Showing 113 results for Author: David C. Radford
Jan, 2024
Journal
The Majorana Demonstrator was a search for neutrinoless double-beta decay (0νββ) in the 76Ge isotope. It was staged at the 4850-foot level of the Sanford Underground Research Facility (SURF) in Lead, SD. The experiment consisted of 58 germanium detectors housed in a low background shield and was calibrated once per week by deploying a 228Th line source for 1 to 2 hours. Th…
Dec, 2023
Journal
The Majorana Demonstrator is searching for neutrinoless double-beta decay (0νββ) in 76Ge using arrays of point-contact germanium detectors operating at the Sanford Underground Research Facility. Background results in the 0νββ region of interest from data taken during construction, commissioning, and the start of full operations have been recently published. A pulse shape a…
Dec, 2023
Journal
We report on the preparation of and calibration measurements with a 83mKr source for the CENNS-10 liquid argon detector. 83mKr atoms generated in the decay of a 83Rb source were introduced into the detector via injection into the Ar circulation loop. Scintillation light arising from the 9.4 keV and 32.1 keV conversion electrons in the decay of 83mKr in the detector volume…
Dec, 2023
Journal
The majorana demonstrator is a neutrinoless double-β decay search consisting of a low-background modular array of high-purity germanium detectors, ∼2/3 of which are enriched to 88% in 76Ge. The experiment is also searching for double-beta decay of 76Ge to excited states (e.s.) in 76Se. 76Ge can decay into three daughter states of 76Se, with clear event signatures consistin…
Dec, 2023
Journal
P-type point contact (PPC) HPGe detectors are a leading technology for rare event searches due to their excellent energy resolution, low thresholds, and multi-site event rejection capabilities. We have characterized a PPC detector’s response to α particles incident on the sensitive passivated and p+ surfaces, a previously poorly-understood source of background. The detecto…
Dec, 2023
Journal
The Majorana Demonstrator comprises two arrays of high-purity germanium detectors constructed to search for neutrinoless double-beta decay in 76Ge and other physics beyond the Standard Model. Its readout electronics were designed to have low electronic noise, and radioactive backgrounds were minimized by using low-mass components and low-radioactivity materials near the de…
Dec, 2023
Journal
Neutron captures and delayed decays of reaction products are common sources of backgrounds in ultrarare event searches. In this work, we studied 13C(α,n)16O reactions induced by α particles emitted within the calibration sources of the Majorana Demonstrator. These sources are thorium-based calibration standards enclosed in carbon-rich materials. The reaction rate was estim…
Dec, 2023
Journal
LEGEND, the Large Enriched Germanium Experiment for Neutrinoless ββ Decay, is a ton-scale experimental program to search for neutrinoless double beta (0νββ) decay in the isotope 76Ge with an unprecedented sensitivity. Building on the success of the low-background 76Ge-based GERDA and textsc{Majorana Demonstrator} experiments, the LEGEND collaboration is targeting a signal…
Dec, 2023
Journal
Sterile neutrinos are a minimal extension of the standard model of particle physics. A promising model-independent way to search for sterile neutrinos is via high-precision β-spectroscopy. The Karlsruhe tritium neutrino (KATRIN) experiment, equipped with a novel multi-pixel silicon drift detector focal plane array and read-out system, named the TRISTAN detector, has the po…
Dec, 2023
Journal
The SIGMA project aims to develop a p-type segmented inverted coaxial point contact germanium detector for gamma-ray tracking and imaging. The performance of the first prototype of this type of detector is reported. The measurements performed verified the size and shape of the crystal and determined the location of the complex active volumes of the detector segments. The l…
Nov, 2023
Journal
Coherent elastic neutrino-nucleus scattering (CEvNS) is calculated to be the dominant neutrino scattering channel for neutrinos of energy Eν
Nov, 2023
Journal
The COHERENT experiment is well poised to test sub-GeV dark matter models using detectors sensitive to coherent elastic neutrino-nucleus scattering (CEvNS) in the Ï€+ decay-at-rest (Ï€-DAR) neutrino beam produced by the Spallation Neutron Source. We show a planned 750-kg single-phase liquid argon scintillation detector would place leading limits on scalar light dark matter m…