neutrino Experiment with a Xenon TPC) collaboration, we show first time that an 1% FWHM can be achieved at 2.6 MeV, establishing present technology best all searches.
We present evidence of non-excimer-based secondary scintillation in gaseous xenon, obtained using both the NEXT-White TPC and a dedicated setup. Detailed comparison with first-principle calculations allows us to assign this mechanism neutral bremsstrahlung (NBrS), process that has been postulated exist xenon largely overlooked. For photon emission below 1000 nm, NBrS yield increases from about 10$^{-2}$ photon/e$^{-}$ cm$^{-1}$ bar$^{-1}$ at pressure-reduced electric field values 50 V above...
Distributions of the number primary electrons produced per incident mono-energetic x-rays in 1- to 41-keV energy range, which includes xenon L- and K-absorption edges, were simulated gas detectors with Monte Carlo technique. These full-energy absorption distributions are calculated as frequency plots x-ray photon. The simulation de-excitation residual ions, followed by development electron cloud. discontinuities observed Fano factor, w-value, linearity resolution reflect Xe photoionization...
Abstract A review on gas proportional scintillation counters (GPSCs) is presented. Recent achievements towards the portability of simple, inexpensive and compact GPSCs are discussed. Compensation solid angle effects with curved grid technique can be used to produce non‐focused medium‐sized radiation windows, at least up 80% photosensor active diameter, without degradation detector performance. Low power‐consuming vacuum UV photosensors that operate in direct contact gas, as an alternative...
If neutrinos are their own antiparticles the otherwise-forbidden nuclear reaction known as neutrinoless double beta decay can occur. The very long lifetime expected for these exceptional events makes its detection a daunting task. In order to conduct an almost background-free experiment, NEXT collaboration is investigating novel synthetic molecular sensors that may capture Ba dication produced in of certain Xe isotopes high-pressure gas experiment. use such detectors immobilized on surfaces...