SEARCH · Engineering Papers
Results for “WIMPS”
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.
Discriminating WIMP-nucleus response functions in present and future XENON-like direct detection experiments
Not Available
GeV-scale thermal WIMPs: Not even slightly ruled out
Not Available
Nuclear structure factors for general spin-independent WIMP-nucleus scattering
Not Available
First Results on the Scalar WIMP-Pion Coupling, Using the XENON1T Experiment
Not Available
Uncertainties in WIMP dark matter scattering revisited
Not Available
Final Report on Project “Ton-scale Germanium: Beyond Zeptobarn WIMP Cross-section”
The DOE CAREER proposal primarily focused on establishing a modern semiconductor detector fabrication facility that would provide significant improvement in the cost profile and performance of the cryogenic semiconductor detectors used by the CDMS experiment so as to enable a next generation ton-scale experiment. The proposal also included significant work on performing data analysis on the Soudan experiment.
Dedicated Searches for Low and High Mass Wimps with the SuperCDMS Soudan iZIP Detectors
Recent cosmological evidence suggests most of the mass of the universe takes the form of a type of particle that we have not been able to directly detect. Nearly 80 years that have elapsed since the rst hints of this dark matter started to appear from astronomers without any direct detection. The high precision era of cosmology and unifying models of particle physics developed in the 20 th century have presented us with an exciting mystery at the intersection of these two elds that needs to be solved. SuperCDMS Soudan operates specialized germanium detectors (iZIPs) that are cooled to milliKelvin temperatures deep underground in the Soudan Underground Laboratory with the hope of detecting a rare collision between dark matter and a nucleus. A search for low-mass dark matter comes with multiple unique challenges since the background discrimination abilities of these detectors becomes less powerful at the low energies needed to probe low-mass dark matter since the signal to noise ratio deteriorates. Using a sophisticated background model via a pulse rescaling technique, SuperCDMS Soudan was able to produce a world leading exclusion limit on low-mass dark matter. Effort is to extend the analysis to higher masses require long running times during which many aspects of the detectors or the environment can change. Additional challenges are offered by the powerful background discrimination ability of the iZIP. The background distributions are well separated from the signal region, meaning most of the leakage arises from low-probability tails of the background distributions. In the absence of an enormous dataset, extrapolations from the bulk of the distribution are required. While attempting to obtain a model of gamma induced electron-recoils leaking into the signal region of the detector from high radius a curious asymmetry between the sides of the detectors was discovered potentially indicating an electronics or detector design problem. This thesis describes the physics behind SuperCDMS Soudan, the numerous tasks involved in a low-mass search and the rst iZIP array science results with these new detectors, as well as the developments towards a high-mass search result.
Extended Source Gamma-Ray Emission from WIMP Annihilation in the Sagittarius Dwarf Elliptical Galaxy
Explore the source record for details and available documents.
WIMP DISTRIBUTION IN AND EVAPORATION FROM THE SUN.
Explore the source record for details and available documents.
RESONANT ENHANCEMENTS IN WIMP CAPTURE BY THE EARTH
Explore the source record for details and available documents.
DIRECT AND INDIRECT CAPTURE OF WIMPS BY THE EARTH
Explore the source record for details and available documents.
Probing the Earth with WIMPs
Explore the source record for details and available documents.
WIMP-like Dark Matter Without Thermalization At Freeze-Out
In the standard thermal relic scenario, dark matter remains in chemical equilibrium with the Standard Model radiation bath until freeze-out occurs at $T \sim m_X/20$, where $m_X$ is the dark matter mass. In this familiar class of models, the observed relic density is obtained for annihilation cross sections of order $σv \sim 10^{-26}$ cm$^3$/s. We show that comparable cross sections can naturally be realized in hidden-sector models in which the dark matter and Standard Model sectors decouple at a very high temperature, $T \gg m_X$, and subsequently evolve with separate thermal histories. Despite this decoupling, the two sectors have similar temperatures during freeze-out, leading to the usual thermal relic abundance. As a consequence, the coupling between the Standard Model and hidden sectors can be extremely small, potentially placing direct detection and collider signals far below foreseeable sensitivities.
A Dark Matter Search with MALBEK
The Majorana Demonstrator is an array of natural and enriched high purity germanium detectors that will search for the neutrinoless double-beta decay of 76Ge and perform a search for weakly interacting massive particles (WIMPs) with masses below 10 GeV. As part of the Majorana research and development efforts, we have deployed a modified, low-background broad energy germanium detector at the Kimballton Underground Research Facility. With its sub-keV energy threshold, this detector is potentially sensitive to non-Standard Model physics, including interactions with WIMPs. We discuss the backgrounds present in the WIMP region of interest and present results from a WIMP search with 221.49 live days of data from this detector.
DarkSide-20k: A 20 tonne two-phase LAr TPC for direct dark matter detection at LNGS
Abstract. Building on the successful experience in operating the DarkSide-50 detector, the DarkSide Collaboration is going to construct DarkSide-20k, a direct WIMP search detector using a two-phase Liquid Argon Time Projection Chamber (LAr TPC) with an active (fiducial) mass of 23 t (20 t). This paper describes a preliminary design for the experiment, in which the DarkSide-20k LAr TPC is deployed within a shield/veto with a spherical Liquid Scintillator Veto (LSV) inside a cylindrical Water Cherenkov Veto (WCV). This preliminary design provides a baseline for the experiment to achieve its physics goals, while further development work will lead to the final optimization of the detector parameters and an eventual technical design. Operation of DarkSide-50 demonstrated a major reduction in the dominant 39Ar background when using argon extracted from an underground source, before applying pulse shape analysis. Data from DarkSide-50, in combination with MC simulation and analytical modeling, shows that a rejection factor for discrimination between electron and nuclear recoils of > 3 × 109 is achievable. This, along with the use of the veto system and utilizing silicon photomultipliers in the LAr TPC, are the keys to unlocking the path to large LAr TPC detector masses, while maintaining an experiment in which less than < 0.1 events (other than ?-induced nuclear recoils) is expected to occur within the WIMP search region during the planned exposure. DarkSide-20k will have ultra-low backgrounds than can be measured in situ, giving sensitivity to WIMP-nucleon cross sections of 1.2×10 -47 cm2 (1.1×10 -46 cm2) for WIMPs of 1TeV/c2 (10TeV/c2) mass, to be achieved during a 5 yr run producing an exposure of 100 t yr free from any instrumental background.