Kg Of Xenon Research Articles

On-orbit mission overview of the low power hall thruster propulsion system aboard venμs satellite

Venμs is a satellite launched in 2017, for super-spectral Earth imaging and Electric Propulsion System (EPS) demonstration. In this paper we overview EPS design and operation throughout all five mission phases, from open/closed-loop orbit control, through orbit descent (720 → 410 km), orbit maintenance under high drag environment, to orbit raising (410 → 560 km). The EPS consisted of two throttleable Hall thrusters, PPU, Propellant Management Assembly (PMA), and a 9 L propellant tank carrying 16 kg of Xenon. Both thrusters operated in the 300–550 W power range, generated a combined total impulse of 158.1 kN-sec and consumed all propellant. Two methods are described to compute the remaining propellant mass – “Bookkeeping” and “PTV” methods. The advantages and disadvantages of each method are discussed in light of the Venµs mission. Thruster performance was measured on-orbit using the “Orbit Determination” method and compared to laboratory experiments conducted on the ground with identical thrusters. The measured performance on-orbit was found to agree within the error bars with the performance measured on the ground. Lastly, we present several repeating events in which the propulsion system suffered from sudden beam-outs or ignition difficulties. We present the methods used to construct a solution and implement it.

Towards a fiber barrel detector for next-generation high-pressure gaseous xenon TPCs

The NEXT (Neutrino Experiment with a Xenon TPC) project is an international collaboration aimed at finding evidence of neutrinoless double beta decay using gaseous xenon. The current phase of the project involves the construction and operation of NEXT-100, which is designed to hold 100 kg of xenon at 15 bar and is expected to start commissioning in the first quarter of 2024. NEXT-HD will be a tonne scale experiment following NEXT-100 and will incorporate a symmetric design, with one cathode and two anodes. For this detector, the collaboration is considering to implement a barrel of wavelength-shifting fibers read-out by silicon photomultipliers to measure the energy of the particles interacting in the gaseous xenon. In this document, we will discuss the characteristics of this approach and provide an update on the related R&D efforts.

Design, characterization and installation of the NEXT-100 cathode and electroluminescence regions

NEXT-100 is currently being constructed at the Laboratorio Subterráneo de Canfranc in the Spanish Pyrenees and will search for neutrinoless double beta decay using a high-pressure gaseous time projection chamber (TPC) with 100 kg of xenon. Charge amplification is carried out via electroluminescence (EL) which is the process of accelerating electrons in a high electric field region causing secondary scintillation of the medium proportional to the initial charge. The NEXT-100 EL and cathode regions are made from tensioned hexagonal meshes of 1 m diameter. This paper describes the design, characterization, and installation of these parts for NEXT-100. Simulations of the electric field are performed to model the drift and amplification of ionization electrons produced in the detector under various EL region alignments and rotations. Measurements of the electrostatic breakdown voltage in air characterize performance under high voltage conditions and identify breakdown points. The electrostatic deflection of the mesh is quantified and fit to a first-principles mechanical model. Measurements were performed with both a standalone test EL region and with the NEXT-100 EL region before its installation in the detector. Finally, we describe the parts as installed in NEXT-100, following their deployment in Summer 2023.

Modeling grid erosion in the NEXT ion thruster using the CEX2D and CEX3D codes

NASA’s Evolutionary Xenon Thruster (NEXT) is a candidate for future deep space missions that offers high efficiency and specific impulse over a large power throttling range. One of the key life-limiting components is the ion accelerator system, which is subject to sputter erosion by low energy discharge plasma ions incident on the upstream screen grid and higher energy charge exchange ions that impact the downstream accelerator grid. The grid erosion codes CEX2D and CEX3D were validated with data from tests of NEXT as well as the NSTAR ion thruster and then used to assess the time to failure in space due to screen grid erosion and electron backstreaming caused by accelerator grid aperture erosion. Screen grid erosion was found to be important only at the lowest throttle levels, and was conservatively estimated to lead to failure after processing over 900 kg of xenon. The first failure mode at high power levels was found to be electron backstreaming due to accelerator grid hole wall erosion, which would occur after processing over 700 kg of propellant.

Demonstration of One Hundred Kilogram Xenon Throughput by a Low-Power Hall Thruster

The Hall thruster component of the Ascendant Sub-Kilowatt Transcelestial Electric Propulsion System (known ASTRAEUS) successfully demonstrated a propellant throughput of over 100 kg of xenon and demonstrated a total of of impulse in a long-duration wear test. The thruster was operated for a total of 7205 h, with the test broken into five segments each with a different discharge power between 200 and 1350 W: 3291 h at 300 V/1000 W, 1739 h at 500 V/1000 W, 416 h at 400 V/600 W, 388 h at 200 V/200 W, and 1371 h at 300 V/1350 W. Telemetry and temperature measurements periodically recorded throughout the test revealed constant performance across each test segment and over the full test duration. Each segment was sufficiently long to obtain erosion rate data on the thruster by an optical profilometer. Subnominal magnetic field strengths were inadvertently applied to the thruster during the first 5 khr of the test due to an electrical ground-support equipment issue, which caused a downstream shift of the discharge plasma and higher erosion of the thruster’s pole covers than originally expected. This issue was corrected for the latter three test segments; however, the thruster performance and operational behavior at all reference operating conditions remained unaffected. The long-duration wear test was voluntarily terminated after the thruster processed 100.3 kg of xenon (Xe). This marks the world’s first long-duration wear test of a low-power magnetically shielded Hall thruster with a center-mounted hollow cathode wherein over 100 kg Xe throughput was demonstrated.

Experiment and optimization of a large scale xenon/krypton cryogenic distillation system

A highly efficient cryogenic distillation system has been designed, developed and assessed to remove radioactive krypton-85 (85Kr) from xenon (Xe), which is commonly used as a valuable medium for dark matter detectors. By using the self-designed distillation system, the concentration of krypton (Kr) in a commercial xenon product can be reduced from 10−9 to 10−12 mol/mol with 99% xenon collection efficiency at maximum flow rate of 5 kg/h. Over 1000 kg of xenon has been purified and employed as the detection medium in project Panda X, the first dark matter detector developed in China. In this present paper, detailed process simulation was conducted to refine the working parameters and to define the optimum operating conditions for the cryogenic distillation system. The predicted results were compared with those of experimental data obtained from the distillation system. The influence of comprehensive factors was investigated. Simultaneously, a dynamic model for the cryogenic distillation system was established to provide an in depth analysis of the dynamic characteristics of the system.

First ground-level laboratory test of the two-phase xenon emission detector RED-100

RED-100 is a two-phase detector for study of coherent elastic scattering of reactor electron antineutrinos off xenon atomic nuclei. The detector contains a total of 200 kg of liquid xenon in a titanium cryostat with 160 kg of xenon in active volume inside a Teflon-made light collection cage associated with electrode system. The active volume is viewed by two arrays of nineteen 3′′-diameter Hamamatsu R11410-20 PMTs assembled in two planes on top and bottom. The electrode system is equipped with an electron shutter (a patented device) to reduce a “spontaneous” single-electron noise. The detector was tested in a ground-level laboratory. The obtained results demonstrate that detection of coherent elastic scattering of reactor antineutrinos off xenon nuclei at Kalinin nuclear power plant with the RED-100 detector is feasible with a threshold of 4 ionization electrons.

Improved Measurements of the β-Decay Response of Liquid Xenon with the LUX Detector

The LUX experiment was based on a liquid-xenon time-projection chamber that was located on the 4,850’ level of the Sanford Underground Research Facility until it was decommissioned in 2016. In total, the LUX detector contained about 370 kg of xenon, 250 kg of which was active. LUX was designed primarily to detect WIMP dark matter, and produced world-leading limits on the WIMP scattering cross section. In this presentation, I report results from an extensive set of measurements of the β-decay response in liquid xenon. These measurements are derived from high-statistics calibration data from injected sources of both tritium and carbon-14 in the LUX detector after the WIMP-search runs had been completed. The mean light-to-charge ratio is reported for 13 electric field values ranging from 43 to 491 V/cm, and for energies ranging from 1.5 to 145 keV.

First results of KamLAND-Zen 800

KamLAND-Zen is a neutrinoless double beta decay (0vββ) search experiment using xenon 136 and ultra-low background environment of KamLAND (Kamioka Liquid scintillator Anti-Neutrino Detector). KamLAND-Zen collaboration has prepared the KamLAND-Zen 800 project with almost 750 kg of xenon and cleaner container for xenon loaded liquid scintillator. The container production was started in May 2017 and KamLAND-Zen 800 data acquisition was started in January 2019. In this paper, we will describe the KamLAND-Zen 800 project and report on the detector condition, data quality, the first analysis results, and the prospects.

Qualification status of high power ion thruster and flow control unit

Using high power space transportation systems equipped with electric propulsion requires development and qualification of electric thrusters with power equal to tens of kW. The optimal specific impulse of such systems designed for deep space missions should be very high (6000 … 8000 s). Elements for electric propulsion systems are developing at Keldysh Research Center (KeRC). This paper presents qualification status of IT-500 35-kW ion thruster and FCU-500 flow control unit. 2000-hours lifetime test of the IT-500 and FCU-500 was performed as a part of qualification. The ion thruster accomplished 2018 h of operation for the most part at input power of 17,8 kW, utilized 40 kg of xenon. Magnetic field and ion optics improvement and graphite grids development status are also described in this paper.

The NEXT White (NEW) detector

Conceived to host 5 kg of xenon at a pressure of 15 bar in the fiducial volume, the NEXT-White apparatus is currently the largest high pressure xenon gas TPC using electroluminescent amplification in the world. It is also a 1:2 scale model of the NEXT-100 detector for 136Xe ββ0ν decay searches, scheduled to start operations in 2019. Both detectors measure the energy of the event using a plane of photomultipliers located behind a transparent cathode. They can also reconstruct the trajectories of charged tracks in the dense gas of the TPC with the help of a plane of silicon photomultipliers located behind the anode. A sophisticated gas system, common to both detectors, allows the high gas purity needed to guarantee a long electron lifetime. NEXT-White has been operating since October 2016 at the Laboratorio Subterráneo de Canfranc (LSC), in Spain. This paper describes the detector and associated infrastructures, as well as the main aspects of its initial operation.

XEMIS2: A liquid xenon detector for small animal medical imaging

We report a new liquid xenon Compton camera, called XEMIS2 (XEnon Medical Imaging System), developed to image for the first time small animals using 3γ imaging. This technique proposes an alternative to reduce the administered radiopharmaceutical activity while preserving diagnostic image quality using liquid xenon as detection medium. Given the success of its predecessor, a small dimension liquid xenon time projection chamber called XEMIS1, we are currently building a larger scale detector for preclinical applications. This second prototype, XEMIS2, is a single phase liquid xenon cylindrical camera with a large axial field of view for full-body small animal imaging. XEMIS2 holds around 200 kg of xenon and it has been designed to enable high-efficiency and simultaneous detection of the three γ-rays emitted by a 44Sc radionuclide. The innovative geometry of XEMIS2 will allow to discriminate and measure the position and deposited energy of most Compton interactions inside the detector. In order to manage such a large quantity of xenon, an innovative high-pressure subsystem known as ReStoX has been developed and successfully qualified. ReStoX allows to maintain the xenon in liquid state at the desired temperature and pressure, transfer the xenon into XEMIS2 and store it during long term periods. XEMIS2 will be installed at a non controlled radioactive area of Nantes Hospital. The goal is to evaluate image quality of a 20 min whole-body preclinical exam with an injected activity of 20 kBq.

Chromatographic separation of radioactive noble gases from xenon

The Large Underground Xenon (LUX) experiment operates at the Sanford Underground Research Facility to detect nuclear recoils from the hypothetical Weakly Interacting Massive Particles (WIMPs) on a liquid xenon target. Liquid xenon typically contains trace amounts of the noble radioactive isotopes 85Kr and 39Ar that are not removed by the in situ gas purification system. The decays of these isotopes at concentrations typical of research-grade xenon would be a dominant background for a WIMP search experiment. To remove these impurities from the liquid xenon, a chromatographic separation system based on adsorption on activated charcoal was built. 400 kg of xenon was processed, reducing the average concentration of krypton from 130 ppb to 3.5 ppt as measured by a cold-trap assisted mass spectroscopy system. A 50 kg batch spiked to 0.001 g/g of krypton was processed twice and reduced to an upper limit of 0.2 ppt.

3$\gamma $ Medical Imaging with a Liquid Xenon Compton Camera and $^{44}$Sc Radionuclide

The development of a liquid xenon Compton camera called XEMIS2 (XEnon Medical Imaging System) is a step forward to a new type of medical imaging based on the use of 44Sc radionuclide emitting two annihilation rays and a third high energy ray simultaneously. The single phase TPC (Time Projection Chamber) under construction, containing nearly 200 kg of xenon, is designed to measure most of the Compton interactions in the active area with a sub-millimetre position resolution and a good energy resolution of 4% on 511 keV photopeak. The intersection of the Compton cone surface from the third ray with the line of response from the two annihilation rays allows to localize the radionuclide with a precision (FWHM) of about 1 cm along this line. The large field of view of such a liquid xenon camera combined with the 3 imaging technique will provide a good quality image while keeping the injected activity at a very low level. XEMIS2 will be installed in the Nantes University Hospital in order to demonstrate its capability to image small animals injected with a low activity of only 20 kBq in 20 mn acquisition time. To achieve this goal, a precise measurement of the ionization signal is provided by a pixelized anode, shielded by a Frisch Grid and read out by a low noise front-end electronics. In addition, new cryogenic and purification subsystems have been tested, allowing safe recovery of xenon in liquid phase at flow rates of about 1 ton per hour.

EXO-200 results and cosmogenic backgrounds

Status update and recent results from the double beta decay search experiment EXO-200 are presented. Detector is a liquid xenon TPC with charge and light readout located underground in low-background laboratory at 1600 m.w.e. depth. It contains 175 kg of xenon with 80.6% abundance of 136Xe, which acts as both the decaying nucleus and detection medium. Detector showed good performance and achieved remarkable results. The detector has demonstrated excellent energy resolution and background rejection capabilities and has set a lower limit on the 0νββ-decay half-life of 1.1 × 1025 years at 90% C.L. in early 2014. The EXO-200 collaboration has since published several papers on experimental backgrounds and searches for rare or exotic processes. After a two-year data interruption, EXO-200 is now back online with significant hardware improvements, including a radon reduction air system and a front end electronics upgrade for better energy resolution.

Status and plan of the PandaX experiment

PandaX is a large scale apparatus for the detection of rare events in particle physics and astrophysics with xenon. It is located in the China Jinping Underground Laboratory, which is the deepest underground laboratory all over the world to date. The first and second stages of the PandaX experiment utilize the dual phase xenon time projection chamber technology for the direct detection of one hypothetic candidate of dark matter, the weakly interacting massive particles (WIMPs), in the Galaxy halo. The technology makes it possible to measure both the scintillations and ionizations generated by the scattering of WIMP with nucleus, and thus backgrounds can be suppressed by the character of the measured signals. The aim of the first stage of PandaX, PandaX-I, is to test the possible signals reported by other experiments in low dark matter mass region with 120 kg of xenon. The first results of the PandaX-I experiment were released in August, 2014. No dark matter candidates were observed. Thus the 90% exclusion upper limits on the spin-independent WIMP-nucleon elastic scattering cross section were set. The results disfavored the WIMP interpretation of those signals and placed stringent limit to the property of dark matter below 10 GeV/ c 2. The final results of PandaX-I were released in 2015 based on 54×80.1 kg d of exposure with significantly improved analysis. The new analysis supported the conclusion of the first results and gave stringent limitation on the WIMP-nucleon cross section for WIMP mass smaller than 10 GeV, demonstrating the detection potential of xenon at low WIMP mass region. The second stage, PandaX-II, with an updated detector capable of containing 500 kg of xenon, is being tested and will start data taking in the end of 2015. The sensitivity of PandaX-II is expected to go far beyond the current limits being set by all the experiments so far. Unattainable parameter space of WIMPs will be explored by it. PandaX-III, the third stage, will be an experiment to detect the neutrinoless double beta decay with enriched high pressure 136Xe (to 90%) gaseous detector, so that the nature of neutrino is studied. The detector is able to measure the track of radiations inside it, helping to suppress the background by inspecting the different topological properties of desired signals and background. PandaX-III plans to build such a detector with 200 kg enriched 136Xe first, then build another 4 identical modules to reach ton scale. The initial design and prototype testing of PandaX-III is carrying out by different groups from the institutions all over the world. The first detector module of PandaX-III is expected to be finished construction and start operation in 2018. The success running of the PandaX experiments may lead to important discoveries in physics.

China carves out larger role in underground science

As it is doing in so many areas of science, China is racing onto the world stage of underground astroparticle physics.

Large scale xenon purification using cryogenic distillation for dark matter detectors

A high efficiency cryogenic distillation system for removal of radioactive krypton-85 (85Kr) from commercially available xenon (Xe) has been designed, developed and assessed to meet the requirements of high sensitivity, low background dark matter detection experiments. The concentration of krypton (Kr) in a commercial xenon product can be decreased from 10−9 to 10−12 mol/mol based on the theoretical design and simulation. The experimental measurements showed that the concentration of krypton was decreased to 10−11 mol/mol with 99% xenon collection efficiency at maximum flow rate of 5 kg/h. Over 500 kg of xenon has been purified using this system, which has been used as the detection medium in project Panda X, the first dark matter detector developed in China.

Status and Results from the EXO Collaboration

The Enriched Xenon Observatory (EXO) is an experimental program search- ing for neutrinoless double-beta decay using 136 Xe. Such a search can shed light on the Majorana nature of the neutrino (whether the neutrino is its own anti-particle), the ab- solute mass scale of neutrinos, and beyond standard model processes that violate lepton number conservation. The first phase of the experiment, EXO-200, uses 200 kg of xenon with 80% enrichment in 136 Xe in a single-phase liquid xenon time projection chamber (TPC). The double-beta decay of xenon is detected in the ultra-low background TPC by collecting both the scintillation light and the ionization charge. The detector has been tak- ing low background physics data with enriched xenon at the Waste Isolation Pilot Plant (WIPP) in New Mexico since early May 2011. The results produced from the collab- oration include the first observation of two-neutrino double-beta decay of 136 Xe, and a neutrinoless double-beta decay search result that places one of the most stringent limits on the e ective Majorana neutrino mass. Building on the success of EXO-200, the col- laboration is performing feasibility studies and R&D work for a future multi-tonne scale experiment named nEXO. During the talk, I will discuss the latest results from EXO-200 and prospects of neutrinoless double-beta decay search with both EXO-200 and nEXO.

NEXT, high-pressure xenon gas experiments for ultimate sensitivity to Majorana neutrinos

In this paper we describe an innovative type of Time Projection Chamber (TPC), which uses high-pressure xenon gas (HPXe) and electroluminescence amplification of the ionization charge as the basis of an apparatus capable of fully reconstructing the energy and topological signature of rare events.We will discuss a specific design of such HPXe TPC, the NEXT-100 detector, that will search for ββ0ν events using 100–150 kg of xenon enriched in the isotope 136Xe. NEXT-100 is currently under construction, after completion of an accelerated and very successful R&D period. It will be installed at the Laboratorio Subterr'aneo de Canfranc (LSC), in Spain. The commissioning run is expected for late 2013 or early 2014.We will also present physics arguments that suggest that the HPXe technology can be extrapolated to the next-to-next generation (e.g, a fiducial mass of 1 ton of target), which will fully explore the Majorana nature of the neutrino if the mass hierarchy is inverse.