E. W. Hoppe
A5058651085- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Astrophysics and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Radioactive contamination and transfer
- Nuclear Physics and Applications
- Radioactivity and Radon Measurements
- Radioactive element chemistry and processing
- Muon and positron interactions and applications
- Analytical chemistry methods development
- Nuclear and radioactivity studies
- Cosmology and Gravitation Theories
- Graphite, nuclear technology, radiation studies
- Radioactive Decay and Measurement Techniques
- Particle accelerators and beam dynamics
- Mass Spectrometry Techniques and Applications
- Scientific Research and Discoveries
- Nuclear physics research studies
- Radiation Therapy and Dosimetry
- Analytical Chemistry and Chromatography
- Advanced Chemical Sensor Technologies
- Quantum, superfluid, helium dynamics
Pacific Northwest National Laboratory
2015-2024
Campbell Collaboration
2022
Richland College
2020
Battelle
2005-2019
Istituto Nazionale di Fisica Nucleare, Sezione di Roma I
2019
Universitat de València
2017
Institute for Basic Science
2017
Royal Holloway University of London
2017
Strategic Insight (United States)
2017
Moscow Engineering Physics Institute
2017
New results are reported from the operation of PICO-60 dark matter detector, a bubble chamber filled with 52 kg C_{3}F_{8} located in SNOLAB underground laboratory. As previous PICO chambers, exhibits excellent electron recoil and alpha decay rejection, observed multiple-scattering neutron rate indicates single-scatter background less than one event per month. A blind analysis an efficiency-corrected 1167-kg day exposure at 3.3-keV thermodynamic threshold reveals no single-scattering nuclear...
SuperCDMS SNOLAB will be a next-generation experiment aimed at directly detecting low-mass (< 10 GeV/c$^2$) particles that may constitute dark matter by using cryogenic detectors of two types (HV and iZIP) target materials (germanium silicon). The is being designed with an initial sensitivity to nuclear recoil cross sections ~ 1 x 10$^{-43}$ cm$^2$ for particle mass GeV/c$^2$, capacity continue exploration both smaller masses better sensitivities. phonon the HV sufficient detect recoils from...
We present the first limits on inelastic electron-scattering dark matter and photon absorption using a prototype SuperCDMS detector having charge resolution of 0.1 electron-hole pairs (CDMS HVeV, 0.93 g CDMS high-voltage device). These electron-recoil significantly improve experimental constraints particles with masses as low 1 MeV/c^{2}. demonstrate sensitivity to photons competitive other leading approaches but substantially less exposure (0.49 d). results scientific potential...
Final results are reported from operation of the PICO-60 C$_3$F$_8$ dark matter detector, a bubble chamber filled with 52 kg located in SNOLAB underground laboratory. The was operated at thermodynamic thresholds as low 1.2 keV without loss stability. A new blind 1404-kg-day exposure 2.45 threshold acquired approximately same expected total background rate previous 1167-kg-day 3.3 keV. This increased is enabled part by optical tracking analysis to better identify events near detector walls,...
The M ajorana D emonstrator will search for the neutrinoless double-beta<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mo stretchy="false">(</mml:mo><mml:mi>β</mml:mi><mml:mi>β</mml:mi><mml:mfenced separators="|"><mml:mrow><mml:mn fontstyle="italic">0</mml:mn><mml:mi>ν</mml:mi></mml:mrow></mml:mfenced><mml:mo stretchy="false">)</mml:mo></mml:math>decay of isotope<mml:math id="M2"/>Ge with a mixed array enriched and natural germanium detectors. observation this rare...
The SuperCDMS experiment is designed to directly detect weakly interacting massive particles (WIMPs) that may constitute the dark matter in our Galaxy. During its operation at Soudan Underground Laboratory, germanium detectors were run CDMSlite mode gather data sets with sensitivity specifically for WIMPs masses ${<}$10 GeV/$c^2$. In this mode, a higher detector-bias voltage applied amplify phonon signals produced by drifting charges. This paper presents studies of experimental noise and...
The Majorana Collaboration is operating an array of high purity Ge detectors to search for neutrinoless double-β decay in ^{76}Ge. Demonstrator comprises 44.1 kg (29.7 enriched ^{76}Ge) split between two modules contained a low background shield at the Sanford Underground Research Facility Lead, South Dakota. Here we present results from data taken during construction, commissioning, and start full operations. We achieve unprecedented energy resolution 2.5 keV FWHM Q_{ββ} very with no...
This article presents an analysis and the resulting limits on light dark matter inelastically scattering off of electrons, photon axion-like particle absorption, using a second-generation SuperCDMS high-voltage eV-resolution detector. The 0.93 gram Si detector achieved 3 eV phonon energy resolution; for bias 100 V, this corresponds to charge resolution 3% single electron-hole pair. spectrum is reported from blind with 1.2 gram-days exposure acquired in above-ground laboratory. With carrier...
We present limits on spin-independent dark matter-nucleon interactions using a 10.6 g Si athermal phonon detector with baseline energy resolution of ${\ensuremath{\sigma}}_{E}=3.86\ifmmode\pm\else\textpm\fi{}0.04(\mathrm{stat}{)}_{\ensuremath{-}0.00}^{+0.19}(\mathrm{syst})\text{ }\text{ }\mathrm{eV}$. This exclusion analysis sets the most stringent scattering cross-section achieved by cryogenic for matter particle masses from 93 to $140\text{ }\mathrm{MeV}/{c}^{2}$, raw exposure 9.9 d...
The Majorana Demonstrator searched for neutrinoless double-β decay (0νββ) of ^{76}Ge using modular arrays high-purity Ge detectors operated in vacuum cryostats a low-background shield. with up to 40.4 kg (27.2 enriched ∼88% ^{76}Ge). From these measurements, the has accumulated 64.5 yr active exposure. With world-leading energy resolution 2.52 keV FWHM at 2039 Q_{ββ} (0.12%), we set half-life limit 0νββ T_{1/2}>8.3×10^{25} (90% C.L.). This provides range upper limits on m_{ββ} (113-269) meV...
This article presents constraints on dark-matter-electron interactions obtained from the first underground data-taking campaign with multiple SuperCDMS HVeV detectors operated in same housing. An exposure of <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mn>7.63</a:mn><a:mtext> </a:mtext><a:mtext> </a:mtext><a:mi mathvariant="normal">g</a:mi><a:mtext>−</a:mtext><a:mi>days</a:mi></a:mrow></a:math> is used to set upper limits scattering cross section for dark...
This paper introduces the neutrinoless double-beta decay (the rarest nuclear weak process) and describes status of research for this transition, both from point view theoretical physics in terms present future experimental scenarios. Implications phenomenon on crucial aspects particle are briefly discussed. The calculations matrix elements case mass mechanisms reviewed, a range these quantities is proposed most appealing candidates. After introducing general concepts—such as choice best...
We report the result of a blinded search for Weakly Interacting Massive Particles (WIMPs) using majority SuperCDMS Soudan dataset. With an exposure 1690 kg days, single candidate event is observed, consistent with expected backgrounds. This analysis (combined previous Ge results) sets upper limit on spin-independent WIMP--nucleon cross section $1.4 \times 10^{-44}$ ($1.0 10^{-44}$) cm$^2$ at 46 GeV/$c^2$. These results set strongest limits WIMP--germanium-nucleus interactions masses $>$12
As part of the Snowmass process, Cosmic Frontier WIMP Direct Detection subgroup (CF1) has drawn on input from and broader Particle Physics community to produce this document. The charge CF1 was (a) summarize current status projected sensitivity direct detection experiments worldwide, (b) motivate dark matter searches over a broad parameter space by examining spectrum models, (c) establish consensus type experimental program required explore that space, (d) identify common infrastructure...
The PICO collaboration reports results obtained by PICO-2L Run-2 after carefully controlling for particulate contamination. data clearly indicates that previously observed anomalies were due to contamination in the bubble chamber fluid. These observations set new bounds on spin-dependent scattering of dark matter, and help pave way larger scale experiments.
The Cryogenic Dark Matter Search low ionization threshold experiment (CDMSlite) searches for interactions between dark matter particles and germanium nuclei in cryogenic detectors. has achieved a energy with improved sensitivity to low-mass (<10 GeV/c$^2$) particles. We present an analysis of the final CDMSlite data set, taken different detector than was used two previous sets. This includes "salting" method protect against bias, noise discrimination, background modeling, use profile...
The Majorana Collaboration is operating an array of high-purity Ge detectors to search for the neutrinoless double-$\ensuremath{\beta}$ decay $^{76}\mathrm{Ge}$. Demonstrator consists 44.1 kg (29.7 enriched 88% in $^{76}\mathrm{Ge}$) split between two modules constructed from ultraclean materials. Both are contained a low-background shield at Sanford Underground Research Facility Lead, South Dakota. We present updated results on $^{76}\mathrm{Ge}$ with $26.0\ifmmode\pm\else\textpm\fi{}0.5$...
The next-generation Enriched Xenon Observatory (nEXO) is a proposed experiment to search for neutrinoless double beta ($0\nu\beta\beta$) decay in $^{136}$Xe with target half-life sensitivity of approximately $10^{28}$ years using $5\times10^3$ kg isotopically enriched liquid-xenon time projection chamber. This improvement two orders magnitude over current limits obtained by significant increase the mass, monolithic and homogeneous configuration active medium, multi-parameter measurements...
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...
We present constraints on the existence of weakly interacting massive particles (WIMPs) from an 11 kg-day target exposure DAMIC experiment at SNOLAB underground laboratory. The observed energy spectrum and spatial distribution ionization events with electron-equivalent energies $>$200 eV$_{\rm ee}$ in CCDs are consistent backgrounds natural radioactivity. An excess is above analysis threshold 50 ee}$. While origin this low-energy requires further investigation, our data exclude...