Neutron Calibration Studies for the SuperCDMS SNOLAB Experiment
Explore the source record for details and available documents.
SEARCH · Engineering Papers
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A significant facet of modern experimental particle physics research is that of searching for hypothetical rare events. In this context, “rare” means “unusual to detect in the laboratory”, and can be a confirmed phenomenon (e.g. coherent elastic neutrino-nucleus scattering, which has a high cross section at low, difficult to detect energies), or an as-of-yet unobserved phenomenon that may not exist (e.g. dark matter - standard model matter non-gravitational interaction). A salient challenge for experimentalists is to devise detectors optimized for observing such rare events.
Explore the source record for details and available documents.
The constituents of dark matter are still unknown, and the viable possibilities span a very large mass range. Specific scenarios for the origin of dark matter sharpen the focus to within about an MeV to 100 TeV. Most of the stable constituents of known matter have masses in this lower range, and a thermal origin for dark matter works in a simple and predictive manner in this mass range as well. If there is an interaction between light DM and ordinary matter, as there must be in the case of a thermal origin, then there necessarily is a production mechanism in accelerator-based experiments. The Light Dark Matter eXperiment (LDMX) is a planned electron-beam fixed-target missing-momentum experiment at SLAC that has unique sensitivity to light DM in the sub-GeV mass range. Although optimized for a missing momentum technique, LDMX is effectively a fully instrumented beam dump experiment, making it possible to search for visibly decaying signatures of dark sector particles. This would provide another outlet for LDMX to probe complementary regions of dark matter phase space for a variety of models. This contribution will give an overview of the theoretical motivation for LDMX, the main experimental challenges and how they are addressed, as well as projected sensitivities in comparison to other experiments.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Direct detection experiments for light (sub-GeV) dark matter are making enormous leaps in reaching previously unexplored theory space. The need for accurate characterizations of target responses has led to a growing interplay between particle and condensed matter physics. This white paper summarizes recent progress on direct detection calculations that utilize state-of-the-art numerical tools in condensed matter physics and effective field theory techniques. These new results provide the theoretical framework for interpreting ongoing and planned experiments using electronic and collective excitations, and for optimizing future searches.
The present conference on physics and astrophysics from a lunar base encompasses space physics, cosmic ray physics, neutrino physics, experiments in gravitation and general relativity, gravitational radiation physics, cosmic background radiation, particle astrophysics, surface physics, and the physics of gamma rays and X-rays. Specific issues addressed include space-plasma physics research at a lunar base, prospects for neutral particle imaging, the atmosphere as particle detector, medium- and high-energy neutrino physics from a lunar base, muons on the moon, a search for relic supernovae antineutrinos, and the use of clocks in satellites orbiting the moon to test general relativity. Also addressed are large X-ray-detector arrays for physics experiments on the moon, and the measurement of proton decay, arcsec-source locations, halo dark matter and elemental abundances above 10 exp 15 eV at a lunar base.
SpinQuest is a cutting-edge, high-luminosity Drell-Yan experiment utilizing polarized hy- drogen and deuterium targets to measure the Sivers asymmetry for the light sea quarks in the nucleon. Detecting a nonzero Sivers asymmetry would provide clear evidence for nonzero or- bital angular momentum of sea quarks. The Sivers asymmetry presents itself as an azimuthal asymmetry in the production of virtual photons via the Drell-Yan process, and SpinQuest will be able to measure this asymmetry using the existing SeaQuest dimuon spectrometer. In addi- tion to making measurements sensitive to the sea quark Sivers function, we will also measure the azimuthal asymmetry in the production of J/ψ particles, which is sensitive to the gluon Sivers function. Additionally, observing a sign change in the Sivers asymmetry between this measurement and future measurements at the Electron-Ion Collider would be a test of a funda- mental prediction of Quantum Chromodynamics. In this poster we will review the physics and technology underpinning the experiment.
The weak interaction violates a symmetry between particles and anti-particles that is called a CP symmetry. This violation is expected to induce CP violation in the strong interaction by a large amount. However, observations show that the CP violation in the strong interaction is smaller than expected by more than ten orders of magnitude. This discrepancy is called the strong CP problem, and solving it has been one of the motivations for constructing a theory beyond the Standard Model (SM). In this research program, the PI investigated possible signals of solutions to the strong CP problem. The signals were predicted for a variety of experiments and observations. These predictions bridge different subfields of particle physics, cosmology, and astrophysics that are otherwise disconnected. As a byproduct, the PI also applied the techniques developed in this study to theories with axion-like particles to reveal signals of axion-like particles.
Despite advances in recycling technologies and practices, the world still mostly operates on a once-through materials use cycle. The once-through approach to the materials supply chain cannot work into perpetuity. The vast majority of current recycling efforts focus on mechanical or chemical separation-based techniques and are often subsequently limited on the number of times a component can be recycled or upcycled. By looking at things from a particle physics and nuclear history perspective, we propose a thought experiment to determine the physical limit of recycling and propose subsequent limits and standards to evaluate all recycling efforts. This uncommon approach to analysis demonstrates that the current limits to recycling are not physical in nature but engineering.
Experiments & research in astronomy, solar physics, planetary atmospheres, ionospheres & radio physics, particles & fields, and biosciences
Texts of high-energy multicharged particle, ultraviolet light, and galactic irradiation fluxes on exposed biological specimens aboard Apollo 16 are described. Passive nuclear track detectors, passive dosimeters, and thermoluminescent dosimeters, respectively, were used for the measurements. Biological phenomena studied ranged from lipolytic alpha toxin production in Bacillus thuringiensis to animal tissue invasion (of human hair by Trichophyton terrestre). Fluxes observed were lower than those recorded by detectors located in the Biostack and in the passive personnel dosimeters worn by the astronauts, suggesting a greater average shielding in the latter two environments.
Active and planned spacecraft activity and experiments between June 1, 1980 and May 31, 1981 known to the National Space Science Data Center are described. The information covers a wide range of disciplines: astronomy, Earth sciences, meteorology, planetary sciences, aeronomy, particles and fields, solar physics, life sciences, and material sciences. Each spacecraft and experiment is described and its current status presented. Descriptions of navigational and communications satellites and of spacecraft that contain only continuous radio beacons used for ionospheric studies are specifically excluded.
This project investigated the ultra-high energy density (UHED) regime of matter found in the center of stars, using a compact PW-class laser. These extreme conditions are typically only obtained in the laboratory in the central hot-spot of spherically imploded capsules in inertial confinement fusion experiments driven by the world’s largest lasers. We have shown that near-solid density arrays of aligned nanostructures can be volumetrically heated to multi-keV temperatures by irradiation at relativistic intensity with ultrafast laser pulses of modest energy, opening a path for the generation of UHED plasmas with compact lasers. This new UHED plasma generation approach promises to create an environment with extreme energy densities and degrees of ionization, record conversion of optical laser light into ultrafast x-ray pulses, gigantic magnetic fields and pressures, and directed beams of high energy particles . In this project we achieved record degree of ionization in volumetric heating solid density and near-solid density plasmas. Gold plasmas which spectra is characterized by L shell transition emission from ions with charge up to the Ne-like state, Au+ 72 were generated using ultrafast laser pulses of less than 10 J of energy from a compact laser focused to an intensity of ~ 3x10 21 Wcm -2 . We also conducted measurements to determine the heat penetration depth in Ni nanowire arrays as compared to Ni foil targets by monitoring the line emission of a Co buried tracer underneath a variable amount of Ni. The measurements revealed that the nanowire plasmas are roughly six times larger in depth than the solid density target plasmas. A result of this increased plasma in nanowire arrays is a greatly increased conversion of optical laser light into > 1 KeV x-rays, a record conversion efficiency of 20 %. Critical to the realization of the proposed experiments was the generation of ultrafast laser pulses with ultra-high contrast that can deposit the energy deep into the nanowire arrays before the nanowires explode to create a continuous plasma. Supporting the proposed experiments was the recent demonstration at Colorado State University of a Petawatt-class laser that emits 30 fs pulses at high repetition rates. The experiments combined this unique laser tool with a variety of tailored nanowire arrays fabricated in house and with an extensive suite of diagnostics. The experiments were accompanied by 3-dimensional particle-in-cell simulations and detailed atomic physics simulations with transient kinetics and radiation transport. The proposed research allowed us to continue training Ph.D students and post-docs with broad experience in HEDP Science.