9 research outputs found
Dark Matter Search
The SuperCDMS SNOLAB is the first low-mass dark matter detector in the cryogenics system at SLAC. It is designed to be sensitive to detect dark matter down to 300 MeV in mass and resolve individual electrons-hole pairs from low energy scattering events in high purity Ge and Si crystals. The purpose is to simulate electrostatic fields within the detector medium and run detailed particle physics simulations to attempt to match simulation to observed detector response for the first time with detectors of this size using the GEANT4 simulation package, and SuperCDMS solid-state simulations. The simulation code is written in C++, my objective was to modify the probability of the electrons inter-valley scattering in the crystal. The previous function’s input was an electric field voltage the problem with this method was that it did not provide any underlining physics of the electron within the crystal. However, we added a physical model for the inter-valley scattering that instead intakes the energy of the electron and produces the probability of a particular electron’s propagation within the crystal. The results are still in progress and will be discussed in the poster. In conclusion, we hope that this new method will produce the same graphs as the previous method and in addition provides the underlying physics of the electron inside the crystal
First Results from a Broadband Search for Dark Photon Dark Matter in the to eV range with a coaxial dish antenna
We present first results from a dark photon dark matter search in the mass
range from 44 to 52 () using a
room-temperature dish antenna setup called GigaBREAD. Dark photon dark matter
converts to ordinary photons on a cylindrical metallic emission surface with
area and is focused by a novel parabolic reflector onto a horn
antenna. Signals are read out with a low-noise receiver system. A first data
taking run with 24 days of data does not show evidence for dark photon dark
matter in this mass range, excluding dark photon - photon mixing parameters
in this range at 90% confidence level. This surpasses
existing constraints by about two orders of magnitude and is the most stringent
bound on dark photons in this range below 49 eV.Comment: 7 pages, 4 figure
A Stress Induced Source of Phonon Bursts and Quasiparticle Poisoning
The performance of superconducting qubits is degraded by a poorly
characterized set of energy sources breaking the Cooper pairs responsible for
superconductivity, creating a condition often called "quasiparticle poisoning."
Recently, a superconductor with one of the lowest average quasiparticle
densities ever measured exhibited quasiparticles primarily produced in bursts
which decreased in rate with time after cooldown. Similarly, several cryogenic
calorimeters used to search for dark matter have also observed an unknown
source of low-energy phonon bursts that decrease in rate with time after
cooldown. Here, we show that a silicon crystal glued to its holder exhibits a
rate of low-energy phonon events that is more than two orders of magnitude
larger than in a functionally identical crystal suspended from its holder in a
low-stress state. The excess phonon event rate in the glued crystal decreases
with time since cooldown, consistent with a source of phonon bursts which
contributes to quasiparticle poisoning in quantum circuits and the low-energy
events observed in cryogenic calorimeters. We argue that relaxation of
thermally induced stress between the glue and crystal is the source of these
events, and conclude that stress relaxation contributes to quasiparticle
poisoning in superconducting qubits and the athermal phonon background in a
broad class of rare-event searches.Comment: 13 pages, 6 figures. W. A. Page and R. K. Romani contributed equally
to this work. Correspondence should be addressed to R. K. Roman
Dark sectors 2016 Workshop: community report
This report, based on the Dark Sectors workshop at SLAC in April 2016,
summarizes the scientific importance of searches for dark sector dark matter
and forces at masses beneath the weak-scale, the status of this broad
international field, the important milestones motivating future exploration,
and promising experimental opportunities to reach these milestones over the
next 5-10 years
Recommended from our members
A Stress Induced Source of Phonon Bursts and Quasiparticle Poisoning
The performance of superconducting qubits is degraded by a poorly
characterized set of energy sources breaking the Cooper pairs responsible for
superconductivity, creating a condition often called "quasiparticle poisoning."
Recently, a superconductor with one of the lowest average quasiparticle
densities ever measured exhibited quasiparticles primarily produced in bursts
which decreased in rate with time after cooldown. Similarly, several cryogenic
calorimeters used to search for dark matter have also observed an unknown
source of low-energy phonon bursts that decrease in rate with time after
cooldown. Here, we show that a silicon crystal glued to its holder exhibits a
rate of low-energy phonon events that is more than two orders of magnitude
larger than in a functionally identical crystal suspended from its holder in a
low-stress state. The excess phonon event rate in the glued crystal decreases
with time since cooldown, consistent with a source of phonon bursts which
contributes to quasiparticle poisoning in quantum circuits and the low-energy
events observed in cryogenic calorimeters. We argue that relaxation of
thermally induced stress between the glue and crystal is the source of these
events, and conclude that stress relaxation contributes to quasiparticle
poisoning in superconducting qubits and the athermal phonon background in a
broad class of rare-event searches
Mineral Detection of Neutrinos and Dark Matter. A Whitepaper
Minerals are solid state nuclear track detectors - nuclear recoils in a
mineral leave latent damage to the crystal structure. Depending on the mineral
and its temperature, the damage features are retained in the material from
minutes (in low-melting point materials such as salts at a few hundred degrees
C) to timescales much larger than the 4.5 Gyr-age of the Solar System (in
refractory materials at room temperature). The damage features from the
MeV fission fragments left by spontaneous fission of U and other heavy
unstable isotopes have long been used for fission track dating of geological
samples. Laboratory studies have demonstrated the readout of defects caused by
nuclear recoils with energies as small as keV. This whitepaper discusses
a wide range of possible applications of minerals as detectors for keV nuclear recoils: Using natural minerals, one could use the damage
features accumulated over Myr Gyr to measure astrophysical
neutrino fluxes (from the Sun, supernovae, or cosmic rays interacting with the
atmosphere) as well as search for Dark Matter. Using signals accumulated over
months to few-years timescales in laboratory-manufactured minerals, one could
measure reactor neutrinos or use them as Dark Matter detectors, potentially
with directional sensitivity. Research groups in Europe, Asia, and America have
started developing microscopy techniques to read out the nm
damage features in crystals left by keV nuclear recoils. We
report on the status and plans of these programs. The research program towards
the realization of such detectors is highly interdisciplinary, combining
geoscience, material science, applied and fundamental physics with techniques
from quantum information and Artificial Intelligence.Comment: 115 pages, many pictures of tracks. Please see the source file for
higher resolution versions of some plots. v2: matches the published versio
EXCESS workshop: Descriptions of rising low-energy spectra
International audienceMany low-threshold experiments observe sharply rising event rates of yet unknown origins below a few hundred eV, and larger than expected from known backgrounds. Due to the significant impact of this excess on the dark matter or neutrino sensitivity of these experiments, a collective effort has been started to share the knowledge about the individual observations. For this, the EXCESS Workshop was initiated. In its first iteration in June 2021, ten rare event search collaborations contributed to this initiative via talks and discussions. The contributing collaborations were CONNIE, CRESST, DAMIC, EDELWEISS, MINER, NEWS-G, NUCLEUS, RICOCHET, SENSEI and SuperCDMS. They presented data about their observed energy spectra and known backgrounds together with details about the respective measurements. In this paper, we summarize the presented information and give a comprehensive overview of the similarities and differences between the distinct measurements. The provided data is furthermore publicly available on the workshop’s data repository together with a plotting tool for visualization
Concept design of the LiteBIRD satellite for CMB B-mode polarization
LiteBIRD is a candidate for JAXA's strategic large mission to observe the cosmic microwave background (CMB) polarization over the full sky at large angular scales. It is planned to be launched in the 2020s with an H3 launch vehicle for three years of observations at a Sun-Earth Lagrangian point (L2). The concept design has been studied by researchers from Japan, U.S., Canada and Europe during the ISAS Phase-A1. Large scale measurements of the CMB B-mode polarization are known as the best probe to detect primordial gravitational waves. The goal of LiteBIRD is to measure the tensor-to-scalar ratio (r) with precision of r < 0:001. A 3-year full sky survey will be carried out with a low frequency (34 - 161 GHz) telescope (LFT) and a high frequency (89 - 448 GHz) telescope (HFT), which achieve a sensitivity of 2.5 \u3bcK-arcmin with an angular resolution 30 arcminutes around 100 GHz. The concept design of LiteBIRD system, payload module (PLM), cryo-structure, LFT and verification plan is described in this paper