D. Fairbank
A5079060202- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Particle physics theoretical and experimental studies
- Quantum, superfluid, helium dynamics
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- Advanced Frequency and Time Standards
- Scientific Measurement and Uncertainty Evaluation
- Atmospheric Ozone and Climate
- Nuclear physics research studies
- Spectroscopy and Laser Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Mass Spectrometry Techniques and Applications
- Radioactive Decay and Measurement Techniques
- CCD and CMOS Imaging Sensors
- Photocathodes and Microchannel Plates
Colorado State University
2018-2024
Laurentian University
2021
University of Massachusetts Amherst
2019
A search for neutrinoless double-beta decay ($0\nu\beta\beta$) in $^{136}$Xe is performed with the full EXO-200 dataset using a deep neural network to discriminate between $0\nu\beta\beta$ and background events. Relative previous analyses, signal detection efficiency has been raised from 80.8% 96.4$\pm$3.0% energy resolution of detector at Q-value improved $\sigma/E=1.23\%$ $1.15\pm0.02\%$ upgraded detector. Accounting new data, median 90% confidence level half-life sensitivity this analysis...
Abstract The nEXO neutrinoless double beta (0 νββ ) decay experiment is designed to use a time projection chamber and 5000 kg of isotopically enriched liquid xenon search for the in 136 Xe. Progress detector design, paired with higher fidelity its simulation an advanced data analysis, based on one used final results EXO-200, produce sensitivity prediction that exceeds half-life 10 28 years. Specifically, improvements have been made understanding production scintillation photons charge as...
The projected performance and detector configuration of nEXO are described in this pre-Conceptual Design Report (pCDR). is a tonne-scale neutrinoless double beta ($0νββ$) decay search $^{136}$Xe, based on the ultra-low background liquid xenon technology validated by EXO-200. With $\simeq$ 5000 kg enriched to 90% isotope 136, has half-life sensitivity approximately $10^{28}$ years. This represents an improvement about two orders magnitude with respect current results. Based experience gained...
Future tonne-scale liquefied noble gas detectors depend on efficient light detection in the VUV range. In past years Silicon Photomultipliers (SiPMs) have emerged as a valid alternative to standard photomultiplier tubes or large area avalanche photodiodes. The next generation double beta decay experiment, nEXO, with 5 tonne liquid xenon time projection chamber, will use SiPMs for detecting $178\,\text{nm}$ scintillation light, order achieve an energy resolution of $\sigma / Q_{\beta\beta} =...
Liquid xenon (LXe) is employed in a number of current and future detectors for rare event searches. We use the EXO-200 experimental data to measure absolute scintillation ionization yields generated by $\ensuremath{\gamma}$ interactions from $^{228}\mathrm{Th}$ (2615 keV), $^{226}\mathrm{Ra}$ (1764 $^{60}\mathrm{Co}$ (1332 keV 1173 keV) calibration sources, over range electric fields. The $W$ value that defines recombination-independent energy scale measured be...
We present a search for electron-recoil signatures from the charged-current absorption of fermionic dark matter using EXO-200 detector. report an average background rate $6.8\ifmmode\times\else\texttimes\fi{}{10}^{4}\text{ }\text{ }\mathrm{cts}\text{ }{\mathrm{kg}}^{\ensuremath{-}1}\text{ }{\mathrm{yr}}^{\ensuremath{-}1}\text{ }{\mathrm{keV}}^{\ensuremath{-}1}$ above 4 MeV and find no statistically significant excess over our projection. Using total $^{136}\mathrm{Xe}$ exposure 234.1 kg yr,...
A search for Majoron-emitting modes of the neutrinoless double-beta decay $^{136}$Xe is performed with full EXO-200 dataset. This dataset consists a total exposure 234.1 kg$\cdot$yr, and includes data detector upgrades that have improved energy threshold relative to previous searches. lower limit T$_{1/2}^{\rm{^{136}Xe}}>$4.3$\cdot$10$^{24}$ yr at 90\% C.L. on half-life spectral index $n=1$ Majoron was obtained, factor 3.6 more stringent than from EXO-200, corresponding constraint...
Understanding reflective properties of materials and photodetection efficiency (PDE) photodetectors is important for optimizing energy resolution sensitivity the next generation neutrinoless double beta decay, direct detection dark matter, neutrino oscillation experiments that will use noble liquid gases, such as nEXO, DARWIN, DarkSide-20k, DUNE . Little information currently available about reflectivity PDE in because measurements are difficult to conduct a cryogenic environment at short...
Characterization of the vacuum ultraviolet (VUV) reflectance silicon photomultipliers (SiPMs) is important for large-scale SiPM-based photodetector systems. We report angular dependence specular in a SiPMs manufactured by Fondazionc Bruno Kessler (FBK) and Hamamatsu Photonics K.K. (HPK) over wavelengths ranging from 120 nm to 280 nm. Refractive index extinction coefficient thin silicon-dioxide film deposited on surface FBK are derived data wafer with same oxide as SiPMs. The diffuse also...
The EXO-200 experiment searched for neutrinoless double-beta decay of $^{136}$Xe with a single-phase liquid xenon detector. It used an active mass 110 kg 80.6%-enriched in ultra-low background time projection chamber ionization and scintillation detection readout. This paper describes the design performance various support systems necessary detector operation, including cryogenics, handling, controls. Novel features system were driven by need to protect thin-walled containing xenon, achieve...
Neutrinoless double beta decay is one of the most sensitive probes for new physics beyond Standard Model particle physics. One isotopes under investigation <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mmultiscripts><a:mi>Xe</a:mi><a:mprescripts/><a:none/><a:mn>136</a:mn></a:mmultiscripts></a:math>, which would into <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mmultiscripts><b:mi>Ba</b:mi><b:mprescripts/><b:none/><b:mn>136</b:mn></b:mmultiscripts></b:math>. Detecting...
Generative Adversarial Networks trained on samples of simulated or actual events have been proposed as a way generating large datasets at reduced computational cost. In this work, novel approach to perform the simulation photodetector signals from time projection chamber EXO-200 experiment is demonstrated. The method based Wasserstein Network - deep learning technique allowing for implicit non-parametric estimation population distribution given set objects. Our network real calibration data...
nEXO is a proposed experiment to search for the neutrino-less double beta decay (0νββ) of 136Xe in tonne-scale liquid xenon time projection chamber (TPC) . The TPC will be equipped with charge collection tiles form anode. In this work, reconstruction performance anode design studied dedicated simulation package. A multi-variate method and deep neural network are developed distinguish simulated 0νββ signals from backgrounds arising trace levels natural radioactivity detector materials. These...
We report on a comparison between the theoretically predicted and experimentally measured spectra of first-forbidden nonunique β-decay transition 137Xe(7/2−)→137Cs(7/2+). The experimental data were acquired by EXO-200 experiment during deployment an AmBe neutron source. ultralow background environment EXO-200, together with dedicated source analysis procedures, allowed for collection pure sample decays, estimated signal to ratio more than 99 1 in energy range from 1075 4175 keV. In addition...
Silicon photomultipliers are regarded as a very promising technology for next-generation, cutting-edge detectors low-background experiments in particle physics. This work presents systematic reflectivity studies of Photomultipliers (SiPM) and other samples liquid xenon at vacuum ultraviolet (VUV) wavelengths. A dedicated setup the University Münster has been used that allows to acquire angle-resolved reflection measurements various immersed with 0.45° angular resolution. Four investigated...
The search for neutrinoless double beta decay probes the fundamental properties of neutrinos, including whether or not neutrino and antineutrino are distinct. Double detectors large expensive, so background reduction is essential extracting highest sensitivity. identification, 'tagging', $^{136}$Ba daughter atom from $^{136}$Xe provides a technique eliminating backgrounds in nEXO experiment. tagging scheme studied this work utilizes cryogenic probe to trap barium solid xenon, where tagged...
We report on the performance of silicon photomultiplier (SiPM) light sensors operating in electric field strength up to 30 kV/cm and at a temperature 149 K, relative their absence an external field. The SiPM devices used this study show stable gain, photon detection efficiency, rates correlated pulses, when exposed fields, within estimated uncertainties. No visible damage surface was caused by exposure.
Abstract A new search for two-neutrino double-beta (2 νββ ) decay of 136 Xe to the excited state Ba is performed with full EXO-200 dataset. deep learning-based convolutional neural network used discriminate signal from background events. Signal detection efficiency increased relative previous searches by more than a factor two. With addition Phase II dataset taken an upgraded detector, median 90% confidence level half-life sensitivity 2 yr using total exposure 234.1 kg yr. No statistically...
Optical frequencies of the $D$ line transitions in $^{9}{\mathrm{Be}}^{+}$ were measured with a relative uncertainty $\mathrm{\ensuremath{\Delta}}\ensuremath{\nu}/\ensuremath{\nu}=5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}11}$. The results represent highest accuracy achieved on broad electric dipole-allowed (E1) transition trapped ion experiment to date, enabled part by detailed consideration photon recoil and quantum interference. Measurements made single laser-cooled stored...
Hyperfine splittings of the $^{2}P_{3/2}$ manifold in $^{9}\mathrm{Be}^{+}$ were measured directly using a single laser-cooled ion stored radiofrequency Paul trap. As hyperfine structure is unresolved beneath natural linewidth transition, manipulation initial state, polarization, and final-state populations was used to preferentially detect scattering events through specific intermediate excited states. While quantum interference effects typically complicate modeling measurement lineshapes,...