Author: Chi Wai LamPublisher:
ISBN:
Category :
Languages : en
Pages : 224
Book Description
Search for Dark Matter with XENON100 and Future Ton-scale Detectors
Author: Chi Wai LamSearch for Low Mass Dark Matter with the XENON100 Experiment and Simulations for 1 Ton and 10 Ton Dark Matter Detectors
Author: Ethan Craig BrownDirect Dark Matter Search with XENON1T and Developments for Multi-ton Liquid Xenon Detectors
Author: Julien WulfThe Cryogenic Infrastructure of the XENON1T Dark Matter Experiment
Author: Yun ZhangPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
I first give an instrument overview of the systems in XENON1T. I then review the cooling methods in LXe detectors which led to the design of the cooling system implemented in the XENON1T experiment, and suggest a design of the cooling system for future LXe dark matter experiments at the 50 tons scale. I describe and discuss in detail the design and the performance of the XENON1T Cryogenic Infrastructure. Finally, I describe the detector stability and the corresponding data selection in all three XENON1T science runs, and describe the dark matter search results from the one ton-year exposure.
The Search for Dark Matter in XENON100 Using a Two-dimensional Profile Likelihood Analysis
Author: Kevin Joseph LungPublisher:
ISBN:
Category :
Languages : en
Pages : 169
Book Description
Direct dark matter detectors are currently probing the favored supersymmetric theoretical phase space for weakly interacting massive particles (WIMPs) as part of a larger electroweak sector particle search. The XENON100 detector has recently improved upon their world-best upper limits on WIMP-nucleon scattering cross sections from 2011 with new results presented in 2012, which have further ruled out much of the predicted regions for dark matter. In the low mass regime, the results shown so far have been conservative in addressing the claims of a WIMP detection by CoGeNT, DAMA and CRESSTII. This thesis discusses a different approach to analyzing the XENON100 data with a profile likelihood statistical method using the ionization channel to improve both energy reconstruction and energy resolution and probe the low WIMP mass region. A Monte Carlo simulation using a combination of detector geometry and underlying statistical features of signal production has been developed to determine the ionization yield, which has only a few direct measurements, and to model WIMP interactions as input to the statistical technique. The resulting profile likelihood analysis, which includes systematic uncertainties in the energy scales and background and signal models, has been able to improve the current upper limits by a factor of 10 in the low mass region (6-10 GeV/c2) and about a factor of 2 up to 50 GeV/c2. The discovery potential of the dataset is also studied, which has produced a 2.3[sigma] significance for a 7.5 GeV/c2 particle at a cross section of [sigma]_x-N =1.8 X 10−43 cm2 with a 95% confidence interval of [1.74 X 10−44,7.76 & times;10−43] cm2.
A Search for Low-mass Dark Matter with the Cryogenic Dark Matter Search and the Development of Highly Multiplexed Phonon-mediated Particle Detectors
Author: Using MiniCLEAN and Measurements of Microphysical Material Properties in the Vacuum Ultraviolet Regime to Inform Next-generation Dark Matter and Neutrino Detectors
Author: Christopher Pete BensonPublisher:
ISBN:
Category :
Languages : en
Pages : 192
Book Description
Many compelling pieces of indirect evidence pointing to the existence of dark matter. While a confirmed and direct signature of dark matter has yet to be observed, many theoretical models have been developed in an attempt to explain the indirect evidence and to provide phenomenological models that can be tested with targeted experiments. The WIMP is a well-motivated dark matter candidate currently being sought for by several experiments. A variety of detector technologies are utilized, including liquid noble detectors, to look for WIMP scattering as a direct signature of dark matter. The CLEAN experiment is a proposed single-phase, monolithic, large-scale liquid argon experiment designed to look for high-mass WIMPs. A liquid neon target could be exchanged with the argon target to study solar neutrinos and to test the A2 dependence of a possible dark matter signal. Before scaling up to the multi-tonne scale of the full CLEAN detector, the design philosophy and background rejection capabilities required for the next-generation project are being tested using the MiniCLEAN prototype. As of mid-2018, MiniCLEAN has been constructed at SNOLAB and is currently being filled with natural liquid argon for a dark matter run. Following a short dark matter run, MiniCLEAN will be spiked with elevated levels of 39Ar to test the scaling limits of pulse shape discrimination, the primary method for electronic background rejection. These results will inform existing experiments and the next-generation of large-scale liquid argon detectors. A good understanding of light propagation is critical for optical experiments such as CLEAN, whose event reconstruction and background rejection relies primarily on scintillation light collection. This work presents two classes of complementary results which are expected to improve the modeling of scintillation light collection in current and future neutrino and dark matter detectors. These are, first, the dependence of the scintillation light time structure (triplet lifetime) and relative light yield of gaseous argon as a function of impurity level and, second, the measurement of several parameters critical to constructing a microphysically-motivated model of tetraphenyl butadiene (TPB) wavelength shifting thin films - a technology which is commonly used in many existing and proposed liquid noble gas experiments.
Characterizing the Peripheral Dynamics of Xenon Dark Matter Detectors
Author: Jacob Edward CutterPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
One of the most important fundamental problems in physics today is to understand the nature of dark matter. The landscape of explanations for observed dark matter phenomena is vast and still expanding, and an impressive number of experiments have been built to probe the dark sector of the universe. A prominent class of detectors is aimed at discovering (or excluding) a particular kind of dark matter: the Weakly Interacting Massive Particle (WIMP). Searching for this popular dark matter candidate requires an ultra-sensitive, low-background target; xenon detectors serve as such a target for dark matter interactions. The Large Underground Xenon (LUX) detector is a dual-phase xenon time-projection chamber (TPC) which was operated underground at the Homestake Mine in Lead, South Dakota from 2013 to 2016, and was able to achieve the world's leading WIMP exclusion limit. However, successful reconstruction of WIMP-nucleus scatters in such detectors requires thorough understanding of the detection medium, which is made difficult by various confounding effects near the detector walls. Field-fringing is a major component of confusion in the periphery, and the large electric field non-uniformities in Run 4 of LUX provided a significant challenge in the dark matter analysis. Here is presented an algorithm to bijectively map between reconstructed event positions and true spatial coordinates, which serves as an important tool for studying field effects and fiducialization in LUX. Additionally, a successful dark matter search must model interfering background events in the WIMP search region which can't be directly vetoed. One class of unavoidable backgrounds comes from nuclear decay chain daughters in detector materials themselves, which may produce WIMP-like signals (an effect which is amplified due to various detector effects). The Davis Xenon (DAX) test bed system and a dual-phase TPC have been assembled and operated at UC Davis to characterize these common "wall backgrounds", as well as perform other R&D studies for the next-generation LUX-ZEPLIN (LZ) experiment. The DAX TPC specifically measures the xenon response to heavy nuclei produced by custom [alpha] decay sources created using novel chemical deposition procedures. In this thesis, results will be presented for the light and charge yields of immersed localized sources of 206Pb ions in liquid xenon, as well as a method for tagging such recoil events in situ by using PIN diodes as charged particle detectors to capture the correlated [alpha] particles. We also compare our isolated 206Pb events with previous WIMP search data from LUX, and discuss the significance of 206Pb as a WIMP background. Such information is most useful to future experiments if it can improve existing background models and simulations. The Noble Element Simulation Technique (NEST) is the ultimate software package for calculating expected signal yields in xenon detectors, but is an empirical framework that relies on experimental data to inform the models. We discuss the development of current NEST v2 models, specifically the heavy nuclear recoil models, as well as our current understanding of the xenon microphysics. We also show NEST predictions for mono-energetic 206Pb recoils, and discuss how our most recent DAX 206Pb measurements may inform NEST models in future work.
Noble Gas Detectors
Author: Elena AprilePublisher: John Wiley & Sons
ISBN: 3527609636
Category : Science
Languages : en
Pages : 362
Book Description
This book discusses the physical properties of noble fluids, operational principles of detectors based on these media, and the best technical solutions to the design of these detectors. Essential attention is given to detector technology: purification methods and monitoring of purity, information readout methods, electronics, detection of hard ultra-violet light emission, selection of materials, cryogenics etc. The book is mostly addressed to physicists and graduate students involved in the preparation of fundamental next generation experiments, nuclear engineers developing instrumentation for national nuclear security and for monitoring nuclear materials.
Fourteenth Marcel Grossmann Meeting, The: On Recent Developments In Theoretical And Experimental General Relativity, Astrophysics, And Relativistic Field Theories - Proceedings Of The Mg14 Meeting On General Relativity (In 4 Parts)
Author: Massimo BianchiPublisher: World Scientific
ISBN: 9813226617
Category : Science
Languages : en
Pages : 4784
Book Description
The four volumes of the proceedings of MG14 give a broad view of all aspects of gravitational physics and astrophysics, from mathematical issues to recent observations and experiments. The scientific program of the meeting included 35 morning plenary talks over 6 days, 6 evening popular talks and 100 parallel sessions on 84 topics over 4 afternoons.Volume A contains plenary and review talks ranging from the mathematical foundations of classical and quantum gravitational theories including recent developments in string theory, to precision tests of general relativity including progress towards the detection of gravitational waves, and from supernova cosmology to relativistic astrophysics, including topics such as gamma ray bursts, black hole physics both in our galaxy and in active galactic nuclei in other galaxies, and neutron star, pulsar and white dwarf astrophysics.The remaining volumes include parallel sessions which touch on dark matter, neutrinos, X-ray sources, astrophysical black holes, neutron stars, white dwarfs, binary systems, radiative transfer, accretion disks, quasars, gamma ray bursts, supernovas, alternative gravitational theories, perturbations of collapsed objects, analog models, black hole thermodynamics, numerical relativity, gravitational lensing, large scale structure, observational cosmology, early universe models and cosmic microwave background anisotropies, inhomogeneous cosmology, inflation, global structure, singularities, chaos, Einstein-Maxwell systems, wormholes, exact solutions of Einstein's equations, gravitational waves, gravitational wave detectors and data analysis, precision gravitational measurements, quantum gravity and loop quantum gravity, quantum cosmology, strings and branes, self-gravitating systems, gamma ray astronomy, cosmic rays and the history of general relativity.