C.E. Aalseth
A5077060968- Radiation Detection and Scintillator Technologies
- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Nuclear Physics and Applications
- Particle Detector Development and Performance
- Radioactivity and Radon Measurements
- Dark Matter and Cosmic Phenomena
- Radioactive contamination and transfer
- Astrophysics and Cosmic Phenomena
- Radioactive Decay and Measurement Techniques
- Atomic and Subatomic Physics Research
- Superconducting and THz Device Technology
- Scientific Research and Discoveries
- Groundwater and Isotope Geochemistry
- Cosmology and Gravitation Theories
- Advanced NMR Techniques and Applications
- Muon and positron interactions and applications
- Nuclear and radioactivity studies
- Groundwater flow and contamination studies
- Molten salt chemistry and electrochemical processes
- Advanced Semiconductor Detectors and Materials
- Isotope Analysis in Ecology
- Nuclear physics research studies
- Radioactive element chemistry and processing
- Geology and Paleoclimatology Research
Pacific Northwest National Laboratory
2014-2025
Battelle
2005-2025
Office of Scientific and Technical Information
2007-2012
United States Department of Commerce
2007-2012
National Technical Information Service
2007-2012
University of South Carolina
1996-2011
We report on several features in the energy spectrum from an ultralow-noise germanium detector operated deep underground. By implementing a new technique able to reject surface events, number of cosmogenic peaks can be observed for first time. discuss irreducible excess bulklike events below 3 keV ionization energy. These could caused by unknown backgrounds, but also dark matter interactions consistent with DAMA/LIBRA. It is not yet possible determine their origin. Improved constraints are...
Fifteen months of cumulative CoGeNT data are examined for indications an annual modulation, a predicted signature weakly interacting massive particle (WIMP) interactions. Presently available support the presence modulated component unknown origin, with parameters prima facie compatible galactic halo composed light-mass WIMPs. Unoptimized estimators yield statistical significance modulation ∼2.8σ, limited by short exposure.
CoGeNT employs p-type point-contact (PPC) germanium detectors to search for Weakly Interacting Massive Particles (WIMPs). By virtue of its low energy threshold and ability reject surface backgrounds, this type device allows an emphasis on low-mass dark matter candidates (wimp mass about 10 GeV/c2). We report the characteristics PPC detector presently taking data at Soudan Underground Laboratory, elaborating aspects shielding, acquisition, instrumental stability, analysis, background...
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...
The International Germanium Experiment (IGEX) has analyzed 117 mol yr of 76Ge data from its isotopically enriched (86% 76Ge) germanium detectors. Applying pulse-shape discrimination to the more recent data, lower bound on half-life for neutrinoless double-beta decay is T1/2(0ν)>1.57×1025yr (90% C.L.). This corresponds an upper in Majorana neutrino mass parameter, ⟨mν⟩, between 0.33 and 1.35 eV, depending choice theoretical nuclear matrix elements used analysis.Received 29 October...
A claim for evidence of dark matter interactions in the DAMA experiment has been recently reinforced. We employ a new type germanium detector to conclusively rule out standard isothermal galactic halo weakly interacting massive particles as explanation annual modulation effect leading claim. Bounds are similarly imposed on suggestion that pseudoscalars might lead effect. describe sensitivity light achievable with our device, particular, next-to-minimal supersymmetric model candidates.
We comment on the recent claim for experimental observation of neutrinoless double-beta decay. discuss several limitations in analysis provided that paper and conclude there is no basis presented claim.
Weakly Interacting Massive Particles (WIMPs) are well-established dark matter candidates. WIMP interactions with sensitive detectors expected to display a characteristic annual modulation in rate. We release dataset spanning 3.4 years of operation from low-background germanium detector, designed search for this signature. A previously reported persists, concentrated region the energy spectrum populated by an exponential excess unknown origin. Its phase and period agree phenomenological...
The International Germanium Experiment (IGEX) has six HPGe detectors, isotopically enriched to 86% in ${}^{76}\mathrm{Ge},$ containing approximately 90 active moles of ${}^{76}\mathrm{Ge}.$ Three detectors 2 kg each operate the Canfranc Underground Laboratory (Spain) with pulse-shape analysis electronics. One detector (\ensuremath{\sim}0.7 volume) been operating Baksan Low-Background for several years, and two additional similar will Baksan. A maximum likelihood 74.84 mole years data yields...
CoGeNT has taken data for over 3 years, with 1136 live days of accumulated as April 23, 2013. We report on the results a maximum likelihood analysis to extract any possible dark matter signal present in collected data. The extraction uses 2-dimensional probability density functions (PDFs) characterize anticipated variations interaction rates given observable nuclear recoil energies during differing periods Earth's annual orbit around Sun. Cosmogenic and primordial radioactivity backgrounds...
One IGEX 76Ge double-beta decay detector is currently operating in the Canfranc Underground Laboratory a search for dark matter WIMPs, through Ge nuclear recoil produced by WIMP elastic scattering. A new exclusion plot, σ(m), has been derived WIMP-nucleon spin-independent interactions. To obtain this result, 40 days of data from (energy threshold Ethr∼4 keV), recently collected, have analyzed. These improve limits all other ionization germanium detectors mass region 20 to 200 GeV, where...
Pacific Northwest National Laboratory recently commissioned a new shallow underground laboratory, located at depth of approximately 30 meters-water-equivalent. This addition to the small class radiation measurement laboratories modest depths houses latest generation custom-made, high-efficiency, low-background gamma-ray spectrometers and gas proportional counters. paper describes unique capabilities present in laboratory; these include large-scale ultra-pure materials production suite...
Study of the neutrinoless double beta decay and searches for manifestation neutrino mass in ordinary are main sources information about absolute scale, only practical source charge conjugation properties neutrinos. Thus, these studies have a unique role plans better understanding whole fast expanding field physics.
This paper is a response to the preceding Comment by Klapdor-Kleingrothaus, Dietz, and Krivosheina. The criticisms are confronted, questions raised answered. We demonstrate that lower limit quoted IGEX, , correct there was no ``arithmetical error'' as claimed in ``Critical View'' article.