Implantation of xenon in amorphous carbon and silicon for brachytherapy application

International Nuclear Information System (INIS)

Marques, F.C.; Barbieri, P.F.; Viana, G.A.; Silva, D.S. da

2013-01-01

We report a procedure to implant high dose of xenon atoms (Xe) in amorphous carbon, a-C, and amorphous silicon, a-Si, for application in brachytherapy seeds. An ion beam assisted deposition (IBAD) system was used for the deposition of the films, where one ion gun was used for sputtering a carbon (or silicon) target, while the other ion gun was used to simultaneously bombard the growing film with a beam of xenon ion Xe + in the 0–300 eV range. Xe atoms were implanted into the film with concentration up to 5.5 at.%, obtained with Xe bombardment energy in the 50–150 eV range. X-ray absorption spectroscopy was used to investigate the local arrangement of the implanted Xe atoms through the Xe L III absorption edge (4.75 keV). It was observed that Xe atoms tend to agglomerate in nanoclusters in a-C and are dispersed in a-Si.

Scintillating liquid xenon calorimeter for precise electron/photon/jet physics at high energy high luminosity hadron colliders

International Nuclear Information System (INIS)

Chen, M.; Luckey, D.; Pelly, D.; Shotkin, S.; Sumorok, K.; Wadsworth, B.; Yan, X.J.; You, C.; Zhang, X.; Chen, E.G.; Gaudreau, M.P.J.; Montgomery, D.B.; Sullivan, J.D.; Bolozdynya, A.; Chernyshev, V.; Goritchev, P.; Khovansky, V.; Kouchenkov, A.; Kovalenko, A.; Lebedenko, V.; Vinogradov, V.A.; Epstein, V.; Zeldovich, S.; Krasnokutsky, R.; Shuvalov, R.; Aprile, E.; Mukherjee, R.; Suzuki, M.; Moulsen, M.; Sugimoto, S.; Okada, K.; Fujino, T.; Matsuda, T.; Miyajima, M.; Doke, T.; Kikuchi, J.; Hitachi, A.; Kashiwagi, T.; Nagasawa, Y.; Ichinose, H.; Ishida, N.; Nakasugi, T.; Ito, T.; Masuda, K.; Shibamura, E.; Wallraff, W.; Vivargent, M.; Mutterer, M.; Chen, H.S.; Tang, H.W.; Tung, K.L.; Ding, H.L.; Takahashi, T.

1990-01-01

The authors use αs well as e, π, p, d and heavy ion beams to test prototype scintillating liquid xenon detectors, with large UV photodiodes and fast amplifiers submersed directly in liquid xenon. The data show very large photoelectron yields (10 7 /GeV) and high energy resolution (σ(E)/E 1.6 GeV). The α spectra are stable over long term and can be used to calibrate the detectors. Full size liquid xenon detectors have been constructed, to study cosmic μ's and heavy ions. The authors report the progress on the design and construction of the 5 x 5 and 11 x 11 cell liquid xenon detectors which will be tested in high energy beams to determine the e/π ratio. The authors describe the design and the unique properties of the proposed scintillating LXe calorimeter for the SSC

Internal plasma potential measurements of a Hall thruster using xenon and krypton propellant

International Nuclear Information System (INIS)

Linnell, Jesse A.; Gallimore, Alec D.

2006-01-01

For krypton to become a realistic option for Hall thruster operation, it is necessary to understand the performance gap between xenon and krypton and what can be done to reduce it. A floating emissive probe is used with the Plasmadynamics and Electric Propulsion Laboratory's High-speed Axial Reciprocating Probe system to map the internal plasma potential structure of the NASA-173Mv1 Hall thruster [R. R. Hofer, R. S. Jankovsky, and A. D. Gallimore, J. Propulsion Power 22, 721 (2006); and ibid.22, 732 (2006)] using xenon and krypton propellant. Measurements are taken for both propellants at discharge voltages of 500 and 600 V. Electron temperatures and electric fields are also reported. The acceleration zone and equipotential lines are found to be strongly linked to the magnetic-field lines. The electrostatic plasma lens of the NASA-173Mv1 Hall thruster strongly focuses the xenon ions toward the center of the discharge channel, whereas the krypton ions are defocused. Krypton is also found to have a longer acceleration zone than the xenon cases. These results explain the large beam divergence observed with krypton operation. Krypton and xenon have similar maximum electron temperatures and similar lengths of the high electron temperature zone, although the high electron temperature zone is located farther downstream in the krypton case

Effects of temperature and irradiation on the mobility of Xenon in UO2: Profilometric and microstructural study

International Nuclear Information System (INIS)

Marchand, B.

2012-01-01

In France, electricity is mainly produced (78%) through the operation of 58 PWRs (Pressurized Water Reactors). During reactor operation, many fission products (FP) are generated in the fuel which is, in most cases, UO 2 enriched to about 4% in 235 U. Among FPs, gaseous fission products as Xenon and Krypton, are abundantly produced (around 15% stable fission products). Because of their chemical nature, those two gases have a very low solubility in the fuel and therefore tend to form bubbles (to minimize surface tension) and can cause pellets swelling. The formed gas can also be released out of the pellet, and lead to a substantial increase in the pressure within the fuel cladding, thereby limiting the energy production. However, migration mechanisms, traditionally studied indirectly by measuring the amount of gas released after irradiation, are not yet fully understood. It is frequently assumed that atomic diffusion is the only mechanism that can lead to a migration of xenon. The objective of this thesis is to provide direct evidence of the different mechanisms controlling the behavior of Xenon during thermal annealing and irradiation. Therefore, we used ion implantation to introduce Xenon in uranium dioxide samples. After implantation, the Xenon distribution follows a quasi-Gaussian concentration profile (variation of the concentration regard to the depth) located in the first 300 nanometers of the sample. We have performed post-implantation annealing at 1400 C and 1600 C in order to study the impact of the temperature, and irradiation with ions to simulate the impact of fission products in the fuel. Subsequently, concentration depth profiles were measured by ion microprobe (SIMS). Although the feasibility of Xenon measurement has been demonstrated in several articles, no concentration profile had so far been presented in the literature because a classical data processing of SIMS data is not suitable in uranium dioxide. Therefore a new data processing software has

Ionization and scintillation response of high-pressure xenon gas to alpha particles

International Nuclear Information System (INIS)

Álvarez, V; Cárcel, S; Cervera, A; Díaz, J; Ferrario, P; Gil, A; Gómez-Cadenas, J J; Borges, F I G; Conde, C A N; Fernandes, L M P; Freitas, E D C; Cebrián, S; Dafni, T; Gómez, H; Egorov, M; Gehman, V M; Goldschmidt, A; Esteve, R; Evtoukhovitch, P; Ferreira, A L

2013-01-01

High-pressure xenon gas is an attractive detection medium for a variety of applications in fundamental and applied physics. In this paper we study the ionization and scintillation detection properties of xenon gas at 10 bar pressure. For this purpose, we use a source of alpha particles in the NEXT-DEMO time projection chamber, the large scale prototype of the NEXT-100 neutrinoless double beta decay experiment, in three different drift electric field configurations. We measure the ionization electron drift velocity and longitudinal diffusion, and compare our results to expectations based on available electron scattering cross sections on pure xenon. In addition, two types of measurements addressing the connection between the ionization and scintillation yields are performed. On the one hand we observe, for the first time in xenon gas, large event-by-event correlated fluctuations between the ionization and scintillation signals, similar to that already observed in liquid xenon. On the other hand, we study the field dependence of the average scintillation and ionization yields. Both types of measurements may shed light on the mechanism of electron-ion recombination in xenon gas for highly-ionizing particles. Finally, by comparing the response of alpha particles and electrons in NEXT-DEMO, we find no evidence for quenching of the primary scintillation light produced by alpha particles in the xenon gas.

Experimental Investigation from the Operation of a 2 kW Brayton Power Conversion Unit and a Xenon Ion Thruster

Science.gov (United States)

Hervol, David; Mason, Lee; Birchenough, Art; Pinero, Luis

2004-01-01

A 2kW Brayton Power Conversion Unit (PCU) and a xenon ion thruster were integrated with a Power Management and Distribution (PMAD) system as part of a Nuclear Electric Propulsion (NEP) Testbed at NASA's Glenn Research Center. Brayton Converters and ion thrusters are potential candidates for use on future high power NEP mission such as the proposed Jupiter Icy Moons Orbiter (JIMO). The use of a existing lower power test hardware provided a cost effective means to investigate the critical electrical interface between the power conversion system and the propulsion system. The testing successfully demonstrated compatible electrical operations between the converter and the thruster, including end-to-end electric power throughput, high efficiency AC to DC conversion, and thruster recycle fault protection. The details of this demonstration are reported herein.

Improved Fluid Perturbation Theory: Equation of state for Fluid Xenon

OpenAIRE

Li, Qiong; Liu, Hai-Feng; Zhang, Gong-Mu; Zhao, Yan-Hong; Tian, Ming-Feng; Song, Hai-Feng

2016-01-01

The traditional fluid perturbation theory is improved by taking electronic excitations and ionizations into account, in the framework of average ion spheres. It is applied to calculate the equation of state for fluid Xenon, which turns out in good agreement with the available shock data.

ATLAS Event Display: First Xenon-Xenon Run 2017

CERN Multimedia

ATLAS Collaboration

2017-01-01

Event display from the xenon-xenon collision run of 12-13 October 2017. Curved cyan lines show the trajectories of charged particles in the tracking systems. The bottom right plot shows the distribution of energy deposited in the calorimeters, demonstrating the high particle multiplicity of the event. Two muon candidates are reconstructed at high pseudorapidity, as seen in the bottom left plot

ExB Measurements of a 200 W Xenon Hall Thruster (Preprint)

National Research Council Canada - National Science Library

Ekholm, Jared M; Hargus, Jr, William A

2007-01-01

Angularly resolved ion species fractions of Xe+1, Xe+2, and Xe+3 in a low power xenon Hall thruster Busek BHT-200 plume were measured using an ExB probe under a variety of thruster operating conditions and background pressures...

Appropriate xenon-inhalation speed in xenon-enhanced CT using the end-tidal gas-sampling method

International Nuclear Information System (INIS)

Suga, Sadao; Toya, Shigeo; Kawase, Takeshi; Koyama, Hideki; Shiga, Hayao

1986-01-01

This report describes some problems when end-tidal xenon gas is substituted for the arterial xenon concentration in xenon-enhanced CT. The authors used a newly developed xenon inhalator with a xenon-gas-concentration analyzer and performed xenon-enhanced CT by means of the ''arterio-venous shunt'' method and the ''end-tidal gas-sampling'' method simultaneously. By the former method, the arterial build-up rate (K) was obtained directly from the CT slices of a blood circuit passing through the phantom. By the latter method, it was calculated from the xenon concentration of end-tidal gas sampled from the mask. The speed of xenon supply was varied between 0.6 - 1.2 L/min. in 11 patients with or without a cerebral lesion. The results revealed that rapid xenon inhalation caused a discrepancy in the arterial K between the ''shunt'' method and the ''end-tidal'' method. This discrepancy may be responsible for the mixing of inhalated gas and expired gas in respiratory dead space, such as the nasal cavity or the mask. The cerebral blood flow was underestimated because of the higher arterial K in the latter method. Too much slow inhalation, however, was timewasting, and it increased the body motion in the subanesthetic state. Therefore, an inhalation speed of the arterial K of as much as 0.2 was ideal to represent the end-tidal xenon concentration for the arterial K in the ''end-tidal gas-sampling'' method. When attention is given to this point, this method may offer a reliable absolute value in xenon-enhanced CT. (author)

Optimization of Xenon Difluoride Vapor Delivery

International Nuclear Information System (INIS)

Sweeney, Joseph; Marganski, Paul; Kaim, Robert; Wodjenski, Mike; Gregg, John; Yedave, Sharad; Sergi, Steve; Bishop, Steve; Eldridge, David; Zou Peng

2008-01-01

Xenon difluoride (XeF 2 ) has been shown to provide many process benefits when used as a daily maintenance recipe for ion implant. Regularly flowing XeF 2 into the ion source cleans the deposits generated by ion source operation. As a result, significant increases in productivity have been demonstrated. However, XeF 2 is a toxic oxidizer that must be handled appropriately. Furthermore, it is a low vapor pressure solid under standard conditions (∼4.5 torr at 25 deg. C). These aspects present unique challenges for designing a package for delivering the chemistry to an ion implanter. To address these challenges, ATMI designed a high-performance, re-usable cylinder for dispensing XeF 2 in an efficient and reliable manner. Data are presented showing specific attributes of the cylinder, such as the importance of internal heat transfer media and the cylinder valve size. The impact of mass flow controller (MFC) selection and ion source tube design on the flow rate of XeF 2 are also discussed. Finally, cylinder release rate data are provided.

Optical pumping and xenon NMR

International Nuclear Information System (INIS)

Raftery, M.D.

1991-11-01

Nuclear Magnetic Resonance (NMR) spectroscopy of xenon has become an important tool for investigating a wide variety of materials, especially those with high surface area. The sensitivity of its chemical shift to environment, and its chemical inertness and adsorption properties make xenon a particularly useful NMR probe. This work discusses the application of optical pumping to enhance the sensitivity of xenon NMR experiments, thereby allowing them to be used in the study of systems with lower surface area. A novel method of optically-pumping 129 Xe in low magnetic field below an NMR spectrometer and subsequent transfer of the gas to high magnetic field is described. NMR studies of the highly polarized gas adsorbed onto powdered samples with low to moderate surface areas are now possible. For instance, NMR studies of optically-pumped xenon adsorbed onto polyacrylic acid show that xenon has a large interaction with the surface. By modeling the low temperature data in terms of a sticking probability and the gas phase xenon-xenon interaction, the diffusion coefficient for xenon at the surface of the polymer is determined. The sensitivity enhancement afforded by optical pumping also allows the NMR observation of xenon thin films frozen onto the inner surfaces of different sample cells. The geometry of the thin films results in interesting line shapes that are due to the bulk magnetic susceptibility of xenon. Experiments are also described that combine optical pumping with optical detection for high sensitivity in low magnetic field to observe the quadrupoler evolution of 131 Xe spins at the surface of the pumping cells. In cells with macroscopic asymmetry, a residual quadrupolar interaction causes a splitting in the 131 Xe NMR frequencies in bare Pyrex glass cells and cells with added hydrogen

RESULTS FROM THE XENON100 EXPERIMENT

Directory of Open Access Journals (Sweden)

Rino Persiani

2013-12-01

Full Text Available The XENON program consists in operating and developing double-phase time projection chambers using liquid xenon as the target material. It aims to directly detect dark matter in the form of WIMPs via their elastic scattering off xenon nuclei. The current phase is XENON100, located at the Laboratori Nazionali del Gran Sasso (LNGS, with a 62 kg liquid xenon target. We present the 100.9 live days of data, acquired between January and June 2010, with no evidence of dark matter, as well as the new results of the last scientific run, with about 225 live days. The next phase, XENON1T, will increase the sensitivity by two orders of magnitude.

Latest results from XENON100 data

International Nuclear Information System (INIS)

Scotto Lavina, L.

2014-01-01

XENON100 is the current phase of the XENON dark matter program, which aims for the direct detection of WIMPs with liquid xenon time-projection chambers. We present the status of the experiment after 224.6 live days taken in 2011 and 2012 during which the detector successfully improved in terms of more calibration data, higher xenon purity, lower threshold and better background removal. The analysis has yielded no evidence for dark matter interactions. The status of the next generation XENON1T detector will be briefly described. The goal of XENON1T is to increase the fiducial volume by a factor 10 and reduce the background noise by a factor 100

Appropriate xenon-inhalation time in xenon-enhanced CT using the end-tidal gas-sampling method

Energy Technology Data Exchange (ETDEWEB)

Asada, Hideo; Furuhata, Shigeru; Onozuka, Satoshi; Uchida, Koichi; Fujii, Koji; Suga, Sadao; Kawase, Takeshi; Toya, Shigeo; Shiga, Hayao

1988-12-01

For the end-tidal gas-sampling method of xenon-enhanced CT (Xe-CT), the respective functional images of K, lambda, and the regional cerebral blood flow (rCBF) were studied and compared using the data at 7-, 10-, 15- and 25-minute inhalations. The most appropriate inhalation time of xenon gas was evaluated in 14 clinical cases. An end-tidal xenon curve which represents the arterial xenon concentration was monitored with a xenon analyzer; the xenon concentration was gradually increased to a level of 50% by using a xenon inhalator with a closed circuit to prevent the overestimation of the xenon concentration sampled from the mask. Serial CT scans were taken over a period of 25 minutes of inhalation. The functional images of K, lambda, and rCBF were calculated for serial CT scans for 7, 10, 15 and 25 minutes using Fick's equation. Those various images and absolute values were then compared. The rCBF value of a 15-minute inhalation was approximately 15% greater than that of 25 minutes, while the values of K, lambda, rCBF from a 15-minute inhalation were significantly correlated to those from 25 minutes. The regression line made it possible to estimate 25-minute inhalation values from those of 15 minutes. In imaging, the rCBF mapping of the 15-minute inhalation was found to be more reliable than that of 25 minutes. This study suggests that the minimal time of xenon inhalation is 15 minutes for the end-tidal gas-sampling method. A longer inhalation may be necessary for the estimation of rCBF in the low-flow area, such as the white matter or the pathological region.

Ionization of xenon Rydberg atoms at Si(1 0 0) surfaces

Energy Technology Data Exchange (ETDEWEB)

Dunham, H.R. [Department of Physics and Astronomy, Rice University MS-61, 6100 Main Street, Houston, TX 77005-1892 (United States); Wethekam, S. [Institut fuer Physik der Humboldt-Universitaet zu Berlin, Newtonstra. 15, D-12489, Berlin (Germany); Lancaster, J.C. [Department of Physics and Astronomy, Rice University MS-61, 6100 Main Street, Houston, TX 77005-1892 (United States); Dunning, F.B. [Department of Physics and Astronomy, Rice University MS-61, 6100 Main Street, Houston, TX 77005-1892 (United States)]. E-mail: fbd@rice.edu

2007-03-15

The ionization of xenon Rydberg atoms excited to the lowest states in the n = 17 and n = 20 Stark manifolds at Si(1 0 0) surfaces is investigated. It is shown that, under appropriate conditions, a sizable fraction of the incident atoms can be detected as ions. Although the onset in the ion signal is perturbed by stray fields present at the surface, the data are consistent with ionization rates similar to those measured earlier at metal surfaces.

Xenon Fractionation and Archean Hydrogen Escape

Science.gov (United States)

Zahnle, K. J.

2015-01-01

Xenon is the heaviest gas found in significant quantities in natural planetary atmospheres. It would seem the least likely to escape. Yet there is more evidence for xenon escape from Earth than for any element other than helium and perhaps neon. The most straightforward evidence is that most of the radiogenic Xe from the decay of (129)I (half-life 15.7 Myr) and (244)Pu (half-life 81 Myr) that is Earth's birthright is missing. The missing xenon is often attributed to the impact erosion of early atmospheres of Earth and its ancestors. It is obvious that if most of the radiogenic xenon were driven off by impacts, most of the rest of the atmophiles fared the same fate. The other line of evidence is in the nonradiogenic isotopes of xenon and its silent partner, krypton. Atmospheric xenon is strongly mass fractionated (at about 4% per amu) compared to any known solar system source (Figure 1). This is in stark contrast to krypton, which may not be fractionated at all: atmospheric Kr is slightly heavier than solar Kr (at about 0.5% per amu), but it is the same as in carbonaceous chondrites. Nonradiogenic xenon is also under abundant relative to krypton (the so-called "missing xenon" problem). Together these observations imply that xenon has been subject to fractionating escape and krypton not.

Separation and purification of xenon

International Nuclear Information System (INIS)

Schlea, C.S.

1978-01-01

Xenon is separated from a mixture of xenon and krypton by extractive distillation using carbon tetrafluoride as the partitioning agent. Krypton is flushed out of the distillation column with CF 4 in the gaseous overhead stream while purified xenon is recovered from the liquid bottoms. The distillation is conducted at about atmospheric pressure or at subatmospheric pressure

Molecular MRI based on hyper-polarized xenon

International Nuclear Information System (INIS)

Tassali, Nawal

2012-01-01

Magnetic Resonance Imaging (MRI) has a high importance in medicine as it enables the observation of the organs inside the body without the use of radiative or invasive techniques. However it is known to suffer from poor sensitivity. To circumvent this limitation, a key solution resides in the use of hyper-polarized species. Among the entities with which we can drastically increase nuclear polarization, xenon has very specific properties through its interactions with its close environment that lead to a wide chemical shift bandwidth. The goal is thus to use it as a tracer. This PhD thesis focuses on the concept of 129 Xe MRI-based sensors for the detection of biological events. In this approach, hyper-polarized xenon is vectorized to biological targets via functionalized host systems, and then localized thanks to fast dedicated MRI sequences. The conception and set-up of a spin-exchange optical pumping device is first described. Then studies about the interaction of the hyper-polarized noble gas with new cryptophanes susceptible to constitute powerful host molecules are detailed. Also the implementation of recent MRI sequences optimized for the transient character of the hyper-polarization and taking profit of the xenon in-out exchange is described. Applications of this approach for the detection of metallic ions and cellular receptors are studied. Finally, our first in vivo results on a small animal model are presented. (author) [fr

Studies of selenium and xenon in inductively coupled plasma mass spectrometry

International Nuclear Information System (INIS)

Bricker, T.

1994-01-01

Since its development, inductively coupled plasma mass spectrometry (ICP-MS) has been a widely used analytical technique. ICP-MS offers low detection limits, easy determination of isotope ratios, and simple mass spectra from analyte elements. ICP-MS has been successfully employed for many applications including geological, environmental, biological, metallurgical, food, medical, and industrial. One specific application important to many areas of study involves elemental speciation by using ICP-MS as an element specific detector interfaced to liquid chromatography. Elemental speciation information is important and cannot be obtained by atomic spectrometric methods alone which measure only the total concentration of the element present. Part 1 of this study describes the speciation of selenium in human serum by size exclusion chromatography (SEC) and detection by ICP-MS. Although ICP-MS has been widely sued, room for improvement still exists. Difficulties in ICP-MS include noise in the background, matrix effects, clogging of the sampling orifice with deposited solids, and spectral interference caused by polyatomic ions. Previous work has shown that the addition of xenon into the central channel of the ICP decreases polyatomic ion levels. In Part 2 of this work, a fundamental study involving the measurement of the excitation temperature is carried out to further understand xenon's role in the reduction of polyatomic ions. 155 refs

Simultaneous detection of xenon and krypton in equine plasma by gas chromatography-tandem mass spectrometry for doping control.

Science.gov (United States)

Kwok, Wai Him; Choi, Timmy L S; So, Pui-Kin; Yao, Zhong-Ping; Wan, Terence S M

2017-02-01

Xenon can activate the hypoxia-inducible factors (HIFs). As such, it has been allegedly used in human sports for increasing erythropoiesis. Krypton, another noble gas with reported narcosis effect, can also be expected to be a potential and less expensive erythropoiesis stimulating agent. This has raised concern about the misuse of noble gases as doping agents in equine sports. The aim of the present study is to establish a method for the simultaneous detection of xenon and krypton in equine plasma for the purpose of doping control. Xenon- or krypton-fortified equine plasma samples were prepared according to reported protocols. The target noble gases were simultaneously detected by gas chromatography-triple quadrupole mass spectrometry using headspace injection. Three xenon isotopes at m/z 129, 131, and 132, and four krypton isotopes at m/z 82, 83, 84, and 86 were targeted in selected reaction monitoring mode (with the precursor ions and product ions at identical mass settings), allowing unambiguous identification of the target analytes. Limits of detection for xenon and krypton were about 19 pmol/mL and 98 pmol/mL, respectively. Precision for both analytes was less than 15%. The method has good specificity as background analyte signals were not observed in negative equine plasma samples (n = 73). Loss of analytes under different storage temperatures has also been evaluated. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Xenon preconditioning: molecular mechanisms and biological effects

Directory of Open Access Journals (Sweden)

Liu Wenwu

2013-01-01

Full Text Available Abstract Xenon is one of noble gases and has been recognized as an anesthetic for more than 50 years. Xenon possesses many of the characteristics of an ideal anesthetic, but it is not widely applied in clinical practice mainly because of its high cost. In recent years, numerous studies have demonstrated that xenon as an anesthetic can exert neuroprotective and cardioprotective effects in different models. Moreover, xenon has been applied in the preconditioning, and the neuroprotective and cardioprotective effects of xenon preconditioning have been investigated in a lot of studies in which some mechanisms related to these protections are proposed. In this review, we summarized these mechanisms and the biological effects of xenon preconditioning.

Ion Acceleration by Double Layers with Multi-Component Ion Species

Science.gov (United States)

Good, Timothy; Aguirre, Evan; Scime, Earl; West Virginia University Team

2017-10-01

Current-free double layers (CFDL) models have been proposed to explain observations of magnetic field-aligned ion acceleration in plasmas expanding into divergent magnetic field regions. More recently, experimental studies of the Bohm sheath criterion in multiple ion species plasma reveal an equilibration of Bohm speeds at the sheath-presheath boundary for a grounded plate in a multipole-confined filament discharge. We aim to test this ion velocity effect for CFDL acceleration. We report high resolution ion velocity distribution function (IVDF) measurements using laser induced fluorescence downstream of a CFDL in a helicon plasma. Combinations of argon-helium, argon-krypton, and argon-xenon gases are ionized and measurements of argon or xenon IVDFs are investigated to determine whether ion acceleration is enhanced (or diminished) by the presence of lighter (or heavier) ions in the mix. We find that the predominant effect is a reduction of ion acceleration consistent with increased drag arising from increased gas pressure under all conditions, including constant total gas pressure, equal plasma densities of different ions, and very different plasma densities of different ions. These results suggest that the physics responsible for acceleration of multiple ion species in simple sheaths is not responsible for the ion acceleration observed in these expanding plasmas. Department of Physics, Gettysburg College.

The quantitative analysis of silicon carbide surface smoothing by Ar and Xe cluster ions

Science.gov (United States)

Ieshkin, A. E.; Kireev, D. S.; Ermakov, Yu. A.; Trifonov, A. S.; Presnov, D. E.; Garshev, A. V.; Anufriev, Yu. V.; Prokhorova, I. G.; Krupenin, V. A.; Chernysh, V. S.

2018-04-01

The gas cluster ion beam technique was used for the silicon carbide crystal surface smoothing. The effect of processing by two inert cluster ions, argon and xenon, was quantitatively compared. While argon is a standard element for GCIB, results for xenon clusters were not reported yet. Scanning probe microscopy and high resolution transmission electron microscopy techniques were used for the analysis of the surface roughness and surface crystal layer quality. The gas cluster ion beam processing results in surface relief smoothing down to average roughness about 1 nm for both elements. It was shown that xenon as the working gas is more effective: sputtering rate for xenon clusters is 2.5 times higher than for argon at the same beam energy. High resolution transmission electron microscopy analysis of the surface defect layer gives values of 7 ± 2 nm and 8 ± 2 nm for treatment with argon and xenon clusters.

Xenon lighting adjusted to plant requirements

Energy Technology Data Exchange (ETDEWEB)

Koefferlein, M.; Doehring, T.; Payer, H.D.; Seidlitz, H.K. [GSF-Forschungszentrum fuer Umwelt und Gesundheit, Oberschleissheim (Germany)

1994-12-31

The high luminous flux and spectral properties of xenon lamps would provide an ideal luminary for plant lighting if not excess IR radiation poses several problems for an application: the required filter systems reduce the irradiance at spectral regions of particular importance for plant development. Most of the economical drawbacks of xenon lamps are related to the difficult handling of that excess IR energy. Furthermore, the temporal variation of the xenon output depending on the oscillations of the applied AC voltage has to be considered for the plant development. However, xenon lamps outperform other lighting systems with respect to spectral stability, immediate response, and maximum luminance. Therefore, despite considerable competition by other lighting techniques, xenon lamps provide a very useful tool for special purposes. In plant lighting however, they seem to play a less important role as other lamp and lighting developments can meet these particular requirements at lower costs.

Xenon changes under power-burst conditions

International Nuclear Information System (INIS)

Diamond, D.J.

1983-01-01

Under ordinary operating conditions the xenon concentration in a reactor core can change significantly in times on the order of hours. Core transients of safety significance are much more rapid and hence calculations are done with xenon concentration held constant. However, in certain transients (such as reactivity initiated accidents) there is a very large power surge and the question arises as to whether under these circumstances the xenon concentration could change. This would be particularly important if the xenon were reduced thereby tending to make the accident autocatalytic. The objective of the present study is to quantify this effect to see if it could be important

Control aid for xenon vibration in reactor

International Nuclear Information System (INIS)

Kanekawa, Takashi.

1990-01-01

In the present invention, the control operation for suppressing xenon vibrations in a reactor is aided for saving forecasting analysis and operator's skills. That is, parameters to be controlled for the suppression of xenon vibrations are power distribution, iodine distribution and xenon distribution. But what can be observed by operaters by the conventional fast overtone method is only the output distribution. In the present invention, the output level of the reactor core is always observed. Then, mathematical processings are conducted for the iodine distribution, the xenon distribution and the power distribution in the reactor core based on the histeresis of the parameters obtained by the measurement using physical constants and reactor design data. The xenon vibration control is aided by displaying the change with time of the distortion in axial direction. Accordingly, operators can always recognize the axial distortion of the power distribution, the iodine distribution and the xenon distribution. (I.S.)

Liquid xenon detector engineering

International Nuclear Information System (INIS)

Chen, E.; Chen, M.; Gaudreau, M.P.J.; Montgomery, D.B.; Pelly, J.D.; Shotkin, S.; Sullivan, J.D.; Sumorok, K.; Yan, X.; Zhang, X.; Lebedenko, V.

1991-01-01

The design, engineering constraints and R and D status of a 15 m 3 precision liquid xenon, electromagnetic calorimeter for the Superconducting Super Collider are discussed in this paper. Several prototype liquid xenon detectors have been built, and preliminary results are described. The design of a conical 7 cell by 7 cell detector capable of measuring fully contained high energy electron showers is described in detail

Sensitivity of gaseous xenon ionisation chambers (1961); Sensibilite des chambres d'ionisation a xenon gazeux (1961)

Energy Technology Data Exchange (ETDEWEB)

Schuhl, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

It seems advantageous to fill an ionization chamber with xenon gas when this chamber is used for measuring a low intensity and high energy electron or positron beam, or monitoring a gamma beam. In the study of 5 to 50 MeV electrons, xenon allows for the ionization chamber yield, an improvement of a factor 4,5. (author) [French] Il apparait interessant d'utiliser du xenon comme gaz dans une chambre d'ionisation destinee a mesurer un faisceau d'electrons ou de positons de faible intensite et de grande energie ou pour monitorer un faisceau de gamma. Dans les etudes des electrons de 5 a 50 MeV, le xenon permet de gagner un facteur 4,5 sur l'air pour la sensibilite d'une chambre d'ionisation. (auteur)

Xenon-based Penning mixtures for proportional counters

International Nuclear Information System (INIS)

Ramsey, B.D.; Agrawal, P.C.; National Aeronautics and Space Administration, Huntsville, AL

1989-01-01

The choice of quench gas can have a significant effect on the gas gain and energy resolution of gas-filed proportional counters. Details are given on the performance obtained with a variety of quench additives of varying ionization potentials for use in xenon-filled systems. It is confirmed that optimum performance is obtained when the ionization potential is closely matched to the first metastable level of xenon (8.3 eV) as is the case with xenon + trimethylamine and xenon + dimethylamine. For these mixtures the Penning effect is at its strongest. (orig.)

Solubility of xenon in liquid sodium

International Nuclear Information System (INIS)

Veleckis, E.; Cafasso, F.A.; Feder, H.M.

1976-01-01

The solubility of xenon in liquid sodium was measured as a function of pressure (2-8 atm) and temperature (350-600 0 C). Henry's law was obeyed with the value of the Henry's law constant, K/sub H/ = N/sub Xe//P, ranging from 1.38 x 10 -10 atm -1 at 350C, to 1.59 x 10 -8 atm -1 at 600 0 C where N/sub Xe/ and P are the atom fraction and the partial pressure of xenon, respectively. The temperature dependence of solubility may be represented by log 10 lambda = (0.663 +- 0.01) - (4500 +- 73) T -1 , where lambda is the Ostwald coefficient (the volume of xenon dissolved per unit volume of sodium at the temperature of the experiment). The heat of solution of xenon in sodium was 20.6 +- 0.7 kcal/mole, where the standard state of xenon is defined as that of 1 mole of an ideal gas, confined to a volume equal to the molar volume of sodium

Xenon recovery from molybdenum-99 production

International Nuclear Information System (INIS)

Jubin, R.T.; Paviet, P.D.; Bresee, J.C.

2016-01-01

The U.S. Department of Energy Office of Nuclear Energy (DOE-NE) sponsors research and development on the recycle of used commercial nuclear fuel as an option for future nuclear fuel cycles that offers increased use of uranium and thorium resources and a possible reduction in the overall cost of nuclear waste management. The two alternatives, direct disposal of used fuel and fuel recycle, are broadly referred to as open and closed fuel cycles. One requirement of a closed fuel cycle is the safe management of radioactive off-gases, which includes 14 C, radioiodine and the noble gases, including radio-xenon. The longest lived relevant radio-xenon isotope is 127 Xe; with a half-life of just 36.35 days it is feasible to trap and hold the radio-xenon to allow for decay to safe environmental levels. However, the very weak chemical bonds of noble gases, in this case xenon, make them difficult to trap, which led to an extensive DOE-NE study of noble gas adsorption on various molecular sieves as an alternative to costly cryogenics processes. Preliminary results indicate that xenon adsorption at near room temperature on molecular sieves, both synthetic and natural, may have both cost and efficiency advantages over cryogenic processes. These results appear to have direct application in helping achieve the United Nations Security Council goal of reducing xenon emissions from medical isotope producers

The XENON1T dark matter experiment

Science.gov (United States)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Antunes, B.; Arneodo, F.; Balata, M.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breskin, A.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Chiarini, A.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Corrieri, R.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; Gangi, P. Di; Giovanni, A. Di; Diglio, S.; Disdier, J.-M.; Doets, M.; Duchovni, E.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Franco, D.; Front, D.; Fulgione, W.; Rosso, A. Gallo; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Giboni, K.-L.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Huhmann, C.; Itay, R.; James, A.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Maier, R.; Manfredini, A.; Maris, I.; Undagoitia, T. Marrodán; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morå, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Orlandi, D.; Othegraven, R.; Pakarha, P.; Parlati, S.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M.-C.; Plante, G.; Priel, N.; García, D. Ramírez; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Santos, J. M. F. dos; Saldanha, R.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Lavina, L. Scotto; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. v.; Stern, M.; Stein, A.; Tatananni, D.; Tatananni, L.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Upole, N.; Vargas, M.; Wack, O.; Walet, R.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wittweg, C.; Wulf, J.; Ye, J.; Zhang, Y.

2017-12-01

The XENON1T experiment at the Laboratori Nazionali del Gran Sasso (LNGS) is the first WIMP dark matter detector operating with a liquid xenon target mass above the ton-scale. Out of its 3.2 t liquid xenon inventory, 2.0 t constitute the active target of the dual-phase time projection chamber. The scintillation and ionization signals from particle interactions are detected with low-background photomultipliers. This article describes the XENON1T instrument and its subsystems as well as strategies to achieve an unprecedented low background level. First results on the detector response and the performance of the subsystems are also presented.

The XENON1T dark matter experiment

International Nuclear Information System (INIS)

Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Giboni, K.L.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Plante, G.; Rizzo, A.; Stern, M.; Tatananni, D.; Zhang, Y.; Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Doets, M.; Hogenbirk, E.; Tiseni, A.; Walet, R.; Agostini, F.; Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Othegraven, R.; Scheibelhut, M.; Schindler, S.; Amaro, F.D.; Antunes, B.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos; Silva, M.; Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I.; Balata, M.; Bruno, G.; Corrieri, R.; Disdier, J.M.; Rosso, A.G.; Molinario, A.; Orlandi, D.; Parlati, S.; Tatananni, L.; Wang, Z.; Barrow, P.; Baudis, L.; Franco, D.; Galloway, M.; James, A.; Kazama, S.; Kessler, G.; Kish, A.; Maier, R.; Mayani, D.; Pakarha, P.; Piastra, F.; Wulf, J.; Bauermeister, B.; Calven, J.; Conrad, J.; Ferella, A.D.; Moraa, K.; Pelssers, B.; Berger, T.; Brown, E.; Piro, M.C.; Breskin, A.; Budnik, R.; Duchovni, E.; Front, D.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N.; Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Undagoitia, T.M.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H.; Wack, O.; Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. von; Chiarini, A.; Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M.; Cussonneau, J.P.; Diglio, S.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D.; Fei, J.; Lombardi, F.; Ni, K.; Ye, J.; Fieguth, A.; Huhmann, C.; Murra, M.; Rosendahl, S.; Vargas, M.; Weinheimer, C.; Wittweg, C.; Fulgione, W.; Grandi, L.; Saldanha, R.; Shockley, E.; Tunnell, C.; Upole, N.; Lindemann, S.; Messina, M.; Naganoma, J.; Shagin, P.; Pienaar, J.; Garcia, D.R.; Reichard, S.; Lavina, L.S.; Stein, A.; Wang, H.; Trinchero, G.; Wei, Y.

2017-01-01

The XENON1T experiment at the Laboratori Nazionali del Gran Sasso (LNGS) is the first WIMP dark matter detector operating with a liquid xenon target mass above the ton-scale. Out of its 3.2 t liquid xenon inventory, 2.0 t constitute the active target of the dual-phase time projection chamber. The scintillation and ionization signals from particle interactions are detected with low-background photomultipliers. This article describes the XENON1T instrument and its subsystems as well as strategies to achieve an unprecedented low background level. First results on the detector response and the performance of the subsystems are also presented. (orig.)

The XENON1T dark matter experiment

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Giboni, K.L.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Plante, G.; Rizzo, A.; Stern, M.; Tatananni, D.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Doets, M.; Hogenbirk, E.; Tiseni, A.; Walet, R. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Othegraven, R.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Antunes, B.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, LIBPhys, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Balata, M.; Bruno, G.; Corrieri, R.; Disdier, J.M.; Rosso, A.G.; Molinario, A.; Orlandi, D.; Parlati, S.; Tatananni, L.; Wang, Z. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Barrow, P.; Baudis, L.; Franco, D.; Galloway, M.; James, A.; Kazama, S.; Kessler, G.; Kish, A.; Maier, R.; Mayani, D.; Pakarha, P.; Piastra, F.; Wulf, J. [University of Zurich, Physik Institut, Zurich (Switzerland); Bauermeister, B.; Calven, J.; Conrad, J.; Ferella, A.D.; Moraa, K.; Pelssers, B. [Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Breskin, A.; Budnik, R.; Duchovni, E.; Front, D.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Undagoitia, T.M.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H.; Wack, O. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M. [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Sivers, M. von [Freiburg Univ. (Germany). Physikalisches Inst.; Bern Univ. (Switzerland). Albert Einstein Center for Fundamental Physics; Cervantes, M.; Lang, R.F.; Masson, D.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Chiarini, A.; Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Cussonneau, J.P.; Diglio, S.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [CNRS/IN2P3, Universite de Nantes, SUBATECH, IMT Atlantique, Nantes (France); Fei, J.; Lombardi, F.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Huhmann, C.; Murra, M.; Rosendahl, S.; Vargas, M.; Weinheimer, C.; Wittweg, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Grandi, L.; Saldanha, R.; Shockley, E.; Tunnell, C.; Upole, N. [University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Lindemann, S. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Messina, M. [Columbia University, Physics Department, New York, NY (United States); New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Pienaar, J. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Garcia, D.R. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Reichard, S. [University of Zurich, Physik Institut, Zurich (Switzerland); Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Lavina, L.S. [Universite Pierre et Marie Curie, Universite Paris Diderot, CNRS/IN2P3, LPNHE, Paris (France); Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Wei, Y. [University of Zurich, Physik Institut, Zurich (Switzerland); University of California, Department of Physics, San Diego, CA (United States); Collaboration: XENON Collaboration

2017-12-15

The XENON1T experiment at the Laboratori Nazionali del Gran Sasso (LNGS) is the first WIMP dark matter detector operating with a liquid xenon target mass above the ton-scale. Out of its 3.2 t liquid xenon inventory, 2.0 t constitute the active target of the dual-phase time projection chamber. The scintillation and ionization signals from particle interactions are detected with low-background photomultipliers. This article describes the XENON1T instrument and its subsystems as well as strategies to achieve an unprecedented low background level. First results on the detector response and the performance of the subsystems are also presented. (orig.)

Xenon recovery from molybdenum-99 production

Energy Technology Data Exchange (ETDEWEB)

Jubin, R.T. [Oak Ridge National Laboratory, 1 Bethel Valley Rd, Oak Ridge, TN, 37931 (United States); Paviet, P.D.; Bresee, J.C. [U.S. Department of Energy,1000 Independence Ave, S.W., Washington DC, 20585-1290 (United States)

2016-07-01

The U.S. Department of Energy Office of Nuclear Energy (DOE-NE) sponsors research and development on the recycle of used commercial nuclear fuel as an option for future nuclear fuel cycles that offers increased use of uranium and thorium resources and a possible reduction in the overall cost of nuclear waste management. The two alternatives, direct disposal of used fuel and fuel recycle, are broadly referred to as open and closed fuel cycles. One requirement of a closed fuel cycle is the safe management of radioactive off-gases, which includes {sup 14}C, radioiodine and the noble gases, including radio-xenon. The longest lived relevant radio-xenon isotope is {sup 127}Xe; with a half-life of just 36.35 days it is feasible to trap and hold the radio-xenon to allow for decay to safe environmental levels. However, the very weak chemical bonds of noble gases, in this case xenon, make them difficult to trap, which led to an extensive DOE-NE study of noble gas adsorption on various molecular sieves as an alternative to costly cryogenics processes. Preliminary results indicate that xenon adsorption at near room temperature on molecular sieves, both synthetic and natural, may have both cost and efficiency advantages over cryogenic processes. These results appear to have direct application in helping achieve the United Nations Security Council goal of reducing xenon emissions from medical isotope producers.

GANIL Workshop on Ion Sources; Journees Sources d'Ions

Energy Technology Data Exchange (ETDEWEB)

Leroy, Renan [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)

1999-07-01

The proceedings of the GANIL Workshop on Ion Sources held at GANIL - Caen on 18-19 March 1999 contains 13 papers aiming at improving the old source operation and developing new types of sources for nuclear research and studies of ion physics. A number of reports are devoted to applications like surface treatment, ion implantation or fusion injection. The 1+{yields}n+ transformation, charged particle transport in ECR sources, addition of cesium and xenon in negative ion sources and other basic issues in ion sources are also addressed.

On electron attachment effect on characteristics of the DBD in chlorine and its mixtures with xenon

Science.gov (United States)

Avtaeva, S. V.

2017-11-01

The electron attachment effect on DBD characteristics in chlorine and its mixtures with xenon has been studied. Characteristics of the DBDs in pure chlorine and in xenon-chlorine mixtures with a chlorine fraction of 0.1-5% were modeled using the fluid model. It is shown that the electron attachment limits a magnitude of the DBD current, contributes to formation of multiple current spikes, appearance of a double layer near the dielectric surface and formation of XeCl* excimer molecules, and leads to a redistribution of the power deposited into the discharge: more power is deposited into ions and less power is deposited into electrons.

Chromatographic separation of radioactive noble gases from xenon

Science.gov (United States)

Akerib, D. S.; Araújo, H. M.; Bai, X.; Bailey, A. J.; Balajthy, J.; Beltrame, P.; Bernard, E. P.; Bernstein, A.; Biesiadzinski, T. P.; Boulton, E. M.; Bramante, R.; Cahn, S. B.; Carmona-Benitez, M. C.; Chan, C.; Chiller, A. A.; Chiller, C.; Coffey, T.; Currie, A.; Cutter, J. E.; Davison, T. J. R.; Dobi, A.; Dobson, J. E. Y.; Druszkiewicz, E.; Edwards, B. N.; Faham, C. H.; Fiorucci, S.; Gaitskell, R. J.; Gehman, V. M.; Ghag, C.; Gibson, K. R.; Gilchriese, M. G. D.; Hall, C. R.; Hanhardt, M.; Haselschwardt, S. J.; Hertel, S. A.; Hogan, D. P.; Horn, M.; Huang, D. Q.; Ignarra, C. M.; Ihm, M.; Jacobsen, R. G.; Ji, W.; Kamdin, K.; Kazkaz, K.; Khaitan, D.; Knoche, R.; Larsen, N. A.; Lee, C.; Lenardo, B. G.; Lesko, K. T.; Lindote, A.; Lopes, M. I.; Manalaysay, A.; Mannino, R. L.; Marzioni, M. F.; McKinsey, D. N.; Mei, D.-M.; Mock, J.; Moongweluwan, M.; Morad, J. A.; Murphy, A. St. J.; Nehrkorn, C.; Nelson, H. N.; Neves, F.; O'Sullivan, K.; Oliver-Mallory, K. C.; Palladino, K. J.; Pease, E. K.; Pech, K.; Phelps, P.; Reichhart, L.; Rhyne, C.; Shaw, S.; Shutt, T. A.; Silva, C.; Solovov, V. N.; Sorensen, P.; Stephenson, S.; Sumner, T. J.; Szydagis, M.; Taylor, D. J.; Taylor, W.; Tennyson, B. P.; Terman, P. A.; Tiedt, D. R.; To, W. H.; Tripathi, M.; Tvrznikova, L.; Uvarov, S.; Verbus, J. R.; Webb, R. C.; White, J. T.; Whitis, T. J.; Witherell, M. S.; Wolfs, F. L. H.; Yazdani, K.; Young, S. K.; Zhang, C.

2018-01-01

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.

Autoionization in xenon

International Nuclear Information System (INIS)

Knight, R.D.; Wang, L.G.

1986-01-01

The authors have studied both even- and odd-parity autoionizing levels in xenon. These levels lie between the Xe/sup +/ /sup 2/P/sub 3/2/ and /sup 2/P/sub 1/2/ ionization limits. Their technique is laser spectroscopy of a thermal metastable atomic beam of xenon. One-photon laser spectroscopy from the 6s'[1/2]/sub 0/ level has been used to study the np'[1/2]/sub 1/ and np'[3/2]/sub 1/ autoionization doublets, n = 7-20. These had previously been observed only for n = 7,8. The authors are using a MQDT analysis of both discrete and autoionizing even-parity J = 1 levels (five channels) to understand the autoionization line profiles. They have also used two-photon laser spectroscopy from the 6s[3/2]/sub 2/ metastable level via various J = 1,2 6p' levels to observe the odd-parity ns'[1/2]/sub 0 1/, nd'[3/2]/sub 1 2/, and nd'[5/2]/sub 2 3/ autoionizing levels to n > 50. This is the first observation of J not equal to 1 odd-parity autoionization in xenon. The most striking feature of these spectra is the complete absence of the very intense, very broad transitions to nd'[3/2]/sub 1/, which dominate the photoabsorption spectrum from the xenon J = 0 ground state. The other nd' levels (J = 2.3) and ns'[1/2]/sub 0/ are all comparable in width to the previously observed ns'[1/2]/sub 1/ levels. The authors present the results of position and width measurements for these levels

The atmosphere of Mars - Detection of krypton and xenon

Science.gov (United States)

Owen, T.; Biemann, K.; Biller, J. E.; Lafleur, A. L.; Rushneck, D. R.; Howarth, D. W.

1976-01-01

Krypton and xenon have been discovered in the Martian atmosphere with the mass spectrometer on the second Viking lander. Krypton is more abundant than xenon. The relative abundances of the krypton isotopes appear normal, but the ratio of xenon-129 to xenon-132 is enhanced on Mars relative to the terrestrial value for this ratio. Some possible implications of these findings are discussed.

Spectroscopic studies of xenon EUV emission in the 40-80 nm wavelength range using an absolutely calibrated monochromator

Energy Technology Data Exchange (ETDEWEB)

Merabet, H [Mathematic and Sciences Unit, Dhofar University, Salalah 211, Sultanate of (Oman); Bista, R [Department of Physics, University of Nevada Reno, Reno, NV 89557 (United States); Bruch, R [Department of Physics, University of Nevada Reno, Reno, NV 89557 (United States); Fuelling, S [Department of Physics, University of Nevada Reno, Reno, NV 89557 (United States)

2007-03-01

We have measured and identified numerous Extreme UltraViolet (EUV) radiative line structures arising from xenon (Xe) ions in charge state q = 1 to 10 in the wavelength range 40-80 nm. To obtain reasonable intensities of different charged Xe ions, we have used a compact microwave plasma source which was designed and developed at the Lawrence Berkeley National Laboratory (LBNL). The EUV emission of the ECR plasma has been measured by a 1.5 m grazing incidence monochromator that was absolutely calibrated in the 10-80 nm wavelength range using well known and calibrated EUV light at the Advanced Light Source (ALS), LBNL. This calibration has enabled us to determine absolute intensities of previously measured EUV radiative lines in the wavelengths regions investigated for different ionization stages of Xe. In addition, emission spectra of xenon ions for corresponding measured lines have been calculated. The calculations have been carried out within the relativistic Hartree-Fock (HF) approximation. Results of calculations are found to be in good agreement with current and available experimental and theoretical data.

Radon screening for XENON1T

Energy Technology Data Exchange (ETDEWEB)

Lindemann, Sebastian [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

2015-07-01

Radon with its isotope {sup 222}Rn is one of the dominant sources of internal background in liquid xenon detectors searching for low energetic rare events like WIMP-nucleon scattering. In my talk I briefly review the problem posed by {sup 222}Rn and motivate the screening strategy followed by XENON1T. I introduce the radon emanation technique making use of ultra low background proportional counters and present selected results obtained during the design and construction phases of XENON1T. Finally, I sketch advances in radon emanation assay techniques and give a short outlook on upcoming measurements.

Electron drift in a large scale solid xenon

International Nuclear Information System (INIS)

Yoo, J.; Jaskierny, W.F.

2015-01-01

A study of charge drift in a large scale optically transparent solid xenon is reported. A pulsed high power xenon light source is used to liberate electrons from a photocathode. The drift speeds of the electrons are measured using a 8.7 cm long electrode in both the liquid and solid phase of xenon. In the liquid phase (163 K), the drift speed is 0.193 ± 0.003 cm/μs while the drift speed in the solid phase (157 K) is 0.397 ± 0.006 cm/μs at 900 V/cm over 8.0 cm of uniform electric fields. Therefore, it is demonstrated that a factor two faster electron drift speed in solid phase xenon compared to that in liquid in a large scale solid xenon

Properties of excited xenon atoms in a plasma display panel

International Nuclear Information System (INIS)

Uhm, Han S.; Hong, Byoung H.; Oh, Phil Y.; Choi, Eun H.

2009-01-01

The luminance efficiency of a plasma display panel is directly related to the vacuum ultraviolet (VUV) light that is emitted from excited xenon (Xe) atoms and molecules. It is therefore necessary to investigate the properties of excited xenon atoms. This study presents experimental data associated with the behavior of excited xenon atoms in a PDP discharge cell and compares the data with the theoretical results obtained using an analytical model. The properties of excited xenon atoms in the discharge cells of a plasma display panel are investigated by measuring the excited atom density through the use of laser absorption spectroscopy. The density of the excited xenon atoms increases from zero, reaches its peak, and decreases with time in the discharge cells. The profile of the excited xenon atoms is also studied in terms of the xenon mole fraction. The typical density of the excited xenon atoms in the metastable state is on the order of 10 13 atoms per cubic cm.

Radon depletion in xenon boil-off gas

Energy Technology Data Exchange (ETDEWEB)

Bruenner, S.; Cichon, D.; Lindemann, S.; Undagoitia, T.M.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany)

2017-03-15

An important background in detectors using liquid xenon for rare event searches arises from the decays of radon and its daughters. We report for the first time a reduction of {sup 222}Rn in the gas phase above a liquid xenon reservoir. We show a reduction factor of >or similar 4 for the {sup 222}Rn concentration in boil-off xenon gas compared to the radon enriched liquid phase. A semiconductor-based α-detector and miniaturized proportional counters are used to detect the radon. As the radon depletion in the boil-off gas is understood as a single-stage distillation process, this result establishes the suitability of cryogenic distillation to separate radon from xenon down to the 10{sup -15} mol/mol level. (orig.)

Optimization of Xenon Biosensors for Detection of Protein Interactions

International Nuclear Information System (INIS)

Lowery, Thomas J.; Garcia, Sandra; Chavez, Lana; Ruiz, E.Janette; Wu, Tom; Brotin, Thierry; Dutasta, Jean-Pierre; King, David S.; Schultz, Peter G.; Pines, Alex; Wemmer, David E.

2005-08-01

Hyperpolarized 129Xe NMR can detect the presence of specific low-concentration biomolecular analytes by means of the xenon biosensor, which consists of a water-soluble, targeted cryptophane-A cage that encapsulates xenon. In this work we use the prototypical biotinylated xenon biosensor to determine the relationship between the molecular composition of the xenon biosensor and the characteristics of protein-bound resonances. The effects of diastereomer overlap, dipole-dipole coupling, chemical shift anisotropy, xenon exchange, and biosensor conformational exchange on protein-bound biosensor signal were assessed. It was found that optimal protein-bound biosensor signal can be obtained by minimizing the number of biosensor diastereomers and using a flexible linker of appropriate length. Both the linewidth and sensitivity of chemical shift to protein binding of the xenon biosensor were found to be inversely proportional to linker length

Gross xenon stability

International Nuclear Information System (INIS)

Lewins, J.D.; Wilson, P.P.H.

1997-01-01

The effect of xenon in thermal reactors on steady operation is generally destabilizing. Illustrating this involves the study of appropriate transfer functions, which may be conveniently displayed in three ways: as Bode, Nyquist, and root-locus diagrams. The three forms allow different aspects to be highlighted. These are illustrated for the effect of xenon with allowance not only for the stabilizing effect of the direct yield in fission but also to show the consequences of neglecting the time dependence due to the thermal capacity of the reactor. With careful interpretation, all these forms give an interpretation of stability that is consistent with direct evaluation and promote the understanding of the onset of gross oscillations in power

NMR investigations of surfaces and interfaces using spin-polarized xenon

International Nuclear Information System (INIS)

Gaede, H.C.; Lawrence Berkeley Lab., CA

1995-07-01

129 Xe NMR is potentially useful for the investigation of material surfaces, but has been limited to high surface area samples in which sufficient xenon can be loaded to achieve acceptable signal to noise ratios. In Chapter 2 conventional 129 Xe NMR is used to study a high surface area polymer, a catalyst, and a confined liquid crystal to determine the topology of these systems. Further information about the spatial proximity of different sites of the catalyst and liquid crystal systems is determined through two dimensional exchange NMR in Chapter 3. Lower surface area systems may be investigated with spin-polarized xenon, which may be achieved through optical pumping and spin exchange. Optically polarized xenon can be up to 10 5 times more sensitive than thermally polarized xenon. In Chapter 4 highly polarized xenon is used to examine the surface of poly(acrylonitrile) and the formation of xenon clathrate hydrates. An attractive use of polarized xenon is as a magnetization source in cross polarization experiments. Cross polarization from adsorbed polarized xenon may allow detection of surface nuclei with drastic enhancements. A non-selective low field thermal mixing technique is used to enhance the 13 C signal of CO 2 of xenon occluded in solid CO 2 by a factor of 200. High-field cross polarization from xenon to proton on the surface of high surface area polymers has enabled signal enhancements of ∼1,000. These studies, together with investigations of the efficiency of the cross polarization process from polarized xenon, are discussed in Chapter 5. Another use of polarized xenon is as an imaging contrast agent in systems that are not compatible with traditional contrast agents. The resolution attainable with this method is determined through images of structured phantoms in Chapter 6

Fast electrons from multi-electron dynamics in xenon clusters induced by inner-shell ionization

International Nuclear Information System (INIS)

Bostedt, Christoph; Thomas, Heiko; Hoener, Matthias; Moeller, Thomas; Saalmann, Ulf; Georgescu, Ionut; Gnodtke, Christian; Rost, Jan-Michael

2010-01-01

Fast electrons emitted from xenon clusters in strong femtosecond 90 eV pulses have been measured at the Free-electron Laser in Hamburg (FLASH). Energy absorption occurs mainly through atomic inner-shell photo-ionization. Photo-electrons are trapped in the strong Coulomb potential of the cluster ions and form a non-equilibrium plasma with supra-atomic density. Its equilibration through multiple energy-exchanging collisions within the entire cluster volume produces electrons with energies well beyond the dominant emission line of atomic xenon. Here, in contrast to traditional low-frequency laser plasma heating, the plasma gains energy from electrons delivered through massive single-photon excitation from bound states. Electron emission induced by thermalization of a non-equilibrium plasma is expected to be a general phenomenon occurring for strong atomic x-ray absorption in extended systems.

Photoionization of xenon below the atomic ionization potential

International Nuclear Information System (INIS)

Laporte, P.; Saile, V.; Reininger, R.; Asaf, U.; Steinberger, I.T.

1982-10-01

Experiments using monochromated synchrotron radiation revealed that for densities of the order of 10 19 atoms/cm 3 and more xenon exhibits a continuous photoresponse excitation spectrum below the atomic ionization potential (12.12 eV). The lower limit of the continuum is at about 11.10 eV, the energy difference between the ground state of the molecular ion Xe 2+ and that of the free atom. This is attributed to the Hornbeck-Molnar process occurring at the line wings as well as at the line centres. Dips appearing in the continuum very near to positions of atomic lines are discussed invoking the quasi-static theory. (orig.)

Cosmogenic activation of xenon and copper

Energy Technology Data Exchange (ETDEWEB)

Baudis, Laura; Kish, Alexander; Piastra, Francesco [University of Zuerich, Department of Physics, Zuerich (Switzerland); Schumann, Marc [University of Bern, Albert Einstein Center for Fundamental Physics, Bern (Switzerland)

2015-10-15

Rare event search experiments using liquid xenon as target and detection medium require ultra-low background levels to fully exploit their physics potential. Cosmic ray induced activation of the detector components and, even more importantly, of the xenon itself during production, transportation and storage at the Earth's surface, might result in the production of radioactive isotopes with long half-lives, with a possible impact on the expected background. We present the first dedicated study on the cosmogenic activation of xenon after 345 days of exposure to cosmic rays at the Jungfraujoch research station at 3470 m above sea level, complemented by a study of copper which has been activated simultaneously. We have directly observed the production of {sup 7}Be, {sup 101}Rh, {sup 125}Sb, {sup 126}I and {sup 127}Xe in xenon, out of which only {sup 125}Sb could potentially lead to background for a multi-ton scale dark matter search. The production rates for five out of eight studied radioactive isotopes in copper are in agreement with the only existing dedicated activation measurement, while we observe lower rates for the remaining ones. The specific saturation activities for both samples are also compared to predictions obtained with commonly used software packages, where we observe some underpredictions, especially for xenon activation. (orig.)

Lambda-guided calculation method (LGC method) for xenon/CT CBF

Energy Technology Data Exchange (ETDEWEB)

Sase, Shigeru [Anzai Medical Co., Ltd., Tokyo (Japan); Honda, Mitsuru; Kushida, Tsuyoshi; Seiki, Yoshikatsu; Machida, Keiichi; Shibata, Iekado [Toho Univ., Tokyo (Japan). School of Medicine

2001-12-01

A quantitative CBF calculation method for xenon/CT was developed by logically estimating time-course change rate (rate constant) of arterial xenon concentration from that of end-tidal xenon concentration. A single factor ({gamma}) was introduced to correlate the end-tidal rate constant (Ke) with the arterial rate constant (Ka) in a simplified equation. This factor ({gamma}) is thought to reflect the diffusing capacity of the lung for xenon. When an appropriate value is given to {gamma}, it is possible to calculate the arterial rate constant (Calculated Ka) from Ke. To determine {gamma} for each xenon/CT CBF examination, a procedure was established which utilizes the characteristics of white matter lambda; lambda refers to xenon brain-blood partition coefficient. Xenon/CT studies were performed on four healthy volunteers. Hemispheric CBF values (47.0{+-}9.0 ml/100 g/min) with use of Calculated Ka were close to the reported normative values. For a 27-year-old healthy man, the rate constant for the common carotid artery was successfully measured and nearly equal to Calculated Ka. The authors conclude the method proposed in this work, lambda-guided calculation method, could make xenon/CT CBF substantially reliable and quantitative by effective use of end-tidal xenon. (author)

Lambda-guided calculation method (LGC method) for xenon/CT CBF

International Nuclear Information System (INIS)

Sase, Shigeru; Honda, Mitsuru; Kushida, Tsuyoshi; Seiki, Yoshikatsu; Machida, Keiichi; Shibata, Iekado

2001-01-01

A quantitative CBF calculation method for xenon/CT was developed by logically estimating time-course change rate (rate constant) of arterial xenon concentration from that of end-tidal xenon concentration. A single factor (γ) was introduced to correlate the end-tidal rate constant (Ke) with the arterial rate constant (Ka) in a simplified equation. This factor (γ) is thought to reflect the diffusing capacity of the lung for xenon. When an appropriate value is given to γ, it is possible to calculate the arterial rate constant (Calculated Ka) from Ke. To determine γ for each xenon/CT CBF examination, a procedure was established which utilizes the characteristics of white matter lambda; lambda refers to xenon brain-blood partition coefficient. Xenon/CT studies were performed on four healthy volunteers. Hemispheric CBF values (47.0±9.0 ml/100 g/min) with use of Calculated Ka were close to the reported normative values. For a 27-year-old healthy man, the rate constant for the common carotid artery was successfully measured and nearly equal to Calculated Ka. The authors conclude the method proposed in this work, lambda-guided calculation method, could make xenon/CT CBF substantially reliable and quantitative by effective use of end-tidal xenon. (author)

Improvements in or relating to trapping and reuse of radioactive xenon

International Nuclear Information System (INIS)

Bolmsjoe, M.S.; Persson, B.R.

1981-01-01

A method is described suitable for recovering, from a mixture of gases contaning radioactive xenon, a mixture of gases containing an increased concentration of radioactive xenon, which method comprises the steps of passing xenon-containing gas through a bed of activated charcoal to adsorb the xenon therein, thereafter heating the charcoal bed to a temperature within the range of from 200 to 400 0 C, passing a moisture-free sweep gas through the bed when heated to said temperature to desorb xenon therefrom and then collecting the xenon-containing gas thus formed. (author)

Charge transfer rates for xenon Rydberg atoms at metal and semiconductor surfaces

Energy Technology Data Exchange (ETDEWEB)

Dunning, F.B. [Department of Physics and Astronomy, Rice University, MS 61, 6100 Main Street, Houston, TX 77005-1892 (United States)]. E-mail: fbd@rice.edu; Wethekam, S. [Institut fuer Physik der Humboldt-Universitaet zu Berlin, Newtonstr. 15, D-12489 Berlin (Germany); Dunham, H.R. [Department of Physics and Astronomy, Rice University, MS 61, 6100 Main Street, Houston, TX 77005-1892 (United States); Lancaster, J.C. [Department of Physics and Astronomy, Rice University, MS 61, 6100 Main Street, Houston, TX 77005-1892 (United States)

2007-05-15

Recent progress in the study of charge exchange between xenon Rydberg atoms and surfaces is reviewed. Experiments using Au(1 1 1) surfaces show that under appropriate conditions each incident atom can be detected as an ion. The ionization dynamics, however, are strongly influenced by the perturbations in the energies and structure of the atomic states that occur as the ion collection field is applied and as the atom approaches the surface. These lead to avoided crossings between different atomic levels causing the atom to successively assume the character of a number of different states and lose much of its initial identity. The effects of this mixing are discussed. Efficient surface ionization is also observed at Si(1 0 0) surfaces although the ion signal is influenced by stray fields present at the surface.

Reliability and error analysis on xenon/CT CBF

International Nuclear Information System (INIS)

Zhang, Z.

2000-01-01

This article provides a quantitative error analysis of a simulation model of xenon/CT CBF in order to investigate the behavior and effect of different types of errors such as CT noise, motion artifacts, lower percentage of xenon supply, lower tissue enhancements, etc. A mathematical model is built to simulate these errors. By adjusting the initial parameters of the simulation model, we can scale the Gaussian noise, control the percentage of xenon supply, and change the tissue enhancement with different kVp settings. The motion artifact will be treated separately by geometrically shifting the sequential CT images. The input function is chosen from an end-tidal xenon curve of a practical study. Four kinds of cerebral blood flow, 10, 20, 50, and 80 cc/100 g/min, are examined under different error environments and the corresponding CT images are generated following the currently popular timing protocol. The simulated studies will be fed to a regular xenon/CT CBF system for calculation and evaluation. A quantitative comparison is given to reveal the behavior and effect of individual error resources. Mixed error testing is also provided to inspect the combination effect of errors. The experiment shows that CT noise is still a major error resource. The motion artifact affects the CBF results more geometrically than quantitatively. Lower xenon supply has a lesser effect on the results, but will reduce the signal/noise ratio. The lower xenon enhancement will lower the flow values in all areas of brain. (author)

Potential for large-scale uses for fission-product Xenon

International Nuclear Information System (INIS)

Rohrmann, C.A.

1983-03-01

Of all fission products in spent, low-enrichment-uranium power-reactor fuels, xenon is produced in the highest yield - nearly one cubic meter, STP, per metric ton. In aged fuels which may be considered for processing in the US, radioactive xenon isotopes approach the lowest limits of detection. The separation from accompanying radioactive 85 Kr is the essential problem; however, this is state-of-the-art technology which has been demonstrated on the pilot scale to yield xenon with pico-curie levels of 85 Kr contamination. If needed for special applications, such levels could be further reduced. Environmental considerations require the isolation of essentially all fission-product krypton during fuel processing. Economic restraints assure that the bulk of this krypton will need to be separated from the much-more-voluminous xenon fraction of the total amount of fission gas. Xenon may thus be discarded or made available for uses at probably very low cost. In contrast with many other fission products which have unique radioactive characteristics which make them useful as sources of heat, gamma and x-rays, and luminescence - as well as for medicinal diagnostics and therapeutics - fission-product xenon differs from naturally occurring xenon only in its isotopic composition which gives it a slightly hgiher atomic weight, because of the much higher concentrations of the 134 Xe and 136 Xe isotopes. Therefore, fission-product xenon can most likely find uses in applications which already exist but which can not be exploited most beneficially because of the high cost and scarcity of natural xenon. Unique uses would probably include applications in improved incandescent light illumination in place of krypton and in human anesthesia

The XENON project for dark matter direct detection at LNGS

Science.gov (United States)

Molinario, Andrea

2017-12-01

The XENON project at INFN Laboratori Nazionali del Gran Sasso, Italy, aims at dark matter direct detection with liquid xenon dual-phase time projection chambers. Latest results of XENON100 detector exclude various models of leptophilic dark matter. A search for low mass weakly interacting massive particles was also performed, lowering the energy threshold for detection to 0.7 keV for nuclear recoils. The multi-ton XENON1T detector is fully installed and operating. It is expected to reach a sensitivity a factor 100 better than XENON100 with a 2 ton·year exposure.

Ventilator-driven xenon ventilation studies

International Nuclear Information System (INIS)

Chilcoat, R.T.; Thomas, F.D.; Gerson, J.I.

1984-01-01

A modification of a common commercial Xe-133 ventilation device is described for mechanically assisted ventilation imaging. The patient's standard ventilator serves as the power source controlling the ventilatory rate and volume during the xenon study, but the gases in the two systems are not intermixed. This avoids contamination of the ventilator with radioactive xenon. Supplemental oxygen and positive end-expiratory pressure (PEEP) are provided if needed. The system can be converted quickly for conventional studies with spontaneous respiration

Investigations on a highly luminous condensed xenon scintillator

International Nuclear Information System (INIS)

Lansiart, Alain; Seigneur, Alain; Morucci, J.-P.

1976-12-01

The means of creating a maximal amount of light by absorption of gamma radiation in condensed xenon were investigated. One of the methods relies on the light production around wires in liquid xenon when several kilovolts are applied to them. Another method uses the saturating vapor present over solid xenon; the electric field pulls out electrons from the solid and accelerates them in the gas phase where they produce light through inelastic collisions [fr

Search for double beta decay processes of {sup 124}Xe with XENON100 and XENON1T

Energy Technology Data Exchange (ETDEWEB)

Fieguth, Alexander [IKP, Westfaelische-Wilhelms-Universitaet Muenster (Germany)

2016-07-01

Driven by the search for dark matter particles the XENON dark matter project recently installed its next stage multi-ton experiment XENON1T at the LNGS, which will probe the spin-indpendent-WIMP-Nucleon cross section down to 2.10{sup -47} cm{sup 2}. Besides its main purpose different particle physics topics can be addressed by the taken data. One example are the double beta decay processes of natural isotope {sup 124}Xe. This isotope is expected to decay via two-neutrino double electron capture (2νECEC) and due to its high Q-value of 2864 keV additionally through 2νβ{sup +}β{sup +}. Since these processes have not been detected so far, there is only a lower limit the respective half-life (e.g. > 4.7.10{sup 21} yr for 2νECEC). A detection of the 2νECEC is possible using XENON1T data by looking for its clear signature of secondary X-rays or Auger electrons and at least new lower half-life limits for all other decay channels can be obtained. While these processes are expected from standard model physics, a detection of a decay without neutrinos (e.g 0νECEC) would hint towards beyond the standard model physics and could derive conclusions on the neutrino mass. Until XENON1T is taking data, the search for all processes can be tested in the recorded data of its predecessor XENON100.

Xenon Acquisition Strategies for High-Power Electric Propulsion NASA Missions

Science.gov (United States)

Herman, Daniel A.; Unfried, Kenneth G.

2015-01-01

The benefits of high-power solar electric propulsion (SEP) for both NASA's human and science exploration missions combined with the technology investment from the Space Technology Mission Directorate have enabled the development of a 50kW-class SEP mission. NASA mission concepts developed, including the Asteroid Redirect Robotic Mission, and those proposed by contracted efforts for the 30kW-class demonstration have a range of xenon propellant loads from 100's of kg up to 10,000 kg. A xenon propellant load of 10 metric tons represents greater than 10% of the global annual production rate of xenon. A single procurement of this size with short-term delivery can disrupt the xenon market, driving up pricing, making the propellant costs for the mission prohibitive. This paper examines the status of the xenon industry worldwide, including historical xenon supply and pricing. The paper discusses approaches for acquiring on the order of 10 MT of xenon propellant considering realistic programmatic constraints to support potential near-term NASA missions. Finally, the paper will discuss acquisitions strategies for mission campaigns utilizing multiple high-power solar electric propulsion vehicles requiring 100's of metric tons of xenon over an extended period of time where a longer term acquisition approach could be implemented.

Removing krypton from xenon by cryogenic distillation to the ppq level

Science.gov (United States)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; Di Gangi, P.; Di Giovanni, A.; Diglio, S.; Duchovni, E.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Franco, D.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Huhmann, C.; Itay, R.; Kaminsky, B.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Calloch, M. Le; Lin, Q.; Lindemann, S.; Lindner, M.; Lopes, J. A. M.; Manfredini, A.; Maris, I.; Undagoitia, T. Marrodán; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Meng, Y.; Messina, M.; Micheneau, K.; Miguez, B.; Molinario, A.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Orrigo, S. E. A.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Piro, M.-C.; Pizzella, V.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Saldanha, R.; Santos, J. M. F. dos; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Lavina, L. Scotto; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. v.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Upole, N.; Wang, H.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.; Cristescu, I.

2017-05-01

The XENON1T experiment aims for the direct detection of dark matter in a detector filled with 3.3 tons of liquid xenon. In order to achieve the desired sensitivity, the background induced by radioactive decays inside the detector has to be sufficiently low. One major contributor is the β -emitter ^{85}Kr which is present in the xenon. For XENON1T a concentration of natural krypton in xenon ^{nat}Kr/Xe McCabe-Thiele approach is described. The system demonstrated a krypton reduction factor of 6.4\\cdot 10^5 with thermodynamic stability at process speeds above 3 kg/h. The resulting concentration of ^{nat}Kr/Xe<26 ppq is the lowest ever achieved, almost one order of magnitude below the requirements for XENON1T and even sufficient for future dark matter experiments using liquid xenon, such as XENONnT and DARWIN.

XAS characterisation of xenon bubbles in uranium dioxide

Energy Technology Data Exchange (ETDEWEB)

Martin, P. [CEA Cadarache, DEN/DEC/SESC/LLCC, Bat. 130, 13108 St. Paul Lez Durance (France)], E-mail: martinp@drncad.cea.fr; Garcia, P.; Carlot, G.; Sabathier, C.; Valot, C. [CEA Cadarache, DEN/DEC/SESC/LLCC, Bat. 130, 13108 St. Paul Lez Durance (France); Nassif, V. [CEA Grenoble, DSM/DRFMC/SP2M/NRS, 17 Avenue des Martyrs, 38054 Grenoble Cedex 9 (France); Proux, O. [Laboratoire de Geophysique Interne et Tectonophysique, UMR CNRS/Universite Joseph Fourier, 1381 rue de la Piscine, Domaine Universitaire, 38400 Saint-Martin-D' Heres (France); Hazemann, J.-L. [Institut Neel, CNRS, 25 Avenue des Martyrs, BP 166, 38042 Grenoble Cedex 9 (France)

2008-06-15

X-ray absorption spectroscopy experiments were performed on a set of uranium dioxide samples implanted with 10{sup 17} xenon cm{sup -2} at 800 keV (8 at.% at 140 nm). EXAFS measurements performed at 12 K showed that during implantation the gas forms highly pressurised nanometre size inclusions. Bubble pressures were estimated at 2.8 {+-} 0.3 GPa at low temperature. Following the low energy xenon implantation, samples were annealed between 1073 and 1773 K for several hours. Stability of nanometre size highly pressurized xenon aggregates in UO{sub 2} is demonstrated up to 1073 K as for this temperature almost no modification of the xenon environment was observed. Above this temperature, bubbles will trap migrating vacancies and their inner pressure is seen to decrease substantially.

Dark matter search with XENON1T

NARCIS (Netherlands)

Aalbers, J.

2018-01-01

Most matter in the universe consists of 'dark matter' unknown to particle physics. Deep underground detectors such as XENON1T attempt to detect rare collisions of dark matter with ordinary atoms. This thesis describes the first dark matter search of XENON1T, how dark matter signals would appear in

GANIL Workshop on Ion Sources

International Nuclear Information System (INIS)

Leroy, Renan

1999-01-01

The proceedings of the GANIL Workshop on Ion Sources held at GANIL - Caen on 18-19 March 1999 contains 13 papers aiming at improving the old source operation and developing new types of sources for nuclear research and studies of ion physics. A number of reports are devoted to applications like surface treatment, ion implantation or fusion injection. The 1+→n+ transformation, charged particle transport in ECR sources, addition of cesium and xenon in negative ion sources and other basic issues in ion sources are also addressed

Xenon-computed tomography of kidney transplants

International Nuclear Information System (INIS)

Mutze, S.; Reichmuth, B.; Suess, C.; Lippert, J.; Ewert, R.

1994-01-01

Xenon-CT is an established method for determining cerebral perfusion, while applications in other organs are rare. We evaluated the diagnostic potential of measuring the regional Renal Blood Flow (rRBF) in 10 patients with transplanted kidneys by xenon-CT. We found significant differences in the rRBF between the renal medulla and the cortex. There were no differences between normal renal transplants and transplants with chronic rejection. (orig.) [de

The potential for large scale uses for fission product xenon

International Nuclear Information System (INIS)

Rohrmann, C.A.

1983-01-01

Of all fission products in spent, low enrichment, uranium, power reactor fuels xenon is produced in the highest yield - nearly one cubic meter, STP, per metric ton. In aged fuels which may be considered for processing in the U.S. radioactive xenon isotopes approach the lowest limits of detection. The separation from accompanying radioactive 85 Kr is the essential problem; however, this is state of the art technology which has been demonstrated on the pilot scale to yield xenon with pico-curie levels of 85 Kr contamination. If needed for special applications, such levels could be further reduced. Environmental considerations require the isolation of essentially all fission product krypton during fuel processing. Economic restraints assure that the bulk of this krypton will need to be separated from the much more voluminous xenon fraction of the total amount of fission gas. Xenon may thus be discarded or made available for uses at probably very low cost. In contrast with many other fission products which have unique radioactive characteristics which make them useful as sources of heat, gamma and x-rays and luminescence as well as for medicinal diagnostics and therapeutics fission product xenon differs from naturally occurring xenon only in its isotopic composition which gives it a slightly higher atomic weight, because of the much higher concentrations of the 134 X and 136 Xe isotopes. Therefore, fission product xenon can most likely find uses in applications which already exist but which can not be exploited most beneficially because of the high cost and scarcity of natural xenon. Unique uses would probably include applications in improved incandescent light illumination in place of krypton and in human anesthesia

Hugoniot measurements of double-shocked precompressed dense xenon plasmas

Science.gov (United States)

Zheng, J.; Chen, Q. F.; Gu, Y. J.; Chen, Z. Y.

2012-12-01

The current partially ionized plasmas models for xenon show substantial differences since the description of pressure and thermal ionization region becomes a formidable task, prompting the need for an improved understanding of dense xenon plasmas behavior at above 100 GPa. We performed double-shock compression experiments on dense xenon to determine accurately the Hugoniot up to 172 GPa using a time-resolved optical radiation method. The planar strong shock wave was produced using a flyer plate impactor accelerated up to ˜6 km/s with a two-stage light-gas gun. The time-resolved optical radiation histories were acquired by using a multiwavelength channel optical transience radiance pyrometer. Shock velocity was measured and mass velocity was determined by the impedance-matching methods. The experimental equation of state of dense xenon plasmas are compared with the self-consistent fluid variational calculations of dense xenon in the region of partial ionization over a wide range of pressures and temperatures.

The unbearable lightness of being: CDMS versus XENON

CERN Document Server

Frandsen, Mads T; McCabe, Christopher; Sarkar, Subir; Schmidt-Hoberg, Kai

2013-01-01

The CDMS-II collaboration has reported 3 events in a Si detector, which are consistent with being nuclear recoils due to scattering of Galactic dark matter particles with a mass of about 8.6 GeV and a cross-section on neutrons of about 2 x 10^-41 cm^2. While a previous result from the XENON10 experiment has supposedly ruled out such particles as dark matter, we find by reanalysing the XENON10 data that this is not the case. Some tension remains however with the upper limit placed by the XENON100 experiment, independently of astrophysical uncertainties concerning the Galactic dark matter distribution. We explore possible ways of ameliorating this tension by altering the properties of dark matter interactions. Nevertheless, even with standard couplings, light dark matter is consistent with both CDMS and XENON10/100.

Xenon ventilation CT using dual-source and dual-energy technique in children with bronchiolitis obliterans: correlation of xenon and CT density values with pulmonary function test results

International Nuclear Information System (INIS)

Goo, Hyun Woo; Yang, Dong Hyun; Seo, Joon Beom; Chae, Eun Jin; Lee, Jeongjin; Hong, Soo-Jong; Yu, Jinho; Kim, Byoung-Ju; Krauss, Bernhard

2010-01-01

Xenon ventilation CT using dual-source and dual-energy technique is a recently introduced, promising functional lung imaging method. To expand its clinical applications evidence of additional diagnostic value of xenon ventilation CT over conventional chest CT is required. To evaluate the usefulness of xenon ventilation CT using dual-source and dual-energy technique in children with bronchiolitis obliterans (BO). Seventeen children (age 7-18 years; 11 boys) with BO underwent xenon ventilation CT using dual-source and dual-energy technique. Xenon and CT density values were measured in normal and hyperlucent lung regions on CT and were compared between the two regions. Volumes of hyperlucent regions and ventilation defects were calculated with thresholds determined by visual and histogram-based analysis. Indexed volumes of hyperlucent lung regions and ventilation defects were correlated with pulmonary function test results. Effective doses of xenon CT were calculated. Xenon (14.6 ± 6.4 HU vs 26.1 ± 6.5 HU; P 25-75 , (γ = -0.68-0.88, P ≤ 0.002). Volume percentages of xenon ventilation defects (35.0 ± 16.4%)] were not significantly different from those of hyperlucent lung regions (38.2 ± 18.6%). However, mismatches between the volume percentages were variable up to 21.4-33.3%. Mean effective dose of xenon CT was 1.9 ± 0.5 mSv. In addition to high-resolution anatomic information, xenon ventilation CT using dual-source and dual-energy technique demonstrates impaired regional ventilation and its heterogeneity accurately in children with BO without additional radiation exposure. (orig.)

Performance of an iodine-fueled radio-frequency ion-thruster

Science.gov (United States)

Holste, Kristof; Gärtner, Waldemar; Zschätzsch, Daniel; Scharmann, Steffen; Köhler, Peter; Dietz, Patrick; Klar, Peter J.

2018-01-01

Two sets of performance data of the same radio-frequency ion-thruster (RIT) have been recorded using iodine and xenon, respectively, as propellant. To characterize the thruster's performance, we have recorded the radio-frequency DC-power, required for yielding preset values of the extracted ion-beam currents, as a function of mass flow. For that purpose, an iodine mass flow system had to be developed, calibrated, and integrated into a newly-built test facility for studying corrosive propellants. The performance mappings for iodine and xenon differ significantly despite comparable operation conditions. At low mass flows, iodine exhibits the better performance. The situation changes at higher mass flows where the performance of iodine is significantly poorer than that of xenon. The reason is very likely related to the molecular nature of iodine. Our results show that iodine as propellant is compatible with RIT technology. Furthermore, it is a viable alternative as propellant for dedicated space missions. In particular, when taking into account additional benefits such as possible storage as a solid and its low price the use of iodine as propellant in ion thrusters is competitive.

Distribution of xenon between gaseous and liquid CO2

International Nuclear Information System (INIS)

Ackley, R.D.; Notz, K.J.

1976-10-01

The distribution of xenon at low concentrations between gaseous and liquid CO 2 was measured over essentially the entire liquid range of CO 2 . These measurements involved using a collimated radiation-detection cell to determine the relative quantities of 133 Xe-traced xenon in the separate phases contained in a vertical cylinder under isothermal conditions. The results are expressed in terms of a distribution ratio (mole fraction of xenon in the gaseous phase divided by mole fraction of xenon in the liquid phase) which decreased from 7.53 at -54.8 0 C to 1.10 at 30.5 0 C. These data were used to calculate various other solubility-related quantities

Sensitivity of gaseous xenon ionisation chambers (1961)

International Nuclear Information System (INIS)

Schuhl, C.

1960-01-01

It seems advantageous to fill an ionization chamber with xenon gas when this chamber is used for measuring a low intensity and high energy electron or positron beam, or monitoring a gamma beam. In the study of 5 to 50 MeV electrons, xenon allows for the ionization chamber yield, an improvement of a factor 4,5. (author) [fr

Effect of capacitor loss on discharging characteristics of xenon flash lamp

International Nuclear Information System (INIS)

Zhang Chu; Lin Dejiang; Xu Chunmei; Shen Hongbin; Chen Xiaohan

2012-01-01

The effect of storage capacitor's loss on the discharging characteristics of the xenon flash lamp was studied, and the xenon flash lamp discharging circuit was analyzed and improved. The capacitor can be equivalent to a series of an ideal capacitor and loss resistance. The improved formula of the xenon lamp discharging characteristics was given when actual capacitance loss is not zero, and the xenon lamp discharging current and discharging power are calculated and analyzed in detail with the increase of the capacitor loss. The results show that the increase of loss will lead to the decrease of xenon lamp discharging current and peak power and the xenon lamp flash time, and influence laser pumping efficiency. The loss will also lead to the capacitor inverse charging in LC discharging circuit; this will influence normal working of the capacitor and decrease the lift of the xenon lamp. The actual energy storage capacitor charging and discharging experiments show that the increase of capacitor loss will lead to the decrease of xenon lamp light-emitting waveform peak, shortening of the flash time and increase of the electrode sputter, thus verity, the reasonableness of theoretical analysis. In addition, the experiments show that environmental factors have very significant impact on the increase of the storage capacitor loss. (authors)

Xenon Acquisition Strategies for High-Power Electric Propulsion NASA Missions

Science.gov (United States)

Herman, Daniel A.; Unfried, Kenneth G.

2015-01-01

Solar electric propulsion (SEP) has been used for station-keeping of geostationary communications satellites since the 1980s. Solar electric propulsion has also benefitted from success on NASA Science Missions such as Deep Space One and Dawn. The xenon propellant loads for these applications have been in the 100s of kilograms range. Recent studies performed for NASA's Human Exploration and Operations Mission Directorate (HEOMD) have demonstrated that SEP is critically enabling for both near-term and future exploration architectures. The high payoff for both human and science exploration missions and technology investment from NASA's Space Technology Mission Directorate (STMD) are providing the necessary convergence and impetus for a 30-kilowatt-class SEP mission. Multiple 30-50- kilowatt Solar Electric Propulsion Technology Demonstration Mission (SEP TDM) concepts have been developed based on the maturing electric propulsion and solar array technologies by STMD with recent efforts focusing on an Asteroid Redirect Robotic Mission (ARRM). Xenon is the optimal propellant for the existing state-of-the-art electric propulsion systems considering efficiency, storability, and contamination potential. NASA mission concepts developed and those proposed by contracted efforts for the 30-kilowatt-class demonstration have a range of xenon propellant loads from 100s of kilograms up to 10,000 kilograms. This paper examines the status of the xenon industry worldwide, including historical xenon supply and pricing. The paper will provide updated information on the xenon market relative to previous papers that discussed xenon production relative to NASA mission needs. The paper will discuss the various approaches for acquiring on the order of 10 metric tons of xenon propellant to support potential near-term NASA missions. Finally, the paper will discuss acquisitions strategies for larger NASA missions requiring 100s of metric tons of xenon will be discussed.

Numerical study on xenon positive column discharges of mercury-free lamp

International Nuclear Information System (INIS)

Ouyang, Jiting; He, Feng; Miao, Jinsong; Wang, Jianqi; Hu, Wenbo

2007-01-01

In this paper, the numerical study has been performed on the xenon positive column discharges of mercury-free fluorescent lamp. The plasma discharge characteristics are analyzed by numerical simulation based on two-dimensional fluid model. The effects of cell geometry, such as the dielectric layer, the electrode width, the electrode gap, and the cell height, and the filling gas including the pressure and the xenon percentage are investigated in terms of discharge current and discharge efficiency. The results show that a long transient positive column will form in the xenon lamp when applying ac sinusoidal power and the lamp can operate in a large range of voltage and frequency. The front dielectric layer of the cell plays an important role in the xenon lamp while the back layer has little effect. The ratio of electrode gap to cell height should be large to achieve a long positive column xenon lamp and higher efficiency. Increase of pressure or xenon concentration results in an increase of discharge efficiency and voltage. The discussions will be helpful for the design of commercial xenon lamp cells

Removing krypton from xenon by cryogenic distillation to the ppq level

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Goetzke, L.W.; Greene, Z.; Messina, M.; Plante, G.; Rizzo, A.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso (Italy); Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Orrigo, S.E.A.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L.; Franco, D.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wei, Y.; Wulf, J. [Physik-Institut, University of Zurich, Zurich (Switzerland); Bauermeister, B. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindemann, S.; Lindner, M.; Undagoitia, T.M.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Gallo Rosso, A.; Molinario, A. [INFN-Laboratori Nazionali del Gran Sasso (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; Duchovni, E.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. v. [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Calven, J.; Conrad, J.; Ferella, A.D.; Pelssers, B. [Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, Stockholm (Sweden); Cervantes, M.; Lang, R.F.; Masson, D.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Le Calloch, M.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [Universite de Nantes, SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (France); Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Fei, J.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Huhmann, C.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Grandi, L.; Saldanha, R.; Shockley, E.; Upole, N. [University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Lin, Q. [Laboratori Nazionali del Gran Sasso, Assergi (Italy); Meng, Y.; Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Miguez, B.; Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Lavina, L.S. [LPNHE, Universite Pierre et Marie Curie, Universite Paris Diderot, CNRS/IN2P3, Paris (France); Tunnell, C. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Cristescu, I. [Karlsruhe Institute of Technology, Tritium Laboratory Karlsruhe, Eggenstein-Leopoldshafen (Germany); Collaboration: XENON Collaboration

2017-05-15

The XENON1T experiment aims for the direct detection of dark matter in a detector filled with 3.3 tons of liquid xenon. In order to achieve the desired sensitivity, the background induced by radioactive decays inside the detector has to be sufficiently low. One major contributor is the β-emitter {sup 85}Kr which is present in the xenon. For XENON1T a concentration of natural krypton in xenon {sup nat}Kr/Xe < 200 ppq (parts per quadrillion, 1 ppq = 10{sup -15} mol/mol) is required. In this work, the design, construction and test of a novel cryogenic distillation column using the common McCabe-Thiele approach is described. The system demonstrated a krypton reduction factor of 6.4 . 10{sup 5} with thermodynamic stability at process speeds above 3 kg/h. The resulting concentration of {sup nat}Kr/Xe < 26 ppq is the lowest ever achieved, almost one order of magnitude below the requirements for XENON1T and even sufficient for future dark matter experiments using liquid xenon, such as XENONnT and DARWIN. (orig.)

Dynamic adsorption property of xenon on activated carbon and carbon molecular sieves

International Nuclear Information System (INIS)

Feng Shujuan; Zhou Guoqing; Jin Yuren; Zhou Chongyang

2010-01-01

In order to select well adsorptive xenon adsorbent, the dynamic adsorption property of xenon on activated carbon and carbon molecular sieves (CMS) was studied by measuring the xenon dynamic adsorption coefficient as a function velocity of gas, temperature, carrier gas, pressure and concentration of CO 2 . The results show that the highest value of xenon dynamic adsorption coefficient is on CMS1, and the second highest value is on CMS2; when the xenon concentration is less than 10 -5 mol/L or concentration of CO 2 is less than 5 x 10 -5 mol/L, the xenon dynamic adsorption coefficient nearly keeps constant at the specific experimental flow rate. Then the xenon dynamic adsorption coefficient would vary when it was mixed with different kind of carrier gas and become less at more than 5 x 10 -5 mol/L concentration of CO 2 . And the maximal effect factors are temperature and pressure. Therefore, the feasible measures to improve the xenon capability are to cool the adsorbent and increase adsorption pressure. (authors)

NASA's Evolutionary Xenon Thruster (NEXT) Project Qualification Propellant Throughput Milestone: Performance, Erosion, and Thruster Service Life Prediction After 450 kg

Science.gov (United States)

Herman, Daniel A.

2010-01-01

The NASA s Evolutionary Xenon Thruster (NEXT) program is tasked with significantly improving and extending the capabilities of current state-of-the-art NSTAR thruster. The service life capability of the NEXT ion thruster is being assessed by thruster wear test and life-modeling of critical thruster components, such as the ion optics and cathodes. The NEXT Long-Duration Test (LDT) was initiated to validate and qualify the NEXT thruster propellant throughput capability. The NEXT thruster completed the primary goal of the LDT; namely to demonstrate the project qualification throughput of 450 kg by the end of calendar year 2009. The NEXT LDT has demonstrated 28,500 hr of operation and processed 466 kg of xenon throughput--more than double the throughput demonstrated by the NSTAR flight-spare. Thruster performance changes have been consistent with a priori predictions. Thruster erosion has been minimal and consistent with the thruster service life assessment, which predicts the first failure mode at greater than 750 kg throughput. The life-limiting failure mode for NEXT is predicted to be loss of structural integrity of the accelerator grid due to erosion by charge-exchange ions.

Observation of a barium xenon exciplex within a large argon cluster.

Science.gov (United States)

Briant, M; Gaveau, M-A; Mestdagh, J-M

2010-07-21

Spectroscopic measurements provide fluorescence and excitation spectra of a single barium atom codeposited with xenon atoms on argon clusters of average size approximately 2000. The spectra are studied as a function of the number of xenon atoms per cluster. The excitation spectrum with approximately 10 xenon atoms per cluster is qualitatively similar to that observed when no xenon atom is present on the cluster. It consists of two bands located on each side of the 6s6p (1)P-6s(2) (1)S resonance line of the free barium. In contrast, the fluorescence spectrum differs qualitatively since a barium-xenon exciplex is observed, which has no counterpart in xenon free clusters. In particular an emission is observed, which is redshifted by 729 cm(-1) with respect to the Ba(6s6p (1)P-6s(2) (1)S) resonance line.

Comparison of Medium Power Hall Effect Thruster Ion Acceleration for Krypton and Xenon Propellants

Science.gov (United States)

2016-09-14

Pumping is provided by four single-stage cryogenic panels (single-stage cold heads at 25 K) and one 50 cm two stage cryogenic pump (12 K). This vacuum...test chamber has a mea- sured pumping speed of 36 kL/s on xenon. The Hall thruster used in this study is a medium power laboratory Hall effect...The first compo- nent passes through a krypton opto-galvanic cell and is terminated by a beam dump . The opto-galvanic cell current is capacitively

Core level photoelectron spectroscopy probed heterogeneous xenon/neon clusters

International Nuclear Information System (INIS)

Pokapanich, Wandared; Björneholm, Olle; Öhrwall, Gunnar; Tchaplyguine, Maxim

2017-01-01

Binary rare gas clusters; xenon and neon which have a significant contrariety between sizes, produced by a co-expansion set up and have been studied using synchrotron radiation based x-ray photoelectron spectroscopy. Concentration ratios of the heterogeneous clusters; 1%, 3%, 5% and 10% were controlled. The core level spectra were used to determine structure of the mixed cluster and analyzed by considering screening mechanisms. Furthermore, electron binding energy shift calculations demonstrated cluster aggregation models which may occur in such process. The results showed that in the case of low mixing ratios of 3% and 5% of xenon in neon, the geometric structures exhibit xenon in the center and xenon/neon interfaced in the outer shells. However, neon cluster vanished when the concentration of xenon was increased to 10%. - Highlights: • Co-expansion setup is suitable for producing binary Xe/Ne clusters. • Appropriate temperature, pressure, and mixing ratios should be strictly controlled. • Low mixing ratio, Xe formed in the core and Xe/Ne interfacing in the outer shell. • High mixing ratio, only pure Xe clusters were detected.

High-Power Ion Thruster Technology

Science.gov (United States)

Beattie, J. R.; Matossian, J. N.

1996-01-01

Performance data are presented for the NASA/Hughes 30-cm-diam 'common' thruster operated over the power range from 600 W to 4.6 kW. At the 4.6-kW power level, the thruster produces 172 mN of thrust at a specific impulse of just under 4000 s. Xenon pressure and temperature measurements are presented for a 6.4-mm-diam hollow cathode operated at emission currents ranging from 5 to 30 A and flow rates of 4 sccm and 8 sccm. Highly reproducible results show that the cathode temperature is a linear function of emission current, ranging from approx. 1000 C to 1150 C over this same current range. Laser-induced fluorescence (LIF) measurements obtained from a 30-cm-diam thruster are presented, suggesting that LIF could be a valuable diagnostic for real-time assessment of accelerator-arid erosion. Calibration results of laminar-thin-film (LTF) erosion badges with bulk molybdenum are presented for 300-eV xenon, krypton, and argon sputtering ions. Facility-pressure effects on the charge-exchange ion current collected by 8-cm-diam and 30-cm-diam thrusters operated on xenon propellant are presented to show that accel current is nearly independent of facility pressure at low pressures, but increases rapidly under high-background-pressure conditions.

Radon removal from gaseous xenon with activated charcoal

Energy Technology Data Exchange (ETDEWEB)

Abe, K.; Hieda, K.; Hiraide, K.; Hirano, S.; Kishimoto, Y.; Kobayashi, K.; Koshio, Y. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Liu, J.; Martens, K. [Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Moriyama, S. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Nakahata, M. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Nishiie, H.; Ogawa, H.; Sekiya, H.; Shinozaki, A. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Suzuki, Y. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Takachio, O.; Takeda, A.; Ueshima, K.; Umemoto, D. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Kamioka, Hida, Gifu 506-1205 (Japan); and others

2012-01-01

Many low background experiments using xenon need to remove radioactive radon to improve their sensitivities. However, no method of continually removing radon from xenon has been described in the literature. We studied a method to remove radon from xenon gas through an activated charcoal trap. From our measurements we infer a linear relationship between the mean propagation velocity v{sub Rn} of radon and v{sub Xe} of xenon in the trap with v{sub Rn}/v{sub Xe}=(0.96{+-}0.10) Multiplication-Sign 10{sup -3} at -85 Degree-Sign C. As the mechanism for radon removal in this charcoal trap is its decay, knowledge of this parameter allows us to design an efficient radon removal system for the XMASS experiment. The verification of this system found that it reduces radon by a factor of 0.07, which is in line with its expected average retention time of 14.8 days for radon.

Weird muonium diffusion in solid xenon

International Nuclear Information System (INIS)

Storchak, V.G.; Kirillov, B.F.; Pirogov, A.V.

1992-09-01

Muon and muonium spin rotation and relaxation parameters were studied in liquid and solid xenon. The small diamagnetic fraction (∼ 10%) observed in condensed xenon is believed to be Xeμ + . The muonium hyperfine frequency was measured for the first time in liquid Xe and was found to be in agreement with the vacuum value. A nonmonotonic temperature dependence of the muonium relaxation rate probably indicates that muonium diffusion in solid Xe is of quantum nature. 16 refs., 3 figs

Study of regional lung ventilation and perfusion by xenon 133

International Nuclear Information System (INIS)

Lombard, Yves.

1976-01-01

The present work consists of a regional lung exploration after injection of xenon 133, dissolved in physiological serum, followed a few minutes later by that of 99m Tc-labelled serumalbumin microspheres. The aim is three fold: first of all to study perfusion and ventilation by xenon 133, next to compare the results obtained after xenon 133 and 99 m Tc-labelled microsphere injection, lastly to establish the value of the technique and its routine application. This examination has not solved all problems of lung exploration by xenon 133. For example we deliberately kept to intraveinous injection of the gas dissolved in physiological serum, leaving aside the breathing test. Xenon 133 scintigraphy in our opinion will not tend to replace 99m Tc-labelled microsphere scintigraphy, which has irreplaceable morphological qualities, but will serve as an excellent complement. The basic advantage of xenon 133 is the regional ventilation estimate it provides allowing any anomaly of the lung parenchyma to be located immediately or conversely the functional value of the healthy lung to be established with a view to a surgical removal of a diseased zone [fr

Isotopic composition of primary xenon and the fission of Pu-244

Energy Technology Data Exchange (ETDEWEB)

Levskii, L K

1983-05-01

The hypothesis that the origin of xenon on earth is due to the fission of uranium and/or transuranium elements is examined. The isotopic composition of primary xenon on earth is calculated using a model (Levskii, 1980) of the isotopic composition of rare gases which is based on the hypothesis of the heterogeneity of the isotopic composition of the elements of the solar system. The isotopic composition of fission-produced xenon in the atmosphere and solid earth is determined to correspond to the abundance of xenon isotopes as a result of the spontaneous fission of Pu-244 (half-life of 8.2 x 10 to the 7th years). The amount of fission-produced xenon in the atmosphere is shown to amount to about 30 percent (Xe-136). Under certain conditions, the degree of the degassing of the solid earth for xenon is 25 percent, which corresponds to a ratio of Kr-84/Xe-130 45 for the earth as a whole.

Transportable Xenon Laboratory (TXL-1) Operations Manual

Energy Technology Data Exchange (ETDEWEB)

Thompson, Robert C.; Stewart, Timothy L.; Willett, Jesse A.; Woods, Vincent T.

2011-03-07

The Transportable Xenon Laboratory Operations Manual is a guide to set up and shut down TXL, a fully contained laboratory made up of instruments to identify and measure concentrations of the radioactive isotopes of xenon by taking air samples and analyzing them. The TXL is housed in a standard-sized shipping container. TXL can be shipped to and function in any country in the world.

Electron momentum spectroscopy of xenon: A detailed analysis

International Nuclear Information System (INIS)

Cook, J.P.D.; McCarthy, I.E.; Mitroy, J.; Weigold, E.

1986-01-01

Accurate measurements of the 1000-eV noncoplanar symmetric (e,2e) reaction on xenon are reported. Cross-section calculations are carried out with the use of both the plane-wave and distorted-wave impulse approximations. The distorted-wave impulse approximation accurately describes both the 5p -1 and 5s -1 angular correlations and their relative cross sections. It also describes accurately the 5p/sub 3/2/ -1 :5p/sub 1/2/ -1 branching ratios if Dirac-Fock target wave functions are used. The branching ratios show the inadequacy of Hartree-Fock wave functions for xenon. The plane-wave impulse-approximation overestimates the 5s -1 cross section relative to the 5p -1 and underestimates the cross section at large angles. The 5s -1 spectroscopic factors are assigned up to a separation energy of 45 eV, and the distorted-wave impulse-approximation calculation verifies that all the 5s -1 strength has been found. The spectroscopic factors for the 5s -1 manifold are obtained at 1000 and 1200 eV at a number of angles and are found to be independent of incident energy and ion recoil momentum. The spectroscopic factor for the lowest 5s -1 transition at 23.4 eV is 0.37 +- 0.01, whereas that for the ground-state 5p -1 transition is greater than or equal to 0.98

Muonium formation in xenon and argon up to 60 atmospheres

International Nuclear Information System (INIS)

Kempton, J.R.; Senba, M.; Arseneau, D.J.; Gonzalez, A.C.; Pan, J.J.; Tempelmann, A.; Garner, D.M.; Fleming, D.G.

1991-01-01

Results of muon polarization studies in xenon and argon up to 60 atm are reported. In argon for pressures up to 10 atm, the muon polarization is best explained by an epithermalcharge exchange model. Above this pressure, the decrease in P D and increase in P L are ascribed to charge neutralization and spin exchange reactions, respectively, in the radiolysis track. Measurements with Xe/He mixtures with a xenon pressure of 1 atm indicate that the lost polarization in the pure xenon at this pressure is due to inefficient moderation of the muon. As the pressure in pure xenon is increased above 10 atm, we find that P L remains roughly constant and P D begins to increase. The lost fraction may be due to the formation of a XeMu Van der Waals type complex, while P D is ascribed to XeMu + formation. This suggests that spur processes appear to be less important in xenon that in argon. (orig.)

Converging xenon shock waves driven by megagauss magnetic fields

International Nuclear Information System (INIS)

Shearer, J.W.; Steinberg, D.J.

1986-07-01

We attempted to implode a conducting metal linear at high velocity, and our failure to do so led to switching, or rapidly transferring the field from pushing an aluminum conductor to snow-plowing a half-atmosphere of xenon gas. We successfully initiated convergent xenon gas shocks with the use of a magnetohydrodynamic switch and coaxial high-explosive, flux-compression generators. Principal diagnostics used to study the imploding xenon gas were 133 Xe radioactive tracers, continuous x-ray absorption, and neutron output. We compressed the xenon gas about five to sixfold at a velocity of 10 cm/μs at a radius of 4 cm. The snowplow efficiency was good; going from 13- to 4-cm radius, we lost only about 20% of the mass. The temperature of the imploded sheath was determined by mixing deuterium with the xenon and measuring the neutron output. Using reasonable assumptions about the amount, density, and uniformity of the compressed gas, we estimate that we reached temperatures as high as 155 eV. Energy-loss mechanisms that we encountered included wall ablation and Taylor instabilities of the back surface

Measurement of xenon reactivity in the reactor of the nuclear ship 'MUTSU'

International Nuclear Information System (INIS)

Itagaki, Masafumi; Miyoshi, Yoshinori; Gakuhari, Kazuhiko; Okada, Noboru.

1993-01-01

This report deals with the measurement of reactivity changes caused by the increase and decrease of xenon concentration in the reactor core of the nuclear ship 'MUTSU' after a change from long-term operation at 70 % to zero power. The change in xenon reactivity was compensated by control-rod movements and the compensated reactivity was measured using a digital reactivity meter. The xenon override peak was recognized five and half hours after the start of power reduction. The equilibrium and peak reactivities of xenon were estimated by reading the initial and peak values of a theoretical curve which was fitted to the measured variation in xenon reactivity. The xenon reactivity results obtained by the present method can be considered to be accurate since no control-rod worth data were used and the measured quantity was the reactivity itself. (author)

Emissive properties of xenon ions from a laser-produced plasma in the 100-140 Aa spectral range: Atomic-physics analysis of the experimental data

International Nuclear Information System (INIS)

Gilleron, F.; Poirier, M.; Blenski, T.; Schmidt, M.; Ceccotti, T.

2003-01-01

In order to design extreme ultraviolet (EUV) sources for nanolithography, xenon EUV emission has been experimentally studied in a plasma generated by the interaction of a high-power laser with a droplet jet. A theoretical model assuming that the resulting plasma is optically thick allows one to find the distribution of the relevant ions and transitions involved in the emission process. Atomic physics computations are performed using the HULLAC code to give a detailed account of the transitions involved. The importance of 4p-4d, 4d-4f, and 4d-5p transitions is stressed, as well as the need for configuration-interaction treatment of the Δn=0 transitions. Comparisons of a modeled local thermodynamical equilibrium spectrum with experiment provides qualitative agreement and permits an estimate of the plasma temperature, density, and dimensions

Facility for the separation of krypton and recuperation of xenon

International Nuclear Information System (INIS)

Boell-Djoa, S.H.

1977-01-01

A facility is described by means of which the fission inert gases krypton 85 and xenon from spent fuel particles can be separated by fractionated freezing-out and subsequent distillation to such an extent that the xenon contains less than 1 ppb krypton 85. Then, in accordance with the stringent regulations, the krypton can be conveyed to definitive storage in special bottles, whereas the xenon can be released for industrial uses. (orig.) [de

Study of xenon binding in cryptophane-A using laser-induced NMR polarization enhancement

International Nuclear Information System (INIS)

Luhmer, M.; Goodson, B.M.; Song, Y.Q.; Laws, D.D.; Kaiser, L.; Pines, A.; Lawrence Berkeley National Lab., CA

1999-01-01

Xenon is chemically inert, yet exhibits NMR parameters that are highly sensitive to its chemical environment. Considerable work has therefore capitalized on the utility of 129 Xe (I = 1/2) as a magnetic resonance probe of molecules, materials, and biological systems. In solution, spin-polarization transfer between laser-polarized xenon and the hydrogen nuclei of nearby molecules leads to signal enhancements in the resolved 1 H NMR spectrum, offering new opportunities for probing the chemical environment of xenon atoms. Following binding of laser-polarized xenon to molecules of cryptophane-A, selective enhancements of the 1 H NMR signals were observed. A theoretical framework for the interpretation of such experimental results is provided, and the spin polarization-induced nuclear Overhauser effects are shown to yield information about the molecular environment of xenon. The observed selective 1 H enhancements allowed xenon-proton internuclear distances to be estimated. These distances reveal structural characteristics of the complex, including the preferred molecular conformations adopted by cryptophane-A upon binding of xenon

Ionization and scintillation of nuclear recoils in gaseous xenon

Energy Technology Data Exchange (ETDEWEB)

Renner, J., E-mail: jrenner@lbl.gov [Lawrence Berkeley National Laboratory (LBNL), 1 Cyclotron Road, Berkeley, CA 94720 (United States); Department of Physics, University of California, Berkeley, CA 94720 (United States); Gehman, V.M.; Goldschmidt, A.; Matis, H.S.; Miller, T.; Nakajima, Y.; Nygren, D.; Oliveira, C.A.B.; Shuman, D. [Lawrence Berkeley National Laboratory (LBNL), 1 Cyclotron Road, Berkeley, CA 94720 (United States); Álvarez, V. [Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València, Calle Catedrático José Beltrán, 2, 46980 Paterna, Valencia (Spain); Borges, F.I.G. [Departamento de Fisica, Universidade de Coimbra, Rua Larga, 3004-516 Coimbra (Portugal); Cárcel, S. [Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València, Calle Catedrático José Beltrán, 2, 46980 Paterna, Valencia (Spain); Castel, J.; Cebrián, S. [Laboratorio de Física Nuclear y Astropartículas, Universidad de Zaragoza, Calle Pedro Cerbuna 12, 50009 Zaragoza (Spain); Cervera, A. [Instituto de Física Corpuscular (IFIC), CSIC & Universitat de València, Calle Catedrático José Beltrán, 2, 46980 Paterna, Valencia (Spain); Conde, C.A.N. [Departamento de Fisica, Universidade de Coimbra, Rua Larga, 3004-516 Coimbra (Portugal); and others

2015-09-01

Ionization and scintillation produced by nuclear recoils in gaseous xenon at approximately 14 bar have been simultaneously observed in an electroluminescent time projection chamber. Neutrons from radioisotope α-Be neutron sources were used to induce xenon nuclear recoils, and the observed recoil spectra were compared to a detailed Monte Carlo employing estimated ionization and scintillation yields for nuclear recoils. The ability to discriminate between electronic and nuclear recoils using the ratio of ionization to primary scintillation is demonstrated. These results encourage further investigation on the use of xenon in the gas phase as a detector medium in dark matter direct detection experiments.

Ionization dynamics of a xenon atom in super-strong laser fields

International Nuclear Information System (INIS)

Yamakawa, Koichi; Akahane, Yutaka; Fukuda, Yuji; Aoyama, Makoto; Inoue, Norihiro; Ueda, Hideki; Utsumi, Takayuki

2003-12-01

We report on detailed investigations of ionization dynamics of a xenon atom exposed to intense 800-nm pulses of 20-fs duration in the extensive intensity range from 10 13 to 10 18 W/cm 2 . Ion yields of Xe + to Xe 20+ were observed as a function of laser intensity and compared with the results from a single active electron (SAE) based Ammosov-Delone-Krainov (ADK) model. Unexpected ionization probabilities for lower charge states and also no interplay between the inner- and outer-shells by screening are inferred. Suppression of nonsequential ionization towards higher intensity and few optical cycle regimes is also proved. (author)

Quantitative cerebral blood flow calculation method using xenon CT. Introduction of a factor reflecting diffusing capacity of the lung for xenon

International Nuclear Information System (INIS)

Sase, Shigeru; Honda, Mitsuru; Noguchi, Yoshitaka

2007-01-01

In calculating cerebral blood flow (CBF) using the Fick principle, time-course information on arterial tracer concentration is indispensable and exerts considerable influence on the accuracy of CBF. In xenon-enhanced CT (Xe-CT), the time-course change rate for end-tidal xenon concentration (Ke), which can be measured, and that for arterial xenon concentration (Ka) have been assumed to be equal. However, it has been pointed out that there are large differences between Ke and Ka in many cases. We have introduced a single factor (γ) which correlates Ke with Ka in the equation Ka=γ x (1-e -Ke/γ ). This factor, γ, reflects the diffusing capacity of the lung for xenon; larger γ values correspond to larger diffusing capacities and Ka is equal to Ke when γ is infinity. Kety's equation contains two parameters: CBF and xenon solubility coefficient We added a third parameter, γ, to Kety's equation, and developed an efficient method to obtain the γ value for each Xe-CT study. Applying this method to ten normal subjects (35.4±16.3 years, mean±standard deviation (SD)), we obtained γ value of 1.01±0.17 and the average CBF value of 38.8±7.5 mL/100 g/min in basal ganglia. The wash-in period could be shortened to two minutes using this method. Xe-CT with this factor (γ) as a parameter enhances its clinical availability as well as the accuracy of CBF. (author)

Xenon as an adjunct in computed tomography

International Nuclear Information System (INIS)

Kendall, B.E.; Radue, E.W.; Zilkha, E.; Loh, L.

1979-01-01

Nonradioactive xenon was used for enhancement in computed tomography in a series of 18 patients requiring general anesthesia. The method and results are described. The properties of xenon are radically different from those of intravenous iodides, and the enhancement patterns demonstrate different aspects of both normal and abnormal tissues. In our limited experience, it has been of value in those isodense and low attenuation lesions that have not enhanced after intravenous Conray. (orig.) 891 MG/orig. 892 MB [de

Xenon gas field ion source from a single-atom tip

Science.gov (United States)

Lai, Wei-Chiao; Lin, Chun-Yueh; Chang, Wei-Tse; Li, Po-Chang; Fu, Tsu-Yi; Chang, Chia-Seng; Tsong, T. T.; Hwang, Ing-Shouh

2017-06-01

Focused ion beam (FIB) systems have become powerful diagnostic and modification tools for nanoscience and nanotechnology. Gas field ion sources (GFISs) built from atomic-size emitters offer the highest brightness among all ion sources and thus can improve the spatial resolution of FIB systems. Here we show that the Ir/W(111) single-atom tip (SAT) can emit high-brightness Xe+ ion beams with a high current stability. The ion emission current versus extraction voltage was analyzed from 150 K up to 309 K. The optimal emitter temperature for maximum Xe+ ion emission was ˜150 K and the reduced brightness at the Xe gas pressure of 1 × 10-4 torr is two to three orders of magnitude higher than that of a Ga liquid metal ion source, and four to five orders of magnitude higher than that of a Xe inductively coupled plasma ion source. Most surprisingly, the SAT emitter remained stable even when operated at 309 K. Even though the ion current decreased with increasing temperature, the current at room temperature (RT) could still reach over 1 pA when the gas pressure was higher than 1 × 10-3 torr, indicating the feasibility of RT-Xe-GFIS for application to FIB systems. The operation temperature of Xe-SAT-GFIS is considerably higher than the cryogenic temperature required for the helium ion microscope (HIM), which offers great technical advantages because only simple or no cooling schemes can be adopted. Thus, Xe-GFIS-FIB would be easy to implement and may become a powerful tool for nanoscale milling and secondary ion mass spectroscopy.

Performance test of SAUNA xenon mobile sampling system

International Nuclear Information System (INIS)

Hu Dan; Yang Bin; Yang Weigeng; Jia Huaimao; Wang Shilian; Li Qi; Zhao Yungang; Fan Yuanqing; Chen Zhanying; Chang Yinzhong; Liu Shujiang; Zhang Xinjun; Wang Jun

2011-01-01

In this article, the structure and basic functions of SAUNA noble gas xenon mobile sampling system are introduced. The sampling capability of this system is about 2.2 mL per day, as a result from a 684-h operation. The system can be transported to designated locations conveniently to collect xenon sample for routine or emergency environment monitoring. (authors)

Design and commissioning of ReStoX for XENON1T

Energy Technology Data Exchange (ETDEWEB)

Scheibelhut, Melanie [Institut fuer Physik, Johannes Gutenberg Universitaet Mainz (Germany)

2015-07-01

The XENON1T experiment, currently under construction at the Gran Sasso underground laboratory LNGS, uses the concept of a xenon dual-phase (liquid/gas) time projection chamber to search for Dark Matter particles. This requires cooling to about 175 K and liquefaction of the noble gas. The ReStoX (Recovery and Storage of Xenon) is a novel device to store and recover up to 7 tons of xenon - either in liquid phase at cryogenic temperatures and 1-2 bar of pressure, or in gaseous form at room temperature at about 70 bar of pressure. The ReStoX system consists of a double insulated stainless steel sphere with liquid nitrogen cooling loops distributed across the inner sphere. A condenser on the inside, also operated with liquid nitrogen, provides a cooling power of 3 kW. ReStoX is designed to provide an effective means for various operating modes: to fill the TPC fast, to recover xenon from the TPC under normal and emergency conditions, to store xenon safely in liquid or gaseous form, or to remain in cold standby nearly empty as a safety device. Here we present the design and first commissioning results.

Collision-induced light scattering in a thin xenon layer between graphite slabs - MD study.

Science.gov (United States)

Dawid, A; Górny, K; Wojcieszyk, D; Dendzik, Z; Gburski, Z

2014-08-14

The collision-induced light scattering many-body correlation functions and their spectra in thin xenon layer located between two parallel graphite slabs have been investigated by molecular dynamics computer simulations. The results have been obtained at three different distances (densities) between graphite slabs. Our simulations show the increased intensity of the interaction-induced light scattering spectra at low frequencies for xenon atoms in confined space, in comparison to the bulk xenon sample. Moreover, we show substantial dependence of the interaction-induced light scattering correlation functions of xenon on the distances between graphite slabs. The dynamics of xenon atoms in a confined space was also investigated by calculating the mean square displacement functions and related diffusion coefficients. The structural property of confined xenon layer was studied by calculating the density profile, perpendicular to the graphite slabs. Building of a fluid phase of xenon in the innermost part of the slot was observed. The nonlinear dependence of xenon diffusion coefficient on the separation distance between graphite slabs has been found. Copyright © 2014. Published by Elsevier B.V.

Spatial xenon oscillation control with expert systems

International Nuclear Information System (INIS)

Alten, S.; Danofsky, R.A.

1993-01-01

Spatial power oscillations were attributed to the xenon transients in a reactor core in 1958 by Randall and St. John. These transients are usually initiated by a local reactivity insertion and lead to divergent axial flux oscillations in the core at constant power. Several heuristic manual control strategies and automatic control methods were developed to damp the xenon oscillations at constant power operations. However, after the load-follow operation of the reactors became a necessity of life, a need for better control strategies arose. Even though various advanced control strategies were applied to solve the xenon oscillation control problem for the load-follow operation, the complexity of the system created difficulties in modeling. The strong nonlinearity of the problem requires highly sophisticated analytical approaches that are quite inept for numerical solutions. On the other hand, the complexity of a system and heuristic nature of the solutions are the basic reasons for using artificial intelligence techniques such as expert systems

Exposure mode study to xenon-133 in a reactor building

International Nuclear Information System (INIS)

Perier, Aurelien

2014-01-01

The work described in this thesis focuses on the external and internal dose assessment to xenon-133. During the nuclear reactor operation, fission products and radioactive inert gases, as 133 Xe, are generated and might be responsible for the exposure of workers in case of clad defect. Particle Monte Carlo transport code is adapted in radioprotection to quantify dosimetric quantities. The study of exposure to xenon-133 is conducted by using Monte-Carlo simulations based on GEANT4, an anthropomorphic phantom, a realistic geometry of the reactor building, and compartmental models. The external exposure inside a reactor building is conducted with a realistic and conservative exposure scenario. The effective dose rate and the eye lens equivalent dose rate are determined by Monte-Carlo simulations. Due to the particular emission spectrum of xenon-133, the equivalent dose rate to the lens of eyes is discussed in the light of expected new eye dose limits. The internal exposure occurs while xenon-133 is inhaled. The lungs are firstly exposed by inhalation, and their equivalent dose rate is obtained by Monte-Carlo simulations. A biokinetic model is used to evaluate the internal exposure to xenon-133. This thesis gives us a better understanding to the dosimetric quantities related to external and internal exposure to xenon-133. Moreover the impacts of the dosimetric changes are studied on the current and future dosimetric limits. The dosimetric quantities are lower than the current and future dosimetric limits. (author)

Gravity assisted recovery of liquid xenon at large mass flow rates

Science.gov (United States)

Virone, L.; Acounis, S.; Beaupère, N.; Beney, J.-L.; Bert, J.; Bouvier, S.; Briend, P.; Butterworth, J.; Carlier, T.; Chérel, M.; Crespi, P.; Cussonneau, J.-P.; Diglio, S.; Manzano, L. Gallego; Giovagnoli, D.; Gossiaux, P.-B.; Kraeber-Bodéré, F.; Ray, P. Le; Lefèvre, F.; Marty, P.; Masbou, J.; Morteau, E.; Picard, G.; Roy, D.; Staempflin, M.; Stutzmann, J.-S.; Visvikis, D.; Xing, Y.; Zhu, Y.; Thers, D.

2018-06-01

We report on a liquid xenon gravity assisted recovery method for nuclear medical imaging applications. The experimental setup consists of an elevated detector enclosed in a cryostat connected to a storage tank called ReStoX. Both elements are part of XEMIS2 (XEnon Medical Imaging System): an innovative medical imaging facility for pre-clinical research that uses pure liquid xenon as detection medium. Tests based on liquid xenon transfer from the detector to ReStoX have been successfully performed showing that an unprecedented mass flow rate close to 1 ton per hour can be reached. This promising achievement as well as future areas of improvement will be discussed in this paper.

Some necessary parameters for a critical velocity interaction between the ionospheric plasma and a xenon cloud

International Nuclear Information System (INIS)

Axnaes, I.

1979-12-01

The conditions for an experiment to study the critical ionization velocity effect in the interaction between a Xenon cloud, released from a satellite, and the ionospheric plasma are investigated. The model used is based on the assumption that there exists an effective process that transfers the energy, that is available in the relative motion, to the electrons. Some necessary conditions to obtain significant heating or deceleration of the plasma penetrating the cloud are calculated. The conditions are mainly given by the energy available in the relative motion and the rates of the different binary collision processes involved. As the released gas cloud expands the possibilities for a critical velocity interaction will exist only within a certain range of cloud radii. It is shown that the charge transfer collision cross section between the ionospheric ions and the cloud atoms is an important parameter and that Xenon is a very suitable gas in that respect. (author)

Modeling Xenon Purification Systems in a Laser Inertial Fusion Engine

Science.gov (United States)

Hopkins, Ann; Gentile, Charles

2011-10-01

A Laser Inertial Fusion Engine (LIFE) is a proposed method to employ fusion energy to produce electricity for consumers. However, before it can be built and used as such, each aspect of a LIFE power plant must first be meticulously planned. We are in the process of developing and perfecting models for an exhaust processing and fuel recovery system. Such a system is especially essential because it must be able to recapture and purify expensive materials involved in the reaction so they may be reused. One such material is xenon, which is to be used as an intervention gas in the target chamber. Using Aspen HYSYS, we have modeled several subsystems for exhaust processing, including a subsystem for xenon recovery and purification. After removing hydrogen isotopes using lithium bubblers, we propose to use cryogenic distillation to purify the xenon from remaining contaminants. Aspen HYSYS allows us to analyze predicted flow rates, temperatures, pressures, and compositions within almost all areas of the xenon purification system. Through use of Aspen models, we hope to establish that we can use xenon in LIFE efficiently and in a practical manner.

Xenon-Water Interaction in Bacterial Suspensions as Studied by NMR

DEFF Research Database (Denmark)

Rodin, V.; Ponomarev, Alexander; Gerasimov, Maxim

2017-01-01

suspensions of Escherichia coli in the presence of xenon using nuclear magnetic resonance (NMR). The work studied how the spin-lattice relaxation times of water protons in suspension change under xenon conditions. Xenon is able to form clathrate hydrates with water molecules at a temperature above the melting...... point of ice. The work studied NMR relaxation times which reflect the rotation freedom of water molecules in suspension. Lower relaxation times indicate reduced rotational freedom of water. Single exponential behavior of spin-lattice relaxation of protons in the suspensions of microorganisms has been...

Actinide and Xenon reactivity effects in ATW high flux systems

International Nuclear Information System (INIS)

Woosley, M.; Olson, K.; Henderson, D.L.

1995-01-01

In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides

Actinide and xenon reactivity effects in ATW high flux systems

International Nuclear Information System (INIS)

Woosley, M.; Olson, K.; Henderson, D. L.; Sailor, W. C.

1995-01-01

In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides

Actinide and Xenon reactivity effects in ATW high flux systems

Energy Technology Data Exchange (ETDEWEB)

Woosley, M. [Univ. of Virginia, Charlottesville, VA (United States); Olson, K.; Henderson, D.L. [Univ. of Wisconsin, Madison, WI (United States)] [and others

1995-10-01

In this paper, initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately for a high flux ATW system. The maximum change in reactivity after a flux change due to the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or start-up. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response due to the actinides.

Memory Effects Study of Measuring Radioactive Xenon Isotopes With β-γ Coincidence Method

International Nuclear Information System (INIS)

Jia Huaimao; Wang Shilian; Wang Jun; Li Qi; Zhao Yungang; Fan Yuanqing; Zhang Xinjun

2010-01-01

The β-γ coincidence technique is a kind of the key important method to detect radioactive xenon isotopes for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). This paper describes noble gases memory effects of β-γ coincidence detector. Xenon memory effects were measured and its influence on detector's minimum detectable activity (MDA) was evaluated. The methods of reducing xenon memory effects were studied. In conclusion, aluminium coated plastic scintillator and YAP scintillator can remarkably decrease xenon memory effects. (authors)

A dual-phase xenon TPC for scintillation and ionisation yield measurements in liquid xenon

Science.gov (United States)

Baudis, Laura; Biondi, Yanina; Capelli, Chiara; Galloway, Michelle; Kazama, Shingo; Kish, Alexander; Pakarha, Payam; Piastra, Francesco; Wulf, Julien

2018-05-01

A small-scale, two-phase (liquid/gas) xenon time projection chamber ( Xurich II) was designed, constructed and is under operation at the University of Zürich. Its main purpose is to investigate the microphysics of particle interactions in liquid xenon at energies below 50 keV, which are relevant for rare event searches using xenon as target material. Here we describe in detail the detector, its associated infrastructure, and the signal identification algorithm developed for processing and analysing the data. We present the first characterisation of the new instrument with calibration data from an internal ^83{m} Kr source. The zero-field light yield is 15.0 and 14.0 photoelectrons/keV at 9.4 and 32.1 keV, respectively, and the corresponding values at an electron drift field of 1 kV/cm are 10.8 and 7.9 photoelectrons/keV. The charge yields at these energies are 28 and 31 electrons/keV, with the proportional scintillation yield of 24 photoelectrons per one electron extracted into the gas phase, and an electron lifetime of 200 μ s. The relative energy resolution, σ /E, is 11.9 and 5.8% at 9.4 and 32.1 keV, respectively using a linear combination of the scintillation and ionisation signals. We conclude with measurements of the electron drift velocity at various electric fields, and compare these to literature values.

Dynamic adsorption properties of xenon on activated carbons and their structure characterization

International Nuclear Information System (INIS)

Liu Suiqing; Liu Jing; Qian Yuan; Zeng Youshi; Du Lin; Pi Li; Liu Wei

2013-01-01

Background: In recent years, adsorption of radioactive xenon by activated carbon has been increasingly applied to the treatment of off-gas in nuclear power project. Though pore structure of activated carbon has a great impact on its dynamic adsorption coefficients for xenon, the concerned research is rare. Purpose: It is very necessary to figure out the relationship between the pore structure and the dynamic adsorption coefficients for the purpose of the selection and development of activated carbon. Methods: In this study, the dynamic adsorption coefficients of xenon on four kinds of activated carbons were measured on a dynamic adsorption platform under the condition of 25℃, OMPa (gauge pressure). And these four kinds of activated carbons were characterized by nitrogen adsorption and SEM. Results: The results show that the activated carbon of JH12-16 with the specific surface area of 991.9 m 2 ·g -1 has the largest xenon dynamic adsorption coefficient among these activated carbons. Conclusions: The dynamic adsorption coefficient of xenon on activated carbon doesn't increase with the specific surface area or the pore volume. The mesopore and macropore only play the role of passageway for xenon adsorption. The most suitable pore for xenon adsorption is the pore with the pore size ranged from 0.55 to 0.6 nm. (authors)

Means for obtaining a metal ion beam from a heavy-ion cyclotron source

Science.gov (United States)

Hudson, E.D.; Mallory, M.L.

1975-08-01

A description is given of a modification to a cyclotron ion source used in producing a high intensity metal ion beam. A small amount of an inert support gas maintains the usual plasma arc, except that it is necessary for the support gas to have a heavy mass, e.g., xenon or krypton as opposed to neon. A plate, fabricated from the metal (or anything that can be sputtered) to be ionized, is mounted on the back wall of the ion source arc chamber and is bombarded by returning energetic low-charged gas ions that fail to cross the initial accelerating gap between the ion source and the accelerating electrode. Some of the atoms that are dislodged from the plate by the returning gas ions become ionized and are extracted as a useful beam of heavy ions. (auth)

Experimental studies of a zeeman-tuned xenon laser differential absorption apparatus.

Science.gov (United States)

Linford, G J

1973-06-01

A Zeeman-tuned cw xenon laser differential absorption device is described. The xenon laser was tuned by axial magnetic fields up to 5500 G generated by an unusually large water-cooled dc solenoid. Xenon laser lines at 3.37 micro, 3.51 micro, and 3.99 micro were tuned over ranges of 6 A, 6 A, and 11 A, respectively. To date, this apparatus has been used principally to study the details of formaldehyde absorption lines lying near the 3 .508-micro xenon laser transition. These experiments revealed that the observed absorption spectrum of formaldehyde exhibits a sufficiently unique spectral structure that the present technique may readily be used to measure relative concentrations of formaldehyde in samples of polluted air.

On the spin-dependent sensitivity of XENON100

Energy Technology Data Exchange (ETDEWEB)

Garny, Mathias [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Ibarra, Alejandro; Pato, Miguel; Vogl, Stefan [Technische Univ. Muenchen, Garching (Germany). Physik-Department

2012-11-15

The latest XENON100 data severely constrains dark matter elastic scattering off nuclei, leading to impressive upper limits on the spin-independent cross-section. The main goal of this paper is to stress that the same data set has also an excellent spin-dependent sensitivity, which is of utmost importance in probing dark matter models. We show in particular that the constraints set by XENON100 on the spin-dependent neutron cross-section are by far the best at present, whereas the corresponding spin-dependent proton limits lag behind other direct detection results. The effect of nuclear uncertainties on the structure functions of xenon isotopes is analysed in detail and found to lessen the robustness of the constraints, especially for spin-dependent proton couplings. Notwith-standing, the spin-dependent neutron prospects for XENON1T and DARWIN are very encouraging. We apply our constraints to well-motivated dark matter models and demonstrate that in both mass-degenerate scenarios and the minimal supersymmetric standard model the spin-dependent neutron limits can actually override the spin-independent limits. This opens the possibility of probing additional unexplored regions of the dark matter parameter space with the next generation of ton-scale direct detection experiments.

On the spin-dependent sensitivity of XENON100

International Nuclear Information System (INIS)

Garny, Mathias; Ibarra, Alejandro; Pato, Miguel; Vogl, Stefan

2012-11-01

The latest XENON100 data severely constrains dark matter elastic scattering off nuclei, leading to impressive upper limits on the spin-independent cross-section. The main goal of this paper is to stress that the same data set has also an excellent spin-dependent sensitivity, which is of utmost importance in probing dark matter models. We show in particular that the constraints set by XENON100 on the spin-dependent neutron cross-section are by far the best at present, whereas the corresponding spin-dependent proton limits lag behind other direct detection results. The effect of nuclear uncertainties on the structure functions of xenon isotopes is analysed in detail and found to lessen the robustness of the constraints, especially for spin-dependent proton couplings. Notwith-standing, the spin-dependent neutron prospects for XENON1T and DARWIN are very encouraging. We apply our constraints to well-motivated dark matter models and demonstrate that in both mass-degenerate scenarios and the minimal supersymmetric standard model the spin-dependent neutron limits can actually override the spin-independent limits. This opens the possibility of probing additional unexplored regions of the dark matter parameter space with the next generation of ton-scale direct detection experiments.

Observation and applications of single-electron charge signals in the XENON100 experiment

NARCIS (Netherlands)

Aprile, E.; et al., [Unknown; Alfonsi, M.; Colijn, A.P.; Decowski, M.P.

2014-01-01

The XENON100 dark matter experiment uses liquid xenon in a time projection chamber (TPC) to measure xenon nuclear recoils resulting from the scattering of dark matter weakly interacting massive particles (WIMPs). In this paper, we report the observation of single-electron charge signals which are

Occupational exposure to xenon-133 among hospital workers

International Nuclear Information System (INIS)

Deschamps, M.

1984-11-01

During procedures for pulmonary ventilation studies on patients in hospitals, xenon-133 may escape into ambient air. Measurements of air concentrations were required to permit an evaluation of the exposure to which hospital workers are subjected. Two complementary methods of in situ measurements of air concentrations were employed: a commercial air monitor and evacuated blood sampling tubes. Personal dosimeters (TLDs) were exposed simultaneously with the commercial air monitor, and the results were compared. This report presents the results of the measurements of air concentrations during studies on patients. Substantial leakage of xenon-133 was noted, but workers received less than the maximum permissible dose. Personal dosimeters do not permit accurate evaluation of the skin doses resulting from exposure to xenon-133; measurements of air concentrations are required for such evaluation. A number of procedures are recommended to minimize leakage and personnel exposure

Xenon-induced axial power oscillations in the 400 MW PBMR

International Nuclear Information System (INIS)

Strydom, Gerhard

2008-01-01

The redistribution of the spatial xenon concentration in the 400 MW Pebble Bed Modular Reactor (PBMR) core has a non-linear, time-dependent feedback effect on the spatial power density during several types of operational transient events. Due to the inherent weak coupling that exists between the iodine and xenon formation and destruction rates, as well as the complicating effect of spatial variance in the thermal flux field, reactor cores have been analyzed for a number of decades for the occurrence and severity of xenon-induced axial power oscillations. Of specific importance is the degree of oscillation damping exhibited by the core during transients, which involves axial variations in the local power density. In this paper the TINTE reactor dynamics code is used to assess the stability of the current 400 MW PBMR core design with regard to axial xenon oscillations. The focus is mainly on the determination of the inherent xenon and power oscillation damping properties by utilizing a set of hypothetical control rod insertion transients at various power levels. The oscillation damping properties of two 100%-50%-100% load-follow transients, one of which includes the de-stabilizing axial effects of moving control rods, are also discussed in some detail. The study shows that, although first axial mode oscillations do occur in the 400 MW PBMR core, the inherent damping of these oscillations is high, and that none of the investigated load-follow transients resulted in diverging oscillations. It is also shown that the PBMR core exhibits no radial oscillation components for these xenon-induced axial power oscillations

Modeling the Removal of Xenon from Lithium Hydrate with Aspen HYSYS

Science.gov (United States)

Efthimion, Phillip; Gentile, Charles

2011-10-01

The Laser Inertial Fusion Engine (LIFE) project mission is to provide a long-term, carbon-free source of sustainable energy, in the form of electricity. A conceptual xenon removal system has been modeled with the aid of Aspen HYSYS, a chemical process simulator. Aspen HYSYS provides excellent capability to model chemical flow processes, which generates outputs which includes specific variables such as temperature, pressure, and molar flow. The system is designed to strip out hydrogen isotopes deuterium and tritium. The base design bubbles plasma exhaust laden with x filled with liquid helium. The system separates the xenon from the hydrogen, deuterium, and tritium with a lithium hydrate and a lithium bubbler. After the removal of the hydrogen and its isotopes, the xenon is then purified by way of the process of cryogenic distillation. The pure hydrogen, deuterium, and tritium are then sent to the isotope separation system (ISS). The removal of xenon is an integral part of the laser inertial fusion engine and Aspen HYSYS is an excellent tool to calculate how to create pure xenon.

Ion beam texturing

Science.gov (United States)

Hudson, W. R.

1977-01-01

A microscopic surface texture was created by sputter-etching a surface while simultaneously sputter-depositing a lower sputter yield material onto the surface. A xenon ion-beam source was used to perform the texturing process on samples as large as 3-cm diameter. Textured surfaces have been characterized with SEM photomicrographs for a large number of materials including Cu, Al, Si, Ti, Ni, Fe, stainless steel, Au, and Ag. A number of texturing parameters are studied including the variation of texture with ion-beam powder, surface temperature, and the rate of texture growth with sputter etching time.

Output power characteristics of the neutral xenon long laser

Energy Technology Data Exchange (ETDEWEB)

Linford, G.J. [TRW Space and Electronics Group, Redondo Beach, CA (United States). Space and Technology Div.

1994-12-31

Lasers which oscillate within inhomogeneously broadened gain media exhibit spectral hole burning and concomitant reduction in output power compared with equivalent homogeneously-broadened laser gain media. By increasing the cavity length, it may be possible to demonstrate at least a partial transition from an inhomogeneous laser cavity mode spectrum to a homogeneous spectrum. There are a number of high gain laser lines which are inhomogeneously-broadened transitions in electric discharges of neutral xenon. In neutral xenon lasers, as in the cases of many other gas lasers, the inhomogeneous spectral broadening mechanism arises from Doppler shifts, {Delta}{nu}{sub D}, of individual atoms in thermal motion within the electric discharge comprising the laser gain medium. Optical transitions corresponding to these noble gas atoms have natural linewidths, {Delta}{nu}{sub n}{lt}{Delta}{nu}{sub D}. Simulations of the output power characteristics of the xenon laser were carried out as a function of laser cavity parameters, including the cavity length, L. These calculations showed that when the intracavity mode spacing frequency, c/2L{lt}{Delta}{nu}{sub n}, the inhomogeneously broadened xenon mode spectrum converted to a homogeneously broadened oscillation spectrum with an increase in output power. These simulations are compared with experimental results obtained for the long laser oscillation characteristics of the (5d[5/2]{degree}{sub 2}{r_arrow}6p[3/2]{sub 1}) transition corresponding to the strong, high-gain 3.508 {mu} line in xenon.

The physical and physiological aspects of xenon isotopes in nuclear medical applicants

International Nuclear Information System (INIS)

Bolmsjoe, M.

1981-11-01

A method for trapping radioactive xenon waste from nuclear medical departments has been investigated. Adsorption of xenon acivitaded charcoal was found to be an efficient trapping method. A large gain in capacity was found when the trap was refrigerated, and permitted a large number of patient investigations before break-through of xenon occurred. By heating charcoal traps to 250-350 degrees C, adsorbed xenon gas is freed and is thus made available for re-use. A technique for room-air monitoring of xenon-leakage from patient investigations is described, where the room-air is continously pumped through a small charcoal filter, mounted close to a detector. The low gammaenergy of Xe-133, 81 keV, introduces problems for in vivo measurements due to the small differences in the energies of the primary and Compton-scattered photons. Influence of scatter and of hemispheric cross-talk was studied for cerebral blood-flow measurements. It was shown that substantial artefacts are introduced in the calculation of regional gray matter flow. The applicability of the xenon-washout technique for liver blood-flow measurements in rat was investigated. (author)

Xenon Defects in Uranium Dioxide From First Principles and Interatomic Potentials

Science.gov (United States)

Thompson, Alexander

In this thesis, we examine the defect energetics and migration energies of xenon atoms in uranium dioxide (UO2) from first principles and interatomic potentials. We also parameterize new, accurate interatomic potentials for xenon and uranium dioxide. To achieve accurate energetics and provide a foundation for subsequent calculations, we address difficulties in finding consistent energetics within Hubbard U corrected density functional theory (DFT+U). We propose a method of slowly ramping the U parameter in order to guide the calculation into low energy orbital occupations. We find that this method is successful for a variety of materials. We then examine the defect energetics of several noble gas atoms in UO2 for several different defect sites. We show that the energy to incorporate large noble gas atoms into interstitial sites is so large that it is energetically favorable for a Schottky defect cluster to be created to relieve the strain. We find that, thermodynamically, xenon will rarely ever be in the interstitial site of UO2. To study larger defects associated with the migration of xenon in UO 2, we turn to interatomic potentials. We benchmark several previously published potentials against DFT+U defect energetics and migration barriers. Using a combination of molecular dynamics and nudged elastic band calculations, we find a new, low energy migration pathway for xenon in UO2. We create a new potential for xenon that yields accurate defect energetics. We fit this new potential with a method we call Iterative Potential Refinement that parameterizes potentials to first principles data via a genetic algorithm. The potential finds accurate energetics for defects with relatively low amounts of strain (xenon in defect clusters). It is important to find accurate energetics for these sorts of low-strain defects because they essentially represent small xenon bubbles. Finally, we parameterize a new UO2 potential that simultaneously yields accurate vibrational properties

Beam experiments with the Grenoble test electron cyclotron resonance ion source at iThemba LABS

Energy Technology Data Exchange (ETDEWEB)

Thomae, R., E-mail: rthomae@tlabs.ac.za; Conradie, J.; Fourie, D.; Mira, J.; Nemulodi, F. [iThemba LABS, P.O. Box 722, Somerset West 7130 (South Africa); Kuechler, D.; Toivanen, V. [CERN, BE/ABP/HSL, 1211 Geneva 23 (Switzerland)

2016-02-15

At iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) an electron cyclotron ion source was installed and commissioned. This source is a copy of the Grenoble Test Source (GTS) for the production of highly charged ions. The source is similar to the GTS-LHC at CERN and named GTS2. A collaboration between the Accelerators and Beam Physics Group of CERN and the Accelerator and Engineering Department of iThemba LABS was proposed in which the development of high intensity argon and xenon beams is envisaged. In this paper, we present beam experiments with the GTS2 at iThemba LABS, in which the results of continuous wave and afterglow operation of xenon ion beams with oxygen as supporting gases are presented.

The Large Underground Xenon (LUX) experiment

International Nuclear Information System (INIS)

Akerib, D.S.; Bai, X.; Bedikian, S.; Bernard, E.; Bernstein, A.; Bolozdynya, A.; Bradley, A.; Byram, D.; Cahn, S.B.; Camp, C.; Carmona-Benitez, M.C.; Carr, D.; Chapman, J.J.; Chiller, A.; Chiller, C.; Clark, K.; Classen, T.; Coffey, T.; Curioni, A.

2013-01-01

The Large Underground Xenon (LUX) collaboration has designed and constructed a dual-phase xenon detector, in order to conduct a search for Weakly Interacting Massive Particles (WIMPs), a leading dark matter candidate. The goal of the LUX detector is to clearly detect (or exclude) WIMPS with a spin independent cross-section per nucleon of 2×10 −46 cm 2 , equivalent to ∼1event/100kg/month in the inner 100-kg fiducial volume (FV) of the 370-kg detector. The overall background goals are set to have <1 background events characterized as possible WIMPs in the FV in 300 days of running. This paper describes the design and construction of the LUX detector

Mitigation of {sup 222}Rn induced background in the XENON1T dark matter experiment

Energy Technology Data Exchange (ETDEWEB)

Bruenner, Stefan A.

2017-07-05

{sup 222}Rn is a major source of background in many rare-event experiments such as the XENON1T dark matter search. The noble gas radon is created by radioactive decay inside all detector materials and emanates into the sensitive liquid xenon target disabling any detector shielding. Subsequent beta-decays of radon progenies are the dominant source of background in the XENON1T experiment. In order to mitigate radon induced background the detector's construction materials have been selected according to dedicated {sup 222}Rn emanation measurements. In the first part of this thesis, we summarize the results of the XENON1T radon screening campaign and present the measurement of the integral radon emanation rate of the fully assembled detector. The development of a radon removal system which continuously purifies the liquid xenon target from the emanated radon is the topic of the second part of this thesis. In order to demonstrate the suitability of cryogenic distillation as a technique to separate radon from xenon, we developed an experimental setup to measure the depletion of radon in xenon boil-off gas after a single distillation step. In the last part of the thesis, we demonstrate the operation of a radon removal system for the XENON100 experiment. For this first test employing a running dark matter detector, we integrated a multiple stage, cryogenic distillation column in the XENON100 gas purification loop. From the evolution of the radon concentration in XENON100, we investigate the distillation column's radon removal capability and discuss the design and application of a radon removal system for XENON1T and the upcoming XENONnT experiment.

Control of spatial xenon oscillations in pressurized water reactors via the Kalman filter

International Nuclear Information System (INIS)

Lin, C.; Lin, Y.J.

1994-01-01

A direct control method is developed to control the spatial xenon oscillations in pressurized water reactors. The xenon and iodine concentration difference between the top and bottom halves of the core is estimated by using the extended Kalman filter (EKF), which is a closed-loop estimation method. The measurement equation used in the observer is the axial offset measurement equation, which reflects the xenon unbalanced effect on the axial offset. Meanwhile, some of the coefficients of the observer are estimated on-line to reduce estimation error resulting from model error, i.e., simplified xenon and iodine dynamics. Therefore, the estimation can be guaranteed to be accurate, and the success of the estimation does not greatly depend on the accuracy of the observer model. The predicted one-step ahead xenon concentration, by using the EKF, was used to calculate the possible axial offset variation, and then the control rod motion was calculated to compensate for it. The simulation results show that the proposed method successfully controls the xenon oscillations

Recent developments of ion sources for life-science studies at the Heavy Ion Medical Accelerator in Chiba (invited)

Energy Technology Data Exchange (ETDEWEB)

Kitagawa, A.; Drentje, A. G.; Fujita, T.; Muramatsu, M. [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba 263-8555 (Japan); Fukushima, K.; Shiraishi, N.; Suzuki, T.; Takahashi, K.; Takasugi, W. [Accelerator Engineering Corporation, Chiba (Japan); Biri, S.; Rácz, R. [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/C, H-4026 Debrecen (Hungary); Kato, Y. [Graduate School of Engineering, Osaka University, Osaka (Japan); Uchida, T.; Yoshida, Y. [Bio-Nano Electronics Research Centre, Toyo University, Kawagoe (Japan)

2016-02-15

With about 1000-h of relativistic high-energy ion beams provided by Heavy Ion Medical Accelerator in Chiba, about 70 users are performing various biology experiments every year. A rich variety of ion species from hydrogen to xenon ions with a dose rate of several Gy/min is available. Carbon, iron, silicon, helium, neon, argon, hydrogen, and oxygen ions were utilized between 2012 and 2014. Presently, three electron cyclotron resonance ion sources (ECRISs) and one Penning ion source are available. Especially, the two frequency heating techniques have improved the performance of an 18 GHz ECRIS. The results have satisfied most requirements for life-science studies. In addition, this improved performance has realized a feasible solution for similar biology experiments with a hospital-specified accelerator complex.

Monte Carlo modeling of ion chamber performance using MCNP.

Science.gov (United States)

Wallace, J D

2012-12-01

Ion Chambers have a generally flat energy response with some deviations at very low (2 MeV) energies. Some improvements in the low energy response can be achieved through use of high atomic number gases, such as argon and xenon, and higher chamber pressures. This work looks at the energy response of high pressure xenon-filled ion chambers using the MCNP Monte Carlo package to develop geometric models of a commercially available high pressure ion chamber (HPIC). The use of the F6 tally as an estimator of the energy deposited in a region of interest per unit mass, and the underlying assumptions associated with its use are described. The effect of gas composition, chamber gas pressure, chamber wall thickness, and chamber holder wall thicknesses on energy response are investigated and reported. The predicted energy response curve for the HPIC was found to be similar to that reported by other investigators. These investigations indicate that improvements to flatten the overall energy response of the HPIC down to 70 keV could be achieved through use of 3 mm-thick stainless steel walls for the ion chamber.

Automatic control logics to eliminate xenon oscillation based on Axial Offsets Trajectory Method

International Nuclear Information System (INIS)

Shimazu, Yoichiro

1996-01-01

We have proposed Axial Offsets (AO) Trajectory Method for xenon oscillation control in pressurized water reactors. The features of this method are described as such that it can clearly give necessary control operations to eliminate xenon oscillations. It is expected that using the features automatic control logics for xenon oscillations can be simple and be realized easily. We investigated automatic control logics. The AO Trajectory Method could realize a very simple logic only for eliminating xenon oscillations. However it was necessary to give another considerations to eliminate the xenon oscillation with a given axial power distribution. The other control logic based on the modern control theory was also studied for comparison of the control performance of the new control logic. As the results, it is presented that the automatic control logics based on the AO Trajectory Method are very simple and effective. (author)

Process for recovering xenon from radioactive gaseous wastes

International Nuclear Information System (INIS)

Kishimoto, Tsuneo.

1980-01-01

Purpose: To recover pure xenon economically and efficiently by amply removing radioactive krypton mixed in xenon without changing the rectifying capacity of an xenon rectifying system itself. Method: Xe containing radioactive Kr(Kr-85) is rectified to reduce the concentration of radioactive Kr. Thereafter, non-radioactive Kr or Ar is added to Xe and further the rectification is carried out. The raw material Xe from the Xe adsorption system of, for example, a radioactive gaseous waste disposal system is cooled to about 100 0 C by a heat-exchanger and thereafter supplied to a rectifying tower to carry out normal rectification of Xe thereby to reduce the concentration of Kr contained in Xe at the tower bottom to the rectification limit concentration. Then, non-radioactive Kr is supplied via a precooler to the tower bottom to continue the rectification, thus the Xe fractions at the tower bottom, in which the concentration of radioactive Kr is reduced, being compressed and recovered. (Kamimura, M.)

Material radioassay and selection for the XENON1T dark matter experiment

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Messina, M.; Plante, G.; Rizzo, A.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, LIBPhys, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L.; Di Giovanni, A.; Franco, D.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wei, Y.; Wulf, J. [University of Zurich, Physik Institut, Zurich (Switzerland); Bauermeister, B. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Sivers, M. von [Rensselaer Polytechnic Institute, Troy, NY (United States). Dept. of Physics, Applied Physics and Astronomy; Bern Univ. (Switzerland). Albert Einstein Center for Fundamental Physics; Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindemann, S.; Lindner, M.; Marrodan Undagoitia, T.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Gallo Rosso, A.; Molinario, A.; Laubenstein, M.; Nisi, S. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M. [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Calven, J.; Conrad, J.; Ferella, A.D.; Pelssers, B. [Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, Stockholm (Sweden); Cervantes, M.; Lang, R.F.; Masson, D.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Le Calloch, M.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [Universite de Nantes, SUBATECH, Ecole des Mines de Nantes, CNRS/IN2P3, Nantes (France); Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Fei, J.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Grandi, L.; Saldanha, R.; Shockley, E.; Upole, N. [University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Miguez, B.; Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Scotto Lavina, L. [Universite Pierre et Marie Curie, Universite Paris Diderot, CNRS/IN2P3, LPNHE, Paris (France); Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Tunnell, C. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Collaboration: XENON Collaboration

2017-12-15

The XENON1T dark matter experiment aims to detect weakly interacting massive particles (WIMPs) through low-energy interactions with xenon atoms. To detect such a rare event necessitates the use of radiopure materials to minimize the number of background events within the expected WIMP signal region. In this paper we report the results of an extensive material radioassay campaign for the XENON1T experiment. Using gamma-ray spectroscopy and mass spectrometry techniques, systematic measurements of trace radioactive impurities in over one hundred samples within a wide range of materials were performed. The measured activities allowed for stringent selection and placement of materials during the detector construction phase and provided the input for XENON1T detection sensitivity estimates through Monte Carlo simulations. (orig.)

Intrinsic backgrounds from Rn and Kr in the XENON100 experiment

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M.; Perio, P. de; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Plante, G.; Rizzo, A.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, LIBPhys, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L.; Galloway, M.; Kazama, S.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wulf, J. [University of Zurich, Physik-Institut, Zurich (Switzerland); Bauermeister, B.; Calven, J.; Conrad, J.; Ferella, A.D.; Moraa, K.; Pelssers, B. [Stockholm University, AlbaNova, Oskar Klein Centre, Department of Physics, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Marrodan Undagoitia, T.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Rosso, A.G.; Molinario, A.; Wang, Z. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. von [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Cervantes, M.; Lang, R.F.; Masson, D.; Reichard, S. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [CNRS/IN2P3, Universite de Nantes, SUBATECH, IMT Atlantique, Nantes (France); Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Fei, J.; Lombardi, F.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Murra, M.; Vargas, M.; Weinheimer, C.; Wittweg, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso, L' Aquila (Italy); Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Lindemann, S. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Messina, M. [Columbia University, Physics Department, New York, NY (United States); New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Pienaar, J. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); University of Chicago, Department of Physics, Kavli Institute of Cosmological Physics, Chicago, IL (United States); Ramirez Garcia, D. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Reuter, C. [University of Zurich, Physik-Institut, Zurich (Switzerland); Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Lavina, L.S. [Universite Paris Diderot, CNRS/IN2P3, LPNHE, Universite Pierre et Marie Curie, Paris (France); Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Torino (Italy); Tunnell, C. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); University of Chicago, Department of Physics, Kavli Institute of Cosmological Physics, Chicago, IL (United States); Weber, M. [Columbia University, Physics Department, New York, NY (United States); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Wei, Y. [University of Zurich, Physik-Institut, Zurich (Switzerland); University of California, Department of Physics, San Diego, CA (United States); Collaboration: XENON Collaboration

2018-02-15

In this paper, we describe the XENON100 data analyses used to assess the target-intrinsic background sources radon ({sup 222}Rn), thoron ({sup 220}Rn) and krypton ({sup 85}Kr). We detail the event selections of high-energy alpha particles and decay-specific delayed coincidences. We derive distributions of the individual radionuclides inside the detector and quantify their abundances during the main three science runs of the experiment over a period of ∝ 4 years, from January 2010 to January 2014. We compare our results to external measurements of radon emanation and krypton concentrations where we find good agreement. We report an observed reduction in concentrations of radon daughters that we attribute to the plating-out of charged ions on the negatively biased cathode. (orig.)

Intrinsic backgrounds from Rn and Kr in the XENON100 experiment

International Nuclear Information System (INIS)

Aprile, E.; Anthony, M.; Perio, P. de; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Plante, G.; Rizzo, A.; Zhang, Y.; Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A.; Agostini, F.; Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S.; Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos; Silva, M.; Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I.; Barrow, P.; Baudis, L.; Galloway, M.; Kazama, S.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wulf, J.; Bauermeister, B.; Calven, J.; Conrad, J.; Ferella, A.D.; Moraa, K.; Pelssers, B.; Berger, T.; Brown, E.; Piro, M.C.; Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Marrodan Undagoitia, T.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H.; Bruno, G.; Rosso, A.G.; Molinario, A.; Wang, Z.; Budnik, R.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N.; Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. von; Cervantes, M.; Lang, R.F.; Masson, D.; Reichard, S.; Cussonneau, J.P.; Diglio, S.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D.; Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M.; Fei, J.; Lombardi, F.; Ni, K.; Ye, J.; Fieguth, A.; Murra, M.; Vargas, M.; Weinheimer, C.; Wittweg, C.; Fulgione, W.; Lindemann, S.; Messina, M.; Naganoma, J.; Shagin, P.; Pienaar, J.; Ramirez Garcia, D.; Reuter, C.; Lavina, L.S.; Stein, A.; Wang, H.; Trinchero, G.; Tunnell, C.; Weber, M.; Wei, Y.

2018-01-01

In this paper, we describe the XENON100 data analyses used to assess the target-intrinsic background sources radon ( 222 Rn), thoron ( 220 Rn) and krypton ( 85 Kr). We detail the event selections of high-energy alpha particles and decay-specific delayed coincidences. We derive distributions of the individual radionuclides inside the detector and quantify their abundances during the main three science runs of the experiment over a period of ∝ 4 years, from January 2010 to January 2014. We compare our results to external measurements of radon emanation and krypton concentrations where we find good agreement. We report an observed reduction in concentrations of radon daughters that we attribute to the plating-out of charged ions on the negatively biased cathode. (orig.)

Commissioning of the XENON1T liquid level measurement system

Energy Technology Data Exchange (ETDEWEB)

Geis, Christopher [Institut fuer Physik, Johannes Gutenberg-Universitaet, Mainz (Germany)

2016-07-01

Two-phase xenon time projection chambers (TPCs) have been operated very successfully in direct detection experiments for dark matter. This kind of detector uses liquid xenon as the sensitive target and is operated in two-phase (liquid/gas) mode, where the liquid level needs to be monitored and controlled with sub-millimeter precision. We present the installation, commissioning and first measurement data of two kinds of level meters operated in the XENON1T TPC: short level meters are three-plated capacitors measuring the level of the liquid-gas interface with a measurement range h∼5 mm and a resolution of ΔC/h∼1 pF/mm. The long level meters are cylindrical double-walled capacitors, measuring the overall filling level of the XENON1T TPC at a measurement range of h=1.4 m and a resolution of ΔC/h∼0.1 pF/mm. Further, we present the design and programming of the readout electronic based on the UTI chip by Smartec, which allows to read all six levelmeters simultaneously.

Recent developments in evaluating xenon induced flux transients in large HTRs

Energy Technology Data Exchange (ETDEWEB)

Lauer, A.

1974-03-15

A description is provided of the two-dimensional finite-difference xenon code system ASTERIX (A System for Transient Evaluation of Reactor instabilities Induced by Xenon) that was designed for very exact computations of space dependent xenon transients in HTR's and their control. By its modular structure, the code allows for a most flexible use in calculating load following transients, xenon oscillations in x/y, r/z and r/theta geometries and various control operations with either homogeneous poison or discrete rod representations with flux boundary conditions. The most recent upgrade ASTERIX-T includes a detailed temperature feedback option for azimuthal HTR transient calculations, based on an iterative procedure for the evaluation of the power distribution in each time step with succeeding diffusion, temperature and spectrum calculations for the group constants in every spectral region, thus avoiding earlier more problematic approximations of the temperature dependence of the cross sections.

An investigation of axial xenon stability in WWER-1000 reactor designs

International Nuclear Information System (INIS)

Doshi, P.K.; Miller, R.W.

1993-01-01

The nuclear power plants of the WWER-1000 design have experienced frequent xenon oscillation control problems. In most PWRs, xenon oscillations are largely a problem in the axial direction. An one dimensional core model representative of the WWER-1000 design was set up to examine the controllability of the current design. An investigation of possible improvements to this design was made. There was no indication that xenon oscillations were an inherent problem in WWER-1000 core design. Simple changes to the control rod system coupled with a sound power distribution control strategy that has been proven to be an effective but simple procedure to follow, eliminate xenon control problems. The changes proposed can be implemented in a very cost effective manner. There are no equipment changes needed, existing control rods can be used. Only software changes are required. (Z.S.) 1 tab., 2 figs., 7 refs

Performance optimization of 20 cm xenon ion thruster discharge chamber

International Nuclear Information System (INIS)

Chen Juanjuan; Zhang Tianping; Jia Yanhui; Li Xiaoping

2012-01-01

This paper describes the performance of the LIPS-200 ion thruster discharge chamber which was developed by Lanzhou Institute of Physics. Based on the discharge chamber geometric configuration and magnetic field, the completely self-consistent analytical model is utilized to discuss performance optimization of the discharge chamber of the LIPS-200. The thrust is enhanced from 40 mN up to 60 mN at rated impulse and efficiency. The results show that the 188.515 W/A beam ion production cost at a propellant flow rate of 2.167 × 10 17 m -3 requires that the thruster runs at a discharge current of 6.9 A to produce 1.2 A ion beam current. Also, during the process of LIPS-200 ion thruster discharge chamber performance optimization, the sheath potential is always within 3.80 ∼ 6.65 eV. (authors)

Xenon thermal behavior in sintered titanium nitride, foreseen inert matrix for GFR

International Nuclear Information System (INIS)

Bes, R.

2010-11-01

This work concerns the generation IV future nuclear reactors such as gas-cooled fast reactor (GFR) for which refractory materials as titanium nitride (TiN) are needed to surround fuel and act as a fission product diffusion barrier. This study is about Xe thermal behavior in sintered titanium nitride. Microstructure effects on Xe behavior have been studied. In this purpose, several syntheses have been performed using different sintering temperatures and initial powder compositions. Xenon species have been introduced into samples by ionic implantation. Then, samples were annealed in temperature range from 1300 C to 1600 C, these temperatures being the accidental awaited temperature. A transport of xenon towards sample surface has been observed. Transport rate seems to be slow down when increasing sintering temperature. The composition of initial powder and the crystallographic orientation of each considered grain also influence xenon thermal behavior. Xenon release has been correlated with material oxidation during annealing. Xenon bubbles were observed. Their size is proportional with xenon concentration and increases with annealing temperature. Several mechanisms which could explain Xe intragranular mobility in TiN are proposed. In addition with experiments, very low Xe solubility in TiN has been confirmed by ab initio calculations. So, bi-vacancies were found to be the most favoured Xe incorporation sites in this material. (author)

Luminous flux improvement of xenon fluorescent lamps by applying synchronized high-voltage pulse to the auxiliary external electrode

Energy Technology Data Exchange (ETDEWEB)

Motomura, Hideki; Oka, Kojiro; Sogabe, Toru; Jinno, Masafumi, E-mail: hmoto@mayu.ee.ehime-u.ac.jp [Department of Electrical and Electronic Engineering, Ehime University 3 Bunkyo-cho, Matsuyama, Ehime 790-8577 (Japan)

2011-06-08

As the environmental awareness of people becomes stronger, the demand for mercury-free light sources also becomes stronger. The authors have been developing cold cathode fluorescent lamps in which xenon gas is filled as an ultraviolet radiator instead of mercury. Previously the authors reported the luminous flux enhancement method using a grounded auxiliary external electrode (AEE). In this paper, in order to improve the luminous flux much more, a positive voltage pulse which was synchronized to the main driving negative voltage pulse was applied to the AEE. As a result, the maximum input power increased under which the positive column did not constrict and the luminous flux improved by 70% at the xenon filling pressure of 6.7 kPa. It is proved that the positive voltage pulse application to the AEE with the amplitude of more than 2 kV expands the positive column in the radial direction. It is attributed to the phenomenon that the residual ions and electrons, which are generated by dielectric barrier discharge between the AEE and the anode during the falling edge of the negative pulse to the cathode, spread the discharge path from the anode towards the AEE during the cold cathode discharge mode. By increasing the xenon filling pressure, luminous efficacy was improved to 25 lm W{sup -1}.

An approach to stability analysis of spatial xenon oscillations in WWER-1000 reactors

International Nuclear Information System (INIS)

Parhizkari, H.; Aghaie, M.; Zolfaghari, A.; Minuchehr, A.

2015-01-01

Highlights: • The multipoint methodology is developed for xenon oscillation in the BNPP. • The axial, radial and azimuthal offsets are calculated in the BOC and EOC. • It is shown that the all of oscillation modes are safe in the BOC. • The axial oscillation is not safe in the EOC and needs governor control system. • The multipoint kinetics show good agreement for spatial oscillations. - Abstract: Spatial power oscillations due to spatial distribution of xenon transient are well known as xenon oscillation in large reactors. Xenon-induced spatial power oscillations occur as a result of rapid perturbations to power distribution that cause the xenon and iodine distribution to be out of phase with the perturbed power distribution. This results in a shift in xenon and iodine distributions that causes the power distribution to change in an opposite direction from the initial perturbation. In this paper xenon-induced power oscillation is described by a system of differential equations with non-linearity between xenon and flux distributions; the dynamics of process is described by a discrete distributed parameter model, with the neutron flux, the delayed neutrons, the core temperature and the xenon and iodine concentrations as the “states” of the system. It is shown that it is possible to describe the discrete distributed-parameter as a set of coupled point-reactor models. It is also shown that using this scheme it is possible to analyze the control aspects of a multi-section large core reactor by treating only two adjacent sections of the core. To illustrate the capability and efficiency of the proposed scheme Bushehr Nuclear Power Plant, BNPP, which is a WWER-1000 reactor, is chosen to show the performance of the methodology. The axial, azimuthal and radial power oscillation at the beginning of cycle, BOC, and the end of cycle, EOC, for BNPP are investigated; the results are in good agreement with safety analysis report of the reference plant

Requirements for Xenon International

Energy Technology Data Exchange (ETDEWEB)

Hayes, James C.; Ely, James H.

2013-09-26

This document defines the requirements for the new Xenon International radioxenon system. The output of this project will be a Pacific Northwest National Laboratory (PNNL) developed prototype and a manufacturer-developed production prototype. The two prototypes are intended to be as close to matching as possible; this will be facilitated by overlapping development cycles and open communication between PNNL and the manufacturer.

Requirements for Xenon International

Energy Technology Data Exchange (ETDEWEB)

Hayes, James C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ely, James H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Haas, Derek A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Harper, Warren W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Heimbigner, Tom R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hubbard, Charles W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Humble, Paul H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Madison, Jill C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Morris, Scott J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Panisko, Mark E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ripplinger, Mike D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stewart, Timothy L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-12-30

This document defines the requirements for the new Xenon International radioxenon system. The output of this project will be a Pacific Northwest National Laboratory (PNNL) developed prototype and a manufacturer-developed production prototype. The two prototypes are intended to be as close to matching as possible; this will be facilitated by overlapping development cycles and open communication between PNNL and the manufacturer.

Monitoring xenon purity in the LUX detector with a mass spectrometry system

Science.gov (United States)

Balajthy, Jon; LUX Experiment Collaboration

2015-04-01

The LUX dark matter search experiment is a 350 kg two-phase liquid/gas xenon time projection chamber located at the 4850 ft level of the Sanford Underground Research Facility in Lead, SD. To monitor for radioactive impurities such as krypton and impurities which limit charge yield such as oxygen, LUX uses a xenon sampling system consisting of a mass spectrometer and a liquid nitrogen cold trap. The cold trap separates the gaseous impurities from a small sample of xenon and allows them to pass to the mass spectrometer for analysis. We report here on results from the LUX xenon sampling program. We also report on methods to enhance the sensitivity of the cold trap technique in preparation for the next-generation LUX-ZEPLIN experiment which will have even more stringent purity requirements.

Scalability, Scintillation Readout and Charge Drift in a Kilogram Scale Solid Xenon Particle Detector

Energy Technology Data Exchange (ETDEWEB)

Yoo, J. [Fermilab; Cease, H. [Fermilab; Jaskierny, W. F. [Fermilab; Markley, D. [Fermilab; Pahlka, R. B. [Fermilab; Balakishiyeva, D. [Florida U.; Saab, T. [Florida U.; Filipenko, M. [Erlangen - Nuremberg U., ECAP

2014-10-23

We report a demonstration of the scalability of optically transparent xenon in the solid phase for use as a particle detector above a kilogram scale. We employ a liquid nitrogen cooled cryostat combined with a xenon purification and chiller system to measure the scintillation light output and electron drift speed from both the solid and liquid phases of xenon. Scintillation light output from sealed radioactive sources is measured by a set of high quantum efficiency photomultiplier tubes suitable for cryogenic applications. We observed a reduced amount of photons in solid phase compared to that in liquid phase. We used a conventional time projection chamber system to measure the electron drift time in a kilogram of solid xenon and observed faster electron drift speed in the solid phase xenon compared to that in the liquid phase.

Liquid xenon in nuclear medicine: state-of-the-art and the PETALO approach

Science.gov (United States)

Ferrario, P.

2018-01-01

Liquid xenon has several attractive features, which make it suitable for applications to nuclear medicine, such as high scintillation yield and fast scintillation decay time, better than currently used crystals. Since the '90s, several attempts have been made to build Positron Emission Tomography scanners based on liquid xenon, which can be divided into two different approaches: on one hand, the detection of the ionization charge in TPCs, and, on the other one, the detection of scintillation light with photomultipliers. PETALO (Positron Emission Tof Apparatus with Liquid xenOn) is a novel concept, which combines liquid xenon scintillating cells and silicon photomultipliers for the readout. A first Monte Carlo investigation has pointed out that this technology would provide an excellent intrinsic time resolution, which makes it possible to measure the Time-Of-Flight with high efficiency. Also, the transparency of liquid xenon to UV and blue wavelengths opens the possibility of exploiting both scintillation and Cherenkov light for a high-sensitivity TOF-PET.

Radiation hardening of metals irradiated by heavy ions

International Nuclear Information System (INIS)

Didyk, A.Yu.; Skuratov, V.A.; Mikhajlova, N.Yu.; Regel', V.R.

1988-01-01

The damage dose dependence in the 10 -4 -10 -2 dpa region of radiation hardening of Al, V, Ni, Cu irradiated by xenon ions with 124 MeV energy is investigated using the microhardness technique and transmission electron microscope. It is shown that the pure metals radiation hardening is stimulated for defects clusters with the typical size less than 5 nm, as in the case of neutron and the light charge ion irradiation

Spectroscopy of berylliumlike xenon ions using dielectronic recombination

Science.gov (United States)

Bernhardt, D.; Brandau, C.; Harman, Z.; Kozhuharov, C.; Böhm, S.; Bosch, F.; Fritzsche, S.; Jacobi, J.; Kieslich, S.; Knopp, H.; Nolden, F.; Shi, W.; Stachura, Z.; Steck, M.; Stöhlker, Th; Schippers, S.; Müller, A.

2015-07-01

Be-like 136X{{e}50+} ions have been investigated employing the resonant electron-ion collision process of dielectronic recombination (DR) as a spectroscopic tool. The experiments were performed at the experimental storage ring in Darmstadt, Germany, using its electron cooler as a target for free electrons. DR Rydberg resonance series 2{{s}2}+{{e}-}\\to 2s2{{p}{{j\\prime }}}n{{l}j} for the associated intra-L-shell transitions 2{{s}2}{{ }1}{{S}0}-2s2{{p}1/2}{{ }3}{{P}1},2{{s}2}{{ }1}{{S}0}-2s2{{p}3/2}{{ }3}{{P}2} and 2{{s}2}{{ }1}{{S}0}-2s2{{p}3/2}{{ }1}{{P}1} were observed with high resolution. In addition to these excitations from the ground state we determined resonances associated with excitations 2s2{{p}1/2}{{ }3}{{P}0}\\to 2{{p}1/2}2{{p}3/2}{{ }3}{{P}1} of ions initially in the metastable 2s2{{p}1/2}{{ }3}{{P}0} state. The corresponding excitation energies were determined to be E{{(}1}{{S}0}\\to {{ }3}{{P}1})=127.269(46) eV, E{{(}1}{{S}0}\\to {{ }3}{{P}2})=469.474(81) eV and E{{(}1}{{S}0}\\to {{ }1}{{P}1})=532.801(16) eV, and E{{(}3}{{P}0}\\to 2{{p}1/2}2{{p}3/2}{{ }3}{{P}1})=533.733(22) eV. These excitation energies are compared with previous measurements and with recent state-of-the-art atomic structure calculations.

Xenon oscillation control in large PWR using a characteristic ellipse trajectory drawn by three axial offsets

International Nuclear Information System (INIS)

Yoichiro, Shimazu

2007-01-01

We have proposed a very simple xenon oscillation control procedure based on a characteristic trajectory. The trajectory is drawn by three offsets of power distributions, namely, AOp, AOi and AOx. They are defined as the offset of axial power distribution, the offset of the power distribution under which the current iodine distribution is obtained as the equilibrium and that for xenon distribution, respectively. When these offsets are plotted on X-Y plane for (AOp-AOx, AOi-AOx) the trajectory shows a quite characteristic ellipse (or an elliptic spiral). It shows characteristics such that the center of the ellipse is at the origin, the gradient of the major axis is constant, direction of the trajectory progress is always anti-clock wise, plot goes around the ellipse during a cycle of the xenon oscillation and so on. This characteristic does not change even if the control rods are moved. When the plot is at the origin of the X-Y plane, no xenon oscillation exists. Using the characteristics of the ellipse the xenon oscillation can be eliminated by guiding the plot to the origin with control rod operation. This concept can be applied not only to the axial xenon oscillation but also to the radial xenon oscillation control. Conventionally, the trajectory is drawn based on the xenon dynamics using reactor parameters such as core averaged macroscopic fission cross section, xenon micro absorption cross section, fission yields of iodine and xenon, and so on together with the neutron flux signals. The accuracy is expected to be better. (authors)

Net sputtering rate due to hot ions in a Ne-Xe discharge gas bombarding an MgO layer

International Nuclear Information System (INIS)

Ho, S.; Tamakoshi, T.; Ikeda, M.; Mikami, Y.; Suzuki, K.

2011-01-01

An analytical method is developed for determining net sputtering rate for an MgO layer under hot ions with low energy ( h i , above a threshold energy of sputtering, E th,i , multiplied by a yield coefficient. The threshold energy of sputtering is determined from dissociation energy required to remove an atom from MgO surface multiplied by an energy-transfer coefficient. The re-deposition rate of the sputtered atoms is calculated by a diffusion simulation using a hybridized probabilistic and analytical method. These calculation methods are combined to analyze the net sputtering rate. Maximum net sputtering rate due to the hot neon ions increases above the partial pressure of 4% xenon as E h Ne becomes higher and decreases near the partial pressure of 20% xenon as ion flux of neon decreases. The dependence due to the hot neon ions on partial pressure and applied voltage agrees well with experimental results, but the dependence due to the hot xenon ions deviates considerably. This result shows that the net sputtering rate is dominated by the hot neon ions. Maximum E h Ne (E h Ne,max = 5.3 - 10.3 eV) is lower than E th,Ne (19.5 eV) for the MgO layer; therefore, weak sputtering due to the hot neon ions takes place. One hot neon ion sputters each magnesium and each oxygen atom on the surface and distorts around a vacancy. The ratio of the maximum net sputtering rate is approximately determined by number of the ions at E h i,max multiplied by an exponential factor of -E th,i /E h i,max .

Evaluation of activated charcoal for dynamic adsorption of krypton and xenon

International Nuclear Information System (INIS)

Khan, A.A.; Deshingkar, D.S.; Ramarathinam, K.; Kishore, A.G.

1975-01-01

From the standpoint of radiation safety, the release of radioactive krypton and xenon from power reactors should be kept as low as practicable. The decay of shortlived isotopes of krypton and xenon by adsorptive delay on activated charcoal has shown promising results for this purpose. The delay provided by activated charcoal is proportional to the dynamic adsorption coefficients of these gases which are characteristic of the adsorbent. These coefficients were determined for krypton and xenon on indigenous gas-adsorbing activated charcoal at different moisture contents of carrier air stream and activated charcoal, concentrations of krypton around ambient temperatures, to find its suitability for designing adsorber columns. (author)

Spectra of copperlike and zinclike xenon: Xe XXV and Xe XXVI

International Nuclear Information System (INIS)

Kaufman, V.; Sugar, J.; Rowan, W.L.

1988-01-01

The spectra of highly ionized xenon were generated in a tokamak plasma and photographed in the region 60--350 A with a 2.2-m grazing-incidence spectrograph. The 4s 2 --4s4p transitions of Zn-like xenon (Xe XXV) and all the 4l--4(l+1) transitions of Cu-like xenon (Xe XXVI) were measured with estimated uncertainties of +- 0.005 A. These measurements have been combined with previous wavelength measurements of Xe XXVI to determine energy levels. A value for the ionization energy of Xe 25+ of 6 912 400 +- 3000 cm -1 (857.0 +- 0.4 eV) was derived

Operation and technology development of the radioactive xenon and krypton detection equipment

International Nuclear Information System (INIS)

Lee, Wanno; Choi, Sangdo; Ji, Youngyong; Lim, Jong Myoung; Cho, Young Hyun; Kang, Han Beul; Lee, Hoon; Kang, Moon Ja; Choi, Kun Sik

2013-03-01

Operation and technology development of the radioactive xenon and krypton detection equipment - Advancement, independence of operation technology for BfS-IAR system(the simultaneous analysis of xenon and krypton) installed after North Korea nuclear tests in 2006 and establishment of background base-line for xenon and krypton radioactivity. - Enhanced detection and analysis capabilities for neighborhood nuclear activities through advanced research of noble gas detection technology. Results of the Project · The operation of xenon and krypton analysis system (BfS-IAR) · Operation of fixed adsorption system. · Operation of portable adsorption system · Exercise of emergency response and proficiency test with SAUNA. · Measurement of noble gas background at specific region in Korea. - Radioxenon levels at Dongdu Cheon is approximately 1.6 mBq/m 3 · Development of automation filling system for absorber cooling

Recycle Requirements for NASA's 30 cm Xenon Ion Thruster

Science.gov (United States)

Pinero, Luis R.; Rawlin, Vincent K.

1994-01-01

Electrical breakdowns have been observed during ion thruster operation. These breakdowns, or arcs, can be caused by several conditions. In flight systems, the power processing unit must be designed to handle these faults autonomously. This has a strong impact on power processor requirements and must be understood fully for the power processing unit being designed for the NASA Solar Electric Propulsion Technology Application Readiness program. In this study, fault conditions were investigated using a NASA 30 cm ion thruster and a power console. Power processing unit output specifications were defined based on the breakdown phenomena identified and characterized.

HEMODYNAMIC EFFECTS OF XENON ANESTHESIA IN CHILDREN

Directory of Open Access Journals (Sweden)

M. V. Bykov

2014-01-01

Full Text Available The study was aimed at hemodynamic effects of xenon on operative interventions in children. Patients and methods: the study involved 30 5-17-year-old children – 10 (33.3% girls and 20 (66.7% boys with ASA score 1-3 admitted for surgical treatment. The children underwent endotracheal anesthesia with xenon-oxygen mixture (Xe:O2 = 60-65:30% and fentanyl (2.5‑3.5  mcg/kg per hour for the following operations: appendectomy – 10 (33.3% patients, herniotomy – 8 (26.7% patients, Ivanissevich procedure – 6 (20.0% patients, plastic surgery of posttraumatic defects of skin and soft tissues – 4 (13.3% patients, abdominal adhesiotomy – 2 (6.7% patients. Central hemodynamics was studied echocardiographically (Philips HD 11, the Netherlands using the Teichholz technique along the cephalocaudal axis (parasternal access. Results: the anesthesia was notable for hemodynamic stability during the operation: as a result, a statistically significant (p < 0.05 increase in systolic, diastolic and mean arterial pressure by 10, 18 and 17%, respectively, was observed. Conclusion: the analysis demonstrated that xenon anesthesia improves lusitropic myocardial function statistically significantly increasing cardiac output by 12% by way of increasing stroke volume by 30%. 

Mercury-free electrodeless discharge lamp: effect of xenon pressure and plasma parameters on luminance

International Nuclear Information System (INIS)

Nazri Dagang Ahmad; Kondo, Akira; Motomura, Hideki; Jinno, Masafumi

2009-01-01

Since there is much concern about environmental preservation, the authors have paid attention to the uses of mercury in lighting application. They have focused on the application of the xenon low-pressure inductively coupled plasma (ICP) discharge in developing cylindrical type mercury-free light sources. ICP can be operated at low filling gas pressures and demonstrates significant potential in producing high density plasma. Xenon pressure was varied from 0.1 to 100 Torr and the lamp luminance was measured. The gas pressure dependence shows an increase in luminance at pressures below 1 Torr. In order to clarify this behaviour, measurement of plasma parameters was carried out using the double probe method and its relation to lamp luminance is discussed. As the gas pressure is decreased (from 1 to 0.01 Torr), the electron temperature increases while the electron density decreases while at the same time the lamp luminance increases. There are several factors that are believed to contribute to the increase in luminance in the very low pressure region. Increases in luminance are considered to be due to the electron-ion recombination process which brings a strong recombination radiation in continuum in the visible region and also due to the effect of stochastic heating.

TEM study of xenon bubbles evolution in Xe-implanted Cu. Bubbles shape, epitaxial orientation and adsorption phenomenon

International Nuclear Information System (INIS)

Guillot, J.; Cartraud, M.; Garem, H.; Templier, C.; Desoyer, J.C.

1987-01-01

TEM is used to perform a study of xenon clusters changes in Xe-implanted Cu. After implantation, xenon is gathered into f.c.c. crystalline precipitates with a lattice parameter value of 0.580 nm. During annealing at 600 0 C large (110) facetted bubbles appear (2r≅35 nm) which contain fluid xenon. When cooling down to 100 K, xenon solidifies on bubbles facets in form of a thin membrane. The epitaxial orientations between solid xenon and copper are the same as adsorbed Xe on Cu(110) [fr

New constraints and prospects for sub-GeV dark matter scattering off electrons in xenon

Science.gov (United States)

Essig, Rouven; Volansky, Tomer; Yu, Tien-Tien

2017-08-01

We study in detail sub-GeV dark matter scattering off electrons in xenon, including the expected electron recoil spectra and annual modulation spectra. We derive improved constraints using low-energy XENON10 and XENON100 ionization-only data. For XENON10, in addition to including electron-recoil data corresponding to about 1-3 electrons, we include for the first time events corresponding to about 4-7 electrons. Assuming the scattering is momentum independent (FDM=1 ), this strengthens a previous cross-section bound by almost an order of magnitude for dark matter masses above 50 MeV. The available XENON100 data corresponds to events with about 4-50 electrons, and leads to a constraint that is comparable to the XENON10 bound above 50 MeV for FDM=1 . We demonstrate that a search for an annual modulation signal in upcoming xenon experiments (XENON1T, XENONnT, LZ) could substantially improve the above bounds even in the presence of large backgrounds. We also emphasize that in simple benchmark models of sub-GeV dark matter, the dark matter-electron scattering rate can be as high as one event every ten (two) seconds in the XENON1T (XENONnT or LZ) experiments, without being in conflict with any other known experimental bounds. While there are several sources of backgrounds that can produce single- or few-electron events, a large event rate can be consistent with a dark matter signal and should not be simply written off as purely a detector curiosity. This fact motivates a detailed analysis of the ionization-data ("S2") data, taking into account the expected annual modulation spectrum of the signal rate, as well as the DM-induced electron-recoil spectra, which are another powerful discriminant between signal and background.

Hydrodynamic motion of a heavy-ion-beam-heated plasma

International Nuclear Information System (INIS)

Jacoby, J.; Hoffmann, D.H.H.; Mueller, R.W.; Mahrt-Olt, K.; Arnold, R.C.; Schneider, V.; Maruhn, J.

1990-01-01

The first experimental study is reported of a plasma produced by a heavy-ion beam. Relevant parameters for heating with heavy ions are described, temperature and density of the plasma are determined, and the hydrodynamic motion in the target induced by the beam is studied. The measured temperature and the free-electron density are compared with a two-dimensional hydrodynamic-model calculation. In accordance with the model, a radial rarefaction wave reaching the center of the target was observed and the penetration velocity of the ion beam into the xenon-gas target was measured

Microscopic simulation of xenon-based optical TPCs in the presence of molecular additives

Science.gov (United States)

Azevedo, C. D. R.; González-Díaz, D.; Biagi, S. F.; Oliveira, C. A. B.; Henriques, C. A. O.; Escada, J.; Monrabal, F.; Gómez-Cadenas, J. J.; Álvarez, V.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carrión, J. V.; Cebrián, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Esteve, R.; Felkai, R.; Fernandes, L. M. P.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Goldschmidt, A.; Gutiérrez, R. M.; Hauptman, J.; Hernandez, A. I.; Morata, J. A. Hernando; Herrero, V.; Jones, B. J. P.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; Lopez-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; McDonald, A. D.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Vidal, J. Muñoz; Musti, M.; Nebot-Guinot, M.; Novella, P.; Nygren, D.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; Serra, L.; Shuman, D.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Webb, R.; White, J. T.; Yahlali, N.

2018-01-01

We introduce a simulation framework for the transport of high and low energy electrons in xenon-based optical time projection chambers (OTPCs). The simulation relies on elementary cross sections (electron-atom and electron-molecule) and incorporates, in order to compute the gas scintillation, the reaction/quenching rates (atom-atom and atom-molecule) of the first 41 excited states of xenon and the relevant associated excimers, together with their radiative cascade. The results compare positively with observations made in pure xenon and its mixtures with CO2 and CF4 in a range of pressures from 0.1 to 10 bar. This work sheds some light on the elementary processes responsible for the primary and secondary xenon-scintillation mechanisms in the presence of additives, that are of interest to the OTPC technology.

Ion-beam synthesis and photoluminescence of SiC nanocrystals assisted by MeV-heavy-ion-beam annealing

International Nuclear Information System (INIS)

Khamsuwan, J.; Intarasiri, S.; Kirkby, K.; Chu, P.K.; Singkarat, S.; Yu, L.D.

2012-01-01

This work explored a novel way to synthesize silicon carbide (SiC) nanocrystals for photoluminescence. Carbon ions at 90 keV were implanted in single crystalline silicon wafers at elevated temperature, followed by irradiation using xenon ion beams at an energy of 4 MeV with two low fluences of 5 × 10 13 and 1 × 10 14 ions/cm 2 at elevated temperatures for annealing. X-ray diffraction, Raman scattering, infrared spectroscopy and transmission electron microscopy were used to characterize the formation of nanocrystalline SiC. Photoluminescence was measured from the samples. The results demonstrated that MeV-heavy-ion-beam annealing could indeed induce crystallization of SiC nanocrystals and enhance emission of photoluminescence with violet bands dominance due to the quantum confinement effect.

Experimental aspects of S.H.I.C. (Swift Heavy Ion Channeling)

International Nuclear Information System (INIS)

Andriamonje, S.; Castro Faria, N.V. de; Chevallier, M.; Gaillard, M.J.; Genre, R.; Farizon-Mazuy, B.; Poizat, J.C.; Remillieux, J.; Hage-Ali, M.; Cohen, C.; L'Hoir, A.; Moulin, J.; Schmaus, D.

1989-01-01

The mean stopping power experienced by the ions of exit charge Z and the charge distribution are measured. The experimental set up description is summarized. The experiments were performed at GANIL, using hydrogenoid Xenon ions, with 25 MeV/u on a silicon crystal target. The ion channeling and energy losses are measured. The results concerning the Lyman alpha lines intensity and Xe36 + transmission as a function of the crystal orientation are presented. The suitability of LISE device, for investigating crystalline effects in heavy ion charge exchange phenomena, is confirmed

Global characteristics of an ATON stationary plasma thruster operating with krypton and xenon

International Nuclear Information System (INIS)

Bugrova, A.I.; Lipatov, A.S.; Solomatina, L.V.; Morozov, A.I.

2002-01-01

Paper contains the experimental results of operation of the ATON plasma thruster operating with krypton and xenon. It is shown that consumption of a working gas for consumption of a working gas the krypton base thrust is higher in contrast to xenon base one at lower efficiency. In case of krypton use one obtained the efficiency constituting ∼ 60% at specific pulse reaching 3000 s. Jet divergence in case of krypton use is ∼ ± 22 deg in contrast to ∼ ± 11 deg in case of xenon use [ru

Optimal control of xenon concentration by observer design under reactor model uncertainty

International Nuclear Information System (INIS)

Cho, Nam Z.; Yang, Chae Y.; Woo, Hae S.

1989-01-01

The state feedback in control theory enjoys many advantages, such as stabilization and improved transient response, which could be beneficially used for control of the xenon oscillation in a power reactor. It is, however, not possible in nuclear reactors to measure the state variables, such as xenon and iodine concentrations. For implementation of the optimal state feedback control law, it is thus necessary to estimate the unmeasurable state variables. This paper uses the Luenberger observer to estimate the xenon and iodine concentrations to be used in a linear quadratic problem with state feedback. To overcome the stiffness problem in reactor kinetics, a singular perturbation method is used

p-process xenon isotope anomalies in stardust grains from meteorites

International Nuclear Information System (INIS)

Ott, U.

2013-01-01

Full text: In measurements on 'bulk' samples of meteorites isotopic variations due to the p-process usually have taken a backseat compared to such in s- or r-isotopes, and, in the best case, can be qualitatively attributed to the p-process, with little to no inferences concerning detailed isotopic yields. The situation is different for grains of stardust that survived in primitive meteorites. In fact, isotopically strange xenon was the key feature that led to the first identification of a stardust mineral, nanodiamonds containing xenon with overabundances of up to a factor of ∼2 in both the r-only (≡H-Xe) and p-only (≡L-Xe) isotopes. Relative excesses of the two r-only isotopes ( 134 Xe, 136 Xe) as well as of the two p-only isotopes ( 124 Xe, 126 Xe) are not equal, hence the processes responsible for HL-xenon must differ from the 'average' r- and p-processes as reflected in solar system abundances. However, while considerable effort has been put into explaining H-Xe, there has been little work on the p-side (L-Xe). Relying on scarce nuclear data, Heymann and Dziczkaniec have studied photodisintegration reactions of Xe and Ba seeds in intermediate zones of supernovae and found that the relative production of the p-Xe isotopes depends sensitively on the yield of the (γ, α) reaction on 128 Ba. Another suggestion - applicable to both the r- and p-anomalies in diamond xenon - is that of a 'rapid separation' between stable Xe isotopes and radioactive precursors produced in the 'standard' p- (as well as r-) process. For the p-isotopes to work, this would require the bulk (87%) of 126 Xe to be produced via the 126 Ba precursor, with a half live of ∼100 minutes, in order to explain the high 124 Xe/ 126 Xe. In contrast to diamond xenon, xenon in silicon carbide contains - besides the component from the s-process in their parent AGB stars - 'almost normal' Xe, with indications for 124 Xe/ 126 Xe being few (∼8)% lower than in solar Xe.

Conception and synthesis of new molecular cages for xenon MRI applications

International Nuclear Information System (INIS)

Delacour, L.

2011-01-01

Non-invasive proton magnetic resonance imaging ( 1 H MRI) is a powerful clinical tool for the detection of numerous diseases. Although MRI contrast agents are often used to improve diagnostic specificity, this technique has limited applications in molecular imaging because of its inherently low sensitivity when compared to nuclear medicine or fluorescence imaging. Laser-polarized 129 Xe NMR spectroscopy is a promising tool to circumvent sensitivity limitations. Indeed, optical pumping increases the nuclear spin polarization of xenon by several orders of magnitude (10 4 to 10 5 ), thus small amounts of gas dissolved in biological tissues (blood, lungs...) can be rapidly detected with an excellent signal-to-noise ratio. In addition, the high polarizability of the xenon electron cloud, which induces a very high sensitivity to its environment, makes this nucleus very attractive for molecular imaging. Detection of biomolecules can be achieved by biosensors, which encapsulate xenon atoms in molecular cages that have been functionalized to bind the desired biological target. Cage molecules such as cryptophanes have high affinity for xenon and thus appear as ideal candidates for its encapsulation. During this PhD thesis we worked on the synthesis and the functionalization of new cryptophanes. (author) [fr

XENON-133 IN CALIFORNIA, NEVADA, AND UTAH FROM THE CHERNOBYL ACCIDENT (JOURNAL VERSION)

Science.gov (United States)

The accident at the Chernobyl nuclear reactor in the USSR introduced numerous radioactive nuclides into the atmosphere, including the noble gas xenon-133. EPA's Environmental Monitoring Systems Laboratory, Las Vegas, NV, detected xenon-133 from the Chernobyl accident in air sampl...

A new liquid xenon scintillation detector for positron emission tomography

International Nuclear Information System (INIS)

Chepel, V.Yu.

1993-01-01

A new positron-sensitive detector of annihilation photons filled with liquid xenon is proposed for positron emission tomography. Simultaneous detection of both liquid xenon scintillation and ionization current produces a time resolution of < 1 ns and a position resolution in the tangential direction of the tomograph ring is ∼ 1 mm and in the radial direction is ∼ 5 mm. The advantages of a tomograph with new detectors are discussed. New algorithms of Compton scattering can be used. (author)

Synchrotron-radiation experiments with recoil ions

International Nuclear Information System (INIS)

Levin, J.C.

1989-01-01

Studies of atoms, ions and molecules with synchrotron radiation have generally focused on measurements of properties of the electrons ejected during, or after, the photoionization process. Much can also be learned, however, about the atomic or molecular relaxation process by studies of the residual ions or molecular fragments following inner-shell photoionization. Measurements are reported of mean kinetic energies of highly charged argon, krypton, and xenon recoil ions produced by vacancy cascades following inner-shell photoionization using white and monochromatic synchrotron x radiation. Energies are much lower than for the same charge-state ions produced by charged-particle impact. The results may be applicable to design of future angle-resolved ion-atom collision experiments. Photoion charge distributions are presented and compared with other measurements and calculations. Related experiments with synchrotron-radiation produced recoil ion, including photoionization of stored ions and measurement of shakeoff in near-threshold excitation, are briefly discussed. 24 refs., 6 figs., 1 tab

Microwave Discharge Ion Engines onboard Hayabusa Asteroid Explorer

International Nuclear Information System (INIS)

Kuninaka, Hitoshi

2008-01-01

The Hayabusa spacecraft rendezvoused with the asteroid Itokawa in 2005 after the powered flight in the deep space by the μl0 cathode-less electron cyclotron resonance ion engines. Though the spacecraft was seriously damaged after the successful soft-landing and lift-off, the xenon cold gas jets from the ion engines rescued it. New attitude stabilization method using a single reaction wheel, the ion beam jets, and the photon pressure was established and enabled the homeward journey from April 2007 aiming the Earth return on 2010. The total accumulated operational time of the ion engines reaches 31,400 hours at the end of 2007. One of four thrusters achieved 13,400-hour space operation

Electron loss from 0.74 and 1.4 MeV/u low-charge-state argon and xenon ions colliding with neon, nitrogen, and argon

International Nuclear Information System (INIS)

DuBois, R.D.; Santos, A.C.F.; Olson, R.E.

2003-07-01

Absolute total, single, and multiple electron loss cross sections are measured for Ar + -, Ar 2+ -, and Xe 3+ - Ne, N 2 , Ar collisions at 0.74 and 1.4 MeV/u. In addition, a many-body Classical Trajectory Monte Carlo model was used to calculate total and multiple electron loss cross sections for Ar + impact. For N 2 and Ar targets, excellent agreement between the measured and calculated cross sections is found; for the Ne target the experimental data are approximately 40% smaller than the theoretical predictions. The experimental data are also used to examine cross section scaling characteristics for electron loss from fast, low-charge-state, heavy ions. It is shown that multiple electron loss increased the mean charge states of the outgoing argon and xenon ions by two and three respectively. The cross sections decreased with increasing number of electrons lost and scaled roughly as the inverse of the sum of the ionization potentials required to sequentially remove the most weakly bound, next most weakly bound, etc., electrons. This scaling was found to be independent of projectile, incoming charge state, and target. In addition, the experimental total loss cross sections are found to be nearly constant as a function of initial projectile charge state. As a function of impact energy, the theoretical predictions yield an E -1/3 behavior between 0.5 and 30 MeV/u for the total loss cross sections. Within error bars the data are consistent with this energy dependence but are also consistent with an E -1/2 energy dependence. (orig.)

Performance of a cryogenic system prototype for the XENON1T detector

International Nuclear Information System (INIS)

Aprile, E; Budnik, R; Choi, B; Contreras, H A; Giboni, K L; Goetzke, L W; Lang, R F; Lim, K E; Melgarejo, A J; Plante, G; Rizzo, A; Shagin, P

2012-01-01

We have developed an efficient cryogenic system with heat exchange and associated gas purification system as a prototype for the XENON1T experiment. The XENON1T detector will use about 3 tons of liquid xenon (LXe) at a temperature of 175K as target and detection medium for a dark matter search. In this paper we report results on the cryogenic system performance focusing on the dynamics of the gas circulation-purification through a heated getter, at flow rates above 50 Standard Liter per Minute (SLPM). A maximum flow of 114 SLPM has been achieved, and using two heat exchangers in series, a heat exchange efficiency better than 96% has been measured.

Measurement of vascular flow in the brain with the xenon/CT method

International Nuclear Information System (INIS)

Wist, A.O.; Cothran, A.; Fatouros, P.P.; Kishore, P.R.S.

1988-01-01

The authors are proposing a modification of the xenon/CT method that allows measurement of the flow in the different brain vessels. Based on an improved stable xenon/CT method, they developed several additional algorithms to differentiate the vessel flow from tissue flow and from artifacts and noise, which are based on the height, steepness, and other parameters of the detected flow values. The vessel flow maps, together with the tissue flow maps and new composite flow maps of recent patients, demonstrate that the stable xenon/CT technique can be extended to quantify vascular flow in the brain. The diagnostic capability of this method can be further improved by removing the vessel flow from the flow maps

Online {sup 222}Rn removal by cryogenic distillation in the XENON100 experiment

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M.; De Perio, P.; Gao, F.; Goetzke, L.W.; Greene, Z.; Lin, Q.; Messina, M.; Plante, G.; Rizzo, A.; Zhang, Y. [Columbia University, Physics Department, New York, NY (United States); Aalbers, J.; Breur, P.A.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Hogenbirk, E.; Tiseni, A. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN-Bologna (Italy); Alfonsi, M.; Geis, C.; Grignon, C.; Oberlack, U.; Scheibelhut, M.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Amaro, F.D.; Cardoso, J.M.R.; Lopes, J.A.M.; Orrigo, S.E.A.; Santos, J.M.F. dos; Silva, M. [University of Coimbra, Department of Physics, Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L.; Di Giovanni, A.; Maris, I. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L.; Franco, D.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F.; Wei, Y.; Wulf, J. [University of Zurich, Physik-Institut, Zurich (Switzerland); Bauermeister, B. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Stockholm University, AlbaNova, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Berger, T.; Brown, E.; Piro, M.C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Bruenner, S.; Cichon, D.; Eurin, G.; Hasterok, C.; Lindner, M.; Undagoitia, T.M.; Pizzella, V.; Rauch, L.; Rupp, N.; Schreiner, J.; Simgen, H. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G.; Gallo Rosso, A.; Molinario, A. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); Budnik, R.; Duchovni, E.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Manfredini, A.; Priel, N. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Buetikofer, L.; Coderre, D.; Kaminsky, B.; Schumann, M.; Sivers, M. v. [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Calven, J.; Conrad, J.; Ferella, A.D.; Pelssers, B. [Stockholm University, AlbaNova, Department of Physics, Oskar Klein Centre, Stockholm (Sweden); Cervantes, M.; Lang, R.F.; Masson, D.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Cussonneau, J.P.; Diglio, S.; Le Calloch, M.; Masbou, J.; Micheneau, K.; Persiani, R.; Thers, D. [Universite de Nantes, SUBATECH, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (France); Di Gangi, P.; Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [University of Bologna, Department of Physics and Astrophysics, Bologna (Italy); INFN, Bologna (Italy); Fei, J.; Ni, K.; Ye, J. [University of California, Department of Physics, San Diego, CA (United States); Fieguth, A.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Fulgione, W. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Grandi, L.; Saldanha, R.; Shockley, E.; Upole, N. [University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Lindemann, S. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Meng, Y.; Stein, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Miguez, B.; Trinchero, G. [INFN-Torino (Italy); Osservatorio Astrofisico di Torino, Turin (Italy); Naganoma, J.; Shagin, P. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Lavina, L.S. [LPNHE, Universite Pierre et Marie Curie, Universite Paris Diderot, CNRS/IN2P3, Paris (France); Tunnell, C. [Nikhef and the University of Amsterdam, Science Park, Amsterdam (Netherlands); University of Chicago, Department of Physics and Kavli Institute of Cosmological Physics, Chicago, IL (United States); Cristescu, I. [Karlsruhe Institute of Technology, Tritium Laboratory Karlsruhe, Eggenstein-Leopoldshafen (Germany); Collaboration: XENON Collaboration

2017-06-15

We describe the purification of xenon from traces of the radioactive noble gas radon using a cryogenic distillation column. The distillation column was integrated into the gas purification loop of the XENON100 detector for online radon removal. This enabled us to significantly reduce the constant {sup 222}Rn background originating from radon emanation. After inserting an auxiliary {sup 222}Rn emanation source in the gas loop, we determined a radon reduction factor of R > 27 (95% C.L.) for the distillation column by monitoring the {sup 222}Rn activity concentration inside the XENON100 detector. (orig.)

Design and construction of a cryogenic distillation device for removal of krypton for liquid xenon dark matter detectors.

Science.gov (United States)

Wang, Zhou; Bao, Lei; Hao, Xihuan; Ju, Yonglin

2014-01-01

Liquid xenon (Xe) is one of the commendable detecting media for the dark matter detections. However, the small content of radioactive krypton-85 ((85)Kr) always exists in the commercial xenon products. An efficient cryogenic distillation system to remove this krypton (Kr) from commercial xenon products has been specifically designed, developed, and constructed in order to meet the requirements of the dark matter experiments with high- sensitivity and low-background. The content of krypton in regular commercial xenon products can be reduced from 10(-9) to 10(-12), with 99% xenon collection efficiency at maximum flow rate of 5 kg/h (15SLPM). The purified xenon gases produced by this distillation system can be used as the detecting media in the project of Panda X, which is the first dark matter detector developed in China.

Dark matter analysis of XENON100 data and cut development utilizing the novel PAX raw data processor

Energy Technology Data Exchange (ETDEWEB)

Wittweg, Christian [Institut fuer Kernphysik, Westfaelische Wilhelms-Universitaet, Muenster (Germany)

2016-07-01

The XENON100 experiment located at LNGS is aimed at the direct detection of weakly interacting massive particles (WIMPs). It utilizes an ultra-low background dual-phase xenon TPC which yields two separate scintillation signals that facilitate background discrimination and event selection. Limits on various interaction types have been published by the collaboration (Science 349 (2015) 6250, 851-854). In the analysis dark matter candidate events have to pass cuts with respect to data quality, consistency and physical features of the interaction. The former ones are implemented with regard to the used data processor's capabilities for noise discrimination and peak-finding. The Processor for Analyzing Xenon (PAX), developed for the XENON1T experiment, enhances these capabilities compared to XENON100. A greater robustness against noise and an increased peak-identification efficiency open up new opportunities for physically motivated cuts while rendering old ones obsolete. The poster will focus on the implementation of new cuts into the analysis chain. Both PAX and the xenon analysis will be introduced. A planned full-scale dark matter analysis of PAX-processed XENON100 data will be outlined.

Review of xenon-133 production and related problems; Estudio bibliografico de la produccion de xenon-133 y problemas afines

Energy Technology Data Exchange (ETDEWEB)

Barrachina, M; Ropero, M

1980-07-01

A literature survey is given on the production methods of fission xenon-133 and related problems, such as purification, metrological and dosimetric aspects, preparation of isotopic solutions, recycling, etc. 127 references are included. (Author) 127 refs.

Time dependent analysis of Xenon spatial oscillations in small power reactors

International Nuclear Information System (INIS)

Decco, Claudia Cristina Ghirardello

1997-01-01

This work presents time dependent analysis of xenon spatial oscillations studying the influence of the power density distribution, type of reactivity perturbation, power level and core size, using the one-dimensional and three-dimensional analysis with the MID2 and citation codes, respectively. It is concluded that small pressurized water reactors with height smaller than 1.5 m are stable and do not have xenon spatial oscillations. (author)

Antiprismatic Coordination about Xenon: The Structure of Nitrosonium Octafluoroxenate(VI).

Science.gov (United States)

Peterson, S W; Holloway, J H; Coyle, B A; Williams, J M

1971-09-24

The structure of nitrosonium octafluoroxenate(VI), 2NOF . XeF(6), has been determined by means of single-crystal x-ray counter methods (R-index = 0.046, weighted R-index = 0.042). The space group is Pnma, with a = 8.914(10) angstroms, b = 5.945(10) angstroms, and c = 12.83(2) angstroms (the numbers in parentheses are the standard deviations to the least significant digit or digits); the calculated density (rho) is 3.354 grams per cubic centimeter, and there are four formula units per unit cell. The material consists of well-separated NO(+) and (XeF(8))(2-) ions; the structural formula is thus (NO)(2) (XeF(8)). The anion configuration is that of a slightly distorted Archimedean antiprism. The observed distortion appears incompatible with a lone-pair repulsion model. Xenon-fluorine bond lengths of 1.971(7), 1.946(5), 1.958(7), 2.052(5), and 2.099(5) angstroms were found.

Status of the 2D Bayesian analysis of XENON100 data

Energy Technology Data Exchange (ETDEWEB)

Schindler, Stefan [JGU, Staudingerweg 7, 55128 Mainz (Germany)

2015-07-01

The XENON100 experiment is located in the underground laboratory at LNGS in Italy. Since Dark Matter particles will only interact very rarely with normal matter, an environment with ultra low background, which is shielded from cosmic radiation is needed. The standard analysis of XENON100 data has made use of the profile likelihood method (a most frequent approach) and still provides one of the most sensitive exclusion limits to WIMP Dark Matter. Here we present work towards a Bayesian approach to the analysis of XENON100 data, where we attempt to include the measured primary (S1) and secondary (S2) scintillation signals in a more complete way. The background and signal models in the S1-S2 space have to be defined and a corresponding likelihood function, describing these models, has to be constructed.

Development of a liquid xenon Compton telescope dedicated to functional medical imaging; Etude et developpement d'un telescope compton au xenon liquide dedie a l'imagerie medicale fonctionnelle

Energy Technology Data Exchange (ETDEWEB)

Grignon, C

2007-12-15

Functional imaging is a technique used to locate in three dimensions the position of a radiotracer previously injected in a patient. The two main modalities used for a clinical application to detect tumors, the SPECT and the PET, use solid scintillators as a detection medium. The objective of this thesis was to investigate the possibility of using liquid xenon in order to benefit from the intrinsic properties of this medium in functional imaging. The feasibility study of such a device has been performed by taking into account the technical difficulties specific to the liquid xenon. First of all, simulations of a liquid xenon PET has been performed using Monte-Carlo methods. The results obtained with a large liquid xenon volume are promising : we can expect a reduction of the injected activity of radiotracer, an improvement of the spatial resolution of the image and a parallax free camera. The second part of the thesis was focused on the development of a new concept of medical imaging, the three gamma imaging, based on the use of a new emitter: the 44 scandium. Associated to a classical PET camera, the Compton telescope is used to infer the incoming direction of the third gamma ray by triangulation. Therefore, it is possible to reconstruct the position of each emitter in three dimensions. This work convinced the scientific community to support the construction and characterization of a liquid xenon Compton telescope. The first camera dedicated to small animal imaging should then be operational in 2009. (author)

X-ray detector for automatic exposure control using ionization chamber filled with xenon gas

CERN Document Server

Nakagawa, A; Yoshida, T

2003-01-01

This report refers to our newly developed X-ray detector for reliable automatic X-ray exposure control, which is to be widely used for X-ray diagnoses in various clinical fields. This new detector utilizes an ionization chamber filled with xenon gas, in contrast to conventional X-ray detectors which use ionization chambers filled with air. Use of xenon gas ensures higher sensitivity and thinner design of the detector. The xenon gas is completely sealed in the chamber, so that the influence of the changes in ambient environments is minimized. (author)

Iodide and xenon enhancement of computed tomography (CT) in multiple sclerosis (MS)

International Nuclear Information System (INIS)

Radue, E.W.; Kendall, B.E.

1978-01-01

The characteristic findings on computed tomography (CT) in multiple sclerosis (MS) are discussed. In a series of 49 cases plain CT was normal in 21 (43%), cerebral atrophy alone was present in 17 (35%) and plaques were visible in 11 (23%). These were most often adjacent to the lateral ventricles (14 plaques) and in the parietal white matter (10 plaques). CT was performed after the intravenous administration of iodide in 16 of these cases. Two patients with low attenuation plaques were scanned with xenon enhancement; the plaques absorbed less xenon than the corresponding contralateral brain substance and additional, previously isodense plaques were revealed. In one case the white matter absorbed much less xenon than normal and its uptake relative to grey matter was reduced. (orig.) [de

Assessment of regional emphysema, air-trapping and Xenon-ventilation using dual-energy computed tomography in chronic obstructive pulmonary disease patients.

Science.gov (United States)

Lee, Sang Min; Seo, Joon Beom; Hwang, Hye Jeon; Kim, Namkug; Oh, Sang Young; Lee, Jae Seung; Lee, Sei Won; Oh, Yeon-Mok; Kim, Tae Hoon

2017-07-01

To compare the parenchymal attenuation change between inspiration/expiration CTs with dynamic ventilation change between xenon wash-in (WI) inspiration and wash-out (WO) expiration CTs. 52 prospectively enrolled COPD patients underwent xenon ventilation dual-energy CT during WI and WO periods and pulmonary function tests (PFTs). The parenchymal attenuation parameters (emphysema index (EI), gas-trapping index (GTI) and air-trapping index (ATI)) and xenon ventilation parameters (xenon in WI (Xe-WI), xenon in WO (Xe-WO) and xenon dynamic (Xe-Dyna)) of whole lung and three divided areas (emphysema, hyperinflation and normal) were calculated on virtual non-contrast images and ventilation images. Pearson correlation, linear regression analysis and one-way ANOVA were performed. EI, GTI and ATI showed a significant correlation with Xe-WI, Xe-WO and Xe-Dyna (EI R = -.744, -.562, -.737; GTI R = -.621, -.442, -.629; ATI R = -.600, -.421, -.610, respectively, p emphysema. • The xenon ventilation change correlates with the parenchymal attenuation change. • The xenon ventilation change shows the difference between three lung areas. • The combination of attenuation and xenon can predict more accurate PFTs.

Ionization yield from electron tracks in liquid xenon

International Nuclear Information System (INIS)

Voronova, T.Ya.; Kipsanov, M.A.; Kruglov, A.A.; Obodovskij, I.M.; Pokachalov, S.G.; Shilov, V.A.; Khristich, E.B.

1989-01-01

Methods for calculating coefficients K β , characterizing ionization yield from electron track in liquid xenon are considered. K β calculation is conducted on the base of experimental data on K parameter characterizing ionization yield from a certain combination of photo-, Compton-and Auger electron tracks. K parameter measurements are conducted in liquid xenon at 170 K temperature within 10-30 keV gamma- and X radiation energy ranges. Calculated dependence of K β and K coefficients on the energy in a wide (5-500 keV) range is presented. K β values obtained can be applied for calculating the energy resolution of a gamma-spectrometer and linearity of its calibration characteristics if the electric field intensity in the spectrometer does not exceed some kV/cm

Dense xenon nanoplasmas in intense laser fields

International Nuclear Information System (INIS)

Hilse, P.; Moll, M.; Schlanges, M.; Bornath, Th.

2010-01-01

Complete text of publication follows. One reason for the on-going interest in laser-cluster interactions is the efficient absorption of the radiation energy of near-infrared femtosecond laser pulses by clusters. Consequently, in laser-cluster experiments the emission of highly charged ions, very energetic electrons, higher harmonics, fast fragments as well at strong x-rays in the multi-keV range is observed. The cluster response is highly nonlinear. Different theoretical models and simulations indicate that resonant collective absorption plays a central role. The rapid expansion of irradiated clusters is essential as, at a certain time, the cluster reaches the density fulfilling the resonance condition. This can occur during a single pulse. A better control can be achieved by dual-pulse laser excitation with varying time delay between two pulses. A further optimization is possible by pulse shaping which is a modern tool in laser experiments. With pulse shaping, the dynamics of the system determined by heating, ionization and expansion can be specifically affected. For an understanding of the underlying physical processes in the dynamics of laser-cluster interaction, a theoretical description is presented using a genetic algorithm and basing on the relatively simple nanoplasma model. Recently, experiments as well as calculations were performed for silver clusters. Highly charged silver ions could be produced very efficiently with a pulse structure consisting of a smaller pre-pulse followed by a larger main pulse. The focus of the present contribution is on xenon clusters and their different behavior compared to metallic clusters as silver. Acknowledgements. This work was supported by the Deutsche Forschungsgemeinschaft via SFB 652.

High energy heavy ion beam lithography in silicon

International Nuclear Information System (INIS)

Rout, Bibhudutta; Dymnikov, Alexander D.; Zachry, Daniel P.; Eschenazi, Elia V.; Wang, Yongqiang Q.; Greco, Richard R.; Glass, Gary A.

2007-01-01

As high energy ions travel through a crystalline semiconductor materials they produce damage along the path which results in resistance to some of the wet chemical etching. A series of preliminary experiments have been performed at the Louisiana Accelerator Center (LAC) to examine the feasibility of irradiating high energy (keV-MeV) ions such as protons, xenon and gold through microscale masked structures on crystalline (n-type) Si substrates followed by wet chemical etch with KOH for attaining deep micromachining in Si. The results of these experiments are reported

Dual display of flow/lambda results in xenon CT

International Nuclear Information System (INIS)

Lindstrom, W.W.; Gruenaver, L.M.; Dinewitz, I.J.

1989-01-01

Measurement of cortical blood flow has always been limited by the unavoidable inclusion of white matter and sulcal cerebrospinal fluid (CSF) in selected regions of interest. Xenon CT gives clear separation of anatomy, but precise ROI tracing is time consuming. CSF and gray and white matter have differing xenon solubilities (lambda), however, so the authors produce two-dimensional histograms of flow/lambda values within an ROI encompassing the desired anatomy and select lambda subregions for tissue-specific quantitative flow/lambda means and deviations. They report how this display is dynamic, allowing the physician to roam around the anatomy at will, with 1-second statistical updating

Electric dipole moment searches using the isotope 129-xenon

Energy Technology Data Exchange (ETDEWEB)

Kuchler, Florian

2014-11-13

Two new complementary experiments searching for a permanent electric dipole moment (EDM) of 129-xenon are presented. Besides demonstration of a sensitivity improvement by employing established methods and a highly sensitive SQUID detection system the progress towards a novel measurement approach is discussed. The new method introduces time-varying electric fields and a liquid hyper-polarized xenon sample with a potential improvement in sensitivity of three orders of magnitude. The search for EDMs is motivated by their symmetry-breaking nature. A non-zero EDM provides a new source of CP violation to solve the mystery of the huge excess of matter over anti-matter in our Universe.

Heavy ion source support gas mixing experiments

International Nuclear Information System (INIS)

Hudson, E.D.; Mallory, M.L.

1977-01-01

Experiments on mixing an easily ionized support gas with the primary ion source gas have produced large beam enhancements for high charge state light ions (masses less than or equal to 20). In the Oak Ridge Isochronous Cyclotron (ORIC), the beam increase has been a factor of 5 or greater, depending on ion species and charge state. Approximately 0.1 cc/min of the easily ionized support gas (argon, krypton, or xenon) is supplied to the ion source through a separate gas line and the primary gas flow is reduced by approximately 30 percent. The proposed mechanism for increased intensity is as follows: The heavier support gas ionizes readily to a higher charge state, providing increased cathode heating. The increased heating permits a reduction in primary gas flow (lower pressure) and the subsequent beam increase

The search for dark matter in xenon: Innovative calibration strategies and novel search channels

Science.gov (United States)

Reichard, Shayne Edward

The direct detection dark matter experiment XENON1T became operational in early 2016, heralding the era of tonne-scale dark matter detectors. Direct detection experiments typically search for elastic scatters of dark matter particles off target nuclei. XENON1T's larger xenon target provides the advantage of stronger dark matter signals and lower background rates compared to its predecessors, XENON10 and XENON100; but, at the same time, calibration of the detector's response to backgrounds with traditional external sources becomes exceedingly more difficult. A 220Rn source is deployed on the XENON100 dark matter detector in order to address the challenges in calibration of tonne-scale liquid noble element detectors. I show that the subsequent 212Pb beta emission can be used for low-energy electronic recoil calibration in searches for dark matter. The isotope spreads throughout the entire active region of the detector, and its activity naturally decays below background level within a week after the source is closed. I find no increase in the activity of the troublesome 222Rn background after calibration. Alpha emitters are also distributed throughout the detector and facilitate calibration of its response to 222Rn. Using the delayed coincidence of 220Rn/216Po, I map for the first time the convective motion of particles in the XENON100 detector. Additionally, I make a competitive measurement of the half-life of 212Po, t1/2=293.9+/-(1.0)stat+/-(0.6)ns. In contrast to the elastic scattering of dark matter particles off nuclei, I explore inelastic scattering where the nucleus is excited to a low-lying state of 10-100 keV, with a subsequent prompt de-excitation. I use the inelastic structure factors for the odd-mass xenon isotopes based on state-of-the-art large-scale shell-model calculations with chiral effective field theory WIMP-nucleon currents, finding that the inelastic channel is comparable to or can dominate the elastic channel for momentum transfers around 150 Me

Analysis and design of ion thruster for large space systems

Science.gov (United States)

Poeschel, R. L.; Kami, S.

1980-01-01

Design analyses showed that an ion thruster of approximately 50 cm in diameter will be required to produce a thrust of 0.5 N using xenon or argon as propellants, and operating the thruster at a specific impulse of 3530 sec or 6076 sec respectively. A multipole magnetic confinement discharge chamber was specified.

Development of a liquid xenon Compton telescope dedicated to functional medical imaging

International Nuclear Information System (INIS)

Grignon, C.

2007-12-01

Functional imaging is a technique used to locate in three dimensions the position of a radiotracer previously injected in a patient. The two main modalities used for a clinical application to detect tumors, the SPECT and the PET, use solid scintillators as a detection medium. The objective of this thesis was to investigate the possibility of using liquid xenon in order to benefit from the intrinsic properties of this medium in functional imaging. The feasibility study of such a device has been performed by taking into account the technical difficulties specific to the liquid xenon. First of all, simulations of a liquid xenon PET has been performed using Monte-Carlo methods. The results obtained with a large liquid xenon volume are promising : we can expect a reduction of the injected activity of radiotracer, an improvement of the spatial resolution of the image and a parallax free camera. The second part of the thesis was focused on the development of a new concept of medical imaging, the three gamma imaging, based on the use of a new emitter: the 44 scandium. Associated to a classical PET camera, the Compton telescope is used to infer the incoming direction of the third gamma ray by triangulation. Therefore, it is possible to reconstruct the position of each emitter in three dimensions. This work convinced the scientific community to support the construction and characterization of a liquid xenon Compton telescope. The first camera dedicated to small animal imaging should then be operational in 2009. (author)

Double discharges in unipolar-pulsed dielectric barrier discharge xenon excimer lamps

International Nuclear Information System (INIS)

Liu Shuhai; Neiger, Manfred

2003-01-01

Excitation of dielectric barrier discharge xenon excimer lamps by unipolar short square pulses is studied in this paper. Two discharges with different polarity are excited by each voltage pulse (double discharge phenomenon). The primary discharge occurs at the top or at the rising flank of the applied unipolar square pulse, which is directly energized by the external circuit. The secondary discharge with the reversed polarity occurs at the falling flank or shortly after the falling flank end (zero external voltage) depending on the pulse width, which is energized by the energy stored by memory charges deposited by the primary discharge. Fast-speed ICCD imaging shows the primary discharge has a conic discharge appearance with a channel broadening on the anode side. This channel broadening increases with increasing the pulse top level. Only the anode-side surface discharge is observed in the primary discharge. The surface discharge on the cathode side which is present in bipolar sine voltage excitation is not observed. On the contrary, the secondary discharge has only the cathode-side surface discharge. The surface discharge on the anode side is not observed. The secondary discharge is much more diffuse than the primary discharge. Time-resolved emission measurement of double discharges show the secondary discharge emits more VUV xenon excimer radiation but less infrared (IR) xenon atomic emission than the primary discharge. It was found that the IR xenon atomic emission from the secondary discharge can be reduced by shortening the pulse width. The energy efficiency of unipolar-pulsed xenon excimer lamps (the overall energy efficiency of double discharges) is much higher than that obtained under bipolar sine wave excitation. The output VUV spectrum under unipolar pulse excitation is found to be identical to that under sine wave excitation and independent of injected electric power

The influence of xenon poisoning in high-flux reactors on the choice of control rod speeds (1961); Influence de l'empoisonnement xenon dans les piles a haut flux sur le choix de la vitesse des barres de controle (1961)

Energy Technology Data Exchange (ETDEWEB)

Furet, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

- The general laws are restated concerning the changes in xenon and iodine concentrations in thermal neutron reactors, assuming an uniform neutron flux distribution in the core. It is shown how the evolution in the xenon poisoning influences the selection of the control rod speed, at start-up. Certain simple methods of calculation are developed making it possible to resolve the problem of the choice of this speed in the case where the xenon poisoning is taken into account. (author) [French] - On rappelle les lois generales relatives aux evolutions de concentration xenon et iode dans les piles atomiques a neutrons thermiques lorsqu'on suppose une repartition uniforme du flux de neutrons dans le coeur. On montre comment l'evolution de l'empoisonnement xenon influe sur le choix de la vitesse des barres de controle en periode de demarrage. On developpe certaines methodes de calculs simples permettant de resoudre le probleme du choix de la vitesse des barres de controle, dans le cas ou l'on tient compte de l'empoisonnement xenon. (auteur)

Assessment of regional emphysema, air-trapping and Xenon-ventilation using dual-energy computed tomography in chronic obstructive pulmonary disease patients

International Nuclear Information System (INIS)

Lee, Sang Min; Seo, Joon Beom; Kim, Namkug; Oh, Sang Young; Hwang, Hye Jeon; Lee, Jae Seung; Lee, Sei Won; Oh, Yeon-Mok; Kim, Tae Hoon

2017-01-01

To compare the parenchymal attenuation change between inspiration/expiration CTs with dynamic ventilation change between xenon wash-in (WI) inspiration and wash-out (WO) expiration CTs. 52 prospectively enrolled COPD patients underwent xenon ventilation dual-energy CT during WI and WO periods and pulmonary function tests (PFTs). The parenchymal attenuation parameters (emphysema index (EI), gas-trapping index (GTI) and air-trapping index (ATI)) and xenon ventilation parameters (xenon in WI (Xe-WI), xenon in WO (Xe-WO) and xenon dynamic (Xe-Dyna)) of whole lung and three divided areas (emphysema, hyperinflation and normal) were calculated on virtual non-contrast images and ventilation images. Pearson correlation, linear regression analysis and one-way ANOVA were performed. EI, GTI and ATI showed a significant correlation with Xe-WI, Xe-WO and Xe-Dyna (EI R = -.744, -.562, -.737; GTI R = -.621, -.442, -.629; ATI R = -.600, -.421, -.610, respectively, p < 0.01). All CT parameters showed significant correlation with PFTs except forced vital capacity (FVC). There was a significant difference in GTI, ATI and Xe-Dyna in each lung area (p < 0.01). The parenchymal attenuation change between inspiration/expiration CTs and xenon dynamic change between xenon WI- and WO-CTs correlate significantly. There are alterations in the dynamics of xenon ventilation between areas of emphysema. (orig.)

Assessment of regional emphysema, air-trapping and Xenon-ventilation using dual-energy computed tomography in chronic obstructive pulmonary disease patients

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Min [University of Ulsan College of Medicine, Division of Cardiothoracic Radiology, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Yonsei University College of Medicine, Gangnam Severance Hospital, Department of Radiology, Research Istitute of Radiological Science, Seoul (Korea, Republic of); Seo, Joon Beom; Kim, Namkug; Oh, Sang Young [University of Ulsan College of Medicine, Division of Cardiothoracic Radiology, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Hwang, Hye Jeon [University of Ulsan College of Medicine, Division of Cardiothoracic Radiology, Department of Radiology and Research Institute of Radiology, Asan Medical Center, Seoul (Korea, Republic of); Hallym University Sacred Heart Hospital, Department of Radiology, Hallym University College of Medicine, Anyang-si, Gyeonggi-do (Korea, Republic of); Lee, Jae Seung; Lee, Sei Won; Oh, Yeon-Mok [University of Ulsan College of Medicine, Department of Pulmonary and Critical Care Medicine, and Clinical Research Center for Chronic Obstructive Airway Diseases, Asan Medical Center, Seoul (Korea, Republic of); Kim, Tae Hoon [Yonsei University College of Medicine, Gangnam Severance Hospital, Department of Radiology, Research Istitute of Radiological Science, Seoul (Korea, Republic of)

2017-07-15

To compare the parenchymal attenuation change between inspiration/expiration CTs with dynamic ventilation change between xenon wash-in (WI) inspiration and wash-out (WO) expiration CTs. 52 prospectively enrolled COPD patients underwent xenon ventilation dual-energy CT during WI and WO periods and pulmonary function tests (PFTs). The parenchymal attenuation parameters (emphysema index (EI), gas-trapping index (GTI) and air-trapping index (ATI)) and xenon ventilation parameters (xenon in WI (Xe-WI), xenon in WO (Xe-WO) and xenon dynamic (Xe-Dyna)) of whole lung and three divided areas (emphysema, hyperinflation and normal) were calculated on virtual non-contrast images and ventilation images. Pearson correlation, linear regression analysis and one-way ANOVA were performed. EI, GTI and ATI showed a significant correlation with Xe-WI, Xe-WO and Xe-Dyna (EI R = -.744, -.562, -.737; GTI R = -.621, -.442, -.629; ATI R = -.600, -.421, -.610, respectively, p < 0.01). All CT parameters showed significant correlation with PFTs except forced vital capacity (FVC). There was a significant difference in GTI, ATI and Xe-Dyna in each lung area (p < 0.01). The parenchymal attenuation change between inspiration/expiration CTs and xenon dynamic change between xenon WI- and WO-CTs correlate significantly. There are alterations in the dynamics of xenon ventilation between areas of emphysema. (orig.)

Xenon adsorption on geological media and implications for radionuclide signatures.

Science.gov (United States)

Paul, M J; Biegalski, S R; Haas, D A; Jiang, H; Daigle, H; Lowrey, J D

2018-07-01

The detection of radioactive noble gases is a primary technology for verifying compliance with the pending Comprehensive Nuclear-Test-Ban Treaty. A fundamental challenge in applying this technology for detecting underground nuclear explosions is estimating the timing and magnitude of the radionuclide signatures. While the primary mechanism for transport is advective transport, either through barometric pumping or thermally driven advection, diffusive transport in the surrounding matrix also plays a secondary role. From the study of primordial noble gas signatures, it is known that xenon has a strong physical adsorption affinity in shale formations. Given the unselective nature of physical adsorption, isotherm measurements reported here show that non-trivial amounts of xenon adsorb on a variety of media, in addition to shale. A dual-porosity model is then discussed demonstrating that sorption amplifies the diffusive uptake of an adsorbing matrix from a fracture. This effect may reduce the radioxenon signature down to approximately one-tenth, similar to primordial xenon isotopic signatures. Copyright © 2018 Elsevier Ltd. All rights reserved.

Quantitative analysis technique for Xenon in PWR spent fuel by using WDS

Energy Technology Data Exchange (ETDEWEB)

Kwon, H. M.; Kim, D. S.; Seo, H. S.; Ju, J. S.; Jang, J. N.; Yang, Y. S.; Park, S. D. [KAERI, Daejeon (Korea, Republic of)

2012-01-15

This study includes three processes. First, a peak centering of the X-ray line was performed after a diffraction for Xenon La1 line was installed. Xe La1 peak was identified by a PWR spent fuel sample. Second, standard intensities of Xe was obtained by interpolation of the La1 intensities from a series of elements on each side of xenon. And then Xe intensities across the radial direction of a PWR spent fuel sample were measured by WDS-SEM. Third, the electron and X-ray depth distributions for a quantitative electron probe micro analysis were simulated by the CASINO Monte Carlo program to do matrix correction of a PWR spent fuel sample. Finally, the method and the procedure for local quantitative analysis of Xenon was developed in this study.

Quantitative analysis technique for Xenon in PWR spent fuel by using WDS

International Nuclear Information System (INIS)

Kwon, H. M.; Kim, D. S.; Seo, H. S.; Ju, J. S.; Jang, J. N.; Yang, Y. S.; Park, S. D.

2012-01-01

This study includes three processes. First, a peak centering of the X-ray line was performed after a diffraction for Xenon La1 line was installed. Xe La1 peak was identified by a PWR spent fuel sample. Second, standard intensities of Xe was obtained by interpolation of the La1 intensities from a series of elements on each side of xenon. And then Xe intensities across the radial direction of a PWR spent fuel sample were measured by WDS-SEM. Third, the electron and X-ray depth distributions for a quantitative electron probe micro analysis were simulated by the CASINO Monte Carlo program to do matrix correction of a PWR spent fuel sample. Finally, the method and the procedure for local quantitative analysis of Xenon was developed in this study

XENON100 exclusion limit without considering Leff as a nuisance parameter

Science.gov (United States)

Davis, Jonathan H.; Bœhm, Céline; Oppermann, Niels; Ensslin, Torsten; Lacroix, Thomas

2012-07-01

In 2011, the XENON100 experiment has set unprecedented constraints on dark matter-nucleon interactions, excluding dark matter candidates with masses down to 6 GeV if the corresponding cross section is larger than 10-39cm2. The dependence of the exclusion limit in terms of the scintillation efficiency (Leff) has been debated at length. To overcome possible criticisms XENON100 performed an analysis in which Leff was considered as a nuisance parameter and its uncertainties were profiled out by using a Gaussian likelihood in which the mean value corresponds to the best fit Leff value (smoothly extrapolated to 0 below 3 keVnr). Although such a method seems fairly robust, it does not account for more extreme types of extrapolation nor does it enable us to anticipate how much the exclusion limit would vary if new data were to support a flat behavior for Leff below 3 keVnr, for example. Yet, such a question is crucial for light dark matter models which are close to the published XENON100 limit. To answer this issue, we use a maximum likelihood ratio analysis, as done by the XENON100 Collaboration, but do not consider Leff as a nuisance parameter. Instead, Leff is obtained directly from the fits to the data. This enables us to define frequentist confidence intervals by marginalizing over Leff.

Plasma waves produced by an ion beam: observations by the VLF experiment on Porcupine

International Nuclear Information System (INIS)

Jones, D.

1980-01-01

Results are presented from the VLF electric field experiments flown on Porcupine flights F3 and F4, which also had ejectable xenon ion sources. The xenon ion beam was found to produce plasma instabilities whose frequencies could be linked to the local proton gyrofrequency fsub(cH + ). The main energy in the instabilities lies at approximately 3kHz for events when the Xe + source is close to the rocket, and at approximately 7kHz when the source is farther away. Theory predicts that these frequencies should be the lower-hybrid-resonance and this implies that Xe + is the dominant ion in the first case and that it is the ambient plasma that dominates later. There is no discernable antenna spin-modulation during the Xe events which indicates that the wave k-vectors are not unidirectional. A theory is cited based on the 'setting up' of the proton cyclotron harmonic waves by the Xe + or O + cyclotron harmonic waves. The second Xe + event on both flights exhibited an, as yet, unexplained harmonic structure related to fsub(cH + )/2. (Auth.)

Robust nonlinear model predictive control for nuclear power plants in load following operations with bounded xenon oscillations

International Nuclear Information System (INIS)

Eliasi, H.; Menhaj, M.B.; Davilu, H.

2011-01-01

Research highlights: → In this work, a robust nonlinear model predictive control algorithm is developed. → This algorithm is applied to control the power level for load following. → The state constraints are imposed on the predicted trajectory during optimization. → The xenon oscillations are the main constraint for the load following problem. → In this algorithm, xenon oscillations are bounded within acceptable limits. - Abstract: One of the important operations in nuclear power plants is load-following in which imbalance of axial power distribution induces xenon oscillations. These oscillations must be maintained within acceptable limits otherwise the nuclear power plant could become unstable. Therefore, bounded xenon oscillation considered to be a constraint for the load-following operation. In this paper, a robust nonlinear model predictive control for the load-following operation problem is proposed that ensures xenon oscillations are kept bounded within acceptable limits. The proposed controller uses constant axial offset (AO) strategy to maintain xenon oscillations to be bounded. The constant AO is a robust state constraint for load-following problem. The controller imposes restricted state constraints on the predicted trajectory during optimization which guarantees robust satisfaction of state constraints without restoring to a min-max optimization problem. Simulation results show that the proposed controller for the load-following operation is so effective so that the xenon oscillations kept bounded in the given region.

Proposed LLNL electron beam ion trap

International Nuclear Information System (INIS)

Marrs, R.E.; Egan, P.O.; Proctor, I.; Levine, M.A.; Hansen, L.; Kajiyama, Y.; Wolgast, R.

1985-01-01

The interaction of energetic electrons with highly charged ions is of great importance to several research fields such as astrophysics, laser fusion and magnetic fusion. In spite of this importance there are almost no measurements of electron interaction cross sections for ions more than a few times ionized. To address this problem an electron beam ion trap (EBIT) is being developed at LLNL. The device is essentially an EBIS except that it is not intended as a source of extracted ions. Instead the (variable energy) electron beam interacting with the confined ions will be used to obtain measurements of ionization cross sections, dielectronic recombination cross sections, radiative recombination cross sections, energy levels and oscillator strengths. Charge-exchange recombinaion cross sections with neutral gasses could also be measured. The goal is to produce and study elements in many different charge states up to He-like xenon and Ne-like uranium. 5 refs., 2 figs

Near-infrared scintillation of xenon by 63Ni beta decay

Science.gov (United States)

Yoshimizu, Norimasa; Lal, Amit; Pollock, Clifford R.

2006-07-01

The near-infrared scintillation of xenon gas by the β decay of 37MBq of Ni63 was studied, in the interest of its use in integrated devices for applications such as optical beacons and wavelength calibration. The emission was imaged and analyzed using Spencer's theory of electron penetration using xenon scattering cross sections derived from Thomas-Fermi theory. The total emission was approximately 2×105photons/s at 20kPa and 1×105photons/s at 100kPa. Spectral data show three dominant peaks at 823, 828, and 882nm as well as the formation of metastable states.

The high pressure xenon lamp as a source of radiation

International Nuclear Information System (INIS)

Heerdt, J.A. ter.

1979-01-01

An account is given of an investigation into the radiation properties of a commercially available high pressure xenon lamp (type XBO 900 W) in the spectral range 0.3 to 3 μm. The purpose of the study was to find out whether such a lamp can serve as a (secondary) standard of radiation in spectroscopic and radiometric measurements. The main advantades of the xenon lamp over other secondary standards such as the tungsten strip lamp and the anode of a carbon arc lamp are the high temperature of its discharge and the resulting strong radiation over a broad spectral range. (Auth.)

Review of xenon-133 production and related problems

International Nuclear Information System (INIS)

Barrachina, M.; Ropero, M.

1980-01-01

A literature survey is given on the production methods of fission xenon-133 and related problems, such as purification, metrological and dosimetric aspects, preparation of isotopic solutions, recycling, etc. 127 references are included. (Author) 127 refs

Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Contreras, H.; Goetzke, L.W.; Fernandez, A.J.M.; Messina, M.; Plante, G.; Rizzo, A. [Columbia University, Physics Department, New York, NY (United States); Agostini, F. [INFN-Laboratori Nazionali del Gran Sasso (Italy); Gran Sasso Science Institute, L' Aquila (Italy); Bologna Univ., Department of Physics and Astrophysics, Bologna (Italy); INFN, Bologna (Italy); Alfonsi, M. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Arazi, L.; Budnik, R.; Duchovni, E.; Gross, E.; Itay, R.; Landsman, H.; Lellouch, D.; Levinson, L.; Priel, N.; Vitells, O. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); Arisaka, K.; Lyashenko, A.; Meng, Y.; Pantic, E.; Teymourian, A.; Wang, H. [University of California, Physics and Astronomy Department, Los Angeles, CA (United States); Arneodo, F.; Di Giovanni, A. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Auger, M.; Barrow, P.; Baudis, L.; Behrens, A.; Galloway, M.; Kessler, G.; Kish, A.; Mayani, D.; Pakarha, P.; Piastra, F. [University of Zurich, Physik-Institut, Zurich (Switzerland); Balan, C.; Cardoso, J.M.R.; Lopes, J.A.M.; Santos, J.M.F. dos [University of Coimbra, Department of Physics, Coimbra (Portugal); Bauermeister, B.; Fattori, S.; Geis, C.; Grignon, C.; Oberlack, U.; Schindler, S. [Johannes Gutenberg-Universitaet Mainz, Institut fuer Physik and Exzellenzcluster PRISMA, Mainz (Germany); Beltrame, P. [Weizmann Institute of Science, Department of Particle Physics and Astrophysics, Rehovot (Israel); University of Edinburgh, Edinburgh (United Kingdom); Brown, A.; Lang, R.F.; Macmullin, S.; Pienaar, J.; Reichard, S.; Reuter, C. [Purdue University, Department of Physics and Astronomy, West Lafayette, IN (United States); Brown, E.; Levy, C. [Rensselaer Polytechnic Institute, Department of Physics, Applied Physics and Astronomy, Troy, NY (United States); Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Bruenner, S.; Hampel, W.; Kaether, F.; Lindemann, S.; Lindner, M.; Undagoitia, T.M.; Rauch, L.; Schreiner, J.; Simgen, H.; Weber, M. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Bruno, G. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Buetikofer, L.; Coderre, D.; Schumann, M. [University of Bern, Albert Einstein Center for Fundamental Physics, Bern (Switzerland); Colijn, A.P.; Decowski, M.P.; Tiseni, A.; Tunnell, C. [Nikhef and the University of Amsterdam, Amsterdam (Netherlands); Cussonneau, J.P.; Le Calloch, M.; Masbou, J.; Lavina, L.S.; Thers, D. [Universite de Nantes, Subatech, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (France); Ferella, A.D.; Fulgione, W.; Laubenstein, M. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, L' Aquila (Italy); Fieguth, A.; Murra, M.; Rosendahl, S.; Weinheimer, C. [Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Garbini, M.; Massoli, F.V.; Sartorelli, G.; Selvi, M. [Bologna Univ., Department of Physics and Astrophysics, Bologna (Italy); INFN, Bologna (Italy); Miguez, B.; Molinario, A.; Trinchero, G. [INFN-Torino and Osservatorio Astrofisico di Torino, Turin (Italy); Naganoma, J.; Shagin, P.; Wall, R. [Rice University, Department of Physics and Astronomy, Houston, TX (United States); Orrigo, S.E.A. [University of Coimbra, Department of Physics, Coimbra (Portugal); IFIC, CSIC-Universidad de Valencia, Valencia (Spain); Persiani, R. [Universite de Nantes, Subatech, Ecole des Mines de Nantes, CNRS/In2p3, Nantes (FR); Bologna Univ., Department of Physics and Astrophysics, Bologna (IT); INFN, Bologna (IT); Collaboration: XENON Collaboration

2015-11-15

The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company to produce a highly radio-pure photosensor (version R11410-21) for the XENON1T dark matter experiment. After introducing the photosensor and its components, we show the methods and results of the radioactive contamination measurements of the individual materials employed in the photomultiplier production. We then discuss the adopted strategies to reduce the radioactivity of the various PMT versions. Finally, we detail the results from screening 286 tubes with ultra-low background germanium detectors, as well as their implications for the expected electronic and nuclear recoil background of the XENON1T experiment. (orig.)

Development of a liquid xenon Compton telescope dedicated to functional medical imaging; Etude et developpement d'un telescope compton au xenon liquide dedie a l'imagerie medicale fonctionnelle

Energy Technology Data Exchange (ETDEWEB)

Grignon, C

2007-12-15

Functional imaging is a technique used to locate in three dimensions the position of a radiotracer previously injected in a patient. The two main modalities used for a clinical application to detect tumors, the SPECT and the PET, use solid scintillators as a detection medium. The objective of this thesis was to investigate the possibility of using liquid xenon in order to benefit from the intrinsic properties of this medium in functional imaging. The feasibility study of such a device has been performed by taking into account the technical difficulties specific to the liquid xenon. First of all, simulations of a liquid xenon PET has been performed using Monte-Carlo methods. The results obtained with a large liquid xenon volume are promising : we can expect a reduction of the injected activity of radiotracer, an improvement of the spatial resolution of the image and a parallax free camera. The second part of the thesis was focused on the development of a new concept of medical imaging, the three gamma imaging, based on the use of a new emitter: the 44 scandium. Associated to a classical PET camera, the Compton telescope is used to infer the incoming direction of the third gamma ray by triangulation. Therefore, it is possible to reconstruct the position of each emitter in three dimensions. This work convinced the scientific community to support the construction and characterization of a liquid xenon Compton telescope. The first camera dedicated to small animal imaging should then be operational in 2009. (author)

Collateral ventilation to congenital hyperlucent lung lesions assessed on xenon-enhanced dynamic dual-energy CT: an initial experience.

Science.gov (United States)

Goo, Hyun Woo; Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

2011-01-01

We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a time-xenon value curve analysis and assessing the amplitude of xenon enhancement (A) value, the rate of xenon enhancement (K) value and the time of arrival value. Based on the A value, the lung lesions were categorized into high or low (A value > 10 Hounsfield unit [HU]) resistance to collateral ventilation. In addition, the morphologic CT findings of the lung lesions, including cyst, mucocele and an accessory or incomplete fissure, were assessed on the weighted-average CT images. The xenon-enhanced CT radiation dose was estimated. Five of the eight lung lesions were categorized into the high resistance group and three lesions were categorized into the low resistance group. The A and K values in the normal lung were higher than those in the low resistance group. The time of arrival values were delayed in the low resistance group. Cysts were identified in five lesions, mucocele in four, accessory fissure in three and incomplete fissure in two. Either cyst or an accessory fissure was seen in four of the five lesions showing high resistance to collateral ventilation. The xenon-enhanced CT radiation dose was 2.3 ± 0.6 mSv. Xenon-enhanced dynamic dual-energy CT can help visualize and quantitate various degrees of collateral ventilation to congenital hyperlucent lung lesions in addition to assessing the anatomic details of the lung.

Calculation of xenon-oscillations in the HPLWR

International Nuclear Information System (INIS)

Reiss, T.; Feher, S.; Czifrus, Sz.

2009-01-01

The European version of the Supercritical Water Cooled Reactor (SCWR) is being developed under the name High Performance Light Water Reactor (HPLWR). In the most recent design, a three-pass core is foreseen with a heat-up of the coolant (supercritical pressure water) from 280degC to 500degC. Due to the operating pressure of 25 MPa, there is no phase change in the core but the density drop of the coolant can be as high as one order of magnitude. This results in a system which is sensitive to local temperature, power and density oscillations. This attribute is enhanced by the pseudocritical transformation of supercritical pressure water. Due to the relatively large dimensions of the core, xenon-oscillations are probable. The characteristic time of this process is several hours, thus a coupled quasi-stationary neutronics-thermohydraulics (CQNT) code completed with the xenon poisoning differential equations (XPDE) can predict the extent of xenon-oscillations. A program system is being developed at the Budapest University of Technology which is capable to perform full core CQNT calculations including the XPDE. The program system is designed to calculate one-pass (which was the first core proposal for HPLWRs, today called PWR-SC) and three-pass cores. The CQNT code is made up of an MCNP part (neutronics part) and of a thermohydraulics part developed at our Institute. Since full core MCNP calculations are very time consuming, upon symmetry considerations only one eighth of the core is modelled. On the other hand, this approach of modelling momentarily limits the phenomena which can be studied to axial oscillations. (author)

TEM study of damage recovery in SiC by swift Xe ion irradiation

International Nuclear Information System (INIS)

Skuratov, V.A.; O’Connell, J.; Sohatsky, A.S.; Neethling, J.

2014-01-01

The microstructure of 4H–SiC samples subsequently irradiated with low energy He (10 keV), Ti (220 keV) and high energy (167 MeV) Xe ions has been studied using cross-sectional transmission electron microscopy. It was found that xenon ions with fluences above 10 13 cm −2 restore crystallinity in a heavily damaged partially amorphous zone. No, or negligible damage recovery is observed in fully amorphized layers of silicon carbide

A new high-temperature plasma ion source for the TRISTAN ISOL facility

International Nuclear Information System (INIS)

Piotrowski, A.; Gill, R.L.; McDonald, D.C.

1987-01-01

A vigorous program of ion-source development at TRISTAN has led to several types of ion sources that are especially suited to extended operation at a reactor-based ISOL facility. The latest of these is a high-temperature plasma ion source in which a 5-g 235 U target is located in the cathode and can be heated to 2500 0 C. The ion source has a lifetime of >1000 h and produces a wide array of elements, including palladium. Off-line investigations indicate that the source functions primarily in an electron impact mode of ionization and exhibits typical ionization efficiencies of >30% for xenon. (orig.)

A new high-temperature plasma ion source for the TRISTAN ISOL facility

International Nuclear Information System (INIS)

Piotrowski, A.; Gill, R.L.; McDonald, D.C.

1987-01-01

A vigorous program of ion-source development at TRISTAN has led to several types of ion sources that are especially suited to extended operation at a reactor-based ISOL facility. The latest of these is a high-temperature plasma ion source in which a 5-g /sup 235/U target is located in the cathode and can be heated to 2500 0 C. The ion source has a lifetime of > 1000 h and produces a wide array of elements, including palladium. Off-line investigations indicate that the source functions primarily in an electron impact mode of ionization and exhibits typical ionization efficiencies of > 30% for xenon

Depth distribution of martensite in xenon implanted stainless steels

International Nuclear Information System (INIS)

Johansen, A.; Johnson, E.; Sarholt-Kristensen, L.; Steenstrup, S.; Hayashi, N.; Sakamoto, I.

1989-01-01

The amount of stress-induced martensite and its distribution in depth in xenon implanted austenitic stainless steel poly- and single crystals have been measured by Rutherford backscattering and channeling analysis, depth selective conversion electron Moessbauer spectroscopy, cross-sectional transmission electron microscopy and x-ray diffraction analysis. In low nickel 17/7, 304 and 316 commercial stainless steels and in 17:13 single crystals the martensitic transformation starts at the surface and develops towards greater depth with increasing xenon fluence. The implanted layer is nearly completely transformed, and the interface between martensite and austenite is rather sharp and well defined. In high nickel 310 commercial stainless steel and 15:19 and 20:19 single crystals, on the other hand, only insignificant amounts of martensite are observed. (orig.)

Pairwise additivity in the nuclear magnetic resonance interactions of atomic xenon.

Science.gov (United States)

Hanni, Matti; Lantto, Perttu; Vaara, Juha

2009-04-14

Nuclear magnetic resonance (NMR) of atomic (129/131)Xe is used as a versatile probe of the structure and dynamics of various host materials, due to the sensitivity of the Xe NMR parameters to intermolecular interactions. The principles governing this sensitivity can be investigated using the prototypic system of interacting Xe atoms. In the pairwise additive approximation (PAA), the binary NMR chemical shift, nuclear quadrupole coupling (NQC), and spin-rotation (SR) curves for the xenon dimer are utilized for fast and efficient evaluation of the corresponding NMR tensors in small xenon clusters Xe(n) (n = 2-12). If accurate, the preparametrized PAA enables the analysis of the NMR properties of xenon clusters, condensed xenon phases, and xenon gas without having to resort to electronic structure calculations of instantaneous configurations for n > 2. The binary parameters for Xe(2) at different internuclear distances were obtained at the nonrelativistic Hartree-Fock level of theory. Quantum-chemical (QC) calculations at the corresponding level were used to obtain the NMR parameters of the Xe(n) (n = 2-12) clusters at the equilibrium geometries. Comparison of PAA and QC data indicates that the direct use of the binary property curves of Xe(2) can be expected to be well-suited for the analysis of Xe NMR in the gaseous phase dominated by binary collisions. For use in condensed phases where many-body effects should be considered, effective binary property functions were fitted using the principal components of QC tensors from Xe(n) clusters. Particularly, the chemical shift in Xe(n) is strikingly well-described by the effective PAA. The coordination number Z of the Xe site is found to be the most important factor determining the chemical shift, with the largest shifts being found for high-symmetry sites with the largest Z. This is rationalized in terms of the density of virtual electronic states available for response to magnetic perturbations.

Two-group Analysis of Xenon Stability in Slab Geometry by Modal Expansion

International Nuclear Information System (INIS)

Norinder, O.

1963-05-01

Xenon spatial stability is analyzed with the flux represented by two neutron energy groups. General formulas are given for expansions in a system of modes. Detailed formulas are recorded for a slab described by sinusoidal modes. A short description is given of a Mercury Autocode program for numerical calculations in slab geometry. The essential input parameters and results are noted for 80 computed cases. The main body of the calculations were intended to clarify the xenon stability properties of the Marviken reactor, which was found to have a sufficient margin against unstable xenon oscillations. The neutron flux detection and the control rod insertion in the slab were found to have a large influence on the stability in spite of the nonexistence of space-selective control in the systems investigated. Very good agreement was found between stability limits calculated according to Randall and St. John and stability limits calculated by the program

Two-group Analysis of Xenon Stability in Slab Geometry by Modal Expansion

Energy Technology Data Exchange (ETDEWEB)

Norinder, O

1963-05-15

Xenon spatial stability is analyzed with the flux represented by two neutron energy groups. General formulas are given for expansions in a system of modes. Detailed formulas are recorded for a slab described by sinusoidal modes. A short description is given of a Mercury Autocode program for numerical calculations in slab geometry. The essential input parameters and results are noted for 80 computed cases. The main body of the calculations were intended to clarify the xenon stability properties of the Marviken reactor, which was found to have a sufficient margin against unstable xenon oscillations. The neutron flux detection and the control rod insertion in the slab were found to have a large influence on the stability in spite of the nonexistence of space-selective control in the systems investigated. Very good agreement was found between stability limits calculated according to Randall and St. John and stability limits calculated by the program.

Phase behavior of mixed submonolayer films of krypton and xenon on graphite.

Science.gov (United States)

Patrykiejew, A; Sokołowski, S

2012-04-14

Using the results of extensive Monte Carlo simulations in the canonical and grand canonical ensembles, we discuss the phase behavior of mixed submonolayer films of krypton and xenon adsorbed on the graphite basal plane. The calculations have been performed using two- and three-dimensional models of the systems studied. It has been demonstrated that out-of-plane motion does not affect the properties of the films as long as the total density is well below the monolayer completion and at moderate temperatures. For the total densities close to the monolayer completion, the promotion of particles to the second layer considerably affects the film properties. Our results are in a reasonable agreement with the available experimental data. The melting point of submonolayer films has been shown to exhibit non-monotonous changes with the film composition, and reaches minimum for the xenon concentration of about 50%. At the temperatures below the melting point, the structure of solid phases depends upon the film composition and the temperature; one can also distinguish commensurate and incommensurate phases. Two-dimensional calculations have demonstrated that for the xenon concentration between about 15% and 65% the adsorbed film exhibits the formation of a superstructure, in which each Xe atom is surrounded by six Kr atoms. This superstructure is stable only at very low temperatures and transforms into the mixed commensurate (√3×√3)R30° phase upon the increase of temperature. Such a superstructure does not appear when a three-dimensional model is used. Grand canonical ensemble calculations allowed us to show that for the xenon concentration of about 3% the phase diagram topology of monolayer films changes from the krypton-like (with incipient triple point) to the xenon-like (with ordinary triple point).

Lowering the radioactivity of the photomultiplier tubes for the XENON1T dark matter experiment

NARCIS (Netherlands)

Aprile, E.; et al., [Unknown; Alfonsi, M.; Colijn, A.P.; Decowski, M.P.; Tiseni, A.; Tunnell, C.

2015-01-01

The low-background, VUV-sensitive 3-inch diameter photomultiplier tube R11410 has been developed by Hamamatsu for dark matter direct detection experiments using liquid xenon as the target material. We present the results from the joint effort between the XENON collaboration and the Hamamatsu company

Experimental development of a liquid xenon Compton telescope for functional medical imaging

International Nuclear Information System (INIS)

Oger, Tugdual

2012-01-01

3γ imaging is a new nuclear medical imaging technique which has been suggested by Subatech laboratory. This technique involves locating three-dimensional position of the decay of an innovative radioisotope (β + ,γ) emitter, the 44 Sc. The principle consist in the detection of two photons of 511 keV gamma rays from the decay of the positron, provided by a PET ring detector, associated to the detection of the third photon by a Liquid xenon Compton telescope. The energy deposited in the interaction between the photon and xenon and its position are identified by measuring the ionization signal with a Micromegas chamber (Micro-Mesh Gaseous Structure), while the trigger and time measurement of the interaction are provided by the detection of the scintillation signal. The principle of the TPC is thus used to Compton imaging. In order to demonstrate experimentally the feasibility of imaging 3γ, a small prototype, XEMIS (Xenon Medical Imaging System) was developed. This thesis is an important step towards the proof of feasibility. In this work are exposed the characterization of the detector response for a beam of 511 keV gamma rays and the analysis of data derived from it. The measurement of energy and time resolutions will be presented, as well as the purity of the liquid xenon. (author) [fr

Nausea and Vomiting following Balanced Xenon Anesthesia Compared to Sevoflurane: A Post-Hoc Explorative Analysis of a Randomized Controlled Trial.

Directory of Open Access Journals (Sweden)

Astrid V Fahlenkamp

Full Text Available Like other inhalational anesthetics xenon seems to be associated with post-operative nausea and vomiting (PONV. We assessed nausea incidence following balanced xenon anesthesia compared to sevoflurane, and dexamethasone for its prophylaxis in a randomized controlled trial with post-hoc explorative analysis.220 subjects with elevated PONV risk (Apfel score ≥2 undergoing elective abdominal surgery were randomized to receive xenon or sevoflurane anesthesia and dexamethasone or placebo after written informed consent. 93 subjects in the xenon group and 94 subjects in the sevoflurane group completed the trial. General anesthesia was maintained with 60% xenon or 2.0% sevoflurane. Dexamethasone 4mg or placebo was administered in the first hour. Subjects were analyzed for nausea and vomiting in predefined intervals during a 24h post-anesthesia follow-up.Logistic regression, controlled for dexamethasone and anesthesia/dexamethasone interaction, showed a significant risk to develop nausea following xenon anesthesia (OR 2.30, 95% CI 1.02-5.19, p = 0.044. Early-onset nausea incidence was 46% after xenon and 35% after sevoflurane anesthesia (p = 0.138. After xenon, nausea occurred significantly earlier (p = 0.014, was more frequent and rated worse in the beginning. Dexamethasone did not markedly reduce nausea occurrence in both groups. Late-onset nausea showed no considerable difference between the groups.In our study setting, xenon anesthesia was associated with an elevated risk to develop nausea in sensitive subjects. Dexamethasone 4mg was not effective preventing nausea in our study. Group size or dosage might have been too small, and change of statistical analysis parameters in the post-hoc evaluation might have further contributed to a limitation of our results. Further trials will be needed to address prophylaxis of xenon-induced nausea.EU Clinical Trials EudraCT-2008-004132-20 ClinicalTrials.gov NCT00793663.

Delayed xenon post-conditioning mitigates spinal cord ischemia/reperfusion injury in rabbits by regulating microglial activation and inflammatory factors.

Science.gov (United States)

Yang, Yan-Wei; Wang, Yun-Lu; Lu, Jia-Kai; Tian, Lei; Jin, Mu; Cheng, Wei-Ping

2018-03-01

The neuroprotective effect against spinal cord ischemia/reperfusion injury in rats exerted by delayed xenon post-conditioning is stronger than that produced by immediate xenon post-conditioning. However, the mechanisms underlying this process remain unclear. Activated microglia are the main inflammatory cell type in the nervous system. The release of pro-inflammatory factors following microglial activation can lead to spinal cord damage, and inhibition of microglial activation can relieve spinal cord ischemia/reperfusion injury. To investigate how xenon regulates microglial activation and the release of inflammatory factors, a rabbit model of spinal cord ischemia/reperfusion injury was induced by balloon occlusion of the infrarenal aorta. After establishment of the model, two interventions were given: (1) immediate xenon post-conditioning-after reperfusion, inhalation of 50% xenon for 1 hour, 50% N 2 /50%O 2 for 2 hours; (2) delayed xenon post-conditioning-after reperfusion, inhalation of 50% N 2 /50%O 2 for 2 hours, 50% xenon for 1 hour. At 4, 8, 24, 48 and 72 hours after reperfusion, hindlimb locomotor function was scored using the Jacobs locomotor scale. At 72 hours after reperfusion, interleukin 6 and interleukin 10 levels in the spinal cord of each group were measured using western blot assays. Iba1 levels were determined using immunohistochemistry and a western blot assay. The number of normal neurons at the injury site was quantified using hematoxylin-eosin staining. At 72 hours after reperfusion, delayed xenon post-conditioning remarkably enhanced hindlimb motor function, increased the number of normal neurons at the injury site, decreased Iba1 levels, and inhibited interleukin-6 and interleukin-10 levels in the spinal cord. Immediate xenon post-conditioning did not noticeably affect the above-mentioned indexes. These findings indicate that delayed xenon post-conditioning after spinal cord injury improves the recovery of neurological function by reducing

Gas purity analytics, calibration studies, and background predictions towards the first results of XENON1T

Energy Technology Data Exchange (ETDEWEB)

Hasterok, Constanze

2017-10-25

The XENON1T experiment aims at the direct detection of the well motivated dark matter candidate of weakly interacting massive particles (WIMPs) scattering off xenon nuclei. The first science run of 34.2 live days has already achieved the most stringent upper limit on spin-independent WIMP-nucleon cross-sections above masses of 10 GeV with a minimum of 7.7.10{sup -47} cm{sup 2} at a mass of 35 GeV. Crucial for this unprecedented sensitivity are a high xenon gas purity and a good understanding of the background. In this work, a procedure is described that was developed to measure the purity of the experiment's xenon inventory of more than three tons during its initial transfer to the detector gas system. The technique of gas chromatography has been employed to analyze the noble gas for impurities with the focus on oxygen and krypton contaminations. Furthermore, studies on the calibration of the experiment's dominating background induced by natural gamma and beta radiation were performed. Hereby, the novel sources of radioactive isotopes that can be dissolved in the xenon were employed, namely {sup 220}Rn and tritium. The sources were analyzed in terms of a potential impact on the outcome of a dark matter search. As a result of the promising findings for {sup 220}Rn, the source was successfully deployed in the first science run of XENON1T. The first WIMP search of XENON1T is outlined in this thesis, in which a background component from interactions taking place in close proximity to the detector wall is identified, investigated and modeled. A background prediction was derived that was incorporated into the background model of the WIMP search which was found to be in good agreement with the observation.

The Shaker Potassium Channel Is No Target for Xenon Anesthesia in Short-Sleeping Drosophila melanogaster Mutants

Directory of Open Access Journals (Sweden)

C. Schaper

2012-01-01

Full Text Available Background. Xenon seems to be an ideal anesthetic drug. To explore if next to the antagonism at the NMDA-receptor other molecular targets are involved, we tested the xenon requirement in short sleeping Drosophila shaker mutants and in [ℎ38]. Methods. The Drosophila melanogaster strains wildtype Canton-S, [ℎ38], ℎ102 and ℎ, were raised and sleep was measured. Based on the response of the flies at different xenon concentrations, logEC50 values were calculated. Results. The logEC50-values for WT Canton-S were 1.671 (1.601–1.742 95%-confidence intervall; =238; P versus ℎ102 > 0,05, for ℎ 1.711 (1.650–1.773; =242; P versus WT Canton-S > 0,05. The logEC50-value for ℎ102 was 1.594 (1.493–1.694; =261; P versus ℎ > 0.05. The logEC-value of [ℎ38] was 2.076 (1.619–2.532; =207; P versus ℎ 0.05, while [ℎ38] was found to be hyposensitive compared to wildtype (P < 0.05. Conclusions. The xenon requirement in Drosophila melanogaster is not influenced by a single gene mutation at the shaker locus, whereas a reduced expression of a nonselective cation channel leads to an increased xenon requirement. This supports the thesis that xenon mediates its effects not only via an antagonism at the NMDA-receptor.

Preliminary investigation of actinide and xenon reactivity effects in accelerator transmutation of waste high-flux systems

International Nuclear Information System (INIS)

Olson, K.R.; Henderson, D.L.

1995-01-01

The possibility of an unstable positive reactivity growth in an accelerator transmutation of waste (ATW)-type high-flux system is investigated. While it has always been clear that xenon is an important actor in the reactivity response of a system to flux changes, it has been suggested that in very high thermal flux transuranic burning systems, a positive, unstable reactivity growth could be caused by the actinides alone. Initial system reactivity response to flux changes caused by the actinides and xenon are investigated separately. The maximum change in reactivity after a flux change caused by the effect of the changing quantities of actinides is generally at least two orders of magnitude smaller than either the positive or negative reactivity effect associated with xenon after a shutdown or startup. In any transient flux event, the reactivity response of the system to xenon will generally occlude the response caused by the actinides. The capabilities and applications of both the current actinide model and the xenon model are discussed. Finally, the need for a complete dynamic model for the high-flux fluid-fueled ATW system is addressed

TEM study of damage recovery in SiC by swift Xe ion irradiation

Energy Technology Data Exchange (ETDEWEB)

Skuratov, V.A., E-mail: skuratov@jinr.ru [Joint Institute for Nuclear Research, Dubna (Russian Federation); O’Connell, J. [Centre for HRTEM, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Sohatsky, A.S. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Neethling, J. [Centre for HRTEM, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

2014-05-01

The microstructure of 4H–SiC samples subsequently irradiated with low energy He (10 keV), Ti (220 keV) and high energy (167 MeV) Xe ions has been studied using cross-sectional transmission electron microscopy. It was found that xenon ions with fluences above 10{sup 13} cm{sup −2} restore crystallinity in a heavily damaged partially amorphous zone. No, or negligible damage recovery is observed in fully amorphized layers of silicon carbide.

Studies of the wavelength dependence of non-sequential double ionization of xenon in strong fields

International Nuclear Information System (INIS)

Kaminski, P.; Wiehle, R.; Kamke, W.; Helm, H.; Witzele, B.

2005-01-01

Full text: The non-sequential double ionization of noble gases in strong fields is still a process which is not completely understood. The most challenging question is: what is the dominant physical process behind the knee structure in the yield of doubly charged ions which are produced in the focus of an ultrashort laser pulse in dependence of the intensity? Numerous studies can be explained with the so-called rescattering model, where an electron is freed by the strong laser field and then driven back to its parent ion due to the oscillation of the field. Through this backscattering process it is possible to kick out a second electron. However in the low intensity or multiphoton (MPI) region this model predicts that the first electron can not gain enough energy in the oscillating electric field to further ionize or excite the ion. We present experimental results for xenon in the MPI region which show a significant contribution of doubly charged ions. A Ti:sapphire laser system (800 nm, 100 fs) is used to ionize the atoms. The coincident detection of the momentum distribution of the photoelectrons with an imaging spectrometer and the time of flight spectrum of the ions allows a detailed view into the ionization process. For the first time we also show a systematic study of the wavelength dependence (780-830 nm and 1180-1550 nm) on the non-sequential double ionization. The ratio Xe 2+ /Xe + shows a surprising oscillatory behavior with varying wavelength. Ref. 1 (author)

Studies on adsorption-desorption of xenon on surface of BC-404 plastic scintillator based on soaking method

Energy Technology Data Exchange (ETDEWEB)

Yongchun, Xiang [Institute of Nuclear Physics and Chemistry, China and Academy of Engineer Physics, Mianyang 621900 (China); School of Physics, Peking University, Beijing 100080 (China); Tieshuan, Fan [School of Physics, Peking University, Beijing 100080 (China); Chuanfei, Zhang; Fei, Luo; Qian, Wang; Rende, Ze [Institute of Nuclear Physics and Chemistry, China and Academy of Engineer Physics, Mianyang 621900 (China); Qingpei, Xiang, E-mail: xiangqingpei@163.com [Institute of Nuclear Physics and Chemistry, China and Academy of Engineer Physics, Mianyang 621900 (China)

2017-03-01

The phoswich coincidence detector is used to verify the CTBT treaty by measuring radioxenon and as such needs to possess high detection sensitivity. However, residual xenon adsorbed onto the surface of β detectors greatly influences subsequent measurements of weak samples. In this study, we investigate the adsorption-desorption behavior of xenon on BC-404 scintillator surfaces with different coating thicknesses using the soaking method. The results present the desorption behavior of xenon on a BC-404 surface for the first time. The calculated adsorption capacity for an uncoated surface is consistent with that from previous studies. However, due to factors such as limitations in coating technology, the effectiveness of coating on reducing the “memory effect” of the detector was poor. The proposed method is suitable for studying the adsorption-desorption behavior of gases on solid surfaces due to its simplicity and flexibility. - Highlights: • We investigate the adsorption-desorption of xenon on coated BC-404 surfaces. • The calculated adsorption capacity on an uncoated surface agrees with other results. • The method can be used to simulate xenon adsorption in phoswich detectors.

Bonding xenon and krypton on the surface of uranium dioxide single crystal

Directory of Open Access Journals (Sweden)

Dąbrowski Ludwik

2014-08-01

Full Text Available We present density functional theory (DFT calculation results of krypton and xenon atoms interaction on the surface of uranium dioxide single crystal. A pseudo-potential approach in the generalised gradient approximation (GGA was applied using the ABINIT program package. To compute the unit cell parameters, the 25 atom super-cell was chosen. It has been revealed that close to the surface of a potential well is formed for xenon and krypton atom due to its interaction with the atoms of oxygen and uranium. Depth and shape of the well is the subject of ab initio calculations in adiabatic approximation. The calculations were performed both for the case of oxygenic and metallic surfaces. It has been shown that the potential well for the oxygenic surface is deeper than for the metallic surface. The thermal stability of immobilising the atoms of krypton and xenon in the potential wells were evaluated. The results are shown in graphs.

Research on the measurement of the ultraviolet irradiance in the xenon lamp aging test chamber

Science.gov (United States)

Ji, Muyao; Li, Tiecheng; Lin, Fangsheng; Yin, Dejin; Cheng, Weihai; Huang, Biyong; Lai, Lei; Xia, Ming

2018-01-01

This paper briefly introduces the methods of calibrating the irradiance in the Xenon lamp aging test chamber. And the irradiance under ultraviolet region is mainly researched. Three different detectors whose response wave range are respectively UVA (320 400nm), UVB (275 330nm) and UVA+B (280 400nm) are used in the experiment. Through comparing the measuring results with different detectors under the same xenon lamp source, we discuss the difference between UVA, UVB and UVA+B on the basis of the spectrum of the xenon lamp and the response curve of the detectors. We also point out the possible error source, when use these detectors to calibrate the chamber.

Study of the short-lived fission products. Separation of iodine and xenon fission radionuclides

International Nuclear Information System (INIS)

Barrachina, M.; Villar, M. A.

1965-01-01

The separation by distillation in a sulfuric acid or phosphoric acid-hydrogen peroxide medium of the iodine isotopes (8 day iodine-131, 2,3 hour iodine-132 21 hour iodine-133, 53 minute iodine-134 and 6,7 hour iodine-135) present in a uranium sample after different irradiation and cooling times is here described. It is also reported the use of active charcoal columns for the retention of xenon isotopes (5,27 days xenon-133 and 9,2 hours xenon-135) either released during the dissolution of the uranium irradiated samples or generated along the fission isobaric chains in the solutions of distillated iodine. In both cases the radiochemical purity of the separated products is established by gamma spectrometry. (Author) 15 refs

Xenon NMR measurements of permeability and tortuosity in reservoir rocks.

Science.gov (United States)

Wang, Ruopeng; Pavlin, Tina; Rosen, Matthew Scott; Mair, Ross William; Cory, David G; Walsworth, Ronald Lee

2005-02-01

In this work we present measurements of permeability, effective porosity and tortuosity on a variety of rock samples using NMR/MRI of thermal and laser-polarized gas. Permeability and effective porosity are measured simultaneously using MRI to monitor the inflow of laser-polarized xenon into the rock core. Tortuosity is determined from measurements of the time-dependent diffusion coefficient using thermal xenon in sealed samples. The initial results from a limited number of rocks indicate inverse correlations between tortuosity and both effective porosity and permeability. Further studies to widen the number of types of rocks studied may eventually aid in explaining the poorly understood connection between permeability and tortuosity of rock cores.

Pulse Rise Time Characterization of a High Pressure Xenon Gamma Detector for use in Resolution Enhancement

CERN Document Server

Troyer, G L

2000-01-01

High pressure xenon ionization chamber detectors are possible alternatives to traditional thallium doped sodium iodide (NaI(Tl)) and hyperpure germanium as gamma spectrometers in certain applications. Xenon detectors incorporating a Frisch grid exhibit energy resolutions comparable to cadmium/zinc/telluride (CZT) (e.g. 2% (at) 662keV) but with far greater sensitive volumes. The Frisch grid reduces the position dependence of the anode pulse risetimes, but it also increases the detector vibration sensitivity, anode capacitance, voltage requirements and mechanical complexity. We have been investigating the possibility of eliminating the grid electrode in high-pressure xenon detectors and preserving the high energy resolution using electronic risetime compensation methods. A two-electrode cylindrical high pressure xenon gamma detector coupled to time-to-amplitude conversion electronics was used to characterize the pulse rise time of deposited gamma photons. Time discrimination was used to characterize the pulse r...

Matrix of response functions for xenon gamma-ray detector

International Nuclear Information System (INIS)

Shustov, A.E.; Vlasik, K.F.; Grachev, V.M.; Dmitrenko, V.V.; Novikov, A.S.; P'ya, S.N.; Ulin, S.E.; Uteshev, Z.M.; Chernysheva, I.V.

2014-01-01

An approach of creation of response matrix using simulation GEANT4 gamma-ray Monte-Carlo method has been described for gamma-ray spectrometer based on high pressure xenon impulse ionization chamber with a shielding grid [ru

Supernova Neutrino Physics with Xenon Dark Matter Detectors

NARCIS (Netherlands)

Reichard, S.; Lang, R.F.; McCabe, C.; Selvi, M.; Tamborra, I.

2017-01-01

The dark matter experiment XENON1T is operational and sensitive to all flavors of neutrinos emitted from a supernova. We show that the proportional scintillation signal (S2) allows for a clear observation of the neutrino signal and guarantees a particularly low energy threshold, while the

First Axion Results from the XENON100 Experiment

CERN Document Server

Aprile, E.; Alfonsi, M.; Arisaka, K.; Arneodo, F.; Auger, M.; Balan, C.; Barrow, P.; Baudis, L.; Bauermeister, B.; Behrens, A.; Beltrame, P.; Bokeloh, K.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Cardoso, J.M.R.; Colijn, A.P.; Contreras, H.; Cussonneau, J.P.; Decowski, M.P.; Duchovni, E.; Fattori, S.; Ferella, A.D.; Fulgione, W.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L.W.; Grignon, C.; Gross, E.; Hampel, W.; Itay, R.; Kaether, F.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R.F.; Calloch, M. Le; Lellouch, D.; Levy, C.; Lindemann, S.; Lindner, M.; Lopes, J.A.M.; Lung, K.; Lyashenko, A.; Macmullin, S.; Marrodan Undagoitia, T.; Masbou, J.; Massoli, F.V.; Mayani Paras, D.; Melgarejo Fernandez, A. J.; Meng, Y.; Messina, M.; Miguez, B.; Molinario, A.; Murra, M.; Naganoma, J.; Oberlack, U.; Orrigo, S.E.A.; Pantic, E.; Persiani, R.; Piastra, F.; Pienaar, J.; Plante, G.; Priel, N.; Reichard, S.; Reuter, C.; Rizzo, A.; Rosendahl, S.; dos Santos, J. M. F.; Sartorelli, G.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Simgen, H.; Teymourian, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Vitells, O.; Wang, H.; Weber, M.; Weinheimer, C.

2014-09-09

We present the first results of searches for axions and axion-like-particles with the XENON100 experiment. The axion-electron coupling constant, $g_{Ae}$, has been tested by exploiting the axio-electric effect in liquid xenon. A profile likelihood analysis of 224.6 live days $\\times$ 34 kg exposure has shown no evidence for a signal. By rejecting $g_{Ae}$, larger than $7.7 \\times 10^{-12}$ (90% CL) in the solar axion search, we set the best limit to date on this coupling. In the frame of the DFSZ and KSVZ models, we exclude QCD axions heavier than 0.3 eV/c$^2$ and 80 eV/c$^2$, respectively. For axion-like-particles, under the assumption that they constitute the whole abundance of dark matter in our galaxy, we constrain $g_{Ae}$, to be lower than $1 \\times 10^{-12}$ (90% CL) for masses between 5 and 10 keV/c$^2$.

Ventilation imaging of the paranasal sinuses using xenon-enhanced dynamic single-energy CT and dual-energy CT: a feasibility study in a nasal cast

Energy Technology Data Exchange (ETDEWEB)

Thieme, Sven F.; Helck, Andreas D.; Reiser, Maximilian F.; Johnson, Thorsten R.C. [Ludwig Maximilians University Hospital Munich, Institute for Clinical Radiology, Munich (Germany); Moeller, Winfried; Eickelberg, Oliver [Institute for Lung Biology and Disease (iLBD) and Comprehensive Pneumology Center (CPC), Helmholtz Zentrum Muenchen, Neuherberg, Munich (Germany); Becker, Sven [Ludwig-Maximilians-Universitaet, Department of Otorhinolaryngology - Head and Neck Surgery, Munich (Germany); Schuschnig, Uwe [Pari Pharma GmbH, Graefelfing (Germany)

2012-10-15

To show the feasibility of dual-energy CT (DECT) and dynamic CT for ventilation imaging of the paranasal sinuses in a nasal cast. In a first trial, xenon gas was administered to a nasal cast with a laminar flow of 7 L/min. Dynamic CT acquisitions of the nasal cavity and the sinuses were performed. This procedure was repeated with pulsating xenon flow. Local xenon concentrations in the different compartments of the model were determined on the basis of the enhancement levels. In a second trial, DECT measurements were performed both during laminar and pulsating xenon administration and the xenon concentrations were quantified directly. Neither with dynamic CT nor DECT could xenon-related enhancement be detected in the sinuses during laminar airflow. Using pulsating flow, dynamic imaging showed a xenon wash-in and wash-out in the sinuses that followed a mono-exponential function with time constants of a few seconds. Accordingly, DECT revealed xenon enhancement in the sinuses only after pulsating xenon administration. The feasibility of xenon-enhanced DECT for ventilation imaging was proven in a nasal cast. The superiority of pulsating gas flow for the administration of gas or aerosolised drugs to the paranasal sinuses was demonstrated. (orig.)

Xenon-ion-induced and thermal mixing of Co/Si bilayers and their interplay

Science.gov (United States)

Novaković, M.; Zhang, K.; Popović, M.; Bibić, N.; Hofsäss, H.; Lieb, K. P.

2011-05-01

Studies on ion-irradiated transition-metal/silicon bilayers demonstrate that interface mixing and silicide phase formation depend sensitively on the ion and film parameters, including the structure of the metal/Si interface. Thin Co layers e-gun evaporated to a thickness of 50 nm on Si(1 0 0) wafers were bombarded at room temperature with 400-keV Xe + ions at fluences of up to 3 × 10 16 cm -2. We used either crystalline or pre-amorphized Si wafers the latter ones prepared by 1.0-keV Ar-ion implantation. The as-deposited or Xe-ion-irradiated samples were then isochronally annealed at temperatures up to 700 °C. Changes of the bilayer structures induced by ion irradiation and/or annealing were investigated with RBS, XRD and HRTEM. The mixing rate for the Co/c-Si couples, Δ σ2/ Φ = 3.0(4) nm 4, is higher than the value expected for ballistic mixing and about half the value typical for spike mixing. Mixing of pre-amorphized Si is much weaker relative to crystalline Si wafers, contrary to previous results obtained for Fe/Si bilayers. Annealing of irradiated samples produces very similar interdiffusion and phase formation patterns above 400 °C as in the non-irradiated Co/Si bilayers: the phase evolution follows the sequence Co 2Si → CoSi → CoSi 2.

Xenon-ion-induced and thermal mixing of Co/Si bilayers and their interplay

International Nuclear Information System (INIS)

Novakovic, M.; Zhang, K.; Popovic, M.; Bibic, N.; Hofsaess, H.; Lieb, K.P.

2011-01-01

Studies on ion-irradiated transition-metal/silicon bilayers demonstrate that interface mixing and silicide phase formation depend sensitively on the ion and film parameters, including the structure of the metal/Si interface. Thin Co layers e-gun evaporated to a thickness of 50 nm on Si(1 0 0) wafers were bombarded at room temperature with 400-keV Xe + ions at fluences of up to 3 x 10 16 cm -2 . We used either crystalline or pre-amorphized Si wafers the latter ones prepared by 1.0-keV Ar-ion implantation. The as-deposited or Xe-ion-irradiated samples were then isochronally annealed at temperatures up to 700 o C. Changes of the bilayer structures induced by ion irradiation and/or annealing were investigated with RBS, XRD and HRTEM. The mixing rate for the Co/c-Si couples, Δσ 2 /Φ = 3.0(4) nm 4 , is higher than the value expected for ballistic mixing and about half the value typical for spike mixing. Mixing of pre-amorphized Si is much weaker relative to crystalline Si wafers, contrary to previous results obtained for Fe/Si bilayers. Annealing of irradiated samples produces very similar interdiffusion and phase formation patterns above 400 o C as in the non-irradiated Co/Si bilayers: the phase evolution follows the sequence Co 2 Si → CoSi → CoSi 2 .

Modeling Xenon Tank Pressurization using One-Dimensional Thermodynamic and Heat Transfer Equations

Science.gov (United States)

Gilligan, Ryan P.; Tomsik, Thomas M.

2017-01-01

As a first step in understanding what ground support equipment (GSE) is required to provide external cooling during the loading of 5,000 kg of xenon into 4 aluminum lined composite overwrapped pressure vessels (COPVs), a modeling analysis was performed using Microsoft Excel. The goals of the analysis were to predict xenon temperature and pressure throughout loading at the launch facility, estimate the time required to load one tank, and to get an early estimate of what provisions for cooling xenon might be needed while the tanks are being filled. The model uses the governing thermodynamic and heat transfer equations to achieve these goals. Results indicate that a single tank can be loaded in about 15 hours with reasonable external coolant requirements. The model developed in this study was successfully validated against flight and test data. The first data set is from the Dawn mission which also utilizes solar electric propulsion with xenon propellant, and the second is test data from the rapid loading of a hydrogen cylindrical COPV. The main benefit of this type of model is that the governing physical equations using bulk fluid solid temperatures can provide a quick and accurate estimate of the state of the propellant throughout loading which is much cheaper in terms of computational time and licensing costs than a Computation Fluid Dynamics (CFD) analysis while capturing the majority of the thermodynamics and heat transfer.

Quantitative analysis of dynamic airway changes after methacholine and salbutamol inhalation on xenon-enhanced chest CT

Energy Technology Data Exchange (ETDEWEB)

Park, Sang Joon; Goo, Jin Mo; Kim, Jong Hyo; Park, Eun-Ah [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Radiation Medicine, Medical Research Center, Seoul (Korea, Republic of); Lee, Chang Hyun [Seoul National University College of Medicine, Department of Radiology, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Radiation Medicine, Medical Research Center, Seoul (Korea, Republic of); Seoul National University Hospital, Healthcare Gangnam Center, Seoul (Korea, Republic of); Jung, Jae-Woo; Park, Heung-Woo [Seoul National University College of Medicine, Department of Internal Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Allergy and Clinical Immunology, Seoul (Korea, Republic of); Cho, Sang-Heon [Seoul National University Hospital, Healthcare Gangnam Center, Seoul (Korea, Republic of); Seoul National University College of Medicine, Department of Internal Medicine, Seoul (Korea, Republic of); Seoul National University College of Medicine, Institute of Allergy and Clinical Immunology, Seoul (Korea, Republic of)

2012-11-15

To investigate the dynamic changes in airways in response to methacholine and salbutamol inhalation and to correlate the xenon ventilation index on xenon-enhanced chest CTs in asthmatics. Thirty-one non-smokers (6 normal, 25 asthmatics) underwent xenon-enhanced chest CT and pulmonary function tests. Images were obtained at three stages (basal state, after methacholine inhalation and after salbutamol inhalation), and the total xenon ventilation index (TXVI) as well as airway values were measured and calculated. The repeated measures ANOVA and Spearman's correlation coefficient were used for statistical analysis. TXVI in the normal group did not significantly change (P > 0.05) with methacholine and salbutamol. For asthmatics, however, the TXVI significantly decreased after methacholine inhalation and increased after salbutamol inhalation (P < 0.05). Of the airway parameters, the airway inner area (IA) significantly increased after salbutamol inhalation in all airways (P < 0.01) in asthmatics. Airway IA, wall thickness and wall area percentage did not significantly decrease after methacholine inhalation (P > 0.05). IA of the large airways was well correlated with basal TXVI, FEV{sub 1} and FVC (P < 0.05). Airway IA is the most reliable parameter for reflecting the dynamic changes after methacholine and salbutamol inhalation, and correlates well with TXVI in asthmatics on xenon-enhanced CT. (orig.)

Reflectance measurements of PTFE, Kapton, and PEEK for xenon scintillation light for the LZ detector.

Science.gov (United States)

Arthurs, M.; Batista, E.; Haefner, J.; Lorenzon, W.; Morton, D.; Neff, A.; Okunawo, M.; Pushkin, K.; Sander, A.; Stephenson, S.; Wang, Y.; LZ Collaboration

2017-01-01

LZ (LUX-Zeplin) is an international collaboration that will look for dark matter candidates, WIMPs (Weakly Interacting Massive Particles), through direct detection by dual-phase time projection chamber (TPC) using liquid xenon. The LZ detector will be located nearly a mile underground at SURF, South Dakota, shielded from cosmic background radiation. Seven tons active mass of liquid xenon will be used for detecting the weak interaction of WIMPs with ordinary matter. Over three years of operation it is expected to reach the ultimate sensitivity of 2x10-48 cm2 for a WIMP mass of 50 GeV. As for many other rare event searches, high light collection efficiency is essential for LZ detector. Moreover, in order to achieve greater active volume for detection as well as reduce potential backgrounds, thinner detector walls without significant loss in reflectance are desired. Reflectance measurements of polytetrafluoroethylene (PTFE), Kapton, and PEEK for xenon scintillation light (178 nm), conducted at the University of Michigan using the Michigan Xenon Detector (MiX) will be presented. The University of Michigan, LZ Collaboration, The US Department of Energy.

Build up of Radioactive Krypton and Xenon Analysis System

International Nuclear Information System (INIS)

Lee, D. K.; Choi, C. S.; Chung, K. H.; Lee, W.; Cho, Y. H.; Lee, C. W.

2008-03-01

The objective of this project is to build up an analysis system to measure the activity of the atmospheric radioactive krypton and xenon in Korea. The work scopes of the project include the purchase and the installation of the analysis system to measure the activity of the radioactive krypton and xenon in air, and the establishment of the operation capability of the system through the training of the operator. The system consists of two air sampling systems, and one radioactivity analysis system, which incorporates the enrichment system, the gas chromatography to purify a mixture gas, and the gas proportional counter to count the activity of pure krypton and xenon gas. As planned originally, the establishment of the analysis system has been completed. At present, one air sampler is successfully being operated at a specific site of the South Korea to measure the background radioactivities of Kr-85 and Xe-133 in air. The other air sampler is being reserved at the KAERI in the Daejeon for a emergency like the second nuclear test of the North Korea. During the normal time, the reserved air sampler will be used to collect the air sample for the performance test of the analysis system and the cross analysis for the calibration of the system. The radioactivity analysis system has been installed at the KAERI, and is being used to measure the activity of Kr-85 and Xe-133 in the air sample from a domestic site

Two-photon resonant, stimulated processes in krypton and xenon

International Nuclear Information System (INIS)

Miller, J.C.

1988-11-01

Both on-axis and conical emissions have been observed following two-photon pumping of the 5p states of krypton and the 6p', 7p, 8p, and 4f states of xenon. In the former case, coherent emissions from the 5p states to the 5s are observed, and in the latter case, many p→s, d→p, and f→d cascade emissions are observed. By analogy to the well-studied alkali and alkaline earth examples, the emissions are discussed in terms of amplified spontaneous emission (ASE), stimulated hyper-Raman scattering, and parametric four-wave mixing. The physical processes responsible for the conical emission and for intensity anomalies in the xenon p→s emissions are not understood at present. Interference effects due to coherent cancellation between competing excitation pathways may be occurring. 4 refs., 3 figs

Search for magnetic inelastic dark matter with XENON100

Energy Technology Data Exchange (ETDEWEB)

Aprile, E.; Anthony, M. [Physics Department, Columbia University, New York, NY 10027 (United States); Aalbers, J.; Breur, P.A.; Brown, A. [Nikhef and the University of Amsterdam, Science Park, 1098XG Amsterdam (Netherlands); Agostini, F.; Bruno, G. [INFN-Laboratori Nazionali del Gran Sasso and Gran Sasso Science Institute, 67100 L' Aquila (Italy); Alfonsi, M. [Institut für Physik and Exzellenzcluster PRISMA, Johannes Gutenberg-Universität Mainz, 55099 Mainz (Germany); Amaro, F.D. [LIBPhys, Department of Physics, University of Coimbra, 3004-516 Coimbra (Portugal); Arneodo, F.; Benabderrahmane, M.L. [New York University Abu Dhabi, Abu Dhabi (United Arab Emirates); Barrow, P.; Baudis, L. [Physik-Institut, University of Zurich, 8057 Zurich (Switzerland); Bauermeister, B.; Calvén, J. [Oskar Klein Centre, Department of Physics, Stockholm University, AlbaNova, Stockholm SE-10691 (Sweden); Berger, T.; Brown, E. [Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180 (United States); Bruenner, S. [Max-Planck-Institut für Kernphysik, 69117 Heidelberg (Germany); Budnik, R. [Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 7610001 (Israel); Bütikofer, L., E-mail: lukas.buetikofer@lhep.unibe.ch, E-mail: xenon@lngs.infn.it [Physikalisches Institut, Universität Freiburg, 79104 Freiburg (Germany); and others

2017-10-01

We present the first search for dark matter-induced delayed coincidence signals in a dual-phase xenon time projection chamber, using the 224.6 live days of the XENON100 science run II. This very distinct signature is predicted in the framework of magnetic inelastic dark matter which has been proposed to reconcile the modulation signal reported by the DAMA/LIBRA collaboration with the null results from other direct detection experiments. No candidate event has been found in the region of interest and upper limits on the WIMP's magnetic dipole moment are derived. The scenarios proposed to explain the DAMA/LIBRA modulation signal by magnetic inelastic dark matter interactions of WIMPs with masses of 58.0 GeV/c{sup 2} and 122.7 GeV/c{sup 2} are excluded at 3.3 σ and 9.3 σ, respectively.

Dark matter sensitivity of multi-ton liquid xenon detectors

International Nuclear Information System (INIS)

Schumann, Marc; Bütikofer, Lukas; Baudis, Laura; Kish, Alexander; Selvi, Marco

2015-01-01

We study the sensitivity of multi ton-scale time projection chambers using a liquid xenon target, e.g., the proposed DARWIN instrument, to spin-independent and spin-dependent WIMP-nucleon scattering interactions. Taking into account realistic backgrounds from the detector itself as well as from neutrinos, we examine the impact of exposure, energy threshold, background rejection efficiency and energy resolution on the dark matter sensitivity. With an exposure of 200 t × y and assuming detector parameters which have been already demonstrated experimentally, spin-independent cross sections as low as 2.5 × 10 −49 cm 2 can be probed for WIMP masses around 40 GeV/c 2 . Additional improvements in terms of background rejection and exposure will further increase the sensitivity, while the ultimate WIMP science reach will be limited by neutrinos scattering coherently off the xenon nuclei

Xenon-ion-induced and thermal mixing of Co/Si bilayers and their interplay

Energy Technology Data Exchange (ETDEWEB)

Novakovic, M. [VINCA Institute of Nuclear Sciences, 11001 Belgrade (Serbia); II. Physikalisches Institut, Georg-August-Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Zhang, K. [II. Physikalisches Institut, Georg-August-Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Popovic, M.; Bibic, N. [VINCA Institute of Nuclear Sciences, 11001 Belgrade (Serbia); II. Physikalisches Institut, Georg-August-Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Hofsaess, H. [II. Physikalisches Institut, Georg-August-Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Lieb, K.P., E-mail: plieb@gwdg.d [II. Physikalisches Institut, Georg-August-Universitaet Goettingen, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany)

2011-05-01

Studies on ion-irradiated transition-metal/silicon bilayers demonstrate that interface mixing and silicide phase formation depend sensitively on the ion and film parameters, including the structure of the metal/Si interface. Thin Co layers e-gun evaporated to a thickness of 50 nm on Si(1 0 0) wafers were bombarded at room temperature with 400-keV Xe{sup +} ions at fluences of up to 3 x 10{sup 16} cm{sup -2}. We used either crystalline or pre-amorphized Si wafers the latter ones prepared by 1.0-keV Ar-ion implantation. The as-deposited or Xe-ion-irradiated samples were then isochronally annealed at temperatures up to 700 {sup o}C. Changes of the bilayer structures induced by ion irradiation and/or annealing were investigated with RBS, XRD and HRTEM. The mixing rate for the Co/c-Si couples, {Delta}{sigma}{sup 2}/{Phi} = 3.0(4) nm{sup 4}, is higher than the value expected for ballistic mixing and about half the value typical for spike mixing. Mixing of pre-amorphized Si is much weaker relative to crystalline Si wafers, contrary to previous results obtained for Fe/Si bilayers. Annealing of irradiated samples produces very similar interdiffusion and phase formation patterns above 400 {sup o}C as in the non-irradiated Co/Si bilayers: the phase evolution follows the sequence Co{sub 2}Si {yields} CoSi {yields} CoSi{sub 2}.

Study of emission of a volume nanosecond discharge plasma in xenon, krypton and argon at high pressures

International Nuclear Information System (INIS)

Baksht, E Kh; Lomaev, Mikhail I; Rybka, D V; Tarasenko, Viktor F

2006-01-01

The emission properties of a volume nanosecond discharge plasma produced in xenon, krypton and argon at high pressures in a discharge gap with a cathode having a small radius of curvature are studied. Spectra in the range 120-850 nm and amplitude-time characteristics of xenon emission at different regimes and excitation techniques are recorded and analysed. It is shown that upon excitation of the volume discharge initiated by a beam of avalanche electrons, at least 90% of the energy in the spectral range 120-850 nm is emitted by xenon dimers. For xenon at a pressure of 1.2 atm, ∼45 mJ of the spontaneous emission energy was obtained in the full solid angle in a pulse with the full width at half-maximum ∼130 ns. (laser applications and other topics in quantum electronics)

Collateral Ventilation to Congenital Hyperlucent Lung Lesions Assessed on Xenon-Enhanced Dynamic Dual-Energy CT: an Initial Experience

OpenAIRE

Goo, Hyun Woo; Yang, Dong Hyun; Kim, Namkug; Park, Seung Il; Kim, Dong Kwan; Kim, Ellen Ai-Rhan

2011-01-01

Objective We wanted to evaluate the resistance to collateral ventilation in congenital hyperlucent lung lesions and to correlate that with the anatomic findings on xenon-enhanced dynamic dual-energy CT. Materials and Methods Xenon-enhanced dynamic dual-energy CT was successfully and safely performed in eight children (median age: 5.5 years, 4 boys and 4 girls) with congenital hyperlucent lung lesions. Functional assessment of the lung lesions on the xenon map was done, including performing a ...

900-L liquid xenon cryogenic system operation for the MEG experiment

CERN Document Server

Haruyama, T; Mihara, S; Hisamatsu, Y; Iawamoto, W; Mori, T; Nishiguchi, H; Otani, W; Sawada, R; Uchiyama, Y; Nishitani, T

2009-01-01

A cryogenic system for the MEG (muon rare decay) experiment has started operation at the Paul Sherrer Institute in Zurich. The main part of the MEG detector is the 900-L liquid xenon calorimeter for gamma ray detection, equipped with 850 photo multipliers directly immersed in liquid xenon. A 200 W pulse tube cryocooler enabled LN2-free operation of this calorimeter. A liquid purification system; using a liquid pump and a zero boil-off 1000-L cryogenic buffer dewar is also included in the system. The first entire engineering run was carried out in November-December 2007 and satisfactory cryogenic performances were confirmed.

Analysis method for beta-gamma coincidence spectra from radio-xenon isotopes

International Nuclear Information System (INIS)

Yang Wenjing; Yin Jingpeng; Huang Xiongliang; Cheng Zhiwei; Shen Maoquan; Zhang Yang

2012-01-01

Radio-xenon isotopes monitoring is one important method for the verification of CTBT, what includes the measurement methods of HPGe γ spectrometer and β-γ coincidence. The article describes the analytic flowchart and method of three-dimensional beta-gamma coincidence spectra from β-γ systems, and analyses in detail the principles and methods of the regions of interest of coincidence spectra and subtracting the interference, finally gives the formula of radioactivity of Xenon isotopes and minimum detectable concentrations. Studying on the principles of three-dimensional beta-gamma coincidence spectra, which can supply the foundation for designing the software of β-γ coincidence systems. (authors)

Crystallographic studies with xenon and nitrous oxide provide evidence for protein-dependent processes in the mechanisms of general anesthesia.

Science.gov (United States)

Abraini, Jacques H; Marassio, Guillaume; David, Helene N; Vallone, Beatrice; Prangé, Thierry; Colloc'h, Nathalie

2014-11-01

The mechanisms by which general anesthetics, including xenon and nitrous oxide, act are only beginning to be discovered. However, structural approaches revealed weak but specific protein-gas interactions. To improve knowledge, we performed x-ray crystallography studies under xenon and nitrous oxide pressure in a series of 10 binding sites within four proteins. Whatever the pressure, we show (1) hydrophobicity of the gas binding sites has a screening effect on xenon and nitrous oxide binding, with a threshold value of 83% beyond which and below which xenon and nitrous oxide, respectively, binds to their sites preferentially compared to each other; (2) xenon and nitrous oxide occupancies are significantly correlated respectively to the product and the ratio of hydrophobicity by volume, indicating that hydrophobicity and volume are binding parameters that complement and oppose each other's effects; and (3) the ratio of occupancy of xenon to nitrous oxide is significantly correlated to hydrophobicity of their binding sites. These data demonstrate that xenon and nitrous oxide obey different binding mechanisms, a finding that argues against all unitary hypotheses of narcosis and anesthesia, and indicate that the Meyer-Overton rule of a high correlation between anesthetic potency and solubility in lipids of general anesthetics is often overinterpreted. This study provides evidence that the mechanisms of gas binding to proteins and therefore of general anesthesia should be considered as the result of a fully reversible interaction between a drug ligand and a receptor as this occurs in classical pharmacology.

Study of the short-lived fission products. Separation of iodine and xenon fission radionuclides; Estudio de los productos de fision de periodo corto. Separacion de los radionuclidos de fision del yodo y del xenon

Energy Technology Data Exchange (ETDEWEB)

Barrachina, M; Villar, M A

1965-07-01

The separation by distillation in a sulfuric acid or phosphoric acid-hydrogen peroxide medium of the iodine isotopes (8 day iodine-131, 2,3 hour iodine-132 21 hour iodine-133, 53 minute iodine-134 and 6,7 hour iodine-135) present in a uranium sample after different irradiation and cooling times is here described. It is also reported the use of active charcoal columns for the retention of xenon isotopes (5,27 days xenon-133 and 9,2 hours xenon-135) either released during the dissolution of the uranium irradiated samples or generated along the fission isobaric chains in the solutions of distillated iodine. In both cases the radiochemical purity of the separated products is established by gamma spectrometry. (Author) 15 refs.

Modal analysis of temperature feedback in oscillations induced by xenon

International Nuclear Information System (INIS)

Passos, E.M. dos.

1976-01-01

The flux oscillations induced by Xenon distribution in homogeneous thermal reactors are studied treating the space dependence through the modal expansion technique and the stability limits against power oscillations and spatial oscillations are determined. The effect of the feedbacks due to Xenon and temperature coefficient on the linear stability of the free system is investigated employing several number of terms in the transient expansion, considering the various sizes of the reactor. The heat transfer model considered includes one term due to cooling proportional to the temperature. A PWR model reactor is utilized for numerical calculations. It is found that a slightly higher temperature feedback coefficient is necessary for stability against power oscillations when larger number of terms in the transient modal expansion is maintained. (author)

Imaging local cerebral blood flow by xenon-enhanced computed tomography - technical optimization procedures

Energy Technology Data Exchange (ETDEWEB)

Meyer, J.S.; Shinohara, T.; Imai, A.; Kobari, M.; Sakai, F.; Hata, T.; Oravez, W.T.; Timpe, G.M.; Deville, T.; Solomon, E.

1988-08-01

Methods are described for non-invasive, computer-assisted serial scanning throughout the human brain during eight minutes of inhalation of 27%-30% xenon gas in order to measure local cerebral blood flow (LCBF). Optimized xenon-enhanced computed tomography (XeCT) was achieved by 5-second scanning at one-minute intervals utilizing a state-of-the-art CT scanner and rapid delivery of xenon gas via a face mask. Values for local brain-blood partition coefficients (Llambda) measured in vivo were utilized to calculate LCBF values. Previous methods assumed Llambda values to be normal, introducing the risk of systematic errors, because Llambda values differ throughout normal brain and may be altered by disease. Color-coded maps of Llambda and LCBF values were formatted directly onto CT images for exact correlation of function with anatomic and pathologic observations (spatial resolution: 26.5 cubic mm). Results were compared among eight normal volunteers, aged between 50 and 88 years. Mean cortical gray matter blood flow was 46.3 +- 7.7, for subcortical gray matter it was 50.3 +- 13.2 and for white matter it was 18.8 +- 3.2. Modern CT scanners provide stability, improved signal to noise ratio and minimal radiation scatter. Combining these advantages with rapid xenon saturation of the blood provides correlations of Llambda and LCBF with images of normal and abnormal brain in a safe, useful and non-invasive manner.

Time-resolved X-ray absorption spectroscopy for laser-ablated silicon particles in xenon gas

International Nuclear Information System (INIS)

Makimura, Tetsuya; Sakuramoto, Tamaki; Murakami, Kouichi

1996-01-01

We developed a laboratory-scale in situ apparatus for soft X-ray absorption spectroscopy with a time resolution of 10 ns and a space resolution of 100 μm. Utilizing this spectrometer, we have investigated the dynamics of silicon atoms formed by laser ablation in xenon gas. It was found that 4d-electrons in the xenon atoms are excited through collision with electrons in the laser-generated silicon plasma. (author)

Development of industrial ion implantation technology

International Nuclear Information System (INIS)

Choi, Byung Hoh; Jung, Kee Suk; Kim, Wan; Song, Woo Sub; Hwang, Chul Kyoo

1994-02-01

We developed an ion implanter fitted for the treatment of 12 inch or larger wafers to make 256 or higher Mega D-Ram wafers. Design features are dual usage of gas/solid for the ion source loading, production of multi-balanced ions, and the possible oxygen ion implantation. BOSII program was used for the ion optics calculation. Beams are triangularly scanned to wafers for the even implantation by a proper magnetic field application. More than 10 mA ion current is produced. For the efficient implantation to be made, target is made to rotate with tilted angle at a displaced axis. High speed tools, diamond tools, precision dies, and razor blades were implanted and the performance was evaluated after two or three times of line application. Of those materials studied, PCB drills and end mills are on the commercial treatment stages. Industrial materials as SKD-11, WC-Co, NAK-55 was compositely treated with ion beam and coating. Resultant properties were analyzed using AES, XRD, and TEM. For the case of xenon ions, excellent TiN coating resulted and its application to microcircuit lead frame increased the performance to more than 30 percent. 94 figs, 29 pix, 19 tabs, 50 refs. (Author)

Development of industrial ion implantation technology

Energy Technology Data Exchange (ETDEWEB)

Choi, Byung Hoh; Jung, Kee Suk; Kim, Wan; Song, Woo Sub; Hwang, Chul Kyoo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-02-01

We developed an ion implanter fitted for the treatment of 12 inch or larger wafers to make 256 or higher Mega D-Ram wafers. Design features are dual usage of gas/solid for the ion source loading, production of multi-balanced ions, and the possible oxygen ion implantation. BOSII program was used for the ion optics calculation. Beams are triangularly scanned to wafers for the even implantation by a proper magnetic field application. More than 10 mA ion current is produced. For the efficient implantation to be made, target is made to rotate with tilted angle at a displaced axis. High speed tools, diamond tools, precision dies, and razor blades were implanted and the performance was evaluated after two or three times of line application. Of those materials studied, PCB drills and end mills are on the commercial treatment stages. Industrial materials as SKD-11, WC-Co, NAK-55 was compositely treated with ion beam and coating. Resultant properties were analyzed using AES, XRD, and TEM. For the case of xenon ions, excellent TiN coating resulted and its application to microcircuit lead frame increased the performance to more than 30 percent. 94 figs, 29 pix, 19 tabs, 50 refs. (Author).

Partial-wave analysis for positronium-xenon collisions in the ultralow-energy region

Science.gov (United States)

Shibuya, Kengo; Saito, Haruo

2018-05-01

We propose a method to convert measured positronium annihilation rates in gaseous xenon into total and differential cross sections of positronium-xenon collisions in an ultralow-energy region of less than 80 meV where their experimental determinations as functions of the positronium kinetic energy are extremely difficult. This method makes it possible to determine not only the s -wave collisional parameters but also the p -wave and d -wave parameters. We have found a small positive value of the scattering length, A0=2.06 ±0.10 a0 , which indicates that the positronium-xenon interaction in this energy region is repulsive and suggests that it is dominated by the scattering amplitude of the positron rather than that of the electron. An extrapolation of the analytical result into the experimentally inaccessible energy regions from 80 meV to 1.0 eV indicates that there should not be a Ramsauer-Townsend minimum but rather a peak in the total cross section at an energy of approximately 0.4 eV.

Ion-Collision Emission Excitation Cross Sections for Xenon Electric Thruster Plasmas

National Research Council Canada - National Science Library

Sommerville, Jason D; King, Lyon B; Chiu, Yu-Hui; Dressler, Rainer A

2008-01-01

.... The cross sections are derived from ion beam luminescence spectra produced at single-collision conditions and at pressures for which radiation trapping effects were shown to be negligible. The Xe(exp...

Giant resonance phenomena in the electron impact ionization of heavy atoms and ions

International Nuclear Information System (INIS)

Younger, S.M.

1986-01-01

Heavy atoms and ions offer an interesting opportunity to study atomic physics in a region where the atomic structure is dominated by the interelectronic interactions. One illustration of this is the profound term dependence of atomic orbitals for certain configurations of heavy atoms and ions. The appearance of giant scattering resonances in the cross sections for ionization of heavy atoms by electron impact is a manifestation of resonance behavior. Such resonant structures arise from the double well nature of the scattering potential and have recently been identified in the cross sections for the electron impact ionization of several xenon-like ions. The results of calculations showing effects for a variety of other ions are summarized. 7 refs., 4 figs

Investigation of gas discharge ion sources for on-line mass separation

International Nuclear Information System (INIS)

Kirchner, R.

1976-03-01

The development of efficient gas discharge ion sources with axial beam extraction for on-line mass separation is described. The aim of the investigation was to increase the ion source temperature, the lifetime and the ionisation yield in comparison to present low-pressure are discharge ion sources and to reduce the ion current density from usually 1 to 100 mA/cm 3 . In all ion sources the pressure range below the minimal ignition pressure of the arc discharge was investigated. As a result an ion source was developed which works at small changes in geometry and in electric device of a Nielsen source with high ionization yield (up to 50% for xenon) stabil and without ignition difficulties up to 10 -5 Torr. At a typical pressure of 3 x 10 -5 Torr ion current and ion current density are about 1 μA and 0.1 mA/cm 3 respectively besides high yield and a great emission aperture (diameter 1.2 mm). (orig.) [de

The behavior of xenon dynamic adsorption on granular activated carbon packed bed adsorber

International Nuclear Information System (INIS)

Chongyang Zhou; Shujuan Feng; Guoqing Zhou; Yuren Jin; Junfu Liang; Jingming Xu

2011-01-01

In order to retard radioxenon release into the atmosphere from nuclear power station or to sensitively monitor its concentration to ensure environmental and human safety, it is necessary to know the behavior of xenon dynamic adsorption on granular activated carbon pack bed adsorber. The quantities, including the dynamic adsorption coefficient (k d ), the amount of xenon adsorbed (q), the length of mass transfer zone (L MTZ ) and the length of the unused bed (LUB), used to describe the adsorption behavior, were sorted out and calculated. The factors, including xenon concentrations, pressures and temperatures, to affect these quantities were investigated. The results show that: (1) The values of k d and q decrease with increasing temperatures, but increase with increasing pressures, (2) The values of L MTZ and LUB increase with increasing temperatures or pressures, but are independent of concentrations. Knowledge of these quantities is very helpful for packed bed adsorber operation. (author)

Probe of Multielectron Dynamics in Xenon by Caustics in High-Order Harmonic Generation

Science.gov (United States)

Faccialà, D.; Pabst, S.; Bruner, B. D.; Ciriolo, A. G.; De Silvestri, S.; Devetta, M.; Negro, M.; Soifer, H.; Stagira, S.; Dudovich, N.; Vozzi, C.

2016-08-01

We investigated the giant resonance in xenon by high-order harmonic generation spectroscopy driven by a two-color field. The addition of a nonperturbative second harmonic component parallel to the driving field breaks the symmetry between neighboring subcycles resulting in the appearance of spectral caustics at two distinct cutoff energies. By controlling the phase delay between the two color components it is possible to tailor the harmonic emission in order to amplify and isolate the spectral feature of interest. In this Letter we demonstrate how this control scheme can be used to investigate the role of electron correlations that give birth to the giant resonance in xenon. The collective excitations of the giant dipole resonance in xenon combined with the spectral manipulation associated with the two-color driving field allow us to see features that are normally not accessible and to obtain a good agreement between the experimental results and the theoretical predictions.

Cerebral blood flow mapping using stable xenon-enhanced CT in sickle cell cerebrovascular disease

International Nuclear Information System (INIS)

Numaguchi, Y.; Robinson, A.E.; Carey, J.E.

1990-01-01

The cerebral blood flow (CBF) of 25 patients with sickle cell cerebrovascular disease (SCCVD) was examined using a xenon-CT flow mapping method. Brain CT and MR findings were correlated with those of the xenon-CT flow studies. CBF defects on xenon-CT correlated reasonably well with the areas of cortical infarctions on the MR images, but in 27% of the cases, flow defects were slightly larger than the areas of infarctions on the MR images. In deep watershed or basal ganglia infarctions, abnormal CBF was noted about the cerebral cortex near infarctions in 72% of the patients, regardless of infarction sizes on the MR images. However, decreased CBF was recognized in 4 of the 9 children whose MR images were virtually normal. Thus, the extent of flow depletion cannot be predicted accurately by MR imaging alone. Xenon-CT flow mapping proved a safe and reliable procedure for evaluation of the CBF of patients with SCCVD. Although this study is preliminary, it may have a potential in selecting patients for hypertransfusion therapy, as a noninvasive test and for following children with SCCVD during their therapy. Careful correlation of results of CBF with those of MR imaging or of CT is important for objective interpretations of flow mapping images. (orig.)

1.2 MeV/amu Xe ion induced damage recovery in SiC

International Nuclear Information System (INIS)

O’Connell, J.H.; Skuratov, V.A.; Sohatsky, A.S.; Neethling, J.H.

2014-01-01

The microstructural changes of 4H-SiC samples dual irradiated with either low energy He (10 keV) or Ti (220 keV) and high energy (167 MeV) Xe ions has been studied using cross-sectional transmission electron microscopy. It was found that xenon ions with fluences above 10 13 cm −2 restore crystallinity in a heavily damaged partially amorphous zone. No significant damage recovery was observed in fully amorphized layers of silicon carbide apart from a 5% reduction in the amorphous layer thickness

Charged particle identification with the liquid Xenon calorimeter of the CMD-3 detector

International Nuclear Information System (INIS)

Ivanov, V.L.; Fedotovich, G.V.; Anisenkov, A.V.; Grebenuk, A.A.; Mikhailov, K.Yu.; Kozyrev, A.A.; Shebalin, V.E.; Ruban, A.A.; Bashtovoy, N.S.

2017-01-01

This paper describes a procedure of particle identification with the liquid Xenon calorimeter of the CMD-3 detector currently being developed. The procedure uses the boosted decision tree classification method with specific energy losses of charged particles in the liquid Xenon calorimeter as input variables. The efficiency of the procedure is illustrated by an example of the measurement of the cross section of the process e + e − → K + K − in the center-of-mass energy range from 1.8 to 2.0 GeV.

Cryogenic readout for multiple VUV4 Multi-Pixel Photon Counters in liquid xenon

Science.gov (United States)

Di Giovanni, A.

2018-03-01

This work concerned the preliminary tests and characterization of a cryogenic preamplifier board for an array made of 16 S13370-3050CN (VUV4 family) Multi-Pixel Photon Counters manufactured by Hamamatsu and operated at liquid xenon temperature. The proposed prototype is based on the use of the Analog Devices AD8011 current feedback operational amplifier. The detector allows for single photon detection, making this device a promising choice for the future generation of neutrino and dark matter detectors based on liquid xenon targets.

Local regulation of blood flow evaluated simultaneously by 133-xenon washout and laser Doppler flowmetry

International Nuclear Information System (INIS)

Engelhart, M.; Petersen, L.J.; Kristensen, J.K.

1988-01-01

The laser Doppler flowmeter and the 133-Xenon washout techniques of measuring cutaneous blood flow were compared for measuring the vasoconstrictor response of the hand during orthostatic maneuvres. Important discrepancies were detected for the two methods. When the hand was lowered by 40 cm a 40% decrease in blood flow was detected by the 133-Xenon method, while a 60% decrease was seen by the laser Doppler technique. Lowering the hand by 50 cm resulted in no further blood flow decrease when using the 133-Xenon method, but an 80% blood flow decrease was recorded with the laser Doppler method. A marked decrease in blood flow was recorded by the laser Doppler technique in hands that were sympathectomized or a hand that was subjected to a nerve blockade, strategies which should eliminate the orthostatic vasoconstrictor response of superficial cutaneous vessels. The 133-Xenon technique did not detect any blood flow changes in hands without sympathetic tone. We found the laser Doppler flowmetry technique unsatisfactory for measurement of blood flow changes that occur in nutritional vessels as this method measures total skin blood flow including non-capillary vessels

Ion source for ion beam deposition employing a novel electrode assembly

Science.gov (United States)

Hayes, A. V.; Kanarov, V.; Yevtukhov, R.; Hegde, H.; Druz, B.; Yakovlevitch, D.; Cheesman, W.; Mirkov, V.

2000-02-01

A rf inductively coupled ion source employing a novel electrode assembly for focusing a broad ion beam on a relatively small target area was developed. The primary application of this ion source is the deposition of thin films used in the fabrication of magnetic sensors and optical devices. The ion optics consists of a three-electrode set of multiaperture concave dished grids with a beam extraction diameter of 150 mm. Also described is a variation in the design providing a beam extraction diameter of 120 mm. Grid hole diameters and grid spacing were optimized for low beamlet divergence and low grid impingement currents. The radius of curvature of the grids was optimized to obtain an optimally focused ion beam at the target location. A novel grid fabrication and mounting design was employed which overcomes typical limitations of such grid assemblies, particularly in terms of maintaining optimum beam focusing conditions after multiple cycles of operation. Ion beam generation with argon and xenon gases in energy ranges from 0.3 to 2.0 keV was characterized. For operation with argon gas, beam currents greater than 0.5 A were obtained with a beam energy of 800 eV. At optimal beam formation conditions, beam profiles at distances about equal to the radius of curvature were found to be close to Gaussian, with 99.9% of the beam current located within a 150 mm target diameter. Repeatability of the beam profile over long periods of operation is also reported.

Heat capacity of xenon adsorbed in nanobundle grooves

International Nuclear Information System (INIS)

Chishko, K.A.; Sokolova, E.S.

2016-01-01

A model of one-dimensional real gas under external transverse force field is applied to interpret the experimentally observed thermodynamical properties of xenon deposited into groves on the surface of carbon nanobundles. This non-ideal gas model with pair interaction is not quite adequate to describe the dense adsorbates (especially at low temperature limit), but it makes possible to take into account easily the particle exchange between 1D adsorbate and 3D atmosphere which becomes an essential factor since intermediate (for xenon - of order 35 K) up to high (approx 100 K) temperatures. In this paper we treat the 1D real gas with only Lennard-Jones pair interaction, but at presence of exact equilibrium conditions on the atom numbers between low-dimensional adsorbate and three-dimensional atmosphere of the experimental cell. The low-temperature branch of the heat capacity has been fitted separately within the elastic atomic chain model to get the best agreement between theory and experiment in as wide as possible region just from zero temperature. The gas approximation is introduced from the temperatures where the chain heat capacity tends definitely to 1D equipartition law. In this case the principal parameters for both models can be chosen in such a way that the heat capacity C(T) of the chain goes continuously into the corresponding curve of the gas approximation. So, it seems to be expected that adequate interpretation for temperature dependences of the atomic adsorbate heat capacity can be obtained through a reasonable combination of 1D gas and phonon approaches. The principal parameters of the gas approximation (such a desorption energy) found from the fitting between theory and experiment for xenon heat capacity are in good agreement with corresponding data known in literature.

Sliding Mode Control for Pressurized-Water Nuclear Reactors in load following operations with bounded xenon oscillations

International Nuclear Information System (INIS)

Ansarifar, G.R.; Saadatzi, S.

2015-01-01

Highlights: • We present SMC which is a robust nonlinear controller to control the PWR power. • Xenon oscillations are kept bounded within acceptable limits. • The stability analysis has been based on Lyapunov approach. • Simulation results indicate the high performance of this new control. - Abstract: One of the important operations in nuclear power plants is load-following in which imbalance of axial power distribution induces xenon oscillations. These oscillations must be maintained within acceptable limits otherwise the nuclear power plant could become unstable. Therefore, bounded xenon oscillation considered to be a constraint for the load-following operation. In this paper, sliding mode control (SMC) which is a robust nonlinear controller is designed to control the Pressurized-Water Nuclear Reactor (PWR) power for the load-following operation problem that ensures xenon oscillations are kept bounded within acceptable limits. The proposed controller uses constant axial offset (AO) strategy to maintain xenon oscillations to be bounded. The constant AO is a robust state constraint for load-following problem. The reactor core is simulated based on the two-point nuclear reactor model and one delayed neutron group. The stability analysis is given by means Lyapunov approach, thus the control system is guaranteed to be stable within a large range. The employed method is easy to implement in practical applications and moreover, the sliding mode control exhibits the desired dynamic properties during the entire output-tracking process independent of perturbations. Simulation results are presented to demonstrate the effectiveness of the proposed controller in terms of performance, robustness and stability. Results show that the proposed controller for the load-following operation is sufficiently effective so that the xenon oscillations are kept bounded in the considered region

Pulse Rise Time Characterization of a High Pressure Xenon Gamma Detector for use in Resolution Enhancement

International Nuclear Information System (INIS)

TROYER, G.L.

2000-01-01

High pressure xenon ionization chamber detectors are possible alternatives to traditional thallium doped sodium iodide (NaI(Tl)) and hyperpure germanium as gamma spectrometers in certain applications. Xenon detectors incorporating a Frisch grid exhibit energy resolutions comparable to cadmium/zinc/telluride (CZT) (e.g. 2% (at) 662keV) but with far greater sensitive volumes. The Frisch grid reduces the position dependence of the anode pulse risetimes, but it also increases the detector vibration sensitivity, anode capacitance, voltage requirements and mechanical complexity. We have been investigating the possibility of eliminating the grid electrode in high-pressure xenon detectors and preserving the high energy resolution using electronic risetime compensation methods. A two-electrode cylindrical high pressure xenon gamma detector coupled to time-to-amplitude conversion electronics was used to characterize the pulse rise time of deposited gamma photons. Time discrimination was used to characterize the pulse rise time versus photo peak position and resolution. These data were collected to investigate the effect of pulse rise time compensation on resolution and efficiency

Xenon tissue/blood partition coefficient for pig urinary bladder

DEFF Research Database (Denmark)

Nielsen, K K; Bülow, J; Nielsen, S L

1990-01-01

In four landrace pigs the tissue/blood partition coefficient (lambda) for xenon (Xe) for the urinary bladder was calculated after chemical analysis for lipid, water and protein content and determination of the haematocrit. The coefficients varied from bladder to bladder owing to small differences...

气相色谱质谱联用法测定液氧中微量的氪和氙%Determination of trace krypton and xenon in liquid oxygen by Gas Chromatography/Mass Spectrometry

Institute of Scientific and Technical Information of China (English)

唐轩; 陈鹰; 吴建军

2013-01-01

Trace krypton and xenon was determined by gas chromatography/mass spectrometry with selection ion monitoring mode (SIM). The ions m/z=84 and m/z=132 were chosen as quantitative ion for krypton and xenon respectively. The results show that it is a simple way to implement, rapid detection and good selectivity. The linear relation between the peak area and concentration was excellent within the range of (1.0~100)×10-6 V/V. Meanwhile, the minimum detectable concentration and repeatability was also detected.%利用气相色谱质谱联用技术中的选择离子监测（SIM）方式对液氧中的微量氪气和氙气进行了测定。选择m/z为84的离子作为氪的定量离子、m/z为132的离子作为氙的定量离子。方法简单、快速、选择性好，在浓度为（1.0~100）×10-6 V/V范围内，峰面积与浓度有良好的线性关系。同时考察了方法的最低检测浓度和重复性。

Guiding of slow neon and molecular hydrogen ions through nanocapillaries in PET

International Nuclear Information System (INIS)

Stolterfoht, N.; Hellhammer, R.; Sobocinski, P.; Pesic, Z.D.; Bundesmann, J.; Sulik, B.; Shah, M.B.; Dunn, K.; Pedregosa, J.; McCullough, R.W.

2005-01-01

The transmission profiles of atomic 3keV Ne 7+ ions and molecular 1keV H 2 + and H 3 + ions passing through nanocapillaries were studied. Capillaries with a diameter of 100nm and a length of 10μm in insulating PET polymers were used. The high aspect ratio of 100 is achieved by the method of etching ion tracks produced by high-energy xenon impact. The angular distributions of the transmitted projectiles show that the majority of ions are transported in their initial charge state along the capillary axis even when the capillaries are tilted with respect to the incident beam direction. This result indicates ion-guiding, which is produced by charge-up effects influencing the ion trajectories in a self-supporting manner. The guiding effects are found to be different for highly charged neon and singly charged molecular hydrogen. Negligible fragmentation of the molecular ions was observed

Imaging local cerebral blood flow by xenon-enhanced computed tomography - technical optimization procedures

International Nuclear Information System (INIS)

Meyer, J.S.; Shinohara, T.; Imai, A.; Kobari, M.; Solomon, E.

1988-01-01

Methods are described for non-invasive, computer-assisted serial scanning throughout the human brain during eight minutes of inhalation of 27%-30% xenon gas in order to measure local cerebral blood flow (LCBF). Optimized xenon-enhanced computed tomography (XeCT) was achieved by 5-second scanning at one-minute intervals utilizing a state-of-the-art CT scanner and rapid delivery of xenon gas via a face mask. Values for local brain-blood partition coefficients (Lλ) measured in vivo were utilized to calculate LCBF values. Previous methods assumed Lλ values to be normal, introducing the risk of systematic errors, because Lλ values differ throughout normal brain and may be altered by disease. Color-coded maps of Lλ and LCBF values were formatted directly onto CT images for exact correlation of function with anatomic and pathologic observations (spatial resolution: 26.5 cubic mm). Results were compared among eight normal volunteers, aged between 50 and 88 years. Mean cortical gray matter blood flow was 46.3 ± 7.7, for subcortical gray matter it was 50.3 ± 13.2 and for white matter it was 18.8 ± 3.2. Modern CT scanners provide stability, improved signal to noise ratio and minimal radiation scatter. Combining these advantages with rapid xenon saturation of the blood provides correlations of Lλ and LCBF with images of normal and abnormal brain in a safe, useful and non-invasive manner. (orig.)

Modeling ARRM Xenon Tank Pressurization Using 1D Thermodynamic and Heat Transfer Equations

Science.gov (United States)

Gilligan, Patrick; Tomsik, Thomas

2016-01-01

As a first step in understanding what ground support equipment (GSE) is required to provide external cooling during the loading of 5,000 kg of xenon into 4 aluminum lined composite overwrapped pressure vessels (COPVs), a modeling analysis was performed using Microsoft Excel. The goals of the analysis were to predict xenon temperature and pressure throughout loading at the launch facility, estimate the time required to load one tank, and to get an early estimate of what provisions for cooling xenon might be needed while the tanks are being filled. The model uses the governing thermodynamic and heat transfer equations to achieve these goals. Results indicate that a single tank can be loaded in about 15 hours with reasonable external coolant requirements. The model developed in this study was successfully validated against flight and test data. The first data set is from the Dawn mission which also utilizes solar electric propulsion with xenon propellant, and the second is test data from the rapid loading of a hydrogen cylindrical COPV. The main benefit of this type of model is that the governing physical equations using bulk fluid solid temperatures can provide a quick and accurate estimate of the state of the propellant throughout loading which is much cheaper in terms of computational time and licensing costs than a Computation Fluid Dynamics (CFD) analysis while capturing the majority of the thermodynamics and heat transfer.

Optimal Control Strategy Search Using a Simplest 3-D PWR Xenon Oscillation Simulator

International Nuclear Information System (INIS)

Yoichiro, Shimazu

2004-01-01

Power spatial oscillations due to the transient xenon spatial distribution are well known as xenon oscillation in large PWRs. When the reactor size becomes larger than the current design, then even radial oscillations can be also divergent. Even if the radial oscillation is convergent, when some control rods malfunction occurs, it is necessary to suppress the oscillation in as short time as possible. In such cases, optimal control strategy is required. Generally speaking the optimality search based on the modern control theory requires a lot of calculation for the evaluation of state variables. In the case of control rod malfunctions the xenon oscillation could be three dimensional. In such case, direct core calculations would be inevitable. From this point of view a very simple model, only four point reactor model, has been developed and verified. In this paper, an example of a procedure and the results for optimal control strategy search are presented. It is shown that we have only one optimal strategy within a half cycle of the oscillation with fixed control strength. It is also shown that a 3-D xenon oscillation introduced by a control rod malfunction can not be controlled by only one control step as can be done for axial oscillations. They might be quite strong limitations to the operators. Thus it is recommended that a strategy generator, which is quick in analyzing and easy to use, might be installed in a monitoring system or operator guiding system. (author)

Nuclear spin-spin coupling in a van der Waals-bonded system: xenon dimer.

Science.gov (United States)

Vaara, Juha; Hanni, Matti; Jokisaari, Jukka

2013-03-14

Nuclear spin-spin coupling over van der Waals bond has recently been observed via the frequency shift of solute protons in a solution containing optically hyperpolarized (129)Xe nuclei. We carry out a first-principles computational study of the prototypic van der Waals-bonded xenon dimer, where the spin-spin coupling between two magnetically non-equivalent isotopes, J((129)Xe - (131)Xe), is observable. We use relativistic theory at the four-component Dirac-Hartree-Fock and Dirac-density-functional theory levels using novel completeness-optimized Gaussian basis sets and choosing the functional based on a comparison with correlated ab initio methods at the nonrelativistic level. J-coupling curves are provided at different levels of theory as functions of the internuclear distance in the xenon dimer, demonstrating cross-coupling effects between relativity and electron correlation for this property. Calculations on small Xe clusters are used to estimate the importance of many-atom effects on J((129)Xe - (131)Xe). Possibilities of observing J((129)Xe - (131)Xe) in liquid xenon are critically examined, based on molecular dynamics simulation. A simplistic spherical model is set up for the xenon dimer confined in a cavity, such as in microporous materials. It is shown that the on the average shorter internuclear distance enforced by the confinement increases the magnitude of the coupling as compared to the bulk liquid case, rendering J((129)Xe - (131)Xe) in a cavity a feasible target for experimental investigation.

Reactive quenching of two-photon excited xenon atoms by Cl2

International Nuclear Information System (INIS)

Bruce, M.R.; Layne, W.B.; Meyer, E.; Keto, J.W.

1987-01-01

Total binary and tertiary quench rates have been measured for the reaction Xe (5p 5 6p) + Cl 2 at thermal temperatures. Xenon atoms are excited by state-selective, two-photon absorption with a uv laser. The time dependent fluorescence from the excited atom in the IR and from XeCl* (B) product near 308 nm have been measured with subnanosecond time resolution. The decay rates are measured as a function of Cl 2 pressure to 20 Torr and Xe pressure to 400 Torr. The measured reaction rates (k 2 ∼ 10 -9 cm 3 sec -1 ) are consistent with a harpoon model described in a separate paper. We also measure large termolecular reaction rates for collisions with xenon atoms (k 3 ∼ 10 -28 cm 6 sec -1 ). Total product fluorescence has been examined using a gated optical multichannel analyzer. We measure unit branching fractions for high vibrational levels of XeCl* (B) with very little C state fluorescence observed. The measured termolecular rates suggest similar processes will dominate at the high buffer-gas pressures used in XeCl lasers. The effect of these large reactive cross sections for neutral xenon atoms on models of the XeCl laser will be discussed

High-energy xenon ion irradiation effects on the electrical properties of yttrium iron garnet

International Nuclear Information System (INIS)

Costantini, J.M.; Flament, J.L.; Sinopoli, L.; Trochon, J.; Uzureau, J.L.; Groult, D.; Studer, F.; Toulemonde, M.

1989-01-01

Thin monocristalline samples of yttrium iron garnet Y 3 Fe 5 O 12 (YIG) were irradiated at room temperature with 27 MeV/A 132 Xe ions at varying fluences up to 3.5 x 10 12 ions cm -2 . Sample thickness (100 μm) was smaller than the mean projected range of ions (170 μm) so that we were able to study the effects of irradiation damage solely. At such a high ion energy the nuclear energy loss is negligible and damage is mainly due to electronic excitation energy loss. YIG d.c conductivity is found to rise by a factor 40 for the highest dose while the permittivity increases only slightly after irradiation (40% max.). The dielectric losses are also enhanced as the ion fluence increases especially at lower frequencies (by a factor 6 at 10 KHz). No dielectric relaxation peak is observed in the frequency range explored here (10 KHz - 10 MHz)

Search for 136Xe neutrinoless double beta decay with the Enriched Xenon Observatory (EXO)

International Nuclear Information System (INIS)

Giroux, G.

2014-01-01

The EXO collaboration is searching for the neutrinoless double beta decay of 136 Xe. Such observation would determine an absolute mass scale for the neutrinos, establish their Majorana nature, and uncover physics beyond the Standard Model. The EXO-200 detector is a single phase liquid xenon ultra low background TPC (Time Projection Chamber), with an active mass of 110 kg of 80.6% enriched xenon in the isotope 136. The detector is currently operating at the WIPP site and has been collecting data with enriched xenon since May 2011. The data collected give a lower limit for the neutrinoless double beta decay half-life of 136 Xe: T > 1.6*10 25 years at 90% C.L. The same data give a lower limit for the 2 neutrinos double beta decay of 136 Xe: T > 2.23*10 21 years that agrees with experimental values found in the literature

Krypton Ion Thruster Performance

Science.gov (United States)

Patterson, Michael J.; Williams, George J.

1992-01-01

Preliminary data were obtained from a 30 cm ion thruster operating on krypton propellant over the input power range of 0.4 to 5.5 kW. The data presented are compared and contrasted to the data obtained with xenon propellant over the same input power envelope. Typical krypton thruster efficiency was 70 percent at a specific impulse of approximately 5000 s, with a maximum demonstrated thrust to power ratio of approximately 42 mN/kW at 2090 s specific impulse and 1580 watts input power. Critical thruster performance and component lifetime issues were evaluated. Order of magnitude power throttling was demonstrated using a simplified power-throttling strategy.

1.2 MeV/amu Xe ion induced damage recovery in SiC

Energy Technology Data Exchange (ETDEWEB)

O’Connell, J.H., E-mail: jacques.oconnell@gmail.com [Centre for HRTEM, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Skuratov, V.A.; Sohatsky, A.S. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Neethling, J.H. [Centre for HRTEM, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

2014-05-01

The microstructural changes of 4H-SiC samples dual irradiated with either low energy He (10 keV) or Ti (220 keV) and high energy (167 MeV) Xe ions has been studied using cross-sectional transmission electron microscopy. It was found that xenon ions with fluences above 10{sup 13} cm{sup −2} restore crystallinity in a heavily damaged partially amorphous zone. No significant damage recovery was observed in fully amorphized layers of silicon carbide apart from a 5% reduction in the amorphous layer thickness.

Interdiffusion of krypton and xenon in high-pressure helium

International Nuclear Information System (INIS)

Campana, R.J.; Jensen, D.D.; Epstein, B.D.; Hudson, R.G.; Baldwin, N.L.

1980-01-01

The interdiffusion of gaseous fission products in high-pressure helium is an important factor in the control of radioactivity in gas-cooled fast breeder reactors (GCFRs). As presently conceived, GCFRs use pressure-equalized and vented fuel in which fission gases released from the solid matrix oxide fuel are transported through the fuel rod interstices and internal fission product traps to the fuel assembly vents, where they are swept away to external traps and storage. Since the predominant transport process under steady-state operating conditions is interdiffusion of gaseous fission products in helium, the diffusion properties of krypton-helium and xenon-helium couples have been measured over the range of GCFR temperature and pressure conditions ( -1 ) and expected temperature dependence to the 1.66 power (Tsup(1.66)) at lower pressures and temperatures. Additional work is in progress to measure the behaviour of the krypton-helium and xenon-helium couples in GCFR fuel rod charcoal delay traps. (author)

In Situ Measurement of Atmospheric Krypton and Xenon on Mars with Mars Science Laboratory

Science.gov (United States)

Conrad, P. G.; Malespin, C. A.; Franz, H. B.; Pepin, R. O.; Trainer, M. G.; Schwenzer, S. P.; Atreya, S. K.; Freissinet, C.; Jones, J. H.; Manning, H.;

Multicharged and intense heavy ion beam sources

International Nuclear Information System (INIS)

Kutner, V.B.

1981-01-01

The cyclotron plasma-are source (PIG), duoplasmatron (DP), laser source (LS), electron beam ion source (EBIS) and electron cyclotron resonance source (ECRS) from the viewpoint of generating intense and high charge state beams are considered. It is pointed out that for the last years three types of multicharged ion sources-EBIS, ECR and LS have been essentially developed. In the EBIS source the Xe 48+ ions are produced. The present day level of the development of the electron-beam ionization technique shows that by means of this technique intensive uranium nuclei beams production becomes a reality. On the ECR source Xe 26+ approximately 4x10 10 h/s, Asub(r)sup(12+) approximately 10 12 h/s intensive ion beams are produced. In the laser source a full number of C 6+ ions during one laser pulse constitutes not less than 10 10 from the 5x10mm 2 emission slit. At the present time important results are obtained pointing to the possibility to separate the ion component of laser plasma in the cyclotron central region. On the PIG source the Xe 15+ ion current up to 10μA per pulse is produced. In the duoplasmatron the 11-charge state of xenon ion beams is reached [ru

Nuclear structure studies in the xenon and radon region and the discovery of a new radon isotope by Penning-trap mass spectrometry

CERN Document Server

Neidherr, Dennis

2010-01-01

Nowadays high-precision mass measurements based on Penning traps allow a deep insight into the fundamental properties of nucleonic matter. To this end, the cyclotron frequency of an ion confined in a strong, homogeneous magnetic field B is determined. At the ISOLTRAP mass spectrometer at ISOLDE / CERN the masses of short-lived radioactive nuclei with half-lives down to several ten ms can be measured with an uncertainty in the order of 10$^{-8}$and below. ISOLTRAP consists of an RFQ cooler and buncher to cool and accumulate the ions coming from ISOLDE and a double Penning-trap system to first clean the ion samples and finally perform the mass measurements. Within this thesis the masses of neutron rich xenon and radon isotopes, namely $^{138-146}$Xe and $^{223-229}$Rn were determined, eleven of them for the first time. $^{229}$Rn was even discovered in this experiment and its half-life could be determined to roughly 12$^{+1.2}_{-1.3}$ s. Since the mass reflects all interactions inside the nucleus it is a unique...

Measurement of eDsub(L)/μ of electrons in liquid xenon

International Nuclear Information System (INIS)

Doke, T.; Suzuki, S.; Shibamura, E.; Masuda, K.

1983-01-01

A new method for measuring the spread of electron swarm drifting under uniform electric field in liquid xenon is proposed. This is made by observing the width of scintillation pulse produced by drifting electrons in the vicinity of a thin center wire of a proportional scintillation counter, put in the end part of the electron drift space. From the spread of electron swarm and its drift time, the ratio of longitudinal diffusion coefficient to mobility epsilon sub(L) = eDsub(L)/μ for electrons in liquid xenon is directly obtained. epsilon sub(L) of electron swarms under the various electric fields have been measured and compared with epsilon sub(T) = eDsub(T)/μ previously obtained under the same electric fields. (Authors)

Implementation of an expert system for xenon spatial control in pressurized-water reactors

International Nuclear Information System (INIS)

Chung, S.K.

1988-01-01

Control of the axial xenon oscillations is a knowledge- and experience-intensive activity for reactor operators. To aid reactor operators in the control of axial xenon oscillations, an advisory expert system was developed. A rule-based expert system shell, INSIGHT2+, was used to build the expert system which was interfaced with a microcomputer-based core control model of a pressurized-water reactor, graphic engine, and data base. A core control model described by one-group diffusion theory with moderator temperature and xenon feedbacks was used to develop heuristic control rules and to test the system. Full- and part-length control rods, boron concentration, and coolant inlet temperature were considered as control variables of the core control model. This expert system consists of a search space: the set of possible power level and power shape patterns. The search space was made by combining the following core state variables: the sign of relative power and axial offset (AO) error, sign of the rate of change of power level and AO, and magnitude of relative power and AO error

Transition from linear to nonlinear sputtering of solid xenon

DEFF Research Database (Denmark)

Dutkiewicz, L.; Pedrys, R.; Schou, Jørgen

1995-01-01

Self-sputtering of solid xenon has been studied with molecular dynamics simulations as a model system for the transition from dominantly linear to strongly nonlinear effects. The simulation covered the projectile energy range from 20 to 750 eV. Within a relatively narrow range from 30 to 250 e...

Discovery potential of xenon-based neutrinoless double beta decay experiments in light of small angular scale CMB observations

International Nuclear Information System (INIS)

Gómez-Cadenas, J.J.; Martín-Albo, J.; Vidal, J. Muñoz; Peña-Garay, C.

2013-01-01

The South Pole Telescope (SPT) has probed an expanded angular range of the CMB temperature power spectrum. Their recent analysis of the latest cosmological data prefers nonzero neutrino masses, with Σm ν = (0.32±0.11) eV. This result, if confirmed by the upcoming Planck data, has deep implications on the discovery of the nature of neutrinos. In particular, the values of the effective neutrino mass m ββ involved in neutrinoless double beta decay (ββ0ν) are severely constrained for both the direct and inverse hierarchy, making a discovery much more likely. In this paper, we focus in xenon-based ββ0ν experiments, on the double grounds of their good performance and the suitability of the technology to large-mass scaling. We show that the current generation, with effective masses in the range of 100 kg and conceivable exposures in the range of 500 kg·year, could already have a sizeable opportunity to observe ββ0ν events, and their combined discovery potential is quite large. The next generation, with an exposure in the range of 10 ton·year, would have a much more enhanced sensitivity, in particular due to the very low specific background that all the xenon technologies (liquid xenon, high-pressure xenon and xenon dissolved in liquid scintillator) can achieve. In addition, a high-pressure xenon gas TPC also features superb energy resolution. We show that such detector can fully explore the range of allowed effective Majorana masses, thus making a discovery very likely

Performance analysis of photoresistor and phototransistor for automotive’s halogen and xenon bulbs light output

Science.gov (United States)

Rammohan, A.; Kumar, C. Ramesh

2017-11-01

Illumination of any light is measured using a different kind of calibrated equipment’s available in the market such as a goniometer, spectral radiometer, photometer, Lux meter and camera based systems which directly display the illumination of automotive headlights light distribution in the unit of lux, foot-candles, lumens/sq. ft. and Lambert etc., In this research, we dealt with evaluating the photo resistor or Light Dependent Resistor (LDR) and phototransistor whether it is useful for sensing light patterns of Automotive Halogen and Xenon bulbs. The experiments are conducted during night hours under complete dark space. We have used the headlamp setup available in TATA SUMO VICTA vehicle in the Indian market and conducted the experiments separately for Halogen and Xenon bulbs under low and high beam operations at various degrees and test points within ten meters of distance. Also, we have compared the light intensity of halogen and xenon bulbs to prove the highest light intensity between halogen and Xenon bulbs. After doing a rigorous test with these two sensors it is understood both are good to sensing beam pattern of automotive bulbs and even it is good if we use an array of sensors or a mixed combination of sensors for measuring illumination purposes under perfect calibrations.

Resonant four-wave mixing processes in xenon

International Nuclear Information System (INIS)

Yiu, Y.M.; Bonin, K.D.; McIlrath, T.J.

1982-01-01

Two-photon resonantly enhanced four-wave mixing processes in xenon involving the intermediate states were utilized to generate coherent VUV radiation at several discrete wavelengths between 125.9 nm and 101.8 nm. Maximum efficiencies of the order of 10-4 were achieved. The use of these processes for producing tunable VUV output with Xe is given and generation of tunable VUV using two-photon resonances in other rare gases is discussed

A pulse generator for xenon lamps

CERN Document Server

Janata, E

2002-01-01

A pulse generator is described, which enhances the analyzing light emitted from a xenon lamp as used in kinetic photospectrometry experiments. The lamp current is increased to 600 A for a duration of 3 ms; the current is constant within +-0.2% during a time interval of 2 ms. Because of instabilities of the lamp arc during pulsing, the use of the enhanced light source is limited to measuring times up to 500 mu s. The enhancement in light intensity depends on the wavelength and amounts to more than 400-fold in the UV-region.

First 0ν half-life limit from the Gotthard xenon time projection chamber

International Nuclear Information System (INIS)

Wong, H.T.; Boehm, F.; Fisher, P.

1991-01-01

A xenon Time Projection Chamber with an active volume of 207 liters has been built to study 0ν and 2ν double beta decay in 136 Xe. The TPC has been installed in the Gotthard Tunnel Underground Laboratory, and is currently taking data with 5 atm of xenon enriched in 62.5% 136 Xe. The first 166 hours of data are presented. Based on this data set, we deduce a half-life limit of T(0 + → 0 + ) > 6.2 x 10 21 years for the 0ν mode, at a 90% C.L. (author)

Particle simulation of grid system for krypton ion thrusters

Directory of Open Access Journals (Sweden)

Maolin CHEN

2018-04-01

Full Text Available The transport processes of plasmas in grid systems of krypton (Kr ion thrusters at different acceleration voltages were simulated with a 3D-PIC model, and the result was compared with xenon (Xe ion thrusters. The variation of the screen grid transparency, the accelerator grid current ratio and the divergence loss were explored. It is found that the screen grid transparency increases with the acceleration voltage and decreases with the beam current, while the accelerator grid current ratio and divergence loss decrease first and then increase with the beam current. This result is the same with Xe ion thrusters. Simulation results also show that Kr ion thrusters have more advantages than Xe ion thrusters, such as higher screen grid transparency, smaller accelerator grid current ratio, larger cut-off current threshold, and better divergence loss characteristic. These advantages mean that Kr ion thrusters have the ability of operating in a wide range of current. Through comprehensive analyses, it can be concluded that using Kr as propellant is very suitable for a multi-mode ion thruster design. Keywords: Grid system, Ion thrusters, Krypton, Particle in cell method, Plasma

Thermal Environmental Testing of NSTAR Engineering Model Ion Thrusters

Science.gov (United States)

Rawlin, Vincent K.; Patterson, Michael J.; Becker, Raymond A.

1999-01-01

NASA's New Millenium program will fly a xenon ion propulsion system on the Deep Space 1 Mission. Tests were conducted under NASA's Solar Electric Propulsion Technology Applications Readiness (NSTAR) Program with 3 different engineering model ion thrusters to determine thruster thermal characteristics over the NSTAR operating range in a variety of thermal environments. A liquid nitrogen-cooled shroud was used to cold-soak the thruster to -120 C. Initial tests were performed prior to a mature spacecraft design. Those results and the final, severe, requirements mandated by the spacecraft led to several changes to the basic thermal design. These changes were incorporated into a final design and tested over a wide range of environmental conditions.

Ion beam modification of buckminsterfullerene

International Nuclear Information System (INIS)

Prawer, S.; Nugent, K.W.; McCulloch, D.G.; Leong, W.H.; Hoffman, A.; Kalish, R.

1995-01-01

The response of thin films of buckminsterfullerene (C 60 ) to energetic xenon ion impact is investigated. The diagnostics employed include Fourier Transform Infrared and Raman Spectroscopies, Cross-Sectional Transmission Electron Microscopy, and Atomic Force Microscopy. By combining the information obtained from these diagnostics with that from the dependence of the conductivity on ion dose, it is concluded that each C 60 molecule completely disintegrates when hit by an energetic ion. The cross-section for the destruction of about 7 x 10 -13 cm 2 for irradiation with 620 keV Xe ions. The disintegration occurs when C atoms are knocked-out of the molecule either directly by the impinging ion or by an energetic knock-on C atom with the damage cascade. This process is quite different from the Coulomb Explosion mechanism previously proposed in the literature. For very low ions doses ( 11 Xe/cm 2 ) most of the C 60 molecules remain intact; however this dose is sufficient to completely disrupt the ordering of the C 60 molecules in the van der Waals bonded C 60 solid. Disruption of the lattice ordering at such low doses is considered to be attributable to the weakness of the van der Waals forces which bind the C 60 clusters together into the molecular solid. 13 refs., 7 figs

Electron Impact Excitation Cross Sections of Xenon for Optical Plasma Diagnostic

National Research Council Canada - National Science Library

Srivastava, Rajesh

2007-01-01

In this project the researcher had taken up the calculation of xenon apparent emission-excitation cross sections for emission lines that have diagnostic value in the analysis of Xe-propelled electric thruster plasmas...

WE-AB-202-07: Ventilation CT: Voxel-Level Comparison with Hyperpolarized Helium-3 & Xenon-129 MRI

Energy Technology Data Exchange (ETDEWEB)

Tahir, B; Marshall, H; Hughes, P; Stewart, N; Horn, F; Collier, G; Norquay, G; Hart, K; Swinscoe, J; Hatton, M; Wild, J; Ireland, R [University of Sheffield, Sheffield (United Kingdom)

2016-06-15

Purpose: To compare the spatial correlation of ventilation surrogates computed from inspiratory and expiratory breath-hold CT with hyperpolarized Helium-3 & Xenon-129 MRI in a cohort of lung cancer patients. Methods: 5 patients underwent expiration & inspiration breath-hold CT. Xenon-129 & {sup 1}H MRI were also acquired at the same inflation state as inspiratory CT. This was followed immediately by acquisition of Helium-3 & {sup 1}H MRI in the same breath and at the same inflation state as inspiratory CT. Expiration CT was deformably registered to inspiration CT for calculation of ventilation CT from voxel-wise differences in Hounsfield units. Inspiration CT and the Xenon-129’s corresponding anatomical {sup 1}H MRI were registered to Helium-3 MRI via the same-breath anatomical {sup 1}H MRI. This enabled direct comparison of CT ventilation with Helium-3 MRI & Xenon-129 MRI for the median values in corresponding regions of interest, ranging from finer to coarser in-plane dimensions of 10 by 10, 20 by 20, 30 by 30 and 40 by 40, located within the lungs as defined by the same-breath {sup 1}H MRI lung mask. Spearman coefficients were used to assess voxel-level correlation. Results: The median Spearman’s coefficients of ventilation CT with Helium-3 & Xenon-129 MRI for ROIs of 10 by 10, 20 by 20, 30 by 30 and 40 by 40 were 0.52, 0.56, 0.60 and 0.68 and 0.40, 0.42, 0.52 and 0.70, respectively. Conclusion: This work demonstrates a method of acquiring CT & hyperpolarized gas MRI (Helium-3 & Xenon-129 MRI) in similar breath-holds to enable direct spatial comparison of ventilation maps. Initial results show moderate correlation between ventilation CT & hyperpolarized gas MRI, improving for coarser regions which could be attributable to the inherent noise in CT intensity, non-ventilatory effects and registration errors at the voxel-level. Thus, it may be more beneficial to quantify ventilation at a more regional level.

Energy and Emission Characteristics of a Short-Arc Xenon Flash Lamp Under "Saturated" Optical Brightness Conditions

Science.gov (United States)

Kamrukov, A. S.; Kireev, S. G.; Kozlov, N. P.; Shashkovskii, S. G.

2017-09-01

We present the results of a study of the electrical, energy, and spectral brightness characteristics of an experimental three-electrode high-pressure xenon flash lamp under conditions ensuring close to maximum possible spectral brightness for the xenon emission. We show that under saturated optical brightness conditions (brightness temperature in the visible region of the spectrum 30,000 K), emission of a pulsed discharge in xenon is quite different from the emission from an ideal blackbody: the maximum brightness temperatures are 24,000 K in the short-wavelength UV region and 19,000 K in the near IR range. The relative fraction of UV radiation in the emission spectrum of the lamp is >50%, which lets us consider such lamps as promising broadband sources of radiation with high spectral brightness for many important practical applications.

A neuro-fuzzy controller for xenon spatial oscillations in load-following operation

Energy Technology Data Exchange (ETDEWEB)

Na, Man Gyun [Chosun University, Kwangju (Korea, Republic of); Upadhyaya, Belle R [The University of Tennessee, Knoxville (United States)

1998-12-31

A neuro-fuzzy control algorithm is applied for xenon spatial oscillations in a pressurized water reactor. The consequent and antecedent parameters of the fuzzy rules are tuned by the gradient descent method. The reactor model used for computer simulations is a two-point xenon oscillation model. The reactor core is axially divided into two regions and each region has one input and one output and is coupled with the other region. The interaction between the regions of the reactor core is treated by a decoupling scheme. This proposed control method exhibits very responses to a step or a ramp change of target axial offest without any residual flux oscillations. 9 refs., 5 figs. (Author)

A neuro-fuzzy controller for xenon spatial oscillations in load-following operation

Energy Technology Data Exchange (ETDEWEB)

Na, Man Gyun [Chosun University, Kwangju (Korea, Republic of); Upadhyaya, Belle R. [The University of Tennessee, Knoxville (United States)

1997-12-31

A neuro-fuzzy control algorithm is applied for xenon spatial oscillations in a pressurized water reactor. The consequent and antecedent parameters of the fuzzy rules are tuned by the gradient descent method. The reactor model used for computer simulations is a two-point xenon oscillation model. The reactor core is axially divided into two regions and each region has one input and one output and is coupled with the other region. The interaction between the regions of the reactor core is treated by a decoupling scheme. This proposed control method exhibits very responses to a step or a ramp change of target axial offest without any residual flux oscillations. 9 refs., 5 figs. (Author)

Can pulsed xenon ultraviolet light systems disinfect aerobic bacteria in the absence of manual disinfection?

Science.gov (United States)

Jinadatha, Chetan; Villamaria, Frank C; Ganachari-Mallappa, Nagaraja; Brown, Donna S; Liao, I-Chia; Stock, Eileen M; Copeland, Laurel A; Zeber, John E

2015-04-01

Whereas pulsed xenon-based ultraviolet light no-touch disinfection systems are being increasingly used for room disinfection after patient discharge with manual cleaning, their effectiveness in the absence of manual disinfection has not been previously evaluated. Our study indicates that pulsed xenon-based ultraviolet light systems effectively reduce aerobic bacteria in the absence of manual disinfection. These data are important for hospitals planning to adopt this technology as adjunct to routine manual disinfection. Published by Elsevier Inc.

Modeling Pulse Characteristics in Xenon with NEST

OpenAIRE

Mock, Jeremy; Barry, Nichole; Kazkaz, Kareem; Szydagis, Matthew; Tripathi, Mani; Uvarov, Sergey; Woods, Michael; Walsh, Nicholas

2013-01-01

A comprehensive model for describing the characteristics of pulsed signals, generated by particle interactions in xenon detectors, is presented. An emphasis is laid on two-phase time projection chambers, but the models presented are also applicable to single phase detectors. In order to simulate the pulse shape due to primary scintillation light, the effects of the ratio of singlet and triplet dimer state populations, as well as their corresponding decay times, and the recombination time are ...

Regional cerebral blood studies by the xenon-133 inhalation method in cases of cerebrovascular diseases

International Nuclear Information System (INIS)

Shimomura, Takahide

1982-01-01

rCBF was measured 428 times in 191 patients and 15 healthy volunteers by the Xenon-133 inhalation technique. The two-compartment analysis and the estimate of initial slope index were performed. There was no difference in blood flow between the two hemispheres in the 15 healthy volunteers, whose mean age was 36.5 +- 13.5 years (F 1 , right: 83.1 +- 11.4; left: 85.1 +- 12.1; 1Sl, right: 51.6 +- 6.3; left: 52.4 +- 6.0). Good correlation with a correlation coefficient of 0.965 was observed between the value obtained by the Xenon-133 inhalation and intracarotid methods in 14 patients with brain diseases. Reproducibilities of the Xenon-133 inhalation technique by serial measurement of rCBF at intervals of 30 - 40 minutes and 3 - 5 days were almost the same, with a variation coefficient of 3.7% and a correlation coefficient of 0.98. Repeated rCBF measurement by the Xenon-133 inhalation was performed during a long follow-up period of up to 1 year after bypass surgery. In 28 adult patients with occlusive cerebrovascular disease, CBF values of most patients stabilized in normal range within 3 months after the operation. In 12 patients with Moyamoya disease, CBF values were distributed over a wide range preoperatively, and increased gradually and tended to stabilize in the relatively subnormal range within 3 months after operation. This clinical experience indicates that the Xenon-133 inhalation method is a useful and safe procedure for the determination of rCBF, especially for repeated studies in cases with bypass surgery during long postoperative follow-up periods and for measurement of rCBF in child cases. (J.P.N.)

Unitary theory of xenon instability in nuclear thermal reactors - 1. Reactor at 'zero power'

International Nuclear Information System (INIS)

Novelli, A.

1982-01-01

The question of nuclear thermal-reactor instability against xenon oscillations is widespread in the literature, but most theories, concerned with such an argument, contradict each other and, above all, they conflict with experimentally-observed instability at very low reactor power, i.e. without any power feedback. It is shown that, in any nuclear thermal reactor, xenon instability originates at very low power levels, and a very general stability condition is deduced by an extension of the rigorous, simple and powerful reduction of the Nyquist criterion, first performed by F. Storrer. (author)

Highly charged ion impact induced nanodefects in diamond

Energy Technology Data Exchange (ETDEWEB)

Makgato, T.N., E-mail: thuto.makgato@wits.ac.za [School of Physics, University of the Witwatersrand, Johannesburg 2050 (South Africa); Microscopy and Microanalysis Unit, University of the Witwatersrand, Johannesburg 2050 (South Africa); Sideras-Haddad, E. [School of Physics, University of the Witwatersrand, Johannesburg 2050 (South Africa); Centre of Excellence in Strong Materials, Physics Building, University of the Witwatersrand, Johannesburg 2050 (South Africa); Shrivastava, S. [School of Physics, University of the Witwatersrand, Johannesburg 2050 (South Africa); Schenkel, T. [E.O. Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Ritter, R.; Kowarik, G.; Aumayr, F. [Institute of Applied Physics, TU Wien-Vienna University of Technology, 1040 Vienna (Austria); Crespo Lopez-Urrutia, J.; Bernitt, S.; Beilmann, C.; Ginzel, R. [Max-Planck Institute for Nuclear Physics, Saupfercheckweg 1, 69117 Heidelberg (Germany)

2013-11-01

We investigate the interaction of slow highly charged ion (SHCI) beams with insulating type Ib diamond (1 1 1) surfaces. Bismuth and Xenon SHCI beams produced using an Electron Beam Ion Trap (EBIT) and an Electron Cyclotron Resonance source (ECR) respectively, are accelerated onto type Ib diamond (1 1 1) surfaces with impact velocities up to ≈0.4 υ{sub Bohr}. SHCIs with charge states corresponding to potential energies between 4.5 keV and 110 keV are produced for this purpose. Atomic Force Microscopy analysis (AFM) of the diamond surfaces following SHCI impact reveals surface morphological modifications characterized as nanoscale craters (nano-craters). To interpret the results from Tapping Mode AFM analysis of the irradiated diamond surfaces we discuss the interplay between kinetic and potential energy in nano-crater formation using empirical data together with Stopping and Range of Ions in Matter (SRIM) Monte Carlo Simulations.

Electric field measurements in a xenon discharge using Spark spectroscopy

NARCIS (Netherlands)

Wagenaars, E.; Bowden, M.D.; Kroesen, G.M.W.

2005-01-01

Measurements of electric field distributions in a low-pressure xenon discharge are presented. The measurement technique is based on Stark spectroscopy, using a 2 + 1 excitation scheme with fluorescence dip detection. Electric fields can be measured by detecting Stark shifts of high-lying Rydberg

An automated multidimensional preparative gas chromatographic system for isolation and enrichment of trace amounts of xenon from ambient air.

Science.gov (United States)

Larson, Tuula; Östman, Conny; Colmsjö, Anders

2011-04-01

The monitoring of radioactive xenon isotopes is one of the principal methods for the detection of nuclear explosions in order to identify clandestine nuclear testing. In this work, a miniaturized, multiple-oven, six-column, preparative gas chromatograph was constructed in order to isolate trace quantities of radioactive xenon isotopes from ambient air, utilizing nitrogen as the carrier gas. The multidimensional chromatograph comprised preparative stainless steel columns packed with molecular sieves, activated carbon, and synthetic carbon adsorbents (e.g., Anasorb®-747 and Carbosphere®). A combination of purification techniques--ambient adsorption, thermal desorption, back-flushing, thermal focusing, and heart cutting--was selectively optimized to produce a well-defined xenon peak that facilitated reproducible heart cutting and accurate quantification. The chromatographic purification of a sample requires approximately 4 h and provides complete separation of xenon from potentially interfering components (such as water vapor, methane, carbon dioxide, and radon) with recovery and accuracy close to 100%. The preparative enrichment process isolates and concentrates a highly purified xenon gas fraction that is suitable for subsequent ultra-low-level γ-, ß/γ-spectroscopic or high-resolution mass spectrometric measurement (e.g., to monitor the gaseous fission products of nuclear explosions at remote locations). The Xenon Processing Unit is a free-standing, relatively lightweight, and transportable system that can be interfaced to a variety of sampling and detection systems. It has a relatively inexpensive, rugged, and compact modular (19-inch rack) design that provides easy access to all parts for maintenance and has a low power requirement.

Determination of atmospheric concentrations of xenon radioisotopes. Progress report

International Nuclear Information System (INIS)

Abel, K.H.; Panisko, M.E.; Hensley, W.K.; Bowyer, T.W.; Perkins, R.W.

1995-07-01

Determination of radioactive xenon concentrations in the atmosphere over a two year period has been performed as part of a research program to develop real-time measurement capabilities. The initial measurements were made to develop, prove, and validate the authors technical approach, while the longer-term measurements are being undertaken to establish natural background concentrations and variability with time. The results reported were made using noble gas fraction (typically 90% Kr and 10% Xe by weight) gas samples obtained from a commercial air-reduction plant in the northeastern US over a two-year interval beginning in the fall of 1993. The concentrated gas samples were typically obtained during a 6--8 hour interval at the commercial reduction plant and were shipped overnight to their laboratory. Analysis was typically completed approximately 24 hours after sampling. The analytical separation process typically took approximately 6 hours and gamma-ray spectrometric measurements were conducted for intervals ranging from 3 to 16 hours. The technical approach involved removal of potentially interfering radon daughter radionuclides using a molecular sieve at room temperature, followed by cryogenic concentration of noble gases using a chilled (-76 C) activated carbon molecular sieve. During initial measurements both molecular sieve materials were contained in 30 foot x 1/4 inch gas chromatography columns for analytical separations. Krypton was separated from Xenon during the analytical procedure by warming the activated carbon molecular sieve to room temperature after initial noble gas concentration and actively pumping it away. Xenon-133 adsorbed to the activated charcoal molecular sieve was then quantified via its 81 keV gamma-ray using initially a p-type intrinsic germanium detector and later a higher efficiency (64% relative to a 3 inch x 3 inch sodium iodide) n-type intrinsic germanium detector

Krypton 81m and xenon 133 for complementary ventilation imaging in pulmonary perfusion studies: a clinical comparison. Chapter 12

International Nuclear Information System (INIS)

Weber, P.M.; Remedios, L.V.dos.

1978-01-01

Twenty-four patients with suspected pulmonary embolism were studied to determine the relative usefulness of 133 Xe and 81 Krsup(m) as indicators of pulmonary ventilation in complementing perfusion studies. In most cases, where krypton produced results superior to xenon, this could be attributed to better resolution of the 190 keV photon and to the fact that multiple views could be obtained, with each view paired precisely with a corresponding perfusion image, the direct result of the ease of use of krypton and its short 13 second half-life. This was well demonstrated in both of the patients with presumed pulmonary embolism and co-existing other pulmonary disease in which the results with xenon and krypton differed. In each case the mis-match was obscured by closely related areas of delayed xenon wash-out. In those patients where xenon demonstrated greater sensitivity in identifying areas of pulmonary disease, the lesions noted on wash-out appeared as areas of positive activity, while with krypton the defects were always photogenic and, when small probably obscured by scatter from adjacent normal activity. In the patient who might have been improperly categorized as a mis-match without the krypton study, the xenon study may have been normal because of inadequate equilibration time. (author)

Design of Solid Form Xenon-124 Target for Producing I-123 Radioisotope Using Computer Simulation Techniques

International Nuclear Information System (INIS)

Kamali Moghaddam, K.; Sadeghi, M.; Kakavand, T.; Shokri Bonab, S.

2006-01-01

Recently in Cyclotron and Nuclear Medicine Department of NRCAM, at Atomic Energy organization of Iran (AEOI), a system for producing 1-123 via Xe-124 gas target technology, has been constructed and installed. One of the major problems in this system is the highly expensive cost of the enriched Xenon-124 gas. Therefore, saving this gas inside the system is very important. Unfortunately, by accidental rupture of the window foil or bad function of O-rings, the whole Xenon gas will escape from the system immediately. In this paper, by using computer codes; ALICE91, SRIM and doing some calculations we are going to demonstrate our latest effort for feasibility study of producing I-123 with the above mentioned reactions, but using Xe-124 solid target instead. According to our suggested design, a conical shaped irradiation vessel made of copper with 1 mm thickness, 1 cm outlet diameter, 5 cm length and 12 deg. angle at summit can be fixed inside a liquid nitrogen housing chamber. The Xenon-124 gas will be sent to the inside of this very cold conical trap and eventually deposited on its surface in solid form. Our calculation shows that during bombardment with 17-28 MeV proton energy, the thickness of solidified Xenon layer will remain around .28 mm. Likewise; thermo-dynamical calculation shows that in order to prevent the evaporation of solidified Xenon, the maximum permissible proton beam current for this system should be less than 1.4 μA. According to these working conditions, the production yield of I-123 can be predicted to be around 150 mCi/μAh. (authors)

Novel xenon calibration scheme for two-photon absorption laser induced fluorescence of hydrogen

Energy Technology Data Exchange (ETDEWEB)

Elliott, Drew; Scime, Earl; Short, Zachary, E-mail: zdshort@mix.wvu.edu [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26056 (United States)

2016-11-15

Two photon absorption laser induced fluorescence (TALIF) measurements of neutral hydrogen and its isotopes are typically calibrated by performing TALIF measurements on krypton with the same diagnostic system and using the known ratio of the absorption cross sections [K. Niemi et al., J. Phys. D 34, 2330 (2001)]. Here we present the measurements of a new calibration method based on a ground state xenon scheme for which the fluorescent emission wavelength is nearly identical to that of hydrogen, thereby eliminating chromatic effects in the collection optics and simplifying detector calibration. We determine that the ratio of the TALIF cross sections of xenon and hydrogen is 0.024 ± 0.001.

Signal yields of keV electronic recoils and their discrimination from nuclear recoils in liquid xenon

Science.gov (United States)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Geis, C.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Howlett, J.; Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Mahlstedt, J.; Manfredini, A.; Maris, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morâ, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M.-C.; Plante, G.; Priel, N.; Ramírez García, D.; Rauch, L.; Reichard, S.; Reuter, C.; Rizzo, A.; Rupp, N.; Saldanha, R.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. V.; Stein, A.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wittweg, C.; Wulf, J.; Ye, J.; Zhang, Y.; Zhu, T.; Xenon Collaboration

2018-05-01

We report on the response of liquid xenon to low energy electronic recoils below 15 keV from beta decays of tritium at drift fields of 92 V /cm , 154 V /cm and 366 V /cm using the XENON100 detector. A data-to-simulation fitting method based on Markov Chain Monte Carlo is used to extract the photon yields and recombination fluctuations from the experimental data. The photon yields measured at the two lower fields are in agreement with those from literature; additional measurements at a higher field of 366 V /cm are presented. The electronic and nuclear recoil discrimination as well as its dependence on the drift field and photon detection efficiency are investigated at these low energies. The results provide new measurements in the energy region of interest for dark matter searches using liquid xenon.

The first example of commensurate adsorption of atomic gas in a MOF and effective separation of xenon from other noble gases

KAUST Repository

Wang, Hao

2014-01-01

In industry, cryogenic rectification for separating xenon from other noble gases such as krypton and argon is an energy and capital intensive process. Here we show that a microporous metal-organic framework, namely Co 3(HCOO)6 is capable of effective capture and separation of xenon from other noble gases. Henry\\'s constant, isosteric heat of adsorption (Qst), and IAST selectivity are calculated based on single component sorption isotherms. Having the highest Qst reported to date, Co 3(HCOO)6 demonstrates high adsorption capacity for xenon and its IAST selectivity for Xe-Kr is the largest among all MOFs investigated to date. To mimic real world conditions, breakthrough experiments are conducted on Xe-Kr binary mixtures at room temperature and 1 atmosphere. The results are consistent with the calculated data. These findings show that Co 3(HCOO)6 is a promising candidate for xenon capture and purification. Our gas adsorption measurements and molecular simulation study also reveal that the adsorption of xenon represents the first example of commensurate adsorption of atomic gases near ambient conditions. © 2014 The Royal Society of Chemistry.

Electrochemical investigations of ion-implanted oxide films

International Nuclear Information System (INIS)

Schultze, J.W.; Danzfuss, B.; Meyer, O.; Stimming, U.

1985-01-01

Oxide films (passive films) of 40-50 nm thickness were prepared by anodic polarization of hafnium and titanium electrodes up to 20 V. Multiple-energy ion implantation of palladium, iron and xenon was used in order to obtain modified films with constant concentration profiles of the implanted ions. Rutherford backscattering, X-ray photoelectron spectroscopy measurements and electrochemical charging curves prove the presence of implanted ions, but electrochemical and photoelectrochemical measurements indicate that the dominating effect of ion implantation is the disordering of the oxide film. The capacity of hafnium electrodes increases as a result of an increase in the dielectric constant D. For titanium the Schottky-Mott analysis shows that ion implantation causes an increase in D and the donor concentration N. Additional electronic states in the band gap which are created by the implantation improve the conductivity of the semiconducting or insulating films. This is seen in the enhancement of electron transfer reactions and its disappearance during repassivation and annealing. Energy changes in the band gap are derived from photoelectrochemical measurements; the absorption edge of hafnium oxide films decreases by approximately 2 eV because of ion implantation, but it stays almost constant for titanium oxide films. All changes in electrochemical behavior caused by ion implantation show little variation with the nature of the implanted ion. Hence the dominating effect seems to be a disordering of the oxide. (Auth.)

Strategy generator for optimal xenon oscillation control: Based on a new concept of axial offsets

International Nuclear Information System (INIS)

Shimazu, Yoichiro; Horimoto, Toshiaki

1993-01-01

Recently a new concept for controlling xenon oscillations has been used to optimize the control procedure for stabilizing an oscillation. The concept is based on two additional newly defined axial offsets, AO i and AO x together with the conventional axial offset AO p of axial power distribution. However, as the AOs are evaluated on line, it is impossible to predict the behavior of the AOs in advance. In order to overcome this situation a small auxiliary program has been developed. This program can generate the transients of the three AOs for the free running xenon oscillation. Then the user can input the most favorable conditions to eliminate the xenon oscillation such as total control hours, final AO p or time interval of the control rod movement. And an optimum search for the given final conditions is performed. The program can be used as a tool for a scoping study, the result of which can be obtained in a short time and also very easily

Measurements of the equations of state and spectrum of nonideal xenon plasma under shock compression

International Nuclear Information System (INIS)

Zheng, J.; Gu, Y. J.; Chen, Z. Y.; Chen, Q. F.

2010-01-01

Experimental equations of state on generation of nonideal xenon plasma by intense shock wave compression was presented in the ranges of pressure of 2-16 GPa and temperature of 31-50 kK, and the xenon plasma with the nonideal coupling parameter Γ range from 0.6-2.1 was generated. The shock wave was produced using the flyer plate impact and accelerated up to ∼6 km/s with a two-stage light gas gun. Gaseous specimens were shocked from two initial pressures of 0.80 and 4.72 MPa at room temperature. Time-resolved spectral radiation histories were recorded by using a multiwavelength channel pyrometer. The transient spectra with the wavelength range of 460-700 nm were recorded by using a spectrometer to evaluate the shock temperature. Shock velocity was measured and particle velocity was determined by the impedance matching methods. The equations of state of xenon plasma and ionization degree have been discussed in terms of the self-consistent fluid variational theory.

Measurements of the equations of state and spectrum of nonideal xenon plasma under shock compression

Science.gov (United States)

Zheng, J.; Gu, Y. J.; Chen, Z. Y.; Chen, Q. F.

2010-08-01

Experimental equations of state on generation of nonideal xenon plasma by intense shock wave compression was presented in the ranges of pressure of 2-16 GPa and temperature of 31-50 kK, and the xenon plasma with the nonideal coupling parameter Γ range from 0.6-2.1 was generated. The shock wave was produced using the flyer plate impact and accelerated up to ˜6km/s with a two-stage light gas gun. Gaseous specimens were shocked from two initial pressures of 0.80 and 4.72 MPa at room temperature. Time-resolved spectral radiation histories were recorded by using a multiwavelength channel pyrometer. The transient spectra with the wavelength range of 460-700 nm were recorded by using a spectrometer to evaluate the shock temperature. Shock velocity was measured and particle velocity was determined by the impedance matching methods. The equations of state of xenon plasma and ionization degree have been discussed in terms of the self-consistent fluid variational theory.

Determination of the separation efficiencies of a single-stage cryogenic distillation setup to remove krypton out of xenon by using a (83m)Kr tracer method.

Science.gov (United States)

Rosendahl, S; Brown, E; Cristescu, I; Fieguth, A; Huhmann, C; Lebeda, O; Murra, M; Weinheimer, C

2015-11-01

The separation of krypton and xenon is of particular importance for the field of direct dark matter search with liquid xenon detectors. The intrinsic contamination of the xenon with radioactive (85)Kr makes a significant background for these kinds of low count-rate experiments and has to be removed beforehand. This can be achieved by cryogenic distillation, a technique widely used in industry, using the different vapor pressures of krypton and xenon. In this paper, we present an investigation on the separation performance of a single stage distillation system using a radioactive (83m)Kr-tracer method. The separation characteristics under different operation conditions are determined for very low concentrations of krypton in xenon at the level of (83m)Kr/Xe = 1.9 ⋅ 10(-15), demonstrating, that cryogenic distillation in this regime is working. The observed separation is in agreement with the expectation from the different volatilities of krypton and xenon. This cryogenic distillation station is the first step on the way to a multi-stage cryogenic distillation column for the next generation of direct dark matter experiment XENON1T.

Xenon ventilation-perfusion lung scans. The early diagnosis of inhalation injury

International Nuclear Information System (INIS)

Schall, G.L.; McDonald, H.D.; Carr, L.B.; Capozzi, A.

1978-01-01

The use of xenon Xe-133 ventilation-perfusion lung scans for the early diagnosis of inhalation injury was evaluated in 67 patients with acute thermal burns. Study results were interpreted as normal if there was complete pulmonary clearance of the radioactive gas by 150 seconds. Thirty-two scans were normal, 32 abnormal, and three technically inadequate. There were three true false-positive study results and one false-negative study result. Good correlation was found between the scan results and various historical, physical, and laboratory values currently used to evaluate inhalation injury. The scans appeared to be the most sensitive method for the detection of early involvement, often being abnormal several days before the chest roentgenogram. Xenon lung scanning is a safe, easy, accurate, and sensitive method for the early diagnosis of inhalation injury and has important therapeutic and prognostic implications as well

In situ measurements of krypton in xenon gas with a quadrupole mass spectrometer following a cold-trap at a temporarily reduced pumping speed

Energy Technology Data Exchange (ETDEWEB)

Brown, Ethan; Rosendahl, Stephan; Huhmann, Christian; Kettling, Hans; Schlak, Martin; Weinheimer, Christian [Muenster Univ. (Germany). Inst. fuer Kernphysik

2013-07-01

Liquid xenon detectors have risen to be extremely competitive for dark matter and neutrinoless double-beta decay searches. In order to achieve the required sensitivity, backgrounds must be reduced substantially. One important background is the beta-decay of {sup 85}Kr, which constitutes a uniform internal background in liquid xenon detectors. Cryogenic distillation can be used to reduce the krypton concentration to acceptable levels, but gas diagnostics become incredibly difficult at these ultra-pure levels. A new method for measuring the concentration of krypton in xenon has been developed, expanding on the existing technique of a cold trap and a Residual Gas Analyzer (RGA). By using a liquid nitrogen cold trap, one can take advantage of the difference in vapor pressures of krypton in xenon to freeze most of the xenon gas while allowing the krypton to pass to the measurement chamber. Here, only a few milliliters of xenon is expended in the measurement, while achieving a sensitivity of sub ppb (parts per billion). The key change is the use of a butterfly valve to partially close the opening in front of the turbomolecular pump, thereby reducing the effective pumping speed and enhancing the RGA signal.

Postconditioning by xenon and hypothermia in the rat heart in vivo

NARCIS (Netherlands)

Schwiebert, Christian; Huhn, Ragnar; Heinen, Andre; Weber, Nina C.; Hollmann, Markus W.; Schlack, Wolfgang; Preckel, Benedikt

2010-01-01

Background and objective Hypothermia protects against myocardial reperfusion injury. However, inducing hypothermia takes time, which makes it unsuitable as an emergency treatment. Combining mild hypothermia with low-dose xenon, applied either simultaneously or one after the other, protects the

Experimental ion mobility measurements in Xe-CF4 mixtures

Science.gov (United States)

Cortez, A. F. V.; Kaja, M. A.; Escada, J.; Santos, M. A. G.; Veenhof, R.; Neves, P. N. B.; Santos, F. P.; Borges, F. I. G. M.; Conde, C. A. N.

2018-04-01

In this paper we present the results of the ion mobility measurements made in gaseous mixtures of xenon with carbon tetrafluoride (Xe-CF4) for pressures ranging from 6 to 10 Torr (8-10.6 mbar) and for low reduced electric fields in the 10 to 25 Td range (2.4-6.1 kVṡcm‑1ṡbar‑1), at room temperature. The time-of-arrival spectra revealed one or two peaks depending on the gas relative abundances, which were attributed to CF3+ and to Xe2+ ions. However, for Xe concentrations above 60%, only one peak remains (Xe2+). The reduced mobilities obtained from the peak centroid of the time-of-arrival spectra are presented for Xe concentrations in the 5%-95% range.

Skin blood flow from gas transport: helium xenon and laser Doppler compared

Energy Technology Data Exchange (ETDEWEB)

Neufeld, G.R.; Galante, S.R.; Whang, J.M.; DeVries, D.; Baumgardner, J.E.; Graves, D.J.; Quinn, J.A.

1988-03-01

A study was designed to compare three independent measures of cutaneous blood flow in normal healthy volunteers: xenon-133 washout, helium flux, and laser velocimetry. All measurements were confined to the volar aspect of the forearm. In a large group of subjects we found that helium flux through intact skin changes nonlinearly with the controlled local skin temperature whereas helium flux through stripped skin, which is directly proportional to skin blood flow, changes linearly with cutaneous temperature over the range 33 degrees to 42 degrees. In a second group of six volunteers we compared helium flux through stripped skin to xenon-133 washout (intact skin) at a skin temperature of 33 degrees, and we found an essentially linear relationship between helium flux and xenon measured blood flow. In a third group of subjects we compared helium flux blood flow (stripped skin) to laser doppler velocimetric (LDV) measurements (intact skin) at adjacent skin sites and found a nonlinear increase in the LDV skin blood flow compared to that determined by helium over the same temperature range. A possible explanation for the nonlinear increases of helium flux through intact skin and of LDV output with increasing local skin temperature is that they reflect more than a change in blood flow. They may also reflect physical changes in the stratum corneum, which alters its diffusional resistance to gas flux and its optical characteristics.

Skin blood flow from gas transport: helium xenon and laser Doppler compared

International Nuclear Information System (INIS)

Neufeld, G.R.; Galante, S.R.; Whang, J.M.; DeVries, D.; Baumgardner, J.E.; Graves, D.J.; Quinn, J.A.

1988-01-01

A study was designed to compare three independent measures of cutaneous blood flow in normal healthy volunteers: xenon-133 washout, helium flux, and laser velocimetry. All measurements were confined to the volar aspect of the forearm. In a large group of subjects we found that helium flux through intact skin changes nonlinearly with the controlled local skin temperature whereas helium flux through stripped skin, which is directly proportional to skin blood flow, changes linearly with cutaneous temperature over the range 33 degrees to 42 degrees. In a second group of six volunteers we compared helium flux through stripped skin to xenon-133 washout (intact skin) at a skin temperature of 33 degrees, and we found an essentially linear relationship between helium flux and xenon measured blood flow. In a third group of subjects we compared helium flux blood flow (stripped skin) to laser doppler velocimetric (LDV) measurements (intact skin) at adjacent skin sites and found a nonlinear increase in the LDV skin blood flow compared to that determined by helium over the same temperature range. A possible explanation for the nonlinear increases of helium flux through intact skin and of LDV output with increasing local skin temperature is that they reflect more than a change in blood flow. They may also reflect physical changes in the stratum corneum, which alters its diffusional resistance to gas flux and its optical characteristics

Conception and synthesis of the new cryptophane for the applications in xenon NMR molecular imaging

International Nuclear Information System (INIS)

Gao, Bo

2016-01-01

Among all the imaging techniques, magnetic resonance imaging (MRI) offers several advantages owing to its low invasiveness, its harmlessness and its spatial in-depth resolution but suffers from poor sensitivity. To address this issue, different strategies were proposed, including the utilization of hyper-polarizable species such as "1"2"9Xe. Xenon is an inert gas with a polarizable electronic cloud which leads to an extreme sensitivity to its chemical environment. Its capacity of being hyper-polarized makes it possible to obtain a significant gain of sensitivity. Nevertheless, xenon has no specificity to any biological target therefore it needs to be encapsulated and vectorized. Different molecular cages were proposed and we are particularly interested in cryptophane which is one of the best candidates for xenon encapsulation. In this context, the objective of this thesis is to design new cryptophanes which can be used as molecular platforms to construct novel "1"2"9Xe MRI biosensors usable for in vivo imaging. To meet this demand, these cryptophanes should be mono-functionalizable and enough soluble in water. In this thesis, the polyethylene glycol (PEG) group is used to improve the poor solubility of the hydrophobic molecular cage. And there is a systematic discussion of how to break the symmetry of cryptophanes and different strategies were attempted to synthesize mono-functionalized cryptophanes. As a result, several PEGylated mono-functionalized cryptophanes were obtained and their properties for encapsulating xenon were tested [fr

SPALAX new generation: New process design for a more efficient xenon production system for the CTBT noble gas network.

Science.gov (United States)

Topin, Sylvain; Greau, Claire; Deliere, Ludovic; Hovesepian, Alexandre; Taffary, Thomas; Le Petit, Gilbert; Douysset, Guilhem; Moulin, Christophe

2015-11-01

The SPALAX (Système de Prélèvement Automatique en Ligne avec l'Analyse du Xénon) is one of the systems used in the International Monitoring System of the Comprehensive Nuclear Test Ban Treaty (CTBT) to detect radioactive xenon releases following a nuclear explosion. Approximately 10 years after the industrialization of the first system, the CEA has developed the SPALAX New Generation, SPALAX-NG, with the aim of increasing the global sensitivity and reducing the overall size of the system. A major breakthrough has been obtained by improving the sampling stage and the purification/concentration stage. The sampling stage evolution consists of increasing the sampling capacity and improving the gas treatment efficiency across new permeation membranes, leading to an increase in the xenon production capacity by a factor of 2-3. The purification/concentration stage evolution consists of using a new adsorbent Ag@ZSM-5 (or Ag-PZ2-25) with a much larger xenon retention capacity than activated charcoal, enabling a significant reduction in the overall size of this stage. The energy consumption of the system is similar to that of the current SPALAX system. The SPALAX-NG process is able to produce samples of almost 7 cm(3) of xenon every 12 h, making it the most productive xenon process among the IMS systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Liquid Xenon Ionization Chamber in an All-fluoropolymer Vessel

International Nuclear Information System (INIS)

LePort, F.; Pocar, A.; Bartoszek, L.; DeVoe, R.; Fierlinger, P.; Flatt, B.; Gratta, G.; Green, M.; Montero Diez, M.; Neilson, R.; O'Sullivan, K.; Wodin, J.; Woisard, D.; Baussan, E.; Breidenbach, M.; Conley, R.; Fairbank, W. Jr.; Farine, J.; Hall, K.; Hallman, D.; Hargrove, C.; Stanford U., Phys. Dept.; Applied Plastics Technology, Bristol; Neuchatel U.; SLAC; Colorado State U.; Laurentian U.; Carleton U.; Alabama U.; Moscow, ITEP

2007-01-01

A novel technique has been developed to build vessels for liquid xenon ionization detectors entirely out of ultra-clean fluoropolymer. We describe the advantages in terms of low radioactivity contamination, provide some details of the construction techniques, and show the energy resolution achieved with a prototype all-fluoropolymer ionization detector

Electron-ion collision rates in atomic clusters irradiated by femtosecond laser pulses

International Nuclear Information System (INIS)

Moll, M; Hilse, P; Schlanges, M; Bornath, Th; Krainov, V P

2010-01-01

In atomic clusters irradiated by femtosecond laser pulses, plasmas with high density and high temperature are created. The heating is mainly caused by inverse bremsstrahlung, i.e. determined by electron-ion collisions. In the description of the scattering of electrons on noble gas ions in such plasmas, it is important to account for the inner structure of the ions and the screening by the surrounding plasma medium which can be accomplished by using suitable model potentials. In the wide parameter range met in experiments, the Born approximation is not applicable. Instead, the electron-ion collision frequency is calculated on the basis of classical momentum transport cross sections. Results are presented for xenon, krypton and argon ions in different charge states. A comparison of these results to those for the scattering on Coulomb particles with the same charge shows an enhancement of the collision frequency. The Born approximation, however, leads to an overestimation.

Direct Dark Matter Detection through the use of a Xenon Based TPC Detector

Science.gov (United States)

Daniel, Jonathan; Akerib, Daniel; LZ group at SLAC

2018-01-01

The vast majority of matter in the universe is unaccounted for. Only 15% of the universe's mass density is visible matter, while the other 85% is Dark Matter (DM). The Weakly Interacting Massive Particle (WIMP) is currently the frontrunner of the DM candidates. The Large Underground Xenon (LUX) and next generation LUX-ZEPLIN (LZ) experiments are designed to directly detect WIMPs. Both experiments are xenon-based Time Projection Chambers (TPC) used to observe possible WIMP interactions. These interactions produce photons and electrons with the photons being collected in a set of two photomultiplier tube (PMT) arrays and the electrons drifted upwards in the detector by a strong electric field to create a secondary production of photons in gaseous xenon. These two populations of photons are classified as S1 and S2 signals, respectively. Using these signals we reconstruct the energy and position of the interaction and in doing so we can eliminate background events that would otherwise “light up” the detector. My participation in the experiment, while at SLAC, was the creation of the grids that produce the large electric field, along with additional lab activities aimed at testing the grids. While at Stan State, I work on background modeling in order to distinguish a possible WIMP signal from ambient backgrounds.

Time-synchronized continuous wave laser-induced fluorescence on an oscillatory xenon discharge.

Science.gov (United States)

MacDonald, N A; Cappelli, M A; Hargus, W A

2012-11-01

A novel approach to time-synchronizing laser-induced fluorescence measurements to an oscillating current in a 60 Hz xenon discharge lamp using a continuous wave laser is presented. A sample-hold circuit is implemented to separate out signals at different phases along a current cycle, and is followed by a lock-in amplifier to pull out the resulting time-synchronized fluorescence trace from the large background signal. The time evolution of lower state population is derived from the changes in intensity of the fluorescence excitation line shape resulting from laser-induced fluorescence measurements of the 6s(')[1/2](1)(0)-6p(')[3/2](2) xenon atomic transition at λ = 834.68 nm. Results show that the lower state population oscillates at twice the frequency of the discharge current, 120 Hz.

The production of hadrons in the muon scattering on deuterium and xenon nuclei at 480 GeV

International Nuclear Information System (INIS)

Soeldner-Rembold, S.

1992-10-01

For the present thesis the hadronic final states of 6309 muon-deuterium events and 2064 muon-xenon events in the kinematical range Q 2 >1 (GeV/c) 2 , x>0.002, 0.1 3.5 mrad were studied. The multiplicity distributions of the muon-deuterium events and the muon-xenon events were described by means of the negative binomial distribution in intervals of the c.m. energy W. The two parameters anti n (mean multiplicity) and 1/k show for the muon-deuterium events a linear dependence on ln W 2 . The mean multiplicity anti n on xenon (anti n=10.43±0.19) is distinctly higher than on deuterium (anti n=7.76±0.07). The rapidity distributions of the positively charged and the negatively charged hadrons from muon-deuterium events are very well described by the Monte-Carlo program LUND. In the two-particle rapidity correlation both short-range and long-range correlations can be detected. The two-particle rapidity correlation in the xenon data are different from the deuterium data in the backward range. This difference indicates that the intranuclear cascade takes place in a limited range of small rapidities - relatively independently on the residual fragmentation process. (orig.) [de

[Effects of xenon and krypton-containing breathing mixtures on clinical and biochemical blood indices in animals].

Science.gov (United States)

Kussmaul', A R; Bogacheva, M A; Shkurat, T P; Pavlov, B N

2007-01-01

Effects of 24-hr breathing air mixtures containing xenon (XBM) and krypton (KBM) were compared in terms of hormonal status, and blood biochemical indices and morphology in laboratory animals. Some changes observed in blood and hormone indices could be a nonspecific adaptive response. Hence, we should elicit whether these effects are quickly reversible or long. For several indices krypton was a more favorable factor than xenon. However, some of its effects invite to delve into effects of different krypton concentrations on organism.

Mapping local cerebral blood flow by means of computerized tomography with a short inhalation of low-dose stable xenon

International Nuclear Information System (INIS)

Nakagawara, Jyoji; Karasawa, Jun; Tasawa, Toshiaki; Touho, Hajime; Nakauchi, Mikio; Kagawa, Masa-aki; Asai, Masa-aki; Kuriyama, Yoshihiro; Kikuchi, Haruhiko.

1986-01-01

A non-invasive technique has been developed for mapping the local blood-brain partition coefficient (λi), the local build-up rate constant (κi), and the local cerebral blood flow (l-CBF) by means of xenon-enhanced computerized tomography (CT) using a YMS CT 9000 scanner. After denitrogenation for 10 minutes, a 30 % xenon/oxygen mixture is inhaled for 4 - 8 minutes through a rubber face-mask and a delivery system of stable xenon. The time course of local cerebral CT enhancement is utilized in order to calculate, the λi, κi, and l-CBF values. The CT enhancement data during the washin-washout phase are fitted to the mathematical functions, based on Kety's formula, using least-squares curve-fitting analysis. Several case studies of patients with cerebral vascular accidents are presented to demonstrate the characterization of the λi and l-CBF patterns in various tissues; the results are of sufficient quality for the management of patients. The theoretical assumptions underlying stable xenon CT CBF measurements are discussed. (author)

Spectroscopic Investigations of Highly Charged Ions using X-Ray Calorimeter Spectrometers

Energy Technology Data Exchange (ETDEWEB)

Thorn, Daniel Bristol [Univ. of California, Davis, CA (United States)

2008-11-19

Spectroscopy of K-shell transitions in highly charged heavy ions, like hydrogen-like uranium, has the potential to yield information about quantum electrodynamics (QED) in extremely strong nuclear fields as well as tests of the standard model, specifically parity violation in atomic systems. These measurements would represent the 'holy grail' in high-Z atomic spectroscopy. However, the current state-of-the-art detection schemes used for recording the K-shell spectra from highly charged heavy ions does not yet have the resolving power to be able to attain this goal. As such, to push the field of high-Z spectroscopy forward, new detectors must be found. Recently, x-ray calorimeter spectrometers have been developed that promise to make such measurements. In an effort to make the first steps towards attaining the 'holy grail', measurements have been performed with two x-ray calorimeter spectrometers (the XRS/EBIT and the ECS) designed and built at Goddard Space Flight Center in Greenbelt, MD. The calorimeter spectrometers have been used to record the K-shell spectra of highly charged ions produced in the SuperEBIT electron beam ion trap at Lawrence Livermore National Laboratory in Livermore, CA. Measurements performed with the XRS/EBIT calorimeter array found that the theoretical description of well-above threshold electron-impact excitation cross sections for hydrogen-like iron and nickel ions are correct. Furthermore, the first high-resolution spectrum of hydrogen-like through carbon-like praseodymium ions was recorded with a calorimeter. In addition, the new high-energy array on the EBIT Calorimeter Spectrometer (ECS) was used to resolve the K-shell x-ray emission spectrum of highly charged xenon ions, where a 40 ppm measurement of the energy of the K-shell resonance transition in helium-like xenon was achieved. This is the highest precision result, ever, for an element with such high atomic number. In addition, a first-of-its-kind measurement of

Spectroscopic Investigations of Highly Charged Ions using X-Ray Calorimeter Spectrometers

International Nuclear Information System (INIS)

Thorn, D. B.

2008-01-01

Spectroscopy of K-shell transitions in highly charged heavy ions, like hydrogen-like uranium, has the potential to yield information about quantum electrodynamics (QED) in extremely strong nuclear fields as well as tests of the standard model, specifically parity violation in atomic systems. These measurements would represent the 'holy grail' in high-Z atomic spectroscopy. However, the current state-of-the-art detection schemes used for recording the K-shell spectra from highly charged heavy ions does not yet have the resolving power to be able to attain this goal. As such, to push the field of high-Z spectroscopy forward, new detectors must be found. Recently, x-ray calorimeter spectrometers have been developed that promise to make such measurements. In an effort to make the first steps towards attaining the 'holy grail', measurements have been performed with two x-ray calorimeter spectrometers (the XRS/EBIT and the ECS) designed and built at Goddard Space Flight Center in Greenbelt, MD. The calorimeter spectrometers have been used to record the K-shell spectra of highly charged ions produced in the SuperEBIT electron beam ion trap at Lawrence Livermore National Laboratory in Livermore, CA. Measurements performed with the XRS/EBIT calorimeter array found that the theoretical description of well-above threshold electron-impact excitation cross sections for hydrogen-like iron and nickel ions are correct. Furthermore, the first high-resolution spectrum of hydrogen-like through carbon-like praseodymium ions was recorded with a calorimeter. In addition, the new high-energy array on the EBIT Calorimeter Spectrometer (ECS) was used to resolve the K-shell x-ray emission spectrum of highly charged xenon ions, where a 40 ppm measurement of the energy of the K-shell resonance transition in helium-like xenon was achieved. This is the highest precision result, ever, for an element with such high atomic number. In addition, a first-of-its-kind measurement of the effect of the

Modification of the axial offsets trajectory method to control xenon oscillation during load following operations

International Nuclear Information System (INIS)

Shimazu, Yoichiro

1996-01-01

A new method which can give continuous guidance for controlling axial xenon oscillations in large PWRs has been presented. The method is based on two additional newly defined axial offsets, A Oi and A Ox together with the conventional axial offset of power distribution A Op. A Oi and A Ox are the axial offsets of power distributions which would give the current iodine and xenon distributions under equilibrium conditions, respectively. The information from A Oi, A Ox and A Op are used to display the trajectory of (A Op - A Ox, A Oi - A Ox) in the X-Y plane. The trajectory shows a very characteristic behavior. With the characteristics in mind the xenon oscillation can be controlled quite easily to lead the plot to the origin where three A Os are identical. The method has been proved with the power level constant. However, it is necessary to modify the definition of A Ox so as to apply this method to load following operations. A reasonable way of the modification is described and the results are presented. (author)

Determination of hyperacute kidney rejection in different xenogeneic system by 133xenon washout technique

International Nuclear Information System (INIS)

Welter, H.; Schmidt, K.R.; Pfeifer, K.J.; Hammer, C.; Chaussy, C.

1980-01-01

1. 133 Xenon washout technique is suitable for studying all stages of xenogeneic kidney rejection. 2. Follow-up studies allow differentiation between kidney rejection and kidneys in shock. 3. Changes of intrarenal blood flow distribution correlate with the histologic changes caused by rejection. 4. Total blood flow measurements employing 133 xenon washout yield 10-20% lower values compared with venous outflow measurements. 5. Graft rejection in the xenogeneic cat-dog system can be significantly delayed by ALG pretreatment. 6. The beneficial effect of blood transfusion described in different clinical and experimental studies could not be found after pretreatment of dogs with fox red blood cells. (orig.)

Pyramidal pits created by single highly charged ions in BaF2 single crystals

International Nuclear Information System (INIS)

El-Said, A. S.; Heller, R.; Facsko, S.; Aumayr, F.

2010-01-01

In various insulators, the impact of individual slow highly charged ions (eV-keV) creates surface nanostructures, whose size depends on the deposited potential energy. Here we report on the damage created on a cleaved BaF 2 (111) surface by irradiation with 4.5xq keV highly charged xenon ions from a room-temperature electron-beam ion trap. Up to charge states q=36, no surface topographic changes on the BaF 2 surface are observed by scanning force microscopy. The hidden stored damage, however, can be made visible using the technique of selective chemical etching. Each individual ion impact develops into a pyramidal etch pits, as can be concluded from a comparison of the areal density of observed etch pits with the applied ion fluence (typically 10 8 ions/cm 2 ). The dimensional analysis of the measured pits reveals the significance of the deposited potential energy in the creation of lattice distortions/defects in BaF 2 .

A liquid-xenon calorimeter for the detection of electromagnetic showers

International Nuclear Information System (INIS)

Baranov, A.; Baskakov, V.; Bondarenko, G.; Dolgoshein, B.; Lebedenko, V.N.; Tcherniatin, V.; Gavrilenko, I.; Kozodaeva, O.; Konovalov, S.; Muraviev, S.; Shmeleva, A.; Vassiliev, P.

1990-01-01

The energy and spatial resolution of a 40 l liquid-xenon calorimeter was measured. For electrons in the energy region 1-6 GeV the resolutions are σ E /E=3.4/√E (%), σ x =4.6/√E (mm). The details of construction and running of such a device are discussed. (orig.)

133 xenon muscle clearance as a test parameter in the diagnosis of peripheral diabetic angiopathies

International Nuclear Information System (INIS)

Kuhlmann, J.E.

1980-01-01

In 100 patients with manifest diabetes mellitus the irrigation in both legs at rest and in radioactive hyperemia after ischemic muscle work was measured by means of the 133-xenon muscle clearance. The clearance values measured ranged between 0.8 and 3.5 ml/100 g/60 s at rest and between 3.3 and 40.0 ml/100 gl/60 s during radioactive hyperemia. In 96 pc of the probands the irrigation of the legs was impaired. For the relation between glucose level and irrigation at rest a significant negative correlation was found. The difference between the clearance values for the right and left lower extremity was significant. For the relation between glucose level and reactive hyperemia, too, a significant negative correlation was found. The difference between the clearance values for the right and left lower extremities was significant. The measurement of the irrigation at rest showed no significant correlation between the period of manifestation of the diabetes and the clearance values. By contrast, the irrigation values during reactive hyperemia were shown to be in significantly negative correlation to the duration of the diabetes. No connection was found between the frequency of diabetic gangrene and impaired irrigation at rest. By contrast, there was a relation between decreasing hyperemia values and increased frequency of gangrene. A collection of case histories shows how the measuring results of the xenon clearance fit into the overall clinical picture. A comparison of xenon clearance with other methods of irrigation measurement confirmed obvious advantages of xenon clearance for the detection of diabetic microangiopathies. (orig./MG) [de

Stoichiometric carbon nitride synthesized by ion beam sputtering and post nitrogen ion implantation

International Nuclear Information System (INIS)

Valizadeh, R.; Colligon, J.S.; Katardiev, I.V.; Faunce, C.A.; Donnelly, S.E.

1998-01-01

Full text: Carbon nitride films have been deposited on Si (100) by ion beam sputtering a vitreous graphite target with nitrogen and argon ions with and without concurrent N2 ion bombardment at room temperature. The sputtering beam energy was 1000 eV and the assisted beam energy was 300 eV with ion / atom arrival ratio ranging from 0.5 to 5. The carbon nitride films were deposited both as single layer directly on silicon substrate and as multilayer between two layers of stoichiometric amorphous silicon nitride and polycrystalline titanium nitride. The deposited films were implanted ex-situ with 30 keV nitrogen ions with various doses ranging from 1E17 to 4E17 ions.cm -2 and 2 GeV xenon ion with a dose of 1E12 ions.cm -2 . The nitrogen concentration of the films was measured with Rutherford Backscattering (RBS), Secondary Neutral Mass Spectrometry (SNMS) and Parallel Electron Energy Loss Spectroscopy (PEELS). The nitrogen concentration for as deposited sample was 34 at% and stoichiometric carbon nitride C 3 N 4 was achieved by post nitrogen implantation of the multi-layered films. Post bombardment of single layer carbon nitride films lead to reduction in the total nitrogen concentration. Carbon K edge structure obtained from PEELS analysis suggested that the amorphous C 3 N 4 matrix was predominantly sp 2 bonded. This was confirmed by Fourier Transforrn Infra-Red Spectroscopy (FTIR) analysis of the single CN layer which showed the nitrogen was mostly bonded with carbon in nitrile (C≡N) and imine (C=N) groups. The microstructure of the film was determined by Transmission Electron Microscopy (TEM) which indicated that the films were amorphous

RF Noise Generation in High-Pressure Short-Arc DC Xenon Lamps

Science.gov (United States)

Minayeva, Olga; Doughty, Douglas

2007-10-01

Continuous direct current xenon arcs will generate RF noise under certain circumstance, which can lead to excessive electro- magnetic interference in systems that use these arcs as light sources. Phenomenological observations are presented for xenon arcs having arc gaps ˜1 mm, cold fill pressures of ˜2.5 MPa, and currents up to 30 amps. Using a loop antenna in the vicinity of an operating lamp, it is observed that as the current to the arc is lowered there is a reproducible threshold at which the RF noise generation begins. This threshold is accompanied by a small abrupt drop in voltage (˜0.2 volts). The RF emission appears in pulses ˜150 nsec wide separated by ˜300 nec - the pulse interval decreases with decreasing current. The properties of the RF emission as a function of arc parameters (such as pressure, arc gap, electrode design) will be discussed and a semi-quantitative model presented.

A comparative study of TiN and TiC: Oxidation resistance and retention of xenon at high temperature and under degraded vacuum

International Nuclear Information System (INIS)

Gavarini, S.; Bes, R.; Millard-Pinard, N.; Peaucelle, C.; Perrat-Mabilon, A.; Gaillard, C.; Cardinal, S.; Garnier, V.

2011-01-01

Dense TiN and TiC samples were prepared by hot pressing using micrometric powders. Xenon species (simulating rare gas fission products) were then implanted into the ceramics. The samples were annealed for 1 h at 1500 deg. C under several degraded vacuums with P O 2 varying from 10 -6 to 2x10 -4 mbars. The oxidation resistance of the samples and their retention properties with respect to preimplanted xenon species were analyzed using scanning electron microscopy, grazing incidence x-ray diffraction, Rutherford backscattering spectrometry, and nuclear backscattering spectrometry. Results indicate that TiC is resistant to oxidation and does not release xenon for P O 2 ≤6x10 -6 mbars. When P O 2 increases, geometric oxide crystallites appear at the surface depending on the orientation and size of TiC grains. These oxide phases are Ti 2 O 3 , Ti 3 O 5 , and TiO 2 . Apparition of oxide crystallites is associated with the beginning of xenon release. TiC surface is completely covered by the oxide phases at P O 2 =2x10 -4 mbars up to a depth of 3 μm and the xenon is then completely released. For TiN samples, the results show a progressive apparition of oxide crystallites (Ti 3 O 5 mainly) at the surface when P O 2 increases. The presence of the oxide crystallites is also directly correlated with xenon release, the more oxide crystallites are growing the more xenon is released. TiN surface is completely covered by an oxide layer at P O 2 =2x10 -4 mbars up to 1 μm. A correlation between the initial fine microstructure of TiN and the properties of the growing layer is suggested.

Strength function of xenon 127 and cross section of 127I(νe, e-)127Xe reaction

International Nuclear Information System (INIS)

Lyutostanskij, Yu.S.; Shul'gina, N.B.

1989-01-01

The strenght functions S β (E) and the cross section of the reaction ν e + 127 I → e - + 127 Xe were calculated in the framework of the theory of finite Fermi-systems. The results obtained are used to estimate the possibility of using an iodine-xenon detector in the experiments with solar neutrinos and reactor antineutrinos. The advantages of the iodine-xenon detector over the chlorine-argon one are shown. 13 refs.; 6 figs.; 3 tabs

Time-synchronized continuous wave laser-induced fluorescence on an oscillatory xenon discharge

Energy Technology Data Exchange (ETDEWEB)

MacDonald, N. A.; Cappelli, M. A. [Stanford Plasma Physics Laboratory, Stanford University, Stanford, California 94305 (United States); Hargus, W. A. Jr. [Air Force Research Laboratory, Edwards AFB, California 93524 (United States)

2012-11-15

A novel approach to time-synchronizing laser-induced fluorescence measurements to an oscillating current in a 60 Hz xenon discharge lamp using a continuous wave laser is presented. A sample-hold circuit is implemented to separate out signals at different phases along a current cycle, and is followed by a lock-in amplifier to pull out the resulting time-synchronized fluorescence trace from the large background signal. The time evolution of lower state population is derived from the changes in intensity of the fluorescence excitation line shape resulting from laser-induced fluorescence measurements of the 6s{sup Prime }[1/2]{sub 1}{sup 0}-6p{sup Prime }[3/2]{sub 2} xenon atomic transition at {lambda}= 834.68 nm. Results show that the lower state population oscillates at twice the frequency of the discharge current, 120 Hz.

A liquid-xenon calorimeter for the detection of electromagnetic showers

Energy Technology Data Exchange (ETDEWEB)

Baranov, A.; Baskakov, V.; Bondarenko, G.; Dolgoshein, B.; Lebedenko, V.N.; Tcherniatin, V. (Moskovskij Inzhenerno-Fizicheskij Inst. (USSR)); Gavrilenko, I.; Kozodaeva, O.; Konovalov, S.; Muraviev, S.; Shmeleva, A.; Vassiliev, P. (AN SSSR, Moscow. Fizicheskij Inst. (USSR))

1990-09-15

The energy and spatial resolution of a 40 l liquid-xenon calorimeter was measured. For electrons in the energy region 1-6 GeV the resolutions are {sigma}{sub E}/E=3.4/{radical}E (%), {sigma}{sub x}=4.6/{radical}E (mm). The details of construction and running of such a device are discussed. (orig.).

Production of fusion radionuclides: Molybdenum-99/ Iodine - 131 and Xenon-133; Produccion de los radionucleidos de fision: Molibdeno-99, Yodo-131 y Xenon-133

Energy Technology Data Exchange (ETDEWEB)

Barrachina, M; Carrillo, D

1982-07-01

This report presents a new radiochemical method for industrial production of the radionuclides: molybdenum-99, iodine-131 and xenon-133. The above mentioned method based on the alkaline metathesis reaction of irradiated uranium (IV) fluoride, presents the best characteristics for the proposed objective. The study deals with the analysis of that reaction and the separation and purification processes. (Author) 71 refs.

Prototyping of beam position monitor for medium energy beam transport section of RAON heavy ion accelerator

Energy Technology Data Exchange (ETDEWEB)

Jang, Hyojae, E-mail: lkcom@ibs.re.kr; Jin, Hyunchang; Jang, Ji-Ho; Hong, In-Seok [Rare Isotope Science Project, Institute for Basic Science, Daejeon (Korea, Republic of)

2016-02-15

A heavy ion accelerator, RAON is going to be built by Rare Isotope Science Project in Korea. Its target is to accelerate various stable ions such as uranium, proton, and xenon from electron cyclotron resonance ion source and some rare isotopes from isotope separation on-line. The beam shaping, charge selection, and modulation should be applied to the ions from these ion sources because RAON adopts a superconducting linear accelerator structure for beam acceleration. For such treatment, low energy beam transport, radio frequency quadrupole, and medium energy beam transport (MEBT) will be installed in injector part of RAON accelerator. Recently, development of a prototype of stripline beam position monitor (BPM) to measure the position of ion beams in MEBT section is under way. In this presentation, design of stripline, electromagnetic (EM) simulation results, and RF measurement test results obtained from the prototyped BPM will be described.

Unitary theory of xenon instability in nuclear thermal reactors - 1. Reactor at 'zero power'

Energy Technology Data Exchange (ETDEWEB)

Novelli, A. (Politecnico di Milano (Italy). Centro Studi Nucleari E. Fermi)

1982-01-01

The question of nuclear thermal-reactor instability against xenon oscillations is widespread in the literature, but most theories, concerned with such an argument, contradict each other and, above all, they conflict with experimentally-observed instability at very low reactor power, i.e. without any power feedback. It is shown that, in any nuclear thermal reactor, xenon instability originates at very low power levels, and a very general stability condition is deduced by an extension of the rigorous, simple and powerful reduction of the Nyquist criterion, first performed by F. Storrer.

Swift heavy ion irradiation of CaF2 - from grooves to hillocks in a single ion track

Science.gov (United States)

Gruber, Elisabeth; Salou, Pierre; Bergen, Lorenz; El Kharrazi, Mourad; Lattouf, Elie; Grygiel, Clara; Wang, Yuyu; Benyagoub, Abdenacer; Levavasseur, Delphine; Rangama, Jimmy; Lebius, Henning; Ban-d'Etat, Brigitte; Schleberger, Marika; Aumayr, Friedrich

2016-10-01

A novel form of ion-tracks, namely nanogrooves and hillocks, are observed on CaF2 after irradiation with xenon and lead ions of about 100 MeV kinetic energy. The irradiation is performed under grazing incidence (0.3°-3°) which forces the track to a region in close vicinity to the surface. Atomic force microscopy imaging of the impact sites with high spatial resolution reveals that the surface track consists in fact of three distinct parts: each swift heavy ion impacting on the CaF2 surface first opens a several 100 nm long groove bordered by a series of nanohillocks on both sides. The end of the groove is marked by a huge single hillock and the further penetration of the swift projectile into deeper layers of the target is accompanied by a single protrusion of several 100 nm in length slowly fading until the track vanishes. By comparing experimental data for various impact angles with results of a simulation, based on a three-dimensional version of the two-temperature-model (TTM), we are able to link the crater and hillock formation to sublimation and melting processes of CaF2 due to the local energy deposition by swift heavy ions.

Observation of electron multiplication in liquid xenon with a microstrip plate

International Nuclear Information System (INIS)

Policarpo, A.P.L.; Geltenbort, P.; Ferreira Marques, R.; Araujo, H.; Fraga, F.; Alves, M.A.; Fonte, P.; Lima, E.P.; Fraga, M.M.; Salete Leite, M.; Silander, K.; Onofre, A.; Pinhao, J.M.

1995-01-01

We report here on the observation of electron multiplication in liquid xenon in a microstrip chamber with an amplification factor of the order of 10. The measurements were carried out at a temperature between 208 and 215 K (liquid density of about 2.7 g/cm 3 ). (orig.)

Resonance ionization spectroscopy of argon, krypton, and xenon using vacuum ultraviolet light

International Nuclear Information System (INIS)

Kramer, S.D.

1984-04-01

Resonant, single-photon excitation of ground state inert gases requires light in the vacuum ultraviolet spectral region. This paper discusses methods for generating this light. Efficient schemes for ionizing argon, krypton, and xenon using resonant, stepwise single-photon excitation are presented

Demonstration of Single-Barium-Ion Sensitivity for Neutrinoless Double-Beta Decay Using Single-Molecule Fluorescence Imaging

Energy Technology Data Exchange (ETDEWEB)

McDonald, A. D.; Jones, B. J. P.; Nygren, D. R.; Adams, C.; Álvarez, V.; Azevedo, C. D. R.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carrión, J. V.; Cebrián, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Escada, J.; Esteve, R.; Felkai, R.; Fernandes, L. M. P.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Goldschmidt, A.; Gómez-Cadenas, J. J.; González-Díaz, D.; Gutiérrez, R. M.; Guenette, R.; Hafidi, K.; Hauptman, J.; Henriques, C. A. O.; Hernandez, A. I.; Hernando Morata, J. A.; Herrero, V.; Johnston, S.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; Monrabal, F.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Repond, J.; Renner, J.; Riordan, S.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Webb, R.; White, J. T.; Yahlali, N.

2018-03-01

A new method to tag the barium daughter in the double beta decay of $^{136}$Xe is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba$^{++}$) resolution at a transparent scanning surface has been demonstrated. A single-step photo-bleach confirms the single ion interpretation. Individual ions are localized with super-resolution ($\\sim$2~nm), and detected with a statistical significance of 12.9~$\\sigma$ over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.

Demonstration of Single-Barium-Ion Sensitivity for Neutrinoless Double-Beta Decay Using Single-Molecule Fluorescence Imaging

Science.gov (United States)

McDonald, A. D.; Jones, B. J. P.; Nygren, D. R.; Adams, C.; Álvarez, V.; Azevedo, C. D. R.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carrión, J. V.; Cebrián, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Escada, J.; Esteve, R.; Felkai, R.; Fernandes, L. M. P.; Ferrario, P.; Ferreira, A. L.; Freitas, E. D. C.; Goldschmidt, A.; Gómez-Cadenas, J. J.; González-Díaz, D.; Gutiérrez, R. M.; Guenette, R.; Hafidi, K.; Hauptman, J.; Henriques, C. A. O.; Hernandez, A. I.; Hernando Morata, J. A.; Herrero, V.; Johnston, S.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; Monrabal, F.; Monteiro, C. M. B.; Mora, F. J.; Moutinho, L. M.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Repond, J.; Renner, J.; Riordan, S.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Webb, R.; White, J. T.; Yahlali, N.; NEXT Collaboration

2018-03-01

A new method to tag the barium daughter in the double-beta decay of Xe 136 is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba++ ) resolution at a transparent scanning surface is demonstrated. A single-step photobleach confirms the single ion interpretation. Individual ions are localized with superresolution (˜2 nm ), and detected with a statistical significance of 12.9 σ over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double-beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.

First light on 3d photoionization of multiply charged xenon ions: a new photon-ion merged beam setup at PETRA III

International Nuclear Information System (INIS)

Ricz, S; Schippers, S; Buhr, T; Holste, K; Jr, A Borovik; Hellhund, J; Schäfer, H-J; Schury, D; Klumpp, S; Mertens, K; Martins, M; Flesch, R; Ulrich, G; Rühl, E; Lower, J; Jahnke, T; Metz, D; Schmidt, L; Schöffler, M; Williams, J B

2014-01-01

A photon-ion merged beam endstation has been set up at the variable polarization XUV-beamline P04 of PETRA III in Hamburg. In a commissioning experiment first results could be obtained for multiple photoionization of Xe q+ ions (q = 1,2,..,5) at photon energies around the 3d ionization threshold.

Numerical scheme for optimization of xenon transient processes in a reactor. Problem on fast response without a limitation for phase variables

International Nuclear Information System (INIS)

Gerasimov, A.S.

1975-01-01

A numerical diagram is suggested of minimizing a period of xenon transient process in the reactor without any limitation of xenon-135 concentration. The problem is solved with a computer in a point model. Pontryagin's maximum principle is used so as to check optimization of the transient process

Study of light detection and sensitivity for a ton-scale liquid xenon dark matter detector

International Nuclear Information System (INIS)

Wei, Y; Lin, Q; Xiao, X; Ni, K

2013-01-01

Ton-scale liquid xenon detectors operated in two-phase mode are proposed and being constructed recently to explore the favored parameter space for the Weakly Interacting Massive Particles (WIMPs) dark matter. To achieve a better light collection efficiency while limiting the number of electronics channels compared to the previous generation detectors, large-size photo-multiplier tubes (PMTs) such as the 3-inch-diameter R11410 from Hamamatsu are suggested to replace the 1-inch-square R8520 PMTs. In a two-phase xenon dark matter detector, two PMT arrays on the top and bottom are usually used. In this study, we compare the performance of two different ton-scale liquid xenon detector configurations with the same number of either R11410 (config.1) or R8520 (config.2) for the top PMT array, while both using R11410 PMTs for the bottom array. The self-shielding of liquid xenon suppresses the background from the PMTs and the dominant background is from the pp solar neutrinos in the central fiducial volume. The light collection efficiency for the primary scintillation light is largely affected by the xenon purity and the reflectivity of the reflectors. In the optimistic situation with a 10 m light absorption length and a 95% reflectivity, the light collection efficiency is 43%(34%) for config.1(config.2). In the conservative situation with a 2.5 m light absorption length and a 85% reflectivity, the value is only 18%(13%) for config.1(config.2). The difference between the two configurations is due to the larger PMT coverage on the top for config.1. The slightly different position resolutions for the two configurations have a negligible effect on the sensitivity. Based on the above considerations, we estimate the sensitivity reach of the two detector configurations. Both configurations can reach a sensitivity of 2 ∼ 3 × 10 −47 cm 2 for spin-independent WIMP-nucleon cross section for 100 GeV/c 2 WIMPs after two live-years of operation. The one with R8520 PMTs for the top

Cluster formation restricts dynamic nuclear polarization of xenon in solid mixtures

DEFF Research Database (Denmark)

Kuzma, N. N.; Pourfathi, M.; Kara, H.

2012-01-01

During dynamic nuclear polarization (DNP) at 1.5 K and 5 T, Xe-129 nuclear magnetic resonance (NMR) spectra of a homogeneous xenon/1-propanol/trityl-radical solid mixture exhibit a single peak, broadened by H-1 neighbors. A second peak appears upon annealing for several hours at 125 K. Its...

Control of xenon spatial oscillations during load follow of nuclear reactor via robust servo systems

International Nuclear Information System (INIS)

Ukai, Hiroyuki; Yada, Yukihiro; Iwazumi, Tetsuo; Morita, Yoshifumi.

1990-01-01

This paper investigates the control problem of xenon spatial oscillations in the axial direction during load following operations of a nuclear reactor. The system model is described by a one-group diffusion equation with xenon and power feedbacks and iodine-xenon dynamic equations and controlled by full-length and part-length control rods. In order to achieve the control purpose we formulate the control model as the design problem of robust servo systems for distributed parameter reactor systems. Hence the total thermal power and the axial offset are chosen as outputs to be controlled. The control law is designed based upon finite-dimensional systems which are constructed by linearizing around steady states, approximating by the Galerkin approximate method and reducing dimensions via the singular perturbation method. From a computational point of view a simple computational algorithm to obtain an approximate solution of the steady state neutron balance is developed via the perturbation method. Some results of numerical simulations are represented to show effectiveness of the theory developed in this paper. Particularly it is shown that the designed servo systems are robust against model errors with the linearization and the model truncation. (author)

Iterative Boltzmann plot method for temperature and pressure determination in a xenon high pressure discharge lamp

Energy Technology Data Exchange (ETDEWEB)

Zalach, J.; Franke, St. [INP Greifswald, Felix-Hausdorff-Str. 2, 17489 Greifswald (Germany)

2013-01-28

The Boltzmann plot method allows to calculate plasma temperatures and pressures if absolutely calibrated emission coefficients of spectral lines are available. However, xenon arcs are not very well suited to be analyzed this way, as there are only a limited number of lines with atomic data available. These lines have high excitation energies in a small interval between 9.8 and 11.5 eV. Uncertainties in the experimental method and in the atomic data further limit the accuracy of the evaluation procedure. This may result in implausible values of temperature and pressure with inadmissible uncertainty. To omit these shortcomings, an iterative scheme is proposed that is making use of additional information about the xenon fill pressure. This method is proved to be robust against noisy data and significantly reduces the uncertainties. Intentionally distorted synthetic data are used to illustrate the performance of the method, and measurements performed on a laboratory xenon high pressure discharge lamp are analyzed resulting in reasonable temperatures and pressures with significantly reduced uncertainties.

Studies of the beam extraction system of the GTS-LHC electron cyclotron resonance ion source at CERN.

Science.gov (United States)

Toivanen, V; Küchler, D

2016-02-01

The 14.5 GHz GTS-LHC Electron Cyclotron Resonance Ion Source (ECRIS) provides multiply charged heavy ion beams for the CERN experimental program. The GTS-LHC beam formation has been studied extensively with lead, argon, and xenon beams with varied beam extraction conditions using the ion optical code IBSimu. The simulation model predicts self-consistently the formation of triangular and hollow beam structures which are often associated with ECRIS ion beams, as well as beam loss patterns which match the observed beam induced markings in the extraction region. These studies provide a better understanding of the properties of the extracted beams and a way to diagnose the extraction system performance and limitations, which is otherwise challenging due to the lack of direct diagnostics in this region and the limited availability of the ion source for development work.

Xenon-133 retention in hepatic steatosis - correlation with liver biopsy in 45 patients: concise communication

International Nuclear Information System (INIS)

Ahmad, M.; Perrillo, R.P.; Sunwoo, Y.C.; Donati, R.M.

1979-01-01

This study presents the results of comparison of hepatic fat content with hepatic xenon retention in 45 patients. The degree of hepatic Xe-133 retention was measured during pulmonary ventilation studies. The amount of hepatic steatosis was graded 0 to 4+ on histologic liver sections obtained by needle or surgical biopsy. There was agreement between the amount of hepatic xenon retention determined scintigraphically and the degree of steatosis determined histologically. These results suggest that Xe-133 retention in the liver provides a simple means of evaluating fatty infiltration of the liver. The potential of this technique as a noninvasive means of investigating hepatic fatty infiltration is discussed

Quench gases for xenon- (and krypton-)filled proportional counters

International Nuclear Information System (INIS)

Ramsey, B.D.; Agrawal, P.C.

1988-01-01

Xenon-filled proportional counters are used extensively in astronomy, particularly in the hard X-ray region. The choice of quench gas can have a significant effect on the operating characteristics of the instrument although the data necessary to make the choice are not easily obtainable. We present results which detail the performance obtained from both cylindrical and parallel field geometries for a wide variety of readily available, ultrahigh or research grade purity, quench gases. (orig.)

Application of xenon difluoride for surface modification of polymers

International Nuclear Information System (INIS)

Barsamyan, G.B.; Belokonov, K.V.; Vargasova, N.A.; Sokolov, V.B.; Chaivanov, B.B.; Zubov, V.P.

1994-01-01

Chemical interaction between xenon difluoride (XeF 2 ) and polymeric materials was investigated. It was shown that the reaction occurs on the surface of solid polymer layer and brings to chemical modification of the surface properties of the polymer leaving the bulk properties unchanged. The results of various analysis of the fluorinated samples (IR, FTIR-ATR, ESCA, bulk analysis etc) are presented. The mechanism of reaction is proposed. 12 refs.; 13 figs

Ionization efficiency of a COMIC ion source equipped with a quartz plasma chamber

International Nuclear Information System (INIS)

Suominen, P.; Stora, T.; Sortais, P.; Medard, J.

2012-01-01

Increased ionization efficiencies of light noble gases and molecules are required for new physics experiments in present and future radioactive ion beam facilities. In order to improve these beams, a new COMIC-type ion source with fully quartz made plasma chamber was tested. The beam current stability is typically better than 1 % and beams are easily reproducible. The highest efficiency for xenon is about 15 %. However, the main goal is to produce molecular beam including radioactive carbon (in CO or CO 2 ), in which case the efficiency was measured to be only about 0.2%. This paper describes the experimental prototype and its performance and provides ideas for future development. This paper is followed by the associated poster. (authors)

Operation of TFTR neutral beams with heavy ions

International Nuclear Information System (INIS)

Kamperschroer, J.H.; Stevenson, T.N.; Wright, K.E.; Dudek, L.E.; Grisham, L.R.; Newman, R.A.; O'Connor, T.E.; Oldaker, M.E.; von Halle, A.; Williams, M.D.

1991-07-01

High Z neutral atoms have been injected into TFTR plasmas in an attempt to enhance plasma confinement through modification of the edge electric field. TFTR ion sources have extracted 9 A of 62 keV Ne + for up to 0.2 s during injection into deuterium plasmas, and for 0.5 s during conditioning pulses. Approximately 400 kW of Ne 0 have been injected from each of two ion sources. Operation was at full bending magnet current, with the Ne + barely contained on the ion dump. Beamline design modifications to permit operation up to 120 keV with krypton or xenon are described. Such ions are too massive to be deflected up to the ion dump. The plan, therefore, is to armor those components receiving these ions. Even with this armor, modest increases in the bending magnet current capability are necessary to safely reach 120 kV with Kr or Xe. Information relevant to heavy ion operation was also acquired when several ion sources were inadvertently operated with water contamination. Spectroscopic analysis of certain pathological pulses indicate that up to 6% of the extracted ions were water. After dissociation in the neutralizer, water yields oxygen ions which, as with Ne, Kr, and Xe, are under-deflected by the magnet. Damage to a calorimeter scraper, due to the focal properties of the magnet, has resulted. A magnified power density of 6 KW/cm 2 for 2 s, from ∼ 90 kW of O + , is the suspected cause. 11 refs., 4 figs

Theoretical investigation of the secondary ionization in krypton and xenon

International Nuclear Information System (INIS)

Saffo, M.E.

1986-01-01

A theoretical investigation of the secondary ionization processes that responsible for the pre-breakdown ionization current growth in a uniform electric field was studied in krypton and xenon gases, especially at low values of E/P 0 which is corresponding to high values of pressure, since there are a number of possible secondary ionization processes. It is interesting to carry out a quantitative analysis for the generalized secondary ionization coefficient obtained previously by many workers in terms of the production of excited states and their diffusion to the cathode and their destruction rate in the gas body. From energy balance equation for the electrons in the discharge, the fractional percentage energy losses of ionization, excitation, and elastic collisions to the total energy gained by the electron from the field has been calculated for krypton and xenon, as a result of such calculations; the conclusion drawn is that at low values of E/P 0 the main energy loss of electrons are in excited collision. Therefore, we are adopting a theoretical calculation for W/α under the assumption that the photo-electron emission at the cathode is the predominated secondary ionization process. 14 tabs.; 12 figs.; 64 refs

Energy loading effects in the scaling of atomic xenon lasers

International Nuclear Information System (INIS)

Ohwa, M.; Kushner, M.J.

1990-01-01

The intrinsic power efficiency of the atomic xenon (5d → 6p) infrared (1.73--3.65 μm) laser is sensitive to the rate of pumping due to electron collision mixing of the laser levels. Long duration pumping at moderate power deposition may therefore result in higher energy efficiencies than pumping at higher powers. In this paper the authors examine the consequences of high energy deposition (100's J/1 atm) during long pumping pulses (100's μs) on the intrinsic power and energy efficiency and optimum power deposition of the atomic xenon laser. The dominant effect of high energy loading, gas heating, causes an increase in the electron density and therefore an increase in the electron collision mixing of the laser levels. The optimum power deposition for a given gas density therefore shifts to lower values with increasing gas temperature. For sufficiently long pumping pulses, nonuniform gas heating results in convection and rarification of highly pumped regions. The optimum power deposition therefore shifts to even lower values as the length of the pumping pulse increases. As a result, laser efficiency depends on the spatial distribution of power deposition as well as its magnitude

A knowledge-based system for control of xenon-induced spatial power oscillations during load-follow operations

International Nuclear Information System (INIS)

Chung, Sun-Kyo; Danofsky, R.A.; Spinrad, B.I.

1988-01-01

As is well known, large pressurized water reactors (PWRs) are subject to xenon-induced axial power oscillations at some time during a given cycle. Attention to this behavior is required during load-follow operations. A knowledge-based system for controlling xenon-induced spatial power oscillations is described. Experience with a limited set of load-follow patterns has demonstrated that the system is capable of providing advice on appropriate control actions. A simulation model, coupled with a rule-learning process, has been found to be a useful way for determining appropriate weights for the rules that relate power patterns and control actions

Nuclear recoil energy scale in liquid xenon with application to the direct detection of dark matter

International Nuclear Information System (INIS)

Sorensen, Peter; Dahl, Carl Eric

2011-01-01

We show for the first time that the quenching of electronic excitation from nuclear recoils in liquid xenon is well-described by Lindhard theory, if the nuclear recoil energy is reconstructed using the combined (scintillation and ionization) energy scale proposed by Shutt et al. We argue for the adoption of this perspective in favor of the existing preference for reconstructing nuclear recoil energy solely from primary scintillation. We show that signal partitioning into scintillation and ionization is well described by the Thomas-Imel box model. We discuss the implications for liquid xenon detectors aimed at the direct detection of dark matter.

First Dark Matter Search Results from the XENON1T Experiment

Science.gov (United States)

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Amaro, F. D.; Anthony, M.; Arneodo, F.; Barrow, P.; Baudis, L.; Bauermeister, B.; Benabderrahmane, M. L.; Berger, T.; Breur, P. A.; Brown, A.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Bütikofer, L.; Calvén, J.; Cardoso, J. M. R.; Cervantes, M.; Cichon, D.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; de Perio, P.; di Gangi, P.; di Giovanni, A.; Diglio, S.; Eurin, G.; Fei, J.; Ferella, A. D.; Fieguth, A.; Fulgione, W.; Gallo Rosso, A.; Galloway, M.; Gao, F.; Garbini, M.; Gardner, R.; Geis, C.; Goetzke, L. W.; Grandi, L.; Greene, Z.; Grignon, C.; Hasterok, C.; Hogenbirk, E.; Howlett, J.; Itay, R.; Kaminsky, B.; Kazama, S.; Kessler, G.; Kish, A.; Landsman, H.; Lang, R. F.; Lellouch, D.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Lopes, J. A. M.; Manfredini, A.; Mariş, I.; Marrodán Undagoitia, T.; Masbou, J.; Massoli, F. V.; Masson, D.; Mayani, D.; Messina, M.; Micheneau, K.; Molinario, A.; Morâ, K.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Pakarha, P.; Pelssers, B.; Persiani, R.; Piastra, F.; Pienaar, J.; Pizzella, V.; Piro, M.-C.; Plante, G.; Priel, N.; Rauch, L.; Reichard, S.; Reuter, C.; Riedel, B.; Rizzo, A.; Rosendahl, S.; Rupp, N.; Saldanha, R.; Dos Santos, J. M. F.; Sartorelli, G.; Scheibelhut, M.; Schindler, S.; Schreiner, J.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Sivers, M. V.; Stein, A.; Thapa, S.; Thers, D.; Tiseni, A.; Trinchero, G.; Tunnell, C.; Vargas, M.; Upole, N.; Wang, H.; Wang, Z.; Wei, Y.; Weinheimer, C.; Wulf, J.; Ye, J.; Zhang, Y.; Zhu, T.; Xenon Collaboration

2017-11-01

We report the first dark matter search results from XENON1T, a ˜2000 -kg -target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042 ±12 )-kg fiducial mass and in the [5 ,40 ] keVnr energy range of interest for weakly interacting massive particle (WIMP) dark matter searches, the electronic recoil background was (1.93 ±0.25 )×10-4 events /(kg ×day ×keVee) , the lowest ever achieved in such a dark matter detector. A profile likelihood analysis shows that the data are consistent with the background-only hypothesis. We derive the most stringent exclusion limits on the spin-independent WIMP-nucleon interaction cross section for WIMP masses above 10 GeV /c2 , with a minimum of 7.7 ×10-47 cm2 for 35 -GeV /c2 WIMPs at 90% C.L.

Xenon plasma with caesium as additive

International Nuclear Information System (INIS)

Stojilkovic, S.M.; Novakovic, N.V.; Zivkovic, L.M.

1986-01-01

The concentration dependence of xenon plasma with cesium as additive in the temperature range of 2000 K to 20,000 K is analyzed. Plasma is considered as weakly nonideal in complete local thermodynamic equilibrium and the interaction between plasma and vessel walls is not taken into account. The values of some of the parameters for nonideality of plasma with 1% of cesium (γ=0.01010) and 10% of cesium (γ=0.11111) are computed, for an initial pressure in plasma of p 0 =13,000 Pa and initial temperature T 0 =1000 K. The ratio of electric conductivity of plasma computed by Lorentz's formula and electric conductivity computed by Spitzer's formula in the same temperature interval is also analyzed. (author) 5 figs., 2 tabs., 16 refs

Scintillation efficiency of nuclear recoil in liquid xenon

CERN Document Server

Arneodo, F; Badertscher, A; Benetti, P; Bernardini, E; Bettini, A; Borio di Tigliole, A A; Brunetti, R; Bueno, A G; Calligarich, E; Campanelli, M; Carpanese, C; Cavalli, D; Cavanna, F; Cennini, P; Centro, Sandro; Cesana, A; Cline, D; De Mitri, I; Dolfini, R; Ferrari, A; Gigli-Berzolari, A; Matthey, C; Mauri, F; Mazza, D; Mazzone, L; Meng, G; Montanari, C; Nurzia, G; Otwinowski, S; Palamara, O; Pascoli, D; Pepato, Adriano; Petrera, S; Periale, L; Piano Mortari, G; Piazzoli, A; Picchi, P; Pietropaolo, F; Rancati, T; Rappoldi, A; Raselli, G L; Rebuzzi, D; Revol, Jean Pierre Charles; Rico, J; Rossella, M; Rossi, C; Rubbia, André; Rubbia, Carlo; Sala, P; Scannicchio, D A; Sergiampietri, F; Suzuki, S; Terrani, M; Tian, W; Ventura, Sandro; Vignoli, C; Wang, H; Woo, J; Xu, Z

2000-01-01

We present the results of a test done with a Liquid Xenon (LXe) detector for 'Dark Matter' search, exposed to a neutron beam to produce nuclear recoil events simulating those which would be generated by WIMP's elastic scattering. The aim of the experiment was to measure directly the scintillation efficiency of nuclear recoil. The nuclear recoil considered in the test was in the tens of keV range. The ratio of measured visible energy over the true recoil energy was evaluated to be about 20%, in good agreement with the theoretical predictions.

Study of regional lung function with xenon 133

International Nuclear Information System (INIS)

Devaux, D.; Wagner, R.; Germain, M.; Chardon, G.

1975-01-01

Exploration of regional lung function includes study of the closed circuit perfusion and ventilation respectively by injection and inhalation of xenon 133. The radiation is measured across the chest using 4 fixed scintillation counters, placed opposite the subject's back, 2 per lung field. Theoretical regional values using 15 normal young subjects are determined. Three cases justified the practical interest of this method. The percentage of variation for the parameters studied was about 10%. The method proved very useful for the clinician to whom it provides a numerical assessment of regional ventilation and perfusion [fr

Cryogenic readout for multiple VUV4 Multi-Pixel Photon Counters in liquid xenon

Science.gov (United States)

Arneodo, F.; Benabderrahmane, M. L.; Bruno, G.; Conicella, V.; Di Giovanni, A.; Fawwaz, O.; Messina, M.; Candela, A.; Franchi, G.

2018-06-01

We present the performances and characterization of an array made of S13370-3050CN (VUV4 generation) Multi-Pixel Photon Counters manufactured by Hamamatsu and equipped with a low power consumption preamplifier operating at liquid xenon temperature (∼ 175 K). The electronics is designed for the readout of a matrix of maximum dimension of 8 × 8 individual photosensors and it is based on a single operational amplifier. The detector prototype presented in this paper utilizes the Analog Devices AD8011 current feedback operational amplifier, but other models can be used depending on the application. A biasing correction circuit has been implemented for the gain equalization of photosensors operating at different voltages. The results show single photon detection capability making this device a promising choice for future generation of large scale dark matter detectors based on liquid xenon, such as DARWIN.

Density of uranium ions in the 4I0/sub 9/2/ ground state in a hollow-cathode type discharge

International Nuclear Information System (INIS)

Pianarosa, P.; Bouchard, P.; Saint-Dizier, J.P.; Gagne, J.M.

1983-01-01

A hollow-cathode type discharge cell as generator of uranium ions is investigated. The 4 I 0 /sub 9/2/ ground-state ion density has been obtained by absorption spectroscopy at 5493 and 4244 A. The absorption measurements have been performed using two identical hollow-cathode lamps: one acting as a light source, the other as a reservoir of free ions. Neon and xenon have been used as discharge sustaining gases. In our experimental conditions the measured ion ground-state density is of the order of 10 12 ions cm -3 . Absorption measurements performed at 5915 and 4246 A of U i give a density of the order of 10 12 atoms cm -3 . This latter value is in excellent agreement with a previously measured value obtained by laser-absorption spectroscopy

Mirror dark matter will be confirmed or excluded by XENON1T

Energy Technology Data Exchange (ETDEWEB)

Clarke, J.D., E-mail: j.clarke5@pgrad.unimelb.edu.au; Foot, R., E-mail: rfoot@unimelb.edu.au

2017-03-10

Mirror dark matter, where dark matter resides in a hidden sector exactly isomorphic to the standard model, can be probed via direct detection experiments by both nuclear and electron recoils if the kinetic mixing interaction exists. In fact, the kinetic mixing interaction appears to be a prerequisite for consistent small scale structure: Mirror dark matter halos around spiral galaxies are dissipative – losing energy via dark photon emission. This ongoing energy loss requires a substantial energy input, which can be sourced from ordinary supernovae via kinetic mixing induced processes in the supernova's core. Astrophysical considerations thereby give a lower limit on the kinetic mixing strength, and indeed lower limits on both nuclear and electron recoil rates in direct detection experiments can be estimated. We show here that potentially all of the viable parameter space will be probed in forthcoming XENON experiments including LUX and XENON1T. Thus, we anticipate that these experiments will provide a definitive test of the mirror dark matter hypothesis.

Mirror dark matter will be confirmed or excluded by XENON1T

Directory of Open Access Journals (Sweden)

J.D. Clarke

2017-03-01

Full Text Available Mirror dark matter, where dark matter resides in a hidden sector exactly isomorphic to the standard model, can be probed via direct detection experiments by both nuclear and electron recoils if the kinetic mixing interaction exists. In fact, the kinetic mixing interaction appears to be a prerequisite for consistent small scale structure: Mirror dark matter halos around spiral galaxies are dissipative – losing energy via dark photon emission. This ongoing energy loss requires a substantial energy input, which can be sourced from ordinary supernovae via kinetic mixing induced processes in the supernova's core. Astrophysical considerations thereby give a lower limit on the kinetic mixing strength, and indeed lower limits on both nuclear and electron recoil rates in direct detection experiments can be estimated. We show here that potentially all of the viable parameter space will be probed in forthcoming XENON experiments including LUX and XENON1T. Thus, we anticipate that these experiments will provide a definitive test of the mirror dark matter hypothesis.

Two-dimensional readout in a liquid xenon ionisation chamber

CERN Document Server

Solovov, V; Ferreira-Marques, R; Lopes, M I; Pereira, A; Policarpo, Armando

2002-01-01

A two-dimensional readout with metal strips deposited on both sides of a glass plate is investigated aiming to assess the possibility of its use in a liquid xenon ionisation chamber for positron emission tomography. Here, we present results obtained with an alpha-source. It is shown that position resolution of <=1 mm, fwhm, can be achieved for free charge depositions equivalent to those due to gamma-rays with energy from 220 down to 110 keV.

The interactions of high-energy, highly charged Xe ions with buckyballs

International Nuclear Information System (INIS)

Ali, R.; Berry, H.G.; Cheng, S.

1994-01-01

Ionization and fragmentation have been measured for C 60 molecules bombarded by highly charged (up to 35+) xenon ions with energies ranging up to 625 MeV. The observed mass distribution of positively charged fragments is explained in terms of a theoretical model indicating that the total interaction cross section contains roughly equal contributions from (a) excitation of the giant plasmon resonance, and (b) large-energy-transfer processes that lead to multiple fragmentation of the molecule. Preliminary results of measurements on VUV photons emitted in these interactions are also presented

Flow measurements of the kidney after selective administration of radioactive xenon

International Nuclear Information System (INIS)

Franken, A.H.

1983-01-01

This thesis describes the results of perfusion studies in the kidney through the renal artery in human subjects, after selective administration of the inert radioactive gas Xenon-133. The examinations have been carried out in conjunction with renal angiography. From October 1979 to May 1981, a total of 150 studies have been performed in 86 patients. (Auth.)

Proton and antiproton interactions in hydrogen, argon and xenon at 200 GeV

International Nuclear Information System (INIS)

Malecki, P.

1984-01-01

The detailed analysis of the production of particles emitted into forward hemisphere in 200 GeV proton and antiproton interactions with hydrogen, argon and xenon targets is presented. Two-particle rapidity correlations and long-range multiplicity correlations are also discussed. (author)

Study of the optical properties of the DF2000MA daylight film used in the XENON1T muon veto water tank

Energy Technology Data Exchange (ETDEWEB)

Ramirez, Diego [Institut fuer Physik, Johannes Gutenberg-Universitaet Mainz (Germany)

2016-07-01

XENON1T is the 3rd stage of a series of experiments performed by the XENON collaboration for the direct detection of dark matter candidates, such as WIMPs. Its projected spin-independent WIMP-nucleon elastic scattering cross-section entails an improvement of two orders of magnitude with respect to Xenon100 and requires, for a fiducial mass of the detector of about 1 ton liquid xenon, a similar reduction in background. In order to minimize the neutron background induced by cosmic ray muons, the XENON1T TPC is placed in the center of a 750 m{sup 3} water tank acting as an active Cherenkov muon veto, the walls of which are clad with the high reflective DF2000MA foil by 3M. The improved setup and results of a dedicated study of the reflective properties of the foil is presented, as well as a measurement of its possible wavelength shifting (WLS) properties. The analysis yields a specular reflectance of ∼ 100% for wavelengths larger than 400 nm, while ∼ 90% of the incoming light with wavelengths smaller than 370 nm is absorbed by the foil. The emission spectra of the WLS are dependent on the absorbed wavelength and show Gaussian shapes, with highest intensities at mean values of ∼ 450 nm emission wavelength.

Exclusion of leptophilic dark matter models using XENON100 electronic recoil data

NARCIS (Netherlands)

Aprile, E.; et al., [Unknown; Alfonsi, M.; Brown, A.; Colijn, A.P.; Decowski, M.P.; Tiseni, A.; Tunnell, C.

2015-01-01

Laboratory experiments searching for galactic dark matter particles scattering off nuclei have so far not been able to establish a discovery. We use data from the XENON100 experiment to search for dark matter interacting with electrons. With no evidence for a signal above the low background of our

Clinical observations on the effect of carotid artery occlusion on cerebral blood flow mapped by xenon computed tomography and its correlation with carotid artery back pressure

International Nuclear Information System (INIS)

Steed, D.L.; Webster, M.W.; DeVries, E.J.; Jungreis, C.A.; Horton, J.A.; Sehkar, L.; Yonas, H.

1990-01-01

Xenon computed tomographic cerebral blood flow mapping was correlated with internal carotid artery stump pressures and clinical neurologic assessment during temporary internal carotid artery occlusion. One hundred fourteen patients with skull base tumors or intracranial aneurysms potentially requiring carotid resection or ligation underwent angiography, xenon CT cerebral blood flow mapping, and internal carotid artery blood pressure monitoring. The internal carotid artery was then temporarily occluded with a balloon catheter, stump pressure was measured through the catheter, and the xenon CT cerebral blood flow mapping was repeated. Adequate xenon CT cerebral blood flow was defined as greater than 30 cc/100 gm/min. All patients had normal xenon CT cerebral blood flow before internal carotid artery occlusion. During internal carotid artery occlusion, xenon CT cerebral blood flow was found to be normal (group I, 40 patients), globally reduced but still within the normal range (group II, 50 patients), or low in the distribution of the ipsilateral middle cerebral artery (group III, 13 patients). With balloon occlusion, an immediate neurologic deficit developed in 11 patients (9%) requiring deflation of the balloon preceding xenon CT cerebral blood flow measurement (group IV). In group I internal carotid artery blood pressure was 128 mm Hg. (range 85 to 171 mm Hg) with stump pressure 86 mm Hg (range 46 to 125 mm Hg). In group II internal carotid artery blood pressure was 130 mm Hg. (range 78 to 199 mm Hg), with stump pressure 86 mm Hg (range 31 to 150 mm Hg)

Stability of tetraphenyl butadiene thin films in liquid xenon

International Nuclear Information System (INIS)

Sanguino, P.; Balau, F.; Botelho do Rego, A.M.; Pereira, A.; Chepel, V.

2016-01-01

Tetraphenyl butadiene (TPB) is widely used in particle detectors as a wavelength shifter. In this work we studied the stability of TPB thin films when immersed in liquid xenon (LXe). The thin films were deposited on glass and quartz substrates by thermal evaporation. Morphological and chemical surface properties were monitored before and after immersion into LXe by scanning electron microscopy and X-ray photoelectron spectroscopy. No appreciable changes have been detected with these two methods. Grain size and surface chemical composition were found to be identical before and after submersion into LXe. However, the film thickness, measured via optical transmission in the ultraviolet–visible wavelength regions, decreased by 1.6 μg/cm 2 (24%) after immersion in LXe during 20 h. These results suggest the necessity of using a protective thin film over the Tetraphenyl butadiene when used as a wavelength shifter in LXe particle detectors. - Highlights: • Stability of tetraphenyl butadiene (TPB) thin films immersed in liquid xenon (LXe). • Thermally evaporated TPB thin films were immersed in LXe for 20 h. • Film morphology and chemical surface properties remained unchanged. • Surface density of the films decreased by 1.6 μg/cm 2 (24%) after immersion in LXe. • For using in LXe particle detectors, TPB films should be protected with a coating.

Some observations on the use of the triple points of deuterium and xenon in interpolation schemes for platinum resistance thermometers below 273 K

International Nuclear Information System (INIS)

Kemp, R.C.

1988-01-01

The use of the triple points of deuterium and xenon is investigated in some interpolation schemes for platinum resistance thermometers between 13.8 K and 273 K. The use of these triple points together is shown to lead to a large sensitivity to errors in the realization of the boiling point of water or the triple point of gallium and of the triple point of xenon for interpolated temperatures below 25 K. The behaviour of these interpolation schemes is presented as evidence that the large non-uniqueness observed in temperature scales between 84 K and 273 K is due in part to measurement errors at the boiling point of water. The use of the triple point of xenon and in interpolation scheme between 25 K and 273 K is shown to lead to a large sensitivity to calibration errors in the triple points of xenon and gallium between 25 K and 54 K. (orig.)

Electric field dependence of the total excimer luminescence of xenon excited below the atomic ionization limit

International Nuclear Information System (INIS)

Anon.

1987-01-01

In the spectral region of interest (i.e., 11.1 eV ≤ h nu ≤ 11.9 eV), the photoionization yield of electrons from excited-state dimers of xenon, increases monotonically to relatively high values (e.g., Y(11.7 eV) = 0.43 electrons/absorbed photon). It is also known however, that the luminescence intensity excited by photons in this region is quite high, even at low pressures. These two observations can be reconciled only by assuming that one of the processes leading to excimer luminescence involves dimer-ion + electron recombination. If this assumption is correct, application of an electric field, with concomitant collection of the free charges generated by the incident photons, should lead to a decrease in luminescence intensity; moreover, this decrease should follow the energy dependence of the photoionization yield function. The present report demonstrates experimentally that this is indeed the case. Such experiments combining luminescence and electric fields were made, until now, only by high-energy excitation. In this case the deconvolution of the various decay channels is hardly possible

Surface structure of Cr0.5 Ti0.5N coatings after heavy ions irradiation and annealing

International Nuclear Information System (INIS)

Kislitsin, Sergey; Gorlachev, Igor; Uglov, Vladimir

2015-01-01

Results of surface structure investigations of TiCrN coating on carbon steel after irradiation by helium, krypton and xenon heavy ions are reported in the present publication. The series of Cr50Ti50N coatings on carbon steel with thickness of 50,..., 300 nm were formed by vacuum arc deposition techniques. Specimens with TiCrN coating on carbon steel were irradiated by low energy 4 He +1 (22 keV) and 4 He +2 (40 keV) ions and high energy Xe +18 and Kr +14 ions with energy of 1.5 MeV/nucleon. Fluence of He ions was 1.0x10 17 ion.cm -2 , fluence of Xe and Kr ions was 5x10 14 -1.0x10 15 ion.cm -2 , irradiation temperature did not exceed 150 deg. C. Study of surface structure was performed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Methods of Roentgen diffractometry and Rutherford backscattering was applied for determination of structure and thickness of coating. In case of irradiation with Xe +18 and Kr +14 ions an investigation of surface morphology and structure was done after successive two hours vacuum annealing of irradiated samples at temperatures 400 deg. C, 500 deg. C and 600 deg. C. It was shown that after irradiation by Xe and Kr ions on the surface of coating convexities appear, surface density of which correlates with ion flux. In the case of Xe, ions irradiation generated convexities of spherical and elongated shape with dimensions ranging from ten to hundreds nm. In the case of Kr ions, only spherical globules were generated, dimensions of which are 10-30 nm. The most likely explanation of observed surface damage is that: convexities on the surface are generated at ion bombardment of specimens with coating. Convexities are the traces of ions passing through coating and they are due to structural reconstruction at energy release along a trajectory of ions braking. Convexities of elongated shape represent overlapping traces from two passing ions. When the projective range of Xe and Kr ions exceeds coating thickness, damage

Sawtooth oscillations in EBIT

International Nuclear Information System (INIS)

Radtke, R; Biedermann, C; Bachmann, P; Fussmann, G; Windisch, T

2004-01-01

The dynamics of mixed ensembles of highly charged argon/xenon and krypton/xenon ions in an electron-beam ion trap (EBIT) was studied by recording the characteristic x-ray emission of the trapped ions. Sawtooth-like signatures manifest in the x-ray spectra for a variety of trap parameters. The effect can be understood as arising from the feedback between low-Z and high-Z ions

Compute raided classification of ventilation patterns inpatients with chronic obstructive pulmonary diseases at two-phase xenon-enhanced CT

Energy Technology Data Exchange (ETDEWEB)

Yoon, Son Ho; Goo, Jin Mo; Lee, Chang Hyun; Lee, You Kyung; Jin, Kwang Nam; Choo, Ji Yung; Lee, Nyoung Keun [Seoul National University College of Medicine, Seoul (Korea, Republic of); Jung, Julip; Hong, Helen [Dept. of Multimedia Engineering, Seoul Women' s University, Seoul (Korea, Republic of)

2014-06-15

To evaluate the technical feasibility, performance, and interobserver agreement of a computer-aided classification (CAC) system for regional ventilation at two-phase xenon-enhanced CT in patients with chronic obstructive pulmonary disease (COPD). Thirty-eight patients with COPD underwent two-phase xenon ventilation CT with resulting wash-in (WI) and wash-out (WO) xenon images. The regional ventilation in structural abnormalities was visually categorized into four patterns by consensus of two experienced radiologists who compared the xenon attenuation of structural abnormalities with that of adjacent normal parenchyma in the WI and WO images, and it served as the reference. Two series of image datasets of structural abnormalities were randomly extracted for optimization and validation. The proportion of agreement on a per-lesion basis and receiver operating characteristics on a per-pixel basis between CAC and reference were analyzed for optimization. Thereafter, six readers independently categorized the regional ventilation in structural abnormalities in the validation set without and with a CAC map. Interobserver agreement was also compared between assessments without and with CAC maps using multirater κ statistics. Computer-aided classification maps were successfully generated in 31 patients (81.5%). The proportion of agreement and the average area under the curve of optimized CAC maps were 94% (75/80) and 0.994, respectively. Multirater k value was improved from moderate (k=0.59: 95% confidence interval [CI], 0.56-0.62) at the initial assessment to excellent with the CAC map.

Xenon plasma with caesium as additive

Energy Technology Data Exchange (ETDEWEB)

Stojilkovic, S M; Novakovic, N V; Zivkovic, L M

1986-01-01

The concentration dependence of xenon plasma with cesium as additive in the temperature range of 2000 K to 20,000 K is analyzed. Plasma is considered as weakly nonideal in complete local thermodynamic equilibrium and the interaction between plasma and vessel walls is not taken into account. The values of some of the parameters for nonideality of plasma with 1% of cesium (..gamma..=0.01010) and 10% of cesium (..gamma..=0.11111) are computed, for an initial pressure in plasma of p/sub 0/=13,000 Pa and initial temperature T/sub 0/=1000 K. The ratio of electric conductivity of plasma computed by Lorentz's formula and electric conductivity computed by Spitzer's formula in the same temperature interval is also analyzed. (author) 5 figs., 2 tabs., 16 refs.

Control of xenon oscillations in Advanced Heavy Water Reactor via two-stage decomposition

International Nuclear Information System (INIS)

Munje, R.K.; Parkhe, J.G.; Patre, B.M.

2015-01-01

Highlights: • Singularly perturbed model of Advanced Heavy Water Reactor is explored. • Composite controller is designed using slow subsystem alone, which achieves asymptotic stability. • Nonlinear simulations are carried out under different transient conditions. • Performance of the controller is found to be satisfactory. - Abstract: Xenon induced spatial oscillations developed in large nuclear reactors, like Advanced Heavy Water Reactor (AHWR) need to be controlled for safe operation. Otherwise, a serious situation may arise in which different regions of the core may undergo variations in neutron flux in opposite phase. If these oscillations are left uncontrolled, the power density and rate of change of power at some locations in the reactor core may exceed their respective thermal limits, resulting in fuel failure. In this paper, a state feedback based control strategy is investigated for spatial control of AHWR. The nonlinear model of AHWR including xenon and iodine dynamics is characterized by 90 states, 5 inputs and 18 outputs. The linear model of AHWR, obtained by linearizing the nonlinear equations is found to be highly ill-conditioned. This higher order model of AHWR is first decomposed into two comparatively lower order subsystems, namely, 73rd order ‘slow’ subsystem and 17th order ‘fast’ subsystem using two-stage decomposition. Composite control law is then derived from individual subsystem feedback controls and applied to the vectorized nonlinear model of AHWR. Through the dynamic simulations it is observed that the controller is able to suppress xenon induced spatial oscillations developed in AHWR and the overall performance is found to be satisfactory

Terrestrial xenon isotope constraints on the early history of the earth

International Nuclear Information System (INIS)

Ozima, M.; Igarashi, G.; Podosek, F.A.

1985-01-01

Comparison between 129 I-radiogenic 129 Xe and 244 Pu-fissiogenic 136 Xe components in terrestrial xenon suggests that the Earth's inner region accreted a few tens of millions of years earlier than the outer region from which the atmosphere evolved. The results also indicate that there has been no substantial mixing of the two regions since the Earth's accretion. (author)

Production of fusion radionuclides: Molybdenum-99/ Iodine - 131 and Xenon-133

International Nuclear Information System (INIS)

Barrachina, M.; Carrillo, D.

1982-01-01

This report presents a new radiochemical method for industrial production of the radionuclides: molybdenum-99, iodine-131 and xenon-133. The above mentioned method based on the alkaline metathesis reaction of irradiated uranium (IV) fluoride, presents the best characteristics for the proposed objective. The study deals with the analysis of that reaction and the separation and purification processes. (Author) 71 refs

Two-phase xenon detector with gas amplification and electroluminescent signal detection

International Nuclear Information System (INIS)

Akimov, D.Yu.; Burenkov, A.A.; Grishkin, Yu.L.; Kovalenko, A.G.; Lebedenko, V.N.; Stekhanov, V.N.

2008-01-01

An optical technique for detecting ionization electrons produced during ionization of the liquid phase has been experimentally tested in two-phase (liquid-gas) xenon. The effects of gas and electroluminescent amplifications at the wire anode are simultaneously used for detection. This method allows construction of a supersensitive detector of small ionization signals-down to those corresponding to the detection of single electrons [ru

The status of the Electron Beam Ion Sources

Energy Technology Data Exchange (ETDEWEB)

Stockli, M.P.

1990-01-01

More than twenty years after its invention, 13 examples of the Electron Beam Ion Sources (EBIS) are in operation worldwide. The substantial progress in operation and insight, achieved over the last few years, made the EBISes become reliable tools for the production of beams of very highly charged, low-energy ions. For example, 8 EBISes produce bare argon on a standard basis. The successful production of hydrogen-like xenon presents the ions with the highest ionization energy, whereas the production of Th80+ presents the highest achieved charge state. Several synchrotrons are fed by EBIS injectors, taking advantage of the EBIS batch mode production, which yields the highest charge states. A few EBISes are used for ion source development. However, most of the EBISes' efforts are directed to research the physics of highly charged ions. Some of those are used to study the electron--ion interaction inside the source. But normally, most EBISes deliver the ions for external experiments, which so far concentrate on the recombination of the highly charged ions with atoms, molecules and surfaces. The ions are typically produced at a potential of 1 to a few kilovolts per charge; but in most cases, the EBIS is mounted on a high voltage platform or is followed by an RFQ, and therefore can generate ion energies from a few hundred volts up to a few hundred kilovolts per charge. The delivered beams have a low emittance and a low energy spread, which is an advantage for high-resolution experiments. This paper presents briefly all operational EBISes, their capabilities, their achievements, and their contribution to physics research. 5 figs., 1 tab., 59 refs.

The status of the Electron Beam Ion Sources

International Nuclear Information System (INIS)

Stockli, M.P.

1990-01-01

More than twenty years after its invention, 13 examples of the Electron Beam Ion Sources (EBIS) are in operation worldwide. The substantial progress in operation and insight, achieved over the last few years, made the EBISes become reliable tools for the production of beams of very highly charged, low-energy ions. For example, 8 EBISes produce bare argon on a standard basis. The successful production of hydrogen-like xenon presents the ions with the highest ionization energy, whereas the production of Th80+ presents the highest achieved charge state. Several synchrotrons are fed by EBIS injectors, taking advantage of the EBIS batch mode production, which yields the highest charge states. A few EBISes are used for ion source development. However, most of the EBISes' efforts are directed to research the physics of highly charged ions. Some of those are used to study the electron--ion interaction inside the source. But normally, most EBISes deliver the ions for external experiments, which so far concentrate on the recombination of the highly charged ions with atoms, molecules and surfaces. The ions are typically produced at a potential of 1 to a few kilovolts per charge; but in most cases, the EBIS is mounted on a high voltage platform or is followed by an RFQ, and therefore can generate ion energies from a few hundred volts up to a few hundred kilovolts per charge. The delivered beams have a low emittance and a low energy spread, which is an advantage for high-resolution experiments. This paper presents briefly all operational EBISes, their capabilities, their achievements, and their contribution to physics research. 5 figs., 1 tab., 59 refs

The status of the Electron Beam Ion Sources

Energy Technology Data Exchange (ETDEWEB)

Stockli, M.P.

1990-12-31

More than twenty years after its invention, 13 examples of the Electron Beam Ion Sources (EBIS) are in operation worldwide. The substantial progress in operation and insight, achieved over the last few years, made the EBISes become reliable tools for the production of beams of very highly charged, low-energy ions. For example, 8 EBISes produce bare argon on a standard basis. The successful production of hydrogen-like xenon presents the ions with the highest ionization energy, whereas the production of Th80+ presents the highest achieved charge state. Several synchrotrons are fed by EBIS injectors, taking advantage of the EBIS batch mode production, which yields the highest charge states. A few EBISes are used for ion source development. However, most of the EBISes` efforts are directed to research the physics of highly charged ions. Some of those are used to study the electron--ion interaction inside the source. But normally, most EBISes deliver the ions for external experiments, which so far concentrate on the recombination of the highly charged ions with atoms, molecules and surfaces. The ions are typically produced at a potential of 1 to a few kilovolts per charge; but in most cases, the EBIS is mounted on a high voltage platform or is followed by an RFQ, and therefore can generate ion energies from a few hundred volts up to a few hundred kilovolts per charge. The delivered beams have a low emittance and a low energy spread, which is an advantage for high-resolution experiments. This paper presents briefly all operational EBISes, their capabilities, their achievements, and their contribution to physics research. 5 figs., 1 tab., 59 refs.

Studies on the production of high energy density in matter with intense heavy-ion beams

International Nuclear Information System (INIS)

Jacoby, J.

1989-01-01

In the framework of the present thesis the interaction of an intense heavy-ion beam with a small, but macroscopic, amount of matter is studied. Thereby high energy densities are produced in the target matter. For this experiment it was for the first time possible to heat matter with ion beams from conventional heavy-ion accelerators up to plasma conditions. A Kr + ion beam was first accelerated with the heavy-ion accelerator MAXILAC to 45 keV/u and then focused by a fine-focusing lens on a closed xenon gas target. The light emitted from the target was space- and time-resolved taken up with a spectrometer as well a streak and CCD camera. Thereby the radial development of the plasma and the penetration behaviour of the ion beam were consecuted. The free-electron density of the plasma was determined from the Stark-broadening of emission lines (n e ≅ 4x10 16 cm -3 ). The electron temperature amounted in the center of the pipelet kT ≅ 0.75 eV. (orig./HSI) [de

Radioactive plume from the Three Mile Island accident: xenon-133 in air at a distance of 375 kilometers.

Science.gov (United States)

Wahlen, M; Kunz, C O; Matuszek, J M; Mahoney, W E; Thompson, R C

1980-02-08

The transit of an air mass containing radioactive gas released from the Three Mile Island reactor was recorded in Albany, New York, by measuring xenon-133. These measurements provide an evaluation of Three Mile Island effluents to distances greater than 100 kilometers. Two independent techniques identified xenon-133 in ambient air at concentrations as high as 3900 picocuries per cubic meter. The local gamma-ray whole-body dose from the passing radioactivity amounted to 0.004 millirem, or 0.004 percent of the annual dose from natural sources.

Neutrinoless double beta decay with 82SeF6 and direct ion imaging

Science.gov (United States)

Nygren, D. R.; Jones, B. J. P.; López-March, N.; Mei, Y.; Psihas, F.; Renner, J.

2018-03-01

We present a new neutrinoless double beta decay concept: the high pressure selenium hexafluoride gas time projection chamber. A promising new detection technique is outlined which combines techniques pioneered in high pressure xenon gas, such as topological discrimination, with the high Q-value afforded by the double beta decay isotope 82Se. The lack of free electrons in SeF6 mandates the use of an ion TPC. The microphysics of ion production and drift, which have many nuances, are explored. Background estimates are presented, suggesting that such a detector may achieve background indices of better than 1 count per ton per year in the region of interest at the 100 kg scale, and still better at the ton-scale.

Krypton and xenon in the atmosphere of Venus

Science.gov (United States)

Donahue, T. M.; Hoffman, J. H.; Hodges, R. R., Jr.

1981-01-01

The paper reports a determination by the Pioneer Venus large probe neutral mass spectrometer of upper limits to the concentration of krypton and xenon along with most of their isotopes in the atmosphere of Venus. The upper limit to the krypton mixing ratio is estimated at 47 ppb, with a very conservative estimate at 69 ppb. The probable upper limit to the sum of the mixing ratios of the isotopes Xe-128, Xe-129, Xe-130, Xe-131, and Xe-132 is 40 ppb by volume, with a very conservative upper limit three times this large.

Effect of Xenon Anesthesia Compared to Sevoflurane and Total Intravenous Anesthesia for Coronary Artery Bypass Graft Surgery on Postoperative Cardiac Troponin Release: An International, Multicenter, Phase 3, Single-blinded, Randomized Noninferiority Trial.

Science.gov (United States)

Hofland, Jan; Ouattara, Alexandre; Fellahi, Jean-Luc; Gruenewald, Matthias; Hazebroucq, Jean; Ecoffey, Claude; Joseph, Pierre; Heringlake, Matthias; Steib, Annick; Coburn, Mark; Amour, Julien; Rozec, Bertrand; Liefde, Inge de; Meybohm, Patrick; Preckel, Benedikt; Hanouz, Jean-Luc; Tritapepe, Luigi; Tonner, Peter; Benhaoua, Hamina; Roesner, Jan Patrick; Bein, Berthold; Hanouz, Luc; Tenbrinck, Rob; Bogers, Ad J J C; Mik, Bert G; Coiffic, Alain; Renner, Jochen; Steinfath, Markus; Francksen, Helga; Broch, Ole; Haneya, Assad; Schaller, Manuella; Guinet, Patrick; Daviet, Lauren; Brianchon, Corinne; Rosier, Sebastien; Lehot, Jean-Jacques; Paarmann, Hauke; Schön, Julika; Hanke, Thorsten; Ettel, Joachym; Olsson, Silke; Klotz, Stefan; Samet, Amir; Laurinenas, Giedrius; Thibaud, Adrien; Cristinar, Mircea; Collanges, Olivier; Levy, François; Rossaint, Rolf; Stevanovic, Ana; Schaelte, Gereon; Stoppe, Christian; Hamou, Nora Ait; Hariri, Sarah; Quessard, Astrid; Carillion, Aude; Morin, Hélène; Silleran, Jacqueline; Robert, David; Crouzet, Anne-Sophie; Zacharowski, Kai; Reyher, Christian; Iken, Sonja; Weber, Nina C; Hollmann, Marcus; Eberl, Susanne; Carriero, Giovanni; Collacchi, Daria; Di Persio, Alessandra; Fourcade, Olivier; Bergt, Stefan; Alms, Angela

2017-12-01

Ischemic myocardial damage accompanying coronary artery bypass graft surgery remains a clinical challenge. We investigated whether xenon anesthesia could limit myocardial damage in coronary artery bypass graft surgery patients, as has been reported for animal ischemia models. In 17 university hospitals in France, Germany, Italy, and The Netherlands, low-risk elective, on-pump coronary artery bypass graft surgery patients were randomized to receive xenon, sevoflurane, or propofol-based total intravenous anesthesia for anesthesia maintenance. The primary outcome was the cardiac troponin I concentration in the blood 24 h postsurgery. The noninferiority margin for the mean difference in cardiac troponin I release between the xenon and sevoflurane groups was less than 0.15 ng/ml. Secondary outcomes were the safety and feasibility of xenon anesthesia. The first patient included at each center received xenon anesthesia for practical reasons. For all other patients, anesthesia maintenance was randomized (intention-to-treat: n = 492; per-protocol/without major protocol deviation: n = 446). Median 24-h postoperative cardiac troponin I concentrations (ng/ml [interquartile range]) were 1.14 [0.76 to 2.10] with xenon, 1.30 [0.78 to 2.67] with sevoflurane, and 1.48 [0.94 to 2.78] with total intravenous anesthesia [per-protocol]). The mean difference in cardiac troponin I release between xenon and sevoflurane was -0.09 ng/ml (95% CI, -0.30 to 0.11; per-protocol: P = 0.02). Postoperative cardiac troponin I release was significantly less with xenon than with total intravenous anesthesia (intention-to-treat: P = 0.05; per-protocol: P = 0.02). Perioperative variables and postoperative outcomes were comparable across all groups, with no safety concerns. In postoperative cardiac troponin I release, xenon was noninferior to sevoflurane in low-risk, on-pump coronary artery bypass graft surgery patients. Only with xenon was cardiac troponin I release less than with total intravenous

When the dust settles: stable xenon isotope constraints on the formation of nuclear fallout

International Nuclear Information System (INIS)

Cassata, W.S.; Prussin, S.G.; Knight, K.B.; Hutcheon, I.D.; Isselhardt, B.H.; Renne, P.R.

2014-01-01

Nuclear weapons represent one of the most immediate threats of mass destruction. In the event that a procured or developed nuclear weapon is detonated in a populated metropolitan area, timely and accurate nuclear forensic analysis and fallout modeling would be needed to support attribution efforts and hazard assessments. Here we demonstrate that fissiogenic xenon isotopes retained in radioactive fallout generated by a nuclear explosion provide unique constraints on (1) the timescale of fallout formation, (2) chemical fractionation that occurs when fission products and nuclear fuel are incorporated into fallout, and (3) the speciation of fission products in the fireball. Our data suggest that, in near surface nuclear tests, the presence of a significant quantity of metal in a device assembly, combined with a short time allowed for mixing with the ambient atmosphere (seconds), may prevent complete oxidation of fission products prior to their incorporation into fallout. Xenon isotopes thus provide a window into the chemical composition of the fireball in the seconds that follow a nuclear explosion, thereby improving our understanding of the physical and thermo-chemical conditions under which fallout forms. - Highlights: • Radioactive fallout generated by nuclear explosions contains fissiogenic xenon isotopes. • Xe isotopes provide constraints on timescales of fallout formation and the speciation of fission products in the fireball. • Our data indicate that macroscopic fallout forms rapidly (<3 s). • Chemical fractionation trends suggest that fission products may not have been fully oxidized prior to incorporation

Xenon Reduces Neuronal Hippocampal Damage and Alters the Pattern of Microglial Activation after Experimental Subarachnoid Hemorrhage: A Randomized Controlled Animal Trial

Directory of Open Access Journals (Sweden)

Michael Veldeman

2017-09-01

Full Text Available ObjectiveThe neuroprotective properties of the noble gas xenon have already been demonstrated using a variety of injury models. Here, we examine for the first time xenon’s possible effect in attenuating early brain injury (EBI and its influence on posthemorrhagic microglial neuroinflammation in an in vivo rat model of subarachnoid hemorrhage (SAH.MethodsSprague-Dawley rats (n = 22 were randomly assigned to receive either Sham surgery (n = 9; divided into two groups or SAH induction via endovascular perforation (n = 13, divided into two groups. Of those randomized for SAH, 7 animals were postoperatively ventilated with 50 vol% oxygen/50 vol% xenon for 1 h and 6 received 50 vol% oxygen/50 vol% nitrogen (control. The animals were sacrificed 24 h after SAH. Of each animal, a cerebral coronal section (−3.60 mm from bregma was selected for assessment of histological damage 24 h after SAH. A 5-point neurohistopathological severity score was applied to assess neuronal cell damage in H&E and NeuN stained sections in a total of four predefined anatomical regions of interest. Microglial activation was evaluated by a software-assisted cell count of Iba-1 stained slices in three cortical regions of interest.ResultsA diffuse cellular damage was apparent in all regions of the ipsilateral hippocampus 24 h after SAH. Xenon-treated animals presented with a milder damage after SAH. This effect was found to be particularly pronounced in the medial regions of the hippocampus, CA3 (p = 0.040, and dentate gyrus (DG p = 0.040. However, for the CA1 and CA2 regions, there were no statistical differences in neuronal damage according to our histological scoring. A cell count of activated microglia was lower in the cortex of xenon-treated animals. This difference was especially apparent in the left piriform cortex (p = 0.017.ConclusionIn animals treated with 50 vol% xenon (for 1 h after SAH, a less pronounced neuronal damage was

Search for Dark Matter Interactions using Ionization Yield in Liquid Xenon

Science.gov (United States)

Uvarov, Sergey

Cosmological observations overwhelmingly support the existence of dark matter which constitutes 87% of the universe's total mass. Weakly Interacting Massive Particles (WIMPs) are a prime candidate for dark matter, and the Large Underground Xenon (LUX) experiment aims to a direct-detection of a WIMP-nucleon interaction. The LUX detector is a dual-phase xenon time-projection chamber housed 4,850 feet underground at Sanford Underground Research Facility in Lead, South Dakota. We present the ionization-only analysis of the LUX 2013 WIMP search data. In the 1.04 x 104 kg-days exposure, thirty events were observed out of the 24.8 expected from radioactive backgrounds. We employ a cut-and-count method to set a 1-sided 90% C.L. upper limit for spin-independent WIMP-nucleon cross-sections. A zero charge yield for nuclear-recoils below 0.7 keV is included upper limit calculation. This ionization-only analysis excludes an unexplored region of WIMP-nucleon cross-section for low-mass WIMPs achieving 1.56 x 10-43 cm2 WIMP-nucleon cross-section exclusion for a 5.1 GeV/ c2 WIMP.

Regional bronchoconstriction in asthma. 133Xenon washout scans following parenteral methacholine

International Nuclear Information System (INIS)

Riley, D.J.; Fisher, A.B.; Hansell, J.R.; Brody, J.S.

1976-01-01

To determine the influence of bronchoconstriction on the distribution of ventilation during an asthma attack, pulmonary clearance of 133 xenon was evaluated in four normal and eight asthmatic subjects within three to five minutes after intramuscular injection of methacholine. In asthmatics, administration of 4-10 mg methacholine resulted in a decrease of forced vital capacity of 28.5 +- 5.1 (SE) percent and a decrease in expiratory flow at 60 percent vital capacity of 44.2 +- 6.9 percent (P less than 0.001). The cumulative ventilation required to reach 50 percent of the pre-washout radioactivity increased from 3.6 +- 0.8 to 9.9 +- 1.6 L after administration of the drug (P less than 0.05). The normal subjects showed no ventilatory effects after receiving 10 mg methacholine. Comparison of clearance of 133 xenon from ten areas of lung (each representing approximately 6 percent of the surface area of one lung) showed that all areas were affected to approximately the same extent during drug-induced asthma. These findings suggest that parenteral methacholine is an effective way to demonstrate airway hyperreactivity and that the airway response to methacholine in asthmatics is relatively generalized throughout the lung

First Dark Matter Search Results from the XENON1T Experiment.

Science.gov (United States)

Aprile, E; Aalbers, J; Agostini, F; Alfonsi, M; Amaro, F D; Anthony, M; Arneodo, F; Barrow, P; Baudis, L; Bauermeister, B; Benabderrahmane, M L; Berger, T; Breur, P A; Brown, A; Brown, A; Brown, E; Bruenner, S; Bruno, G; Budnik, R; Bütikofer, L; Calvén, J; Cardoso, J M R; Cervantes, M; Cichon, D; Coderre, D; Colijn, A P; Conrad, J; Cussonneau, J P; Decowski, M P; de Perio, P; Di Gangi, P; Di Giovanni, A; Diglio, S; Eurin, G; Fei, J; Ferella, A D; Fieguth, A; Fulgione, W; Gallo Rosso, A; Galloway, M; Gao, F; Garbini, M; Gardner, R; Geis, C; Goetzke, L W; Grandi, L; Greene, Z; Grignon, C; Hasterok, C; Hogenbirk, E; Howlett, J; Itay, R; Kaminsky, B; Kazama, S; Kessler, G; Kish, A; Landsman, H; Lang, R F; Lellouch, D; Levinson, L; Lin, Q; Lindemann, S; Lindner, M; Lombardi, F; Lopes, J A M; Manfredini, A; Mariş, I; Marrodán Undagoitia, T; Masbou, J; Massoli, F V; Masson, D; Mayani, D; Messina, M; Micheneau, K; Molinario, A; Morå, K; Murra, M; Naganoma, J; Ni, K; Oberlack, U; Pakarha, P; Pelssers, B; Persiani, R; Piastra, F; Pienaar, J; Pizzella, V; Piro, M-C; Plante, G; Priel, N; Rauch, L; Reichard, S; Reuter, C; Riedel, B; Rizzo, A; Rosendahl, S; Rupp, N; Saldanha, R; Dos Santos, J M F; Sartorelli, G; Scheibelhut, M; Schindler, S; Schreiner, J; Schumann, M; Scotto Lavina, L; Selvi, M; Shagin, P; Shockley, E; Silva, M; Simgen, H; Sivers, M V; Stein, A; Thapa, S; Thers, D; Tiseni, A; Trinchero, G; Tunnell, C; Vargas, M; Upole, N; Wang, H; Wang, Z; Wei, Y; Weinheimer, C; Wulf, J; Ye, J; Zhang, Y; Zhu, T

2017-11-03

We report the first dark matter search results from XENON1T, a ∼2000-kg-target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042±12)-kg fiducial mass and in the [5,40]  keV_{nr} energy range of interest for weakly interacting massive particle (WIMP) dark matter searches, the electronic recoil background was (1.93±0.25)×10^{-4}  events/(kg×day×keV_{ee}), the lowest ever achieved in such a dark matter detector. A profile likelihood analysis shows that the data are consistent with the background-only hypothesis. We derive the most stringent exclusion limits on the spin-independent WIMP-nucleon interaction cross section for WIMP masses above 10  GeV/c^{2}, with a minimum of 7.7×10^{-47}  cm^{2} for 35-GeV/c^{2} WIMPs at 90% C.L.

Simplest simulation model for three-dimensional xenon oscillations in large PWRs

International Nuclear Information System (INIS)

Shimazu, Yoichiro

2004-01-01

Xenon oscillations in large PWRs are well understood and there have been no operational problems remained. However, in order to suppress the oscillations effectively, optimal control strategy is preferable. Generally speaking in such optimality search based on the modern control theory, a large volume of transient core analyses is required. For example, three dimensional core calculations are inevitable for the analyses of radial oscillations. From this point of view, a very simple 3-D model is proposed, which is based on a reactor model of only four points. As in the actual reactor operation, the magnitude of xenon oscillations should be limited from the view point of safety, the model further assumes that the neutron leakage can be also small or even constant. It can explicitly use reactor parameters such as reactivity coefficients and control rod worth directly. The model is so simplified as described above that it can predict oscillation behavior in a very short calculation time even on a PC. However the prediction result is good. The validity of the model in comparison with measured data and the applications are discussed. (author)

Measurement of regional cerebral blood flow by intravenous administation of 133 xenon

International Nuclear Information System (INIS)

Ryding, E.

1986-01-01

Reviewing the background and the theory for rCFB measurements the following conditions are established for the use of flow measurement with 133-Xenon as a reliable indicator for indirect measurements of cerebral functional activity. 1. There is a strict coupling between rCBF and regional metabolism. This condition can only be considered to be fulfilled in the normal non-anoxic bran tissue. 2. There is a close correlation between the tissue and the venous concentration of 133-Xenin which can be reliably approximated by the blood-brain partition coefficient. This condition can be considered to be fullfilled in the normal flow range, but not in pathological conditions such as cerebrovascular occlusions. 3. Intercompartment diffusion of 133-Xenon has no significant effect upon the measurement of rCBF values. This condition appear to share its limitations for fulfilement with condition 2. 4. There is no significant contamination by the extracerebral flow components at IH or IV rCBF measurements. 5. There is a negligible 'look through' effect from surrounding areas to region with focal high or low blood flow. (U.W.)

Interaction of cover and target with xenon gas in the IFE-reaction chamber

International Nuclear Information System (INIS)

Kuteev, Boris V.

2001-11-01

Interaction of a direct drive target and a cover, which is shielding the target against gas particle and heat flows in the reaction chamber of the Inertial Confinement Reactor, is considered. The cover is produced from solid gas -deuterium, neon of xenon. It is shown that at the SOMBRERO parameters the xenon cover with 5.6-mm size significantly reduces the heat flows onto the 4-mm target. The gas drag produces the deceleration of the target much larger than that for the cover due to large mass difference between them. The distance between the target and the cover is about 15 mm at the explosion point, which is sufficient for normal irradiation of the target by laser beams. Protection of the target against the wall radiation is necessary during the flight. Along with creation of reflecting layers over the target surface ablating layers from solid hydrogen or neon seem to be a solution. (author)

Comparison of Xenon-Enhanced Area-Detector CT and Krypton Ventilation SPECT/CT for Assessment of Pulmonary Functional Loss and Disease Severity in Smokers.

Science.gov (United States)

Ohno, Yoshiharu; Fujisawa, Yasuko; Takenaka, Daisuke; Kaminaga, Shigeo; Seki, Shinichiro; Sugihara, Naoki; Yoshikawa, Takeshi

2018-02-01

The objective of this study was to compare the capability of xenon-enhanced area-detector CT (ADCT) performed with a subtraction technique and coregistered 81m Kr-ventilation SPECT/CT for the assessment of pulmonary functional loss and disease severity in smokers. Forty-six consecutive smokers (32 men and 14 women; mean age, 67.0 years) underwent prospective unenhanced and xenon-enhanced ADCT, 81m Kr-ventilation SPECT/CT, and pulmonary function tests. Disease severity was evaluated according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification. CT-based functional lung volume (FLV), the percentage of wall area to total airway area (WA%), and ventilated FLV on xenon-enhanced ADCT and SPECT/CT were calculated for each smoker. All indexes were correlated with percentage of forced expiratory volume in 1 second (%FEV 1 ) using step-wise regression analyses, and univariate and multivariate logistic regression analyses were performed. In addition, the diagnostic accuracy of the proposed model was compared with that of each radiologic index by means of McNemar analysis. Multivariate logistic regression showed that %FEV 1 was significantly affected (r = 0.77, r 2 = 0.59) by two factors: the first factor, ventilated FLV on xenon-enhanced ADCT (p < 0.0001); and the second factor, WA% (p = 0.004). Univariate logistic regression analyses indicated that all indexes significantly affected GOLD classification (p < 0.05). Multivariate logistic regression analyses revealed that ventilated FLV on xenon-enhanced ADCT and CT-based FLV significantly influenced GOLD classification (p < 0.0001). The diagnostic accuracy of the proposed model was significantly higher than that of ventilated FLV on SPECT/CT (p = 0.03) and WA% (p = 0.008). Xenon-enhanced ADCT is more effective than 81m Kr-ventilation SPECT/CT for the assessment of pulmonary functional loss and disease severity.

Secondary scintillation yield of xenon with sub-percent levels of CO2 additive for rare-event detection

Science.gov (United States)

Henriques, C. A. O.; Freitas, E. D. C.; Azevedo, C. D. R.; González-Díaz, D.; Mano, R. D. P.; Jorge, M. R.; Fernandes, L. M. P.; Monteiro, C. M. B.; Gómez-Cadenas, J. J.; Álvarez, V.; Benlloch-Rodríguez, J. M.; Borges, F. I. G. M.; Botas, A.; Cárcel, S.; Carríon, J. V.; Cebrían, S.; Conde, C. A. N.; Díaz, J.; Diesburg, M.; Esteve, R.; Felkai, R.; Ferrario, P.; Ferreira, A. L.; Goldschmidt, A.; Gutiérrez, R. M.; Hauptman, J.; Hernandez, A. I.; Hernando Morata, J. A.; Herrero, V.; Jones, B. J. P.; Labarga, L.; Laing, A.; Lebrun, P.; Liubarsky, I.; López-March, N.; Losada, M.; Martín-Albo, J.; Martínez-Lema, G.; Martínez, A.; McDonald, A. D.; Monrabal, F.; Mora, F. J.; Moutinho, L. M.; Muñoz Vidal, J.; Musti, M.; Nebot-Guinot, M.; Novella, P.; Nygren, D. R.; Palmeiro, B.; Para, A.; Pérez, J.; Querol, M.; Renner, J.; Ripoll, L.; Rodríguez, J.; Rogers, L.; Santos, F. P.; dos Santos, J. M. F.; Simón, A.; Sofka, C.; Sorel, M.; Stiegler, T.; Toledo, J. F.; Torrent, J.; Tsamalaidze, Z.; Veloso, J. F. C. A.; Webb, R.; White, J. T.; Yahlali, N.; NEXT Collaboration

2017-10-01

Xe-CO2 mixtures are important alternatives to pure xenon in Time Projection Chambers (TPC) based on secondary scintillation (electroluminescence) signal amplification with applications in the important field of rare event detection such as directional dark matter, double electron capture and double beta decay detection. The addition of CO2 to pure xenon at the level of 0.05-0.1% can reduce significantly the scale of electron diffusion from 10 mm /√{m} to 2.5 mm /√{m}, with high impact on the discrimination efficiency of the events through pattern recognition of the topology of primary ionization trails. We have measured the electroluminescence (EL) yield of Xe-CO2 mixtures, with sub-percent CO2 concentrations. We demonstrate that the EL production is still high in these mixtures, 70% and 35% relative to that produced in pure xenon, for CO2 concentrations around 0.05% and 0.1%, respectively. The contribution of the statistical fluctuations in EL production to the energy resolution increases with increasing CO2 concentration, being smaller than the contribution of the Fano factor for concentrations below 0.1% CO2.

Phase transitions in the argon, krypton and xenon in generalized Van der Waals theory

International Nuclear Information System (INIS)

Cavalcanti, H.M.

1977-01-01

Fluid-solid like phase transitions for three monoatomic substances, argon, krypton and xenon are treated, using the extension of the Van der Waals theory to the crystalline state. The method utilized is based on 'Maxwell construction' of identical areas [pt

Influence of Triply-Charged Ions and Ionization Cross-Sections in a Hybrid-PIC Model of a Hall Thruster Discharge

Science.gov (United States)

Smith, Brandon D.; Boyd, Iain D.; Kamhawi, Hani

2014-01-01

The sensitivity of xenon ionization rates to collision cross-sections is studied within the framework of a hybrid-PIC model of a Hall thruster discharge. A revised curve fit based on the Drawin form is proposed and is shown to better reproduce the measured crosssections at high electron energies, with differences in the integrated rate coefficients being on the order of 10% for electron temperatures between 20 eV and 30 eV. The revised fit is implemented into HPHall and the updated model is used to simulate NASA's HiVHAc EDU2 Hall thruster at discharge voltages of 300, 400, and 500 V. For all three operating points, the revised cross-sections result in an increase in the predicted thrust and anode efficiency, reducing the error relative to experimental performance measurements. Electron temperature and ionization reaction rates are shown to follow the trends expected based on the integrated rate coefficients. The effects of triply-charged xenon are also assessed. The predicted thruster performance is found to have little or no dependence on the presence of triply-charged ions. The fraction of ion current carried by triply-charged ions is found to be on the order of 1% and increases slightly with increasing discharge voltage. The reaction rates for the 0?III, I?III, and II?III ionization reactions are found to be of similar order of magnitude and are about one order of magnitude smaller than the rate of 0?II ionization in the discharge channel.

Separation of the fission product noble gases krypton and xenon from dissolver off-gas in reprocessing HTGR-fuel

Energy Technology Data Exchange (ETDEWEB)

Bohnenstingl, J.; Djoa, S. H.; Laser, M.; Mastera, S.; Merz, E.; Morschl, P.

1976-04-15

This paper describes a process developed for the retainment and separation of volatile (³H, ^{129 +131}I) and gaseous (⁸⁵Kr, Xe) fission products from the off-gas produced during dissolution of HTGR-fuel. To prevent unnecessary dilution of liberated noble gases by surrounding atmosphere, a helium purge-gas cycle is applied to enable a coarse fractionating of krypton and xenon by cold-trapping at about 80 deg K after precleaning the gas stream. The process consists of the following steps: deposition of droplets and solid aerosols; chemisorption of iodine on silver impregnated silica gel; catalytic removal of nitrogen oxides and oxygen; drying of the process gas stream; final filtering of abraded solids; deposition of xenon in solid form at 80 deg K and low subpressure; deposition of krypton in solid form at 80 deg K after compression to about 6 bar; decontamination of ⁸⁵krypton-containing xenon by batch distillation for eventual industrial utilization; and removal of nitrogen and argon enrichment during continuous operation in the purge-gas stream by inleaking air with charcoal. A continuously operating dissolver vessel, closed to the surrounding atmosphere, yields a very high content of noble gases, e.g., 0.35 vol % krypton and 2.0 vol % xenon. The presented off-gas treatment unit is operated in cold runs with 1/3 of the full capacity and can treat about 1 m³ STP/h helium, corresponding to a quantity of about 10,000 MW(e) HTGR-fuel reprocessing plant.

Separation of the fission product noble gases krypton and xenon from dissolver off-gas in reprocessing HTGR-fuel

International Nuclear Information System (INIS)

Bohnenstingl, J.; Djoa, S.H.; Laser, M.; Mastera, S.; Merz, E.; Morschl, P.

1976-01-01

This paper describes a process developed for the retainment and separation of volatile ( 3 H, 129+131 I) and gaseous ( 85 Kr, Xe) fission products from the off-gas produced during dissolution of HTGR-fuel. To prevent unnecessary dilution of liberated noble gases by surrounding atmosphere, a helium purge-gas cycle is applied to enable a coarse fractionating of krypton and xenon by cold-trapping at about 80 0 K after precleaning the gas stream. The process consists of the following steps: deposition of droplets and solid aerosols; chemisorption of iodine on silver impregnated silica gel; catalytic removal of nitrogen oxides and oxygen; drying of the process gas stream; final filtering of abraded solids; deposition of xenon in solid form at 80 0 K and low subpressure; deposition of krypton in solid form at 80 0 K after compression to about 6 bar; decontamination of 85 Kr-containing xenon by batch distillation for eventual industrial utilization; and removal of nitrogen and argon enrichment during continuous operation in the purge-gas stream by inleaking air with charcoal. A continuously operating dissolver vessel, closed to the surrounding atmosphere, yields a very high content of noble gases, i.e., 0.35 vol % krypton and 2.0 vol % xenon. The presented off-gas treatment unit is operated in cold runs with 1 / 3 of the full capacity and can treat about 1 m 3 STP/h helium, corresponding to a quantity of about 10,000 MW/sub e/ HTGR-fuel reprocessing plant

Analysis of reactivity worth for xenon poisoning during restart-up of reactor in iodine pit

International Nuclear Information System (INIS)

Li Xaofeng; Chen Wenzhen; Zhu Qian; Xu Guojun

2009-01-01

The reactivity worth of xenon poisoning and the densities of 135 I and 135 Xe were derived when the reactor was restarted up in iodine pit. Through the expressions obtained we can find the physics characteristics of reactor restarted up in iodine pit comprehensively and essentially. The results were analyzed and discussed. The reactor power before shutdown, the start-up power, the position where the reactor starts up in iodine pit, and so on, all have effect on the reactivity worth of xenon poisoning, and the different conditions can lead to totally different physics characteristics. In addition, the time when the reactor starts up in iodine pit is a very important factor for nuclear reactors safety. The conclusions are very important to the maneuverability and operation safety of ship nuclear reactors. (authors)

Collateral ventilation quantification using xenon-enhanced dynamic dual-energy CT: Differences between canine and swine models of bronchial occlusion

Energy Technology Data Exchange (ETDEWEB)

Kim, Eun Ah; Goo, Jin Mo; Park, Sang Joon; Lee, Chang Hyun; Park, Chng Min [Dept. of Radiology, Seoul National University College of Medicine and Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul (Korea, Republic of)

2015-06-15

The aim of this study was to evaluate whether the difference in the degree of collateral ventilation between canine and swine models of bronchial obstruction could be detected by using xenon-enhanced dynamic dual-energy CT. Eight mongrel dogs and six pigs underwent dynamic dual-energy scanning of 64-slice dual-source CT at 12-second interval for 2-minute wash-in period (60% xenon) and at 24-second interval for 3-minute wash-out period with segmental bronchus occluded. Ventilation parameters of magnitude (A value), maximal slope, velocity (K value), and time-to-peak (TTP) enhancement were calculated from dynamic xenon maps using exponential function of Kety model. A larger difference in A value between parenchyma was observed in pigs than in dogs (absolute difference, -33.0 +/- 5.0 Hounsfield units [HU] vs. -2.8 +/- 7.1 HU, p = 0.001; normalized percentage difference, -79.8 +/- 1.8% vs. -5.4 +/- 16.4%, p = 0.0007). Mean maximal slopes in both periods in the occluded parenchyma only decreased in pigs (all p < 0.05). K values of both periods were not different (p = 0.892) in dogs. However, a significant (p = 0.027) difference was found in pigs in the wash-in period. TTP was delayed in the occluded parenchyma in pigs (p = 0.013) but not in dogs (p = 0.892). Xenon-ventilation CT allows the quantification of collateral ventilation and detection of differences between canine and swine models of bronchial obstruction.

Collateral ventilation quantification using xenon-enhanced dynamic dual-energy CT: Differences between canine and swine models of bronchial occlusion

International Nuclear Information System (INIS)

Kim, Eun Ah; Goo, Jin Mo; Park, Sang Joon; Lee, Chang Hyun; Park, Chng Min

2015-01-01

The aim of this study was to evaluate whether the difference in the degree of collateral ventilation between canine and swine models of bronchial obstruction could be detected by using xenon-enhanced dynamic dual-energy CT. Eight mongrel dogs and six pigs underwent dynamic dual-energy scanning of 64-slice dual-source CT at 12-second interval for 2-minute wash-in period (60% xenon) and at 24-second interval for 3-minute wash-out period with segmental bronchus occluded. Ventilation parameters of magnitude (A value), maximal slope, velocity (K value), and time-to-peak (TTP) enhancement were calculated from dynamic xenon maps using exponential function of Kety model. A larger difference in A value between parenchyma was observed in pigs than in dogs (absolute difference, -33.0 +/- 5.0 Hounsfield units [HU] vs. -2.8 +/- 7.1 HU, p = 0.001; normalized percentage difference, -79.8 +/- 1.8% vs. -5.4 +/- 16.4%, p = 0.0007). Mean maximal slopes in both periods in the occluded parenchyma only decreased in pigs (all p < 0.05). K values of both periods were not different (p = 0.892) in dogs. However, a significant (p = 0.027) difference was found in pigs in the wash-in period. TTP was delayed in the occluded parenchyma in pigs (p = 0.013) but not in dogs (p = 0.892). Xenon-ventilation CT allows the quantification of collateral ventilation and detection of differences between canine and swine models of bronchial obstruction.

H- Enhancement Process in a Multicusp Ion Source Operated with a Barium Insert Structure

Energy Technology Data Exchange (ETDEWEB)

Leung, K.N.; Van Os, C.F.A.; Kunkel, W.B.

1990-05-01

It has been demonstrated that the H{sup -} output current from a small multicusp source can be substantially enhanced if the hydrogen plasma is seeded with barium. Operating with a barium washer insert at the extraction aperture, it is found that the extractable H{sup -} current is increased by a factor of three if the insert bias potential is optimized. By use of a mixture of xenon and hydrogen gas, it is further demonstrated that the positive hydrogen ions are responsible for the observed H{sup -} enhancement.

Site blocking in silver-exchanged zeolite Y by carbon monoxide and ethene using xenon adsorption and 129Xe NMR spectroscopy

Science.gov (United States)

Boddenberg, B.; Watermann, J.

1993-03-01

The adsorption isotherms and 129Xe NMR chemical shifts of xenon in the zeolites NaY, AgY, and in AgY preloaded with ≈ 1 molecule/supercage ethene and carbon monoxide were measured at 25°C. The experimental data reveal the blocking of the silver-cation sites for xenon by the preadsorbed molecules. Ethene and CO are found to block the previously postulated two types of silver-cation species in the supercages of AgY in a different way.

Background in xenon filled X-ray detectors

International Nuclear Information System (INIS)

Feroci, M.; Costa, E.; Dwyer, J.; Ford, E.; Kaaret, P.; Rapisarda, M.; Soffitta, P.

1995-01-01

Xenon based gas mixtures have been often used in proportional counters for X-ray astronomy in order to achieve a good efficiency in the medium/high X-ray energy range. Proportional counters flown on past missions (i.e. HEAO1 and EXOSAT) filled with Xe-based mixtures have shown a higher residual background (after that all the rejection techniques have been applied) with respect to Ar-based ones, operating in the same energy band and in the same radiation environment. We show, by means of Monte Carlo simulations, analytical computations and laboratory measurements, that such difference can be mostly understood in terms of higher internal background production and lower pulse discrimination efficiency in Xe-based gas filling, with respect to Ar-based ones. (orig.)

Three Dimensional Simulation of Ion Thruster Plume-Spacecraft Interaction Based on a Graphic Processor Unit

International Nuclear Information System (INIS)

Ren Junxue; Xie Kan; Qiu Qian; Tang Haibin; Li Juan; Tian Huabing

2013-01-01

Based on the three-dimensional particle-in-cell (PIC) method and Compute Unified Device Architecture (CUDA), a parallel particle simulation code combined with a graphic processor unit (GPU) has been developed for the simulation of charge-exchange (CEX) xenon ions in the plume of an ion thruster. Using the proposed technique, the potential and CEX plasma distribution are calculated for the ion thruster plume surrounding the DS1 spacecraft at different thrust levels. The simulation results are in good agreement with measured CEX ion parameters reported in literature, and the GPU's results are equal to a CPU's. Compared with a single CPU Intel Core 2 E6300, 16-processor GPU NVIDIA GeForce 9400 GT indicates a speedup factor of 3.6 when the total macro particle number is 1.1×10 6 . The simulation results also reveal how the back flow CEX plasma affects the spacecraft floating potential, which indicates that the plume of the ion thruster is indeed able to alleviate the extreme negative floating potentials of spacecraft in geosynchronous orbit

Protonated ions as systemic trapping agents for noble gases: From electronic structure to radiative association.

Science.gov (United States)

Ozgurel, O; Pauzat, F; Pilmé, J; Ellinger, Y; Bacchus-Montabonel, M-C; Mousis, O

2017-10-07

The deficiencies of argon, krypton, and xenon observed in the atmosphere of Titan as well as anticipated in some comets might be related to a scenario of sequestration by H 3 + in the gas phase at the early evolution of the solar nebula. The chemical process implied is a radiative association, evaluated as rather efficient in the case of H 3 + , especially for krypton and xenon. This mechanism of chemical trapping might not be limited to H 3 + only, considering that the protonated ions produced in the destruction of H 3 + by its main competitors present in the primitive nebula, i.e., H 2 O, CO, and N 2 , might also give stable complexes with the noble gases. However the effective efficiency of such processes is still to be proven. Here, the reactivity of the noble gases Ar, Kr, and Xe, with all protonated ions issued from H 2 O, CO, and N 2 , expected to be present in the nebula with reasonably high abundances, has been studied with quantum simulation method dynamics included. All of them give stable complexes and the rate coefficients of their radiative associations range from 10 -16 to 10 -19 cm 3 s -1 , which is reasonable for such reactions and has to be compared to the rates of 10 -16 to 10 -18 cm 3 s -1 , obtained with H 3 + . We can consider this process as universal for all protonated ions which, if present in the primitive nebula as astrophysical models predict, should act as sequestration agents for all three noble gases with increasing efficiency from Ar to Xe.

Ion-surface interaction: simulation of plasma-wall interaction (ITER)

International Nuclear Information System (INIS)

Salou, Pierre

2013-01-01

The wall materials of magnetic confinement in fusion machines are exposed to an aggressive environment; the reactor blanket is bombarded with a high flux of particles extracted from the plasma, leading to the sputtering of surface material. This sputtering causes wall erosion as well as plasma contamination problems. In order to control fusion reactions in complex reactors, it is thus imperative to well understand the plasma-wall interactions. This work proposes the study of the sputtering of fusion relevant materials. We propose to simulate the charged particles influx by few keV single-charged ion beams. This study is based on the catcher method; to avoid any problem of pollution (especially in the case of carbon) we designed a new setup allowing an in situ Auger electron spectroscopy analysis. The results provide the evolution of the angular distribution of the sputtering yield as a function of the ion mass (from helium to xenon) and its energy (from 3 keV to 9 keV). (author) [fr

Cerebral blood flow in acute and chronic ischemic stroke using xenon-133 inhalation tomography

DEFF Research Database (Denmark)

Vorstrup, S; Paulson, O B; Lassen, N A

1986-01-01

Serial measurements of cerebral blood flow (CBF) were performed in 12 patients with acute symptoms of ischemic cerebrovascular disease. CBF was measured by xenon-133 inhalation and single photon emission computer tomography. Six patients had severe strokes and large infarcts on the CT scan...

Efficient extreme ultraviolet plasma source generated by a CO2 laser and a liquid xenon microjet target

Science.gov (United States)

Ueno, Yoshifumi; Ariga, Tatsuya; Soumagne, George; Higashiguchi, Takeshi; Kubodera, Shoichi; Pogorelsky, Igor; Pavlishin, Igor; Stolyarov, Daniil; Babzien, Marcus; Kusche, Karl; Yakimenko, Vitaly

2007-05-01

We demonstrated efficacy of a CO2-laser-produced xenon plasma in the extreme ultraviolet (EUV) spectral region at 13.5nm at variable laser pulse widths between 200ps and 25ns. The plasma target was a 30μm liquid xenon microjet. To ensure the optimum coupling of CO2 laser energy with the plasma, they applied a prepulse yttrium aluminum garnet laser. The authors measured the conversion efficiency (CE) of the 13.5nm EUV emission for different pulse widths of the CO2 laser. A maximum CE of 0.6% was obtained for a CO2 laser pulse width of 25ns at an intensity of 5×1010W/cm2.

Efficient extreme ultraviolet plasma source generated by a CO2 laser and a liquid xenon microjet target

International Nuclear Information System (INIS)

Ueno, Yoshifumi; Ariga, Tatsuya; Soumagne, George; Higashiguchi, Takeshi; Kubodera, Shoichi; Pogorelsky, Igor; Pavlishin, Igor; Stolyarov, Daniil; Babzien, Marcus; Kusche, Karl; Yakimenko, Vitaly

2007-01-01

We demonstrated efficacy of a CO 2 -laser-produced xenon plasma in the extreme ultraviolet (EUV) spectral region at 13.5 nm at variable laser pulse widths between 200 ps and 25 ns. The plasma target was a 30 μm liquid xenon microjet. To ensure the optimum coupling of CO 2 laser energy with the plasma, they applied a prepulse yttrium aluminum garnet laser. The authors measured the conversion efficiency (CE) of the 13.5 nm EUV emission for different pulse widths of the CO 2 laser. A maximum CE of 0.6% was obtained for a CO 2 laser pulse width of 25 ns at an intensity of 5x10 10 W/cm 2

Ultraviolet-B radiation enhancement in dielectric barrier discharge based xenon chloride exciplex source by air

Energy Technology Data Exchange (ETDEWEB)

Gulati, P., E-mail: pgulati1512@gmail.com [CSIR-Central Electronics Engineering Research Institute (CSIR-CEERI), Pilani, Rajasthan-333031 (India); Department of Physics, Banasthali University, P.O. Banasthali Vidyapith, Rajasthan 304022 (India); Prakash, R.; Pal, U. N.; Kumar, M. [CSIR-Central Electronics Engineering Research Institute (CSIR-CEERI), Pilani, Rajasthan-333031 (India); Vyas, V. [Department of Physics, Banasthali University, P.O. Banasthali Vidyapith, Rajasthan 304022 (India)

2014-07-07

A single barrier dielectric barrier discharge tube of quartz with multi-strip Titanium-Gold (Ti-Au) coatings have been developed and utilized for ultraviolet-B (UV-B) radiation production peaking at wavelength 308 nm. The observed radiation at this wavelength has been examined for the mixtures of the Xenon together with chlorine and air admixtures. The gas mixture composition, chlorine gas content, total gas pressure, and air pressure dependency of the UV intensity, has been analyzed. It is found that the larger concentration of Cl{sub 2} deteriorates the performance of the developed source and around 2% Cl{sub 2} in this source produced optimum results. Furthermore, an addition of air in the xenon and chlorine working gas environment leads to achieve same intensity of UV-B light but at lower working gas pressure where significant amount of gas is air.

Ultraviolet-B radiation enhancement in dielectric barrier discharge based xenon chloride exciplex source by air

Science.gov (United States)

Gulati, P.; Prakash, R.; Pal, U. N.; Kumar, M.; Vyas, V.

2014-07-01

A single barrier dielectric barrier discharge tube of quartz with multi-strip Titanium-Gold (Ti-Au) coatings have been developed and utilized for ultraviolet-B (UV-B) radiation production peaking at wavelength 308 nm. The observed radiation at this wavelength has been examined for the mixtures of the Xenon together with chlorine and air admixtures. The gas mixture composition, chlorine gas content, total gas pressure, and air pressure dependency of the UV intensity, has been analyzed. It is found that the larger concentration of Cl2 deteriorates the performance of the developed source and around 2% Cl2 in this source produced optimum results. Furthermore, an addition of air in the xenon and chlorine working gas environment leads to achieve same intensity of UV-B light but at lower working gas pressure where significant amount of gas is air.

A new approach to control of xenon spatial oscillation during load follow operation via robust servo systems

International Nuclear Information System (INIS)

Ukai, Hiroyuki; Iwazumi, Tetsuo

1994-01-01

The control problem of xenon-induced spatial oscillations of PWR in the axial direction during a load following operation is investigated. The system models are described by a one-group diffusion equation with xenon and temperature feed-backs, iodine and xenon dynamic equations, and heat conductions processes. Control is implemented by the full-length and the part-length control rods and the boron concentration. In order to achieve the control purpose, control models are formulated as the design problem of robust servo systems for distributed parameter reactor systems. The total thermal power and the axial offset are chosen as outputs to be controlled. The control systems consist of servo compensators and stabilizing compensators. They are designed based on the finite-dimensional systems which are constructed by linearizing around steady states, approximately by the Galerkin method, and reducing dimensions via the singular perturbation method. A new and simple computational algorithm to obtain an approximate solution of a steady-state neutron balance is developed via the perturbation method. Some results of numerical simulations are shown in order to discuss the effectiveness of the theory developed in this paper. In particular, it is shown that the designed servo systems are robust against model errors with linearization and modal truncation

Making channeling visible: keV noble gas ion trails on Pt(111)

Energy Technology Data Exchange (ETDEWEB)

Redinger, A; Standop, S; Michely, T [II Physikalisches Institut, Universitaet zu Koeln, D-50937 Koeln (Germany); Rosandi, Y; Urbassek, H M, E-mail: urbassek@rhrk.uni-kl.de [Fachbereich Physik und Forschungszentrum OPTIMAS, Universitaet Kaiserslautern, Erwin-Schroedinger-Strasse, D-67663 Kaiserslautern (Germany)

2011-01-15

The impact of argon and xenon noble gas ions on Pt(111) in grazing incidence geometry are studied through direct comparison of scanning tunneling microscopy images and molecular dynamics simulations. The energy range investigated is 1-15 keV and the angles of incidence with respect to the surface normal are between 78.5{sup 0} and 88{sup 0}. The focus of the paper is on events where ions gently enter the crystal at steps and are guided in channels between the top most layers of the crystal. The trajectories of the subsurface channeled ions are visible as trails of surface damage. The mechanism of trail formation is analyzed using simulations and analytical theory. Significant differences between Xe{sup +} and Ar{sup +} projectiles in damage, in the onset energy of subsurface channeling as well as in ion energy dependence of trail length and appearance are traced back to the projectile and ion energy dependence of the stopping force. The asymmetry of damage production with respect to the ion trajectory direction is explained through the details of the channel shape and subchannel structure as calculated from the continuum approximation of the channel potential. Measured and simulated channel switching in directions normal and parallel to the surface as well as an increase of ions entering into channels from the perfect surface with increasing angles of incidence are discussed.

A novel approach to measure the electric dipole moment of 129Xenon

Energy Technology Data Exchange (ETDEWEB)

Kuchler, Florian; Feldmeier, Wolfhardt; Fierlinger, Peter; Taubenheim, Bernd [Excellence Cluster Universe, Technische Universitaet Muenchen, Garching (Germany)

2012-07-01

Permanent electric dipole moments (EDM) are promising systems to find new CP violation. The properties of the diamagnetic atom 129-Xe make it a particularly interesting candidate for an EDM search, as it enables new experimental strategies. Although the current experimental limit of d{sub Xe} < 4.0.10{sup -27} ecm is many orders of magnitude higher than the Standard Model (SM) prediction, theories beyond the SM usually require larger EDMs. Our experiment is based on microscopic hyper-polarized liquid xenon droplets, placed in a low-field NMR setup. Implementation of rotating electric fields enables a conceptually new EDM measurement technique, allowing thorough investigation of systematic effects. Still, a Ramsey-type spin precession experiment with static electric field can be realized at similar sensitivity within the same setup. Employing superconducting pick-up coils and highly sensitive LTc-SQUIDs, a large array of independent measurements can be performed simultaneously with different field configurations. With our novel approach we aim to be sensitive to an EDM of 129-Xe on the order of 10{sup -30} ecm. The talk gives an update on the current status of the xenon EDM experiment.

Proton multiplicity distributions in pion-xenon nucleus collisions at 3.5 GeV/c

International Nuclear Information System (INIS)

Strugalski, Z.; Pawlak, T.; Peryt, W.; Pluta, J.

1980-01-01

Experimental results from the proton emission investigation in 3.5 GeV/c pion minus-xenon nucleus collisions detected in the 180 xenon bubble chamber are presented and analyzed. The emitted protons are of kinetic energies from 20 to 400 MeV. Multiplicity distributions of protons both accompanied and not accompanied by secondary charged and neutral pions are given. Large proton multiplicities are observed in the events without multiparticle production, the proton multiplicity distribution in this class of events being of an irregular character. The experimental results are well described in the model based on the following hypothesis: a high energy hadron traversing the target causes the monotonous emission of the fast protons in numbers nsub(p) being equal to the number of protons encountered in the neighbourhood of its path inside the nucleus target. In this case the multiple production goes through some intermediate states which decay after having left the target nucleus

Supersymmetry and Dark Matter in Light of LHC 2010 and Xenon100 Data

CERN Document Server

Buchmueller, O.; Colling, D.; De Roeck, A.; Dolan, M.J.; Ellis, J.R.; Flacher, H.; Heinemeyer, S.; Isidori, G.; Santos, D.Martinez; Olive, K.A.; Rogerson, S.; Ronga, F.J.; Weiglein, G.

2011-01-01

We make frequentist analyses of the CMSSM, NUHM1, VCMSSM and mSUGRA parameter spaces taking into account all the public results of searches for supersymmetry using data from the 2010 LHC run and the Xenon100 direct search for dark matter scattering. The LHC data set includes ATLAS and CMS searches for jets + ETslash events (with or without leptons) and for the heavier MSSM Higgs bosons, and the upper limit on bs to mu mu including data from LHCb as well as CDF and D0. The absences of signals in the LHC data favour somewhat heavier mass spectra than in our previous analyses of the CMSSM, NUHM1 and VCMSSM, and somewhat smaller dark matter scattering cross sections, all close to or within the pre-LHC 68% CL ranges, but do not impact significantly the favoured regions of the mSUGRA parameter space. We also discuss the impact of the Xenon100 constraint on spin-independent dark matter scattering, stressing the importance of taking into account the uncertainty in the pi-nucleon sigma term, that affects the spin-inde...

Gamma-ray spectrometer utilizing xenon at high pressure

International Nuclear Information System (INIS)

Smith, G.C.; Mahler, G.J.; Yu, B.; Kane, W.R.; Markey, J.K.

1994-01-01

A prototype gamma-ray spectrometer utilizing xenon gas near the critical point (166 degrees C, 58 atm) is under development. The spectrometer will function as a room-temperature ionization chamber detecting gamma rays in the energy range 100 keV2 MeV, with an energy resolution intermediate between semiconductor (Ge) and scintillation (NaI) spectrometers. The energy resolution is superior to that of a NaI scintillation spectrometer by a substantial margin (approximately a factor 5), and accordingly, much more information can be extracted from a given gamma-ray spectrum. Unlike germanium detectors, the spectrometer possesses the capability for sustained operation under ambient temperature conditions without a requirement for liquid nitrogen

Output characteristics of piezoelectric lead zirconate titanate detector using high-energy heavy-ion beam

International Nuclear Information System (INIS)

Takechi, Seiji; Sekiguchi, Masahiro; Miyachi, Takashi; Kobayashi, Masanori; Hattori, Maki; Okudaira, Osamu; Shibata, Hiromi; Fujii, Masayuki; Okada, Nagaya; Murakami, Takeshi; Uchihori, Yukio

2014-01-01

A radiation detector fabricated using piezoelectric lead zirconate titanate (PZT) has been studied by irradiating it with a 400 MeV/n xenon (Xe) beam. The beam diameter was controlled to change the irradiation conditions. It was found that the magnitude of the output observed from the PZT detector may be related to the number of Xe ions per unit area per unit time within the limits of the experimental conditions. -- Highlights: • The performance of PZT detector was studied by irradiation of a 400 MeV/n Xe beam. • The beam diameter was controlled to change the irradiation conditions. • By the control, the number of Xe ions per one pulse was changed from ∼500 to ∼1500. • The output of the PZT detector was not always larger with more intense beam. • The energy of Xe ions per unit area per unit time may determine the output

Evaluation of the relative thermoluminescence efficiency of LiF:Mg,Ti and LiF:Mg,Cu,P TL detectors to low-energy heavy ions

DEFF Research Database (Denmark)

Gieszczyk, W.; Bilski, P.; Olko, P.

2013-01-01

and xenon ion beams, at energies ranging from 5.0 to 9.3 MeV/n. Supra- and sublinear response was found, for the MTS-N and MCP-N, respectively, similarly as observed for γ-rays. However, the level of nonlinearity of response of studied detectors is strongly reduced by increasing values of the ion ionization...... density (no supralinearity for Xe ions, for MTS-N, within calculated uncertainties). The growth of high-temperature TL peaks, with increasing ionization density, was observed for MCP-N, what was not previously reported. At the whole range of applied energies higher efficiencies were noted for MTS......-N, for all ion species. A decrease of the efficiency with decrease of the ion energy was confirmed, for both types of studied detectors. At a given energy, higher efficiency was observed for lighter ions, because of the lower ionization density. Significantly higher decrease of the efficiency was measured...

Experimental modeling of high burn-up structure in SIMFUEL with ion irradiation

International Nuclear Information System (INIS)

Baranov, V.; Isaenkova, M.; Lunev, A.; Tenishev, A.; Khlunov, A.

2013-01-01

Experiments are conducted to simulate high burn-up structure in accelerator conditions. Three ion irradiation schemes are used: 1. Xe 27+ 160 MeV up to 5x10 15 cm -2 (thermal spikes). 2. Xe 16+ 320 keV up to 1x10 17 cm -2 (collision cascades). 3. He + 20 keV up to 5,5x10 17 cm -2 (implantation stage). Structural characterization performed by scanning electron microscopy, X-ray analysis and atomic force microscopy revealed prominent grain refinement in case of Xe 27+ irradiation. Artificial energy variation for incident ions showed varying size of subgrains. At maximum energy of incident ions, subgrain size amounts ∼ 320 nm. Moving to the edge of irradiated region changes the size to ∼ 170 nm. Typical size of coherent scattering regions matches subgrain size for high-energy irradiation. Low-energy irradiation results in less significant structural changes: flaky structure at random sites for samples irradiated with low-energy xenon ions and bubble nucleation for helium irradiation. Dislocation density increases significantly, and it is shown that a single fluence dependence exists for low- and high-energy irradiation. (authors)

Xenon-induced power oscillations in a generic small modular reactor

Science.gov (United States)

Kitcher, Evans Damenortey

As world demand for energy continues to grow at unprecedented rates, the world energy portfolio of the future will inevitably include a nuclear energy contribution. It has been suggested that the Small Modular Reactor (SMR) could play a significant role in the spread of civilian nuclear technology to nations previously without nuclear energy. As part of the design process, the SMR design must be assessed for the threat to operations posed by xenon-induced power oscillations. In this research, a generic SMR design was analyzed with respect to just such a threat. In order to do so, a multi-physics coupling routine was developed with MCNP/MCNPX as the neutronics solver. Thermal hydraulic assessments were performed using a single channel analysis tool developed in Python. Fuel and coolant temperature profiles were implemented in the form of temperature dependent fuel cross sections generated using the SIGACE code and reactor core coolant densities. The Power Axial Offset (PAO) and Xenon Axial Offset (XAO) parameters were chosen to quantify any oscillatory behavior observed. The methodology was benchmarked against results from literature of startup tests performed at a four-loop PWR in Korea. The developed benchmark model replicated the pertinent features of the reactor within ten percent of the literature values. The results of the benchmark demonstrated that the developed methodology captured the desired phenomena accurately. Subsequently, a high fidelity SMR core model was developed and assessed. Results of the analysis revealed an inherently stable SMR design at beginning of core life and end of core life under full-power and half-power conditions. The effect of axial discretization, stochastic noise and convergence of the Monte Carlo tallies in the calculations of the PAO and XAO parameters was investigated. All were found to be quite small and the inherently stable nature of the core design with respect to xenon-induced power oscillations was confirmed. Finally, a

Time dependent analysis of Xenon spatial oscillations in small power reactors; Analise temporal das oscilacoes espaciais de Xenonio em reatores de pequeno porte

Energy Technology Data Exchange (ETDEWEB)

Decco, Claudia Cristina Ghirardello

1997-07-01

This work presents time dependent analysis of xenon spatial oscillations studying the influence of the power density distribution, type of reactivity perturbation, power level and core size, using the one-dimensional and three-dimensional analysis with the MID2 and citation codes, respectively. It is concluded that small pressurized water reactors with height smaller than 1.5 m are stable and do not have xenon spatial oscillations. (author)

Absorption of scintillation light in a 100l liquid xenon γ-ray detector and expected detector performance

International Nuclear Information System (INIS)

Baldini, A.; Bemporad, C.; Cei, F.; Doke, T.; Grassi, M.; Grebenuk, A.A.; Grigoriev, D.N.; Haruyama, T.; Kasami, K.; Kikuchi, J.; Maki, A.; Mashimo, T.; Mihara, S.; Mitsuhashi, T.; Mori, T.; Nicolo, D.; Nishiguchi, H.; Ootani, W.; Ozone, K.; Papa, A.; Pazzi, R.; Ritt, S.; Sawada, R.; Sergiampietri, F.; Signorelli, G.; Suzuki, S.; Terasawa, K.; Yamashita, M.; Yamashita, S.; Yoshimura, T.; Yuri, Yu.

2005-01-01

An 800l liquid xenon scintillation γ-ray detector is being developed for the MEG experiment which will search for μ + ->e + γdecay at the Paul Scherrer Institut. Absorption of scintillation light of xenon by impurities might possibly limit the performance of such a detector. We used a 100l prototype with an active volume of 372x372x496mm 3 to study the scintillation light absorption. We have developed a method to evaluate the light absorption, separately from elastic scattering of light, by measuring cosmic rays and α sources. By using a suitable purification technique, an absorption length longer than 100cm has been achieved. The effects of the light absorption on the energy resolution are estimated by Monte Carlo simulation

Effects of premedication with oral hydroxyzine on patient motion during inhalation of 32% xenon for regional cerebral blood flow mapping

International Nuclear Information System (INIS)

Sesay, M.; Dousset, V.; Caille, J.M.; Maurette, P.; Tanaka, Akira

2000-01-01

Because of its anesthetic properties, inhalation of 30-35% Xenon is associated with uncontrolled patient motion in 3-15% of the cases. This constitutes a major setback to regional cerebral blood flow studies with Xenon-enhanced computed tomography (Xe-CT CBF). The present study attempted to determine the effects of oral premedication with hydroxyzine (H) in the control of motion. Patients scheduled for Xe-CT CBF, aged 20-55 years, were randomly allocated to 3 groups: H 50 mg (n=41), H 100 mg (n=36) or Placebo (n=43). The drugs were administered orally 90 minutes before Xenon inhalation. This consisted a gas mixture of 32% Xe and 25% oxygen. Motion was classified as controlled or uncontrolled depending on whether CBF data acquisition was possible or not. Anxiolysis and sedation were evaluated by a visual analogue scale. Motion was significantly reduced in the H 50 mg (0.8% vs 2.5% in the H 100 mg and 6.7% in the Placebo group). An anxiolytic effect of hydroxyzine was suggested. (author)

Hall effect in non-ideal plasma of argon and xenon

International Nuclear Information System (INIS)

Shilkin, N.S.; Dudin, S.V.; Gryaznov, V.K.; Mintsev, V.B.; Fortov, V.E.

2003-01-01

The first data on the measurement of the electron concentration (10 16 -10 20 cm -3 ) of the low-temperature (0.5-1 eV) non-ideal (0.01 -6 -10 -1 ) inert gases plasma are presented. The measurements of the Hall constant and electric conductivity in the non-ideal partially ionized plasma of argon and xenon are carried out through the sounding methods. The plasma generation was accomplished behind the shock waves front through the linear explosive generators. The obtained results are compared with a number of the plasma models [ru

Potential impact of releases from a new Molybdenum-99 production facility on regional measurements of airborne xenon isotopes

Energy Technology Data Exchange (ETDEWEB)

Bowyer, Ted W.; Eslinger, Paul W.; Cameron, Ian M.; Friese, Judah I.; Hayes, James C.; Metz, Lori A.; Miley, Harry S.

2014-03-01

The monitoring of the radioactive xenon isotopes 131mXe, 133Xe, 133mXe, and 135Xe is important for the detection of nuclear explosions. While backgrounds of the xenon isotopes are short-lived, they are constantly replenished from activities dominated by the fission-based production of 99Mo used for medical procedures. One of the most critical locations on earth for the monitoring of nuclear explosions is the Korean peninsula, where the Democratic Republic of North Korea (DPRK) has announced that it had conducted three nuclear tests between 2009 and 2013. This paper explores the backgrounds that would be caused by the medium to large scale production of 99Mo in the region of the Korean peninsula.

Optimizing ideal ion propulsion systems depending on the nature of the propellant

Directory of Open Access Journals (Sweden)

Grigore CICAN

2016-12-01

Full Text Available From all accounts the ion thrusters are characterized by the fact that they produce a very high exhaust velocity and specific impulse, sometimes too high for many missions. The exhaust velocity of the ionized particles is a function of the ratio between electrical charge and mass. The obvious solution is the use of ions with low electrical charge – mass ratio, but many of these substances have a corrosive effect on the acceleration grids, they are toxic and hard to store on board the spacecraft. Currently the most used propellant for the ionic propulsion systems is xenon gas having many advantages, but it is expensive when compared to other propellants. The current paper aims to make an optimization study of ideal ion thrusters depending on the nature of the propellant using for studying a significant number of substances. It will study the variation of the performances: force, specific impulse, efficiency, etc for the same power available on board, for the same accelerating voltage and the same ionic current.

Infrared matrix isolation and ab initio studies on isothiocyanic acid HNCS and its complexes with nitrogen and xenon

International Nuclear Information System (INIS)

Wierzejewska, Maria; Wieczorek, Robert

2003-01-01

The isothiocyanic acid HNCS (DNCS) and its complexes with nitrogen and xenon have been studied experimentally by FTIR matrix isolation technique and computationally with the use of ab initio calculations at the MP2 level. The spectra show that HNCS (DNCS) interacts specifically with nitrogen forming 1:1 hydrogen bonded complex in argon matrix while non-hydrogen bonded structure is probably formed in solid xenon. Two stable minima were localized on the potential energy surface. One of them involves an almost linear hydrogen bond from NH group of the acid molecule to nitrogen molecule lone pair (structure I) and has an interaction energy ΔE CP equal to -6.85 kJ/mol. The second structure (II) where the nitrogen molecule interacts with the sulfur atom of the HNCS was found to be weaker bound and is characterized by ΔE CP =-1.99 kJ/mol. A low energetic barrier of 5.86 kJ/mol between the structures I and II was found. Both experimental and theoretical results obtained for the Xe···HNCS system point to a structure with the NH group interacting with the xenon atom. An interaction energy ΔE CP for this complex is equal to -3.64 kJ/mol

Evidence for an ultrafast breakdown of the BeO band structure due to swift argon and xenon ions.

Science.gov (United States)

Schiwietz, G; Czerski, K; Roth, M; Grande, P L; Koteski, V; Staufenbiel, F

2010-10-29

Auger-electron spectra associated with Be atoms in the pure metal lattice and in the stoichiometric oxide have been investigated for different incident charged particles. For fast incident electrons, for Ar7+ and Ar15+ ions as well as Xe15+ and Xe31+ ions at velocities of 6% to 10% the speed of light, there are strong differences in the corresponding spectral distributions of Be-K Auger lines. These differences are related to changes in the local electronic band structure of BeO on a femtosecond time scale after the passage of highly charged heavy ions.

Stable xenon CT measurement of cerebral blood flow in cardiac transplantation candidates: Correlation with cognitive function

International Nuclear Information System (INIS)

Bello, J.A.; Fink, M.E.; Hilal, S.K.; Rose, E.A.; Reemtsma, K.

1987-01-01

Thirteen consecutive unselected patients with NYHA class 4 cardiac failure referred for cardiac transplantation underwent neurologic examination and cerebral blood flow measurement (rCBF) using the stable xenon enhanced CT method on a GE9800 system. Eleven men and two women were studied (mean age = 43.8 +- 6.1). On neurological examination, six of the patients demonstrated normal mental function; the remaining seven patients demonstrated memory, language, or learning impairment. There was no difference in mean cardiac output between the groups (4.9 L/min +- 1.68 vs. 4.2L/min +- 1.57). rCBF was significantly reduced in the impaired group. Cognitive impairment in patients with cardiac failure can be correlated with cerebral ischemia. Stable xenon CT measurement of rCBF in transplant candidates may help identify patients requiring more rapid transplantation to prevent permanent cerebral injury

Modeling pulse characteristics in Xenon with NEST

International Nuclear Information System (INIS)

Mock, J; Stolp, D; Szydagis, M; Tripathi, M; Uvarov, S; Woods, M; Walsh, N; Barry, N; Kazkaz, K

2014-01-01

A comprehensive model for describing the characteristics of pulsed signals, generated by particle interactions in xenon detectors, is presented. An emphasis is laid on two-phase time projection chambers, but the models presented are also applicable to single phase detectors. In order to simulate the pulse shape due to primary scintillation light, the effects of the ratio of singlet and triplet dimer state populations, as well as their corresponding decay times, and the recombination time are incorporated into the model. In a two phase time projection chamber, when simulating the pulse caused by electroluminescence light, the ionization electron mean free path in gas, the drift velocity, singlet and triplet decay times, diffusion constants, and the electron trapping time, have been implemented. This modeling has been incorporated into a complete software package, which realistically simulates the expected pulse shapes for these types of detectors

A comparison between 133Xenon washout technique and Laser Doppler flowmetry in the measurement of local vasoconstrictor effects on the microcirculation in subcutaneous tissue and skin

International Nuclear Information System (INIS)

Kastrup, J.; Buelow, J.; Lassen, N.A.

1987-01-01

Changes in skin blood flow measured by Laser Doppler flowmetry and changes in subcutaneous blood flow measured by 133 Xenon washout technique were compared during activation of the local sympathetic mediated veno-arteriolar vaso-constrictor reflex by lowering the area of investigation below heart level. The measurements were performed in tissue with and without sympathetic innervation. In five subjects, who all had been cervically sympathectomized for manual hyperhidrosis, the Laser Doppler and 133 Xenon blood flow measurements were performed simultaneously on the sympathetically denervated forearm, and on the calf with preserved sympathetic nerve supply. The Laser Doppler method registered a 23% reduction in skin blood flow during lowering of the extremities independently of the sympathetic nerve supply to the skin. The 133 Xenon method recorded a 44% decrease in blood flow in innervated and unchanged blood flow in denervated subcutaneous tissue during lowering of the extremities. Our results indicate that the Laser Doppler method and 133 Xenon method are not comparable, and that the Laser Doppler method is not useful in measuring local sympathetic mediated blood flow changes. (author)

Comparison between /sup 133/Xenon washout technique and Laser Doppler flowmetry in the measurement of local vasoconstrictor effects on the microcirculation in subcutaneous tissue and skin

Energy Technology Data Exchange (ETDEWEB)

Kastrup, J.; Buelow, J.; Lassen, N.A.

1987-10-01

Changes in skin blood flow measured by Laser Doppler flowmetry and changes in subcutaneous blood flow measured by /sup 133/Xenon washout technique were compared during activation of the local sympathetic mediated veno-arteriolar vaso-constrictor reflex by lowering the area of investigation below heart level. The measurements were performed in tissue with and without sympathetic innervation. In five subjects, who all had been cervically sympathectomized for manual hyperhidrosis, the Laser Doppler and /sup 133/Xenon blood flow measurements were performed simultaneously on the sympathetically denervated forearm, and on the calf with preserved sympathetic nerve supply. The Laser Doppler method registered a 23% reduction in skin blood flow during lowering of the extremities independently of the sympathetic nerve supply to the skin. The /sup 133/Xenon method recorded a 44% decrease in blood flow in innervated and unchanged blood flow in denervated subcutaneous tissue during lowering of the extremities. Our results indicate that the Laser Doppler method and /sup 133/Xenon method are not comparable, and that the Laser Doppler method is not useful in measuring local sympathetic mediated blood flow changes.

Redistributed Regional Ventilation after the Administration of a Bronchodilator Demonstrated on Xenon-Inhaled Dual-Energy CT in a Patient with Asthma

International Nuclear Information System (INIS)

Goo, Hyun Woo; Yu, Jin Ho

2011-01-01

We report here on the redistributed regional ventilation abnormalities after the administration of a bronchodilator and as seen on xenon-inhaled dual-energy CT in a patient with asthma. The improved ventilation seen in the right lower lobe and the decreased ventilation seen in the right middle lobe after the administration of a bronchodilator on xenon-inhaled dual-energy CT could explain a positive bronchodilator response on a pulmonary function test. These changes may reflect the heterogeneity of the airway responsiveness to a bronchodilator in patients with asthma.

Redistributed Regional Ventilation after the Administration of a Bronchodilator Demonstrated on Xenon-Inhaled Dual-Energy CT in a Patient with Asthma

Energy Technology Data Exchange (ETDEWEB)

Goo, Hyun Woo; Yu, Jin Ho [Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

2011-06-15

We report here on the redistributed regional ventilation abnormalities after the administration of a bronchodilator and as seen on xenon-inhaled dual-energy CT in a patient with asthma. The improved ventilation seen in the right lower lobe and the decreased ventilation seen in the right middle lobe after the administration of a bronchodilator on xenon-inhaled dual-energy CT could explain a positive bronchodilator response on a pulmonary function test. These changes may reflect the heterogeneity of the airway responsiveness to a bronchodilator in patients with asthma.

Mechanism for transient migration of xenon in UO2

International Nuclear Information System (INIS)

Liu, X.-Y.; Uberuaga, B. P.; Andersson, D. A.; Stanek, C. R.; Sickafus, K. E.

2011-01-01

In this letter, we report recent work on atomistic modeling of diffusion migration events of the fission gas product xenon in UO 2 nuclear fuel. Under nonequilibrium conditions, Xe atoms can occupy the octahedral interstitial site, in contrast to the thermodynamically most stable uranium substitutional site. A transient migration mechanism involving Xe and two oxygen atoms is identified using basin constrained molecular dynamics employing a Buckingham type interatomic potential. This mechanism is then validated using density functional theory calculations using the nudged elastic band method. An overall reduction in the migration barrier of 1.6-2.7 eV is obtained compared to vacancy-mediated diffusion on the uranium sublattice.

Multiphoton ionization of many-electron atoms and highly-charged ions in intense laser fields: a relativistic time-dependent density functional theory approach

Science.gov (United States)

Tumakov, Dmitry A.; Telnov, Dmitry A.; Maltsev, Ilia A.; Plunien, Günter; Shabaev, Vladimir M.

2017-10-01

We develop an efficient numerical implementation of the relativistic time-dependent density functional theory (RTDDFT) to study multielectron highly-charged ions subject to intense linearly-polarized laser fields. The interaction with the electromagnetic field is described within the electric dipole approximation. The resulting time-dependent relativistic Kohn-Sham (RKS) equations possess an axial symmetry and are solved accurately and efficiently with the help of the time-dependent generalized pseudospectral method. As a case study, we calculate multiphoton ionization probabilities of the neutral argon atom and argon-like xenon ion. Relativistic effects are assessed by comparison of our present results with existing non-relativistic data.