Download or read book Design of Single Phase Liquid Argon Detectors for Dark Matter Searches written by Daniel E. Gastler and published by . This book was released on 2012 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Within our current understanding of the makeup of the universe, dark matter makes up 25% of the total energy and over 80% of the matter in the universe. Little is known about the makeup of dark matter, but its existence has been indirectly measured using the rotation curves of galaxies, clusters of galaxies, and the Cosmic Microwave Background. To gain a greater understanding of this component of the universe, direct detection of dark matter is a major objective in particle astrophysics. One popular candidate for dark matter is the weakly interacting massive particle, or WIMP. The allowed rate of interaction between a WIMP and normal matter is extremely low, requiring new detection technologies with greater sensitivity to be explored. Though several experiments have already been conducted, no direct detection experiment has unambiguously identified a dark matter signal. This work explores the use of noble liquids, in a single liquid phase design, to detect single scatters of dark matter particles. The goal of current experiments is to investigate matter-dark-matter interaction cross-sections down to 10–45cm2. With that in mind, the MiniCLEAN detector has been designed with a 500 kg liquid argon detector volume and will be viewed by a spherical tt configuration of 92 photo-multiplier tubes. In order to determine the ability for single phase noble liquid to detect nuclear recoils from dark matter, several R&D experiments have been performed. These experiments undertook the measurement of how dark-matter-like nuclear recoils and background-like electronic recoils behave in liquid argon. In addition to reviewing the measurements of pulse shape discrimination and other noble liquid properties, my measurement of the scintillation efficiency is described. The scintillation efficiency characterizes the differing energy responses for nuclear and electron recoils. This was the first measurement of the scintillation efficiency in liquid argon for nuclear recoils over a wide energy range. Additionally, this work covers the design and testing of the front-end electronics and data acquisition software I developed for the MiniCLEAN experiment. This system has been designed to record and process thousands of physics events per second and has been tested using novel simulators, that I developed, that approximately represent the expected PMT signals of the MiniCLEAN detector.
Download or read book Searching for Dark Matter with Single Phase Liquid Argon written by Thomas S. Caldwell (Jr.) and published by . This book was released on 2015 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: A variety of experimental efforts are underway aimed towards direct detection of dark matter through observation of rare scattering of WIMPs in terrestrial detectors. Single phase liquid argon detectors are an appealing WIMP detection technique due to the scintillation properties of liquid argon and the scalability of the single phase approach. The MiniCLEAN dark matter detector is a single phase liquid argon scintillation scintillation detector with a 500 kg active mass. The modular design offers 4[pi] coverage with 92 optical cassettes, each containing TPB coated acrylic and a cryogenic photomultiplier tube. The MiniCLEAN detector has recently completed construction at SNOLAB. The detector is currently being commissioned, and will soon begin operation with the liquid argon target. Utilizing advanced pulse-shape discrimination techniques, MiniCLEAN will probe the WIMP-nucleon cross section parameter space to the level of 10-44 cm2 and demonstrate the pulse-shape discrimination required for next generation experiments capable of further probing the WIMP parameter space in search of WIMP dark matter.
Download or read book Direct Search for Dark Matter by Using Dual phase Liquid Xenon Detector and Measurement of Nuclear Recoils in Liquid Argon written by Yixiong Meng and published by . This book was released on 2015 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cosmological and Astrophysical observations provide compelling evidences for the existence of dark matter in the universe. One class of dark matter candidates, the Weakly Interacting Massive Particles (WIMPs), has been predicted in many particle physics theories. Direct detection experiments using dual- phase liquid noble element detectors report the best sensitivities to the detection of the dark matter particles. The next generation direct detection experiments using the same technology, are actively been built and expected to give a factor of 100 improvement on the current best sensitivity. This thesis discusses the measurement of nuclear recoils in a dual-phase liquid argon detector using a bunched neutron beam generated by linear accelerator facility at accelerator laboratory in Notre Dame University. Nuclear recoils of en- ergy ranging from 10.8 keVnr to 49.9 keVnr are measured under different drift field configurations. An electric field quenching on nuclear recoils in liquid argon is dis- covered and quantified for the first time. This quenching effect is also found to be drift field and recoil energy dependent. By varying the drift field amplitude from 100 V/cm to 1000 V/cm for each nuclear recoil energy, the quenching effect are measured as a function of nuclear recoil energy and drift field amplitude. Results from this measurement is used in the direct dark matter detection experiment to calculate the final sensitivity of direct dark matter search. A separate work on the optimization of detector design for the XENON1T detector is also discussed in detail. Finite element simulation tool is used to design and optimize the electric field in XENON1T time projection chamber. As part of the design of XENON1T detector, electron transparency across metal grids of different geometrical configurations are also studied.
Download or read book Characterization of Liquid Argon Response for the Direct Detection of Dark Matter written by Benjamin R. Schlitzer and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The nature of dark matter remains one of the most significant open questions in modern physics, despite the large body of astrophysical and cosmological evidence supporting its existence. The Weakly Interacting Massive Particle (WIMP) is a well-motivated candidate particle with mass in the range 1 GeV/c2 - 100 TeV/c2 and coupling to Standard Model matter at or below the weak scale. If WIMPs do exist, they should occasionally interact with baryonic particles and leave behind a small amount of energy. DarkSide is a phased experimental program which aims to detect the interaction of a WIMP with a liquid argon target in a dual-phase time projection chamber (TPC). In order to make a WIMP discovery, an accurate understanding of the signal region is required. To this end, small-scale experiments which measure the detector response to a recoiling argon nucleus (NR) or scattering with atomic electrons (ER) are critical in establishing results of the large-scale direct detection experiments. The Argon Response to Ionization and Scintillation (ARIS) experiment was designed to characterize liquid argon's response to both NR and ER events at low recoil energies using a small dual-phase TPC. This work presents a complete chronology of the ARIS experiment and analysis of the collected data. A detailed description of the design of the ARIS TPC and related subsystems is given, as well as an account of the commissioning and calibration performed at the University of California, Los Angeles. The inverse-kinematics neutron source LICORNE was used at the Institute De Physique Nucléaire Orsay to bombard the ARIS TPC with collimated low energy neutrons. Neutron detectors surrounding the TPC were used to tag events which scattered in the TPC at selected angles, and the resulting data were used to characterize both NR and ER events at tightly constrained recoil energies. A description of the low-level reconstruction and data selection cuts is given, as well as corrections made due to trigger efficiency and vertical position in the TPC. ER data were analyzed to provide an improved measurement of the linearity of LAr light yield for incident [gamma]/[beta] particles with energies below 511 keV. ARIS measured a constant light yield to within 1.6% in the [41.5, 511] keV recoil energy range. The linearity of the ER scintillation response measured by ARIS has also been used to derive the spectral shape of forbidden 39Ar [beta] decay, which is a background intrinsic to liquid argon. The NR data were analyzed to measure the relative scintillation efficiency for recoils between [7.1, 117.8] keV, and were in good agreement with the previous SCENE results at low recoil energy. The DarkSide collaboration has used ARIS results to precisely model the response of nuclear recoils in liquid argon in both field-on and field-off configurations. In addition to the characterization of argon response, this work presents an optimization of the electric fields used to drift ionization electrons in DarkSide TPCs. The relevant electrostatics models used by COMSOL simulation software to approximate electric field behavior are described, as well as a technique developed to quantify field uniformity in the TPC. Then, the uniformity of the electric field is optimized for several possible TPC design changes, including the fiducial radius, the first shaping ring voltage, and the cross-sectional geometry of shaping rings. This work was supervised by Dr. Emilija Pantic, and was completed in collaboration with both members of the DarkSide collaboration as well as scientists at the University of California, Davis.
Download or read book Noble Gas Detectors written by Elena Aprile and published by John Wiley & Sons. This book was released on 2007-02-27 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Direct Search for Dark Matter with DarkSide written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Here, the DarkSide experiment is designed for the direct detection of Dark Matter with a double phase liquid Argon TPC operating underground at Laboratori Nazionali del Gran Sasso. The TPC is placed inside a 30 tons liquid organic scintillator sphere, acting as a neutron veto, which is in turn installed inside a 1 kt water Cherenkov detector. The current detector is running since November 2013 with a 50 kg atmospheric Argon fill and we report here the first null results of a Dark Matter search for a (1422 ± 67) kg.d exposure. This result correspond to a 90% CL upper limit on the WIMP-nucleon cross section of 6.1 × 10-44 cm2 (for a WIMP mass of 100 GeV/c2) and it's currently the most sensitive limit obtained with an Argon target.
Download or read book Results from the First Use of Low Radioactivity Argon in a Dark Matter Search written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid argon is a bright scintillator with potent particle identification properties, making it an attractive target for direct-detection dark matter searches. The DarkSide-50 dark matter search here reports the first WIMP search results obtained using a target of low-radioactivity argon. DarkSide-50 is a dark matter detector, using a two-phase liquid argon time projection chamber, located at the Laboratori Nazionali del Gran Sasso. The underground argon is shown to contain Ar39 at a level reduced by a factor (1.4 ± 0.2) × 103 relative to atmospheric argon. Here, we report a background-free null result from (2616 ± 43) kg d of data, accumulated over 70.9 live days. When combined with our previous search using an atmospheric argon, the 90% C.L. upper limit on the WIMP-nucleon spin-independent cross section, based on zero events found in the WIMP search regions, is 2.0 × 10-44 cm2 (8.6 × 10-44 cm2, 8.0 × 10-43 cm2) for a WIMP mass of 100 GeV/c2 (1 TeV/c2, 10 TeV/c2).
Download or read book Light Readout for a 1 Ton Liquid Argon Dark Matter Detector written by Boccone Vittorio and published by . This book was released on 2010 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct Search for Dark Matter with the DarkSide Experiment written by Paolo Agnes and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wide range of observational evidence suggests that the matter content of the Universe is dominated by a non-baryonic and non-luminous component: dark matter. One of the most favored candidate for dark matter is a big-bang relic population of Weakly Interacting Massive Particles (WIMPs). The DarkSide program aims to the direct detection of WIMPs with a dual-phase liquid argon TPC and a background free exposure. The first phase of the experiment, DarkSide-50, is running since Oct 2013 and has (46 ± 0.7) kg active mass. A first run, with an atmospheric argon fill (AAr), provided the most sensitive limit ever obtained by an argon-based experiment. The current run, with an underground argon fill (UAr, depleted in Ar-39), represents a milestone towards the construction of DarkSide-20k, a low-background dual-phase TPC with a fiducial mass of 20 t. This work is been mainly devoted to the description of G4DS, the DarkSide Monte Carlo simulation, and to its applications. G4DS is a GEANT4-based simulation, it provides the geometry description of each detector of the DarkSide program, it is tuned to reproduce the DarkSide-50 response at the percent level and incorporates a custom model for ionization and scintillation mechanisms in liquid argon, tuned on real data. The principal applications of the simulation include the estimate of the neutron and gamma backgrounds for DarkSide-50, the measurement of the Ar-39 depletion factor in UAr with respect to AAr and the design studies for DarkSide-20k.
Download or read book Direct Detection of Dark Matter with Liquid Argon and Neon written by Walter Hugh Lippincott and published by . This book was released on 2010 with total page 540 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Validation of Argon from Underground Sources for Use in the DarkSide 50 Detector written by Thomas R. Alexander and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid argon is an attractive target for dark matter searches due to its low cost and exemplary event discrimination. However, atmospherically derived argon contains the beta-emitter 39Ar which confounds the growth of dual-phase time projection chamber (TPC) style detectors to the ton-scale. The DarkSide Collaboration seeks to bypass this limitation by extracting argon from deep underground, from a location known to contain significantly less 39Ar than atmospherically derived argon. This thesis will summarize the e orts taken to produce the first batch of underground argon, focusing on the first operation of the underground argon in a dual-phase TPC to validate the purity of the product, performed at Fermilab using the SCENE cryostat.
Download or read book Direct Detection of Dark Matter with Liquid Argon and Neon written by Walter Hugh Lippincott and published by . This book was released on 2008 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Vacuum and Argon Gas Fill Data from the MiniCLEAN Dark Matter Experiment written by Stephen H. Jaditz and published by . This book was released on 2015 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: The existence of particle dark matter provides a consistent framework for understanding many astronomical observations. The rotation curves of galaxies and galaxyclusters, for example, indicate the majority of mass in these structures is unseen. The existence of weakly-interacting massive particles (WIMPs) was proposed in the early 1980s to account for the anomalous rotation curves and provide a mechanism for producing the cold dark matter relic density, which along with dark energy is thought to dominate the current energy density of our universe. Efforts to observe the rare interaction of WIMPs with normal matter have continued since their proposal, and so far have set limits on the WIMP-nucleon interaction cross-section extending to 1 x 10-9 pb. Contemporary experiments seek to observe ~ one WIMP-nucleus scatter per year per 100 kg of detector mass. These experiments must be conducted deep underground with stringent cleanliness requirements. The MiniCLEAN dark matter experiment is a single-phase liquid argon scintillation detector which uses the wavelength-shifting fluor tetraphenyl butadiene and cryogenic photomultiplier tubes for light detection. The active spherical region of the detector contains 500 kg of liquid argon at temperature 87 K. Background events which could mimic a WIMP signal are mitigated through pulse-shape discrimination and position reconstruction. At an intermediate stage of ongoing detector assembly 2 km underground at SNOLAB in Ontario, the complete instrumented inner vessel was commissioned by collecting photomultiplier waveform data for periods when the vessel was evacuated and when filled with warm argon gas. Alpha decay events from radon progeny on the wavelength-shifting surface occur in this data at a measured rate of 19.0 ± 0.4 /h/m2 MiniCLEAN's projected sensitivity to spin-independent WIMP-nucleon scattering, derived from simulation of this surface rate, is [sigma]SI
Download or read book Internal Liquid Argon Purification System for Liquid Argon Dark Matter Detectors written by Brooke Astor and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Light Yield in Liquid Argon for Dark Matter Detection written by William Creus and published by . This book was released on 2014 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Direct Dark Matter Search with the DarkSide Experiment written by Anyssa Navrer-Agasson and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The existence of dark matter is known because of its gravitational effects, and although its nature remains undisclosed, one of the leading candidate is the weakly interacting massive particle (WIMP) with mass of the order of 100 GeV/c2 and coupling with ordinary matter at or below the weak scale. In this context, DarkSide-50 aims to direct observe WIMP-nucleon collisions in a liquid argon dual phase time-projection chamber located deep underground at Gran Sasso National Laboratory, in Italy. This work first details the argon calibration realised by the ARIS experiment. ARIS characterised the argon response to low energy nuclear and electronic recoils, down to unprecedented energies. The nuclear quenching was measured with the best precision to this date, and the recombination probability extracted was compared to different models describing the behaviour of argon in presence of an electric field. A search for low mass WIMPs performed with DarkSide-50 data is also presented. This search focuses on the ionisation signal from the TPC, leading much to much lower detection threshold. The achieved exclusion limits are amongst the leading ones, and the most stringent for a liquid argon target. Finally a preliminary search for axions is presented. Axions are an alternative candidate to dark matter, proposed as a solution to the strong CP problem. They are detectable in DarkSide via their coupling to electrons. This search required the improvement of the modelling of the background sources, by taking into account atomic effects in beta emission spectra, as well as a redefinition of the energy scale converting the energy deposited into a number of extracted electrons. The results presented show an encouraging sensitivity to both solar and galactic axions.
Download or read book Pulse Shape Discrimination Studies in Liquid Argon for the DEAP 1 Detector written by Jeffrey Jack Lidgard and published by . This book was released on 2008 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: A detector with a target mass of 7 kg of liquid argon was designed, constructed and operated at Queen's University. This detector is a scaled model for the DEAP project toward a tonne-scale argon detector to search for the WIMP candidate of the so far undetected, dark matter of the universe. The primary intent of the scaled detector was to measure the achievable level to reject background events by use of pulse shape discrimination, being based upon the scintillation timing properties of liquid argon. After refining the apparatus and components, the detector was in operation from the 20th of August until the 16th of October 2007 before being moved to its current location in SNOLAB. During this time, a population of 31 million well-tagged gamma events were collected, of which 15.8 million were in the energy range of interest for calibration. This population was sufficient to demonstrate the discrimination of background events by pulse shape discrimination at the level of 6.3 x 10-8. An analytical model was constructed, based on the scintillation processes and detector response, and has been sufficiently investigated to make predictions of further achievable discrimination.
