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The Occurrence of Xenon

Description: This report is the second in the series of reports carried by the Geological Survey on rare or uncommon elements and their possible sources. The report discusses xenon, an element belonging in a group of elements known as the inert gases, characterized by its lack of reactivity.
Date: May 1945
Creator: Fleischer, Michael
Partner: UNT Libraries Government Documents Department

Analysis of the Interaction of 300-Mev Neutrons with Xenon

Description: Abstract: And investigation of the interactions between 300-Mev neutrons and xenon was made by means of a cloud chamber in a pulsed magnetic field of 21,700 gauss placed in the neutron beam of the 184-inch Berkeley cyclotron. Eighty-seven negative pion events and 257 other stars were analyzed. In addition an experimental check was made on the energy of the incoming neutrons. Classification, identification, and angular and energy distributions of prongs associated with all events are presented. Interpretations of results are given.
Date: October 17, 1956
Creator: Morris, Richard Herbert, 1928-
Partner: UNT Libraries Government Documents Department

Sensitivity Enhancement by Exchange Mediated MagnetizationTransfer of the Xenon Biosensor Signal

Description: Hyperpolarized xenon associated with ligand derivitized cryptophane-A cages has been developed as a NMR based biosensor. To optimize the detection sensitivity we describe use of xenon exchange between the caged and bulk dissolved xenon as an effective signal amplifier. This approach, somewhat analogous to 'remote detection' described recently, uses the chemical exchange to repeatedly transfer spectroscopic information from caged to bulk xenon, effectively integrating the caged signal. After an optimized integration period, the signal is read out by observation of the bulk magnetization. The spectrum of the caged xenon is reconstructed through use of a variable evolution period before transfer and Fourier analysis of the bulk signal as a function of the evolution time.
Date: August 31, 2006
Creator: Garcia, Sandra; Chavez, Lana; Lowery, Thomas J.; Han, Song-I.; Wemmer, David E. & Pines, Alexander
Partner: UNT Libraries Government Documents Department

Xenon-Tagging in Production of EBR-II Mark II Driven-Fuel Elements

Description: About 1200 Mark II driver-fuel elements were xenon-tagged to facilitate qualification for irradiation of Mark II fuel manufactured at ANL-West. Tagging equipment was designed and developed. In this equipment, the plenum in a fuel-element jacket was evacuated then filled with xenon to a predetermined pressure. The equipment design allows tagging and element fabrication to proceed normal rates for production of fuel elements. A Kr-85 tracer in the xenon-tag gas verified by gamma counting the adequate tagging of each element.
Date: March 1976
Creator: Wilkes, C. W.; Ryan, M. J.; Laug, M. T. & Fryer, R. M.
Partner: UNT Libraries Government Documents Department

A General Investigation of Optimized Atmospheric Sample Duration

Description: ABSTRACT The International Monitoring System (IMS) consists of up to 80 aerosol and xenon monitoring systems spaced around the world that have collection systems sensitive enough to detect nuclear releases from underground nuclear tests at great distances (CTBT 1996; CTBTO 2011). Although a few of the IMS radionuclide stations are closer together than 1,000 km (such as the stations in Kuwait and Iran), many of them are 2,000 km or more apart. In the absence of a scientific basis for optimizing the duration of atmospheric sampling, historically scientists used a integration times from 24 hours to 14 days for radionuclides (Thomas et al. 1977). This was entirely adequate in the past because the sources of signals were far away and large, meaning that they were smeared over many days by the time they had travelled 10,000 km. The Fukushima event pointed out the unacceptable delay time (72 hours) between the start of sample acquisition and final data being shipped. A scientific basis for selecting a sample duration time is needed. This report considers plume migration of a nondecaying tracer using archived atmospheric data for 2011 in the HYSPLIT (Draxler and Hess 1998; HYSPLIT 2011) transport model. We present two related results: the temporal duration of the majority of the plume as a function of distance and the behavior of the maximum plume concentration as a function of sample collection duration and distance. The modeled plume behavior can then be combined with external information about sampler design to optimize sample durations in a sampling network.
Date: November 28, 2012
Creator: Eslinger, Paul W. & Miley, Harry S.
Partner: UNT Libraries Government Documents Department

Novel Sorbent Development and Evaluation for the Capture of Krypton and Xenon from Nuclear Fuel Reprocessing Off-Gas Streams

Description: The release of volatile radionuclides generated during Used Nuclear Fuel reprocessing in the US will most certainly need to be controlled to meet US regulatory emission limits. A US DOE sponsored Off-Gas Sigma Team has been tasked with a multi-lab collaborative research and development effort to investigate and evaluate emissions and immobilization control technologies for the volatile radioactive species generated from commercial Used Nuclear Fuel (UNF) Reprocessing. Physical Adsorption technology is a simpler and potential economical alternative to cryogenic distillation processes that can be used for the capture of krypton and xenon and has resulted in a novel composite sorbent development procedure using synthesized mordenite as the active material. Utilizing the sorbent development procedure, INL sigma team members have developed two composite sorbents that have been evaluated for krypton and xenon capacities at ambient and 191 K temperature using numerous test gas compositions. Adsorption isotherms have been generated to predict equilibration and maximum capacities enabling modeling to support process equipment scale-up.
Date: September 1, 2013
Creator: Garn, Troy G.; Greenhalgh, Mitchell R. & Law, Jack D.
Partner: UNT Libraries Government Documents Department

Xenon N4,500 Auger spectrum - a useful calibration source

Description: In the xenon N4,5OO Auger spectrum there are 19 prominent lines ranging from 8 to 36 eV that provide a convenient set of standards for calibrating electron spectrometers. Combining optical data with recent measurements of this spectrum gives energies for these lines that are absolutely accurate to 11 meV. For most lines the relative accuracy is better than 1 meV; for a few it is about 3 meV. The spin-orbit splitting of the xenon 4d lines is measured to be 1979.0 +- 0.5meV.
Date: February 6, 2002
Creator: Carroll, T.X.; Bozek, J.D.; Kukk, E.; Myrseth, V.; Saethre, L.J.; Thomas, T.D. et al.
Partner: UNT Libraries Government Documents Department

Low-energy degassing mechanisms for a fluid-based radioxenon detection system

Description: A method to concentrate heavy noble gases from the atmosphere using certain organic fluids is being developed. To use this technique in a system to monitor the atmosphere for important noble gas fission products (Xe-131, Xe-131m, Xe-133, Xe-133m, and Xe-135) generated by nuclear testing, the radionuclides captured in the fluid must either be detected in the fluid or degassed. This study presents experimental results for a number of possible degassing methods, including heating bubbling with a purge gas, ultrasonic agitation, vacuum, and combinations thereof. Methods were evaluated for energy and time requirements and dilution of the degas product. Initial experiments indicate that in addition to overcoming the standard desorption process dictated by partial pressures per Henry`s Law, a capture mechanism must also be overcome to degas. Some type of agitation, thermal or mechanical, can be used to release weakly trapped gas atoms from the fluid, while diffusional mass transfer can be enhanced through entrainment with a purge gas or use of a vacuum. Ultrasonic agitation of a thin film in a strong vacuum has been shown to be the most effective method of those tested. Implementation of an efficient degas system, along with an absorption system and radioxenon detector could result in an ultrasensitive fluid-based radioxenon measurement system that is more portable, less expensive, and simpler than charcoal-based systems which use cryogenic techniques.
Date: September 1, 1998
Creator: Russ, W. R.; Stuenkel, D. O.; Valentine, J. D. & Gross, K. C.
Partner: UNT Libraries Government Documents Department

Development of a functionalized Xenon biosensor

Description: NMR-based biosensors that utilize laser-polarized xenon offer potential advantages beyond current sensing technologies. These advantages include the capacity to simultaneously detect multiple analytes, the applicability to in vivo spectroscopy and imaging, and the possibility of remote amplified detection. Here we present a detailed NMR characterization of the binding of a biotin-derivatized caged-xenon sensor to avidin. Binding of functionalized xenon to avidin leads to a change in the chemical shift of the encapsulated xenon in addition to a broadening of the resonance, both of which serve as NMR markers of ligand-target interaction. A control experiment in which the biotin-binding site of avidin was blocked with native biotin showed no such spectral changes, confirming that only specific binding, rather than nonspecific contact, between avidin and functionalized xenon leads to the effects on the xenon NMR spectrum. The exchange rate of xenon (between solution and cage) and the xenon spin-lattice relaxation rate were not changed significantly upon binding. We describe two methods for enhancing the signal from functionalized xenon by exploiting the laser-polarized xenon magnetization reservoir. We also show that the xenon chemical shifts are distinct for xenon encapsulated in different diastereomeric cage molecules. This demonstrates the potential for tuning the encapsulated xenon chemical shift, which is a key requirement for being able to multiplex the biosensor.
Date: March 25, 2004
Creator: Spence, Megan M.; Ruiz, E. Janette; Rubin, Seth M.; Lowery, Thomas J.; Winssinger, Nicolas; Schultz, Peter G. et al.
Partner: UNT Libraries Government Documents Department

INITIAL IMAGES FROM A 24-WIRE LIQUID XENON Y -CAMERA.

Description: A prototype liquid xenon {gamma}-camera has been constructed and preliminary results obtained. The sensitive volume is 7 c x 7 cm in area and 1.5 cm thick. Orthogonal coordinates for each interacting {gamma}-ray are provided by 24 anode wires 5 {micro} in diameter spaced 2.8 mm apart and 24 cathode strips.
Date: December 1, 1972
Creator: Zaklad, Haim; Derenzo, Stephen E.; Muller, Richard A. & Smits,Robert G.
Partner: UNT Libraries Government Documents Department

A Modeling Study of Gaseous Rn-222, Xe-133, and He-4 for Uranium Exploration

Description: From introduction: The emanation method of uranium exploration consists of measuring the abundance of one or more uranium decay products at some distance from the orebody itself. The halo of decay products expands the exploration target and improves the chances of detection. This method assumes that indicator nuclides migrate away from the ore by some physio-chemical mechanism such as diffusion or solution in groundwater. The indicators must remain at detectable concentrations and be distinguishable from background levels. This study is concerned with gas-phase transport of Rn-222, Xe-133, and He-4 away from uranium ore deposits. The first of these indicator nuclides, Rn-222, is a member of the uranium series decay chain (Table 1) and has a 3.82 day half-life. The second, Xe-133,. is a spontaneous fission product which has a half-life of 5.26 days. Finally, He-4 is a stable nuclide created from alpha particles emitted by various members of the uranium, actinium, and thorium decay series.
Date: 1980
Creator: Jeter, Hewitt W.
Partner: UNT Libraries Government Documents Department

H- Enhancement Process in a Multicusp Ion Source Operated with a Barium Insert Structure

Description: 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.
Date: May 1, 1990
Creator: Leung, K.N.; Van Os, C.F.A. & Kunkel, W.B.
Partner: UNT Libraries Government Documents Department

A simple drift-diffusion model for calculating the neutralization time of H- in xe gas for choppers placed in the LEBT

Description: The neutralization of H{sup -} beam with a gas like Xe is an important part of low energy beam transport (LEBT). It is well known that choppers which use an electric field when placed in the LEBT strongly affects the neutralization of H{sup -}. The question then naturally arises as to whether a magnetic chopper has a better neutralization time than an electric chopper. To answer this question, a simple 1-space, 1 time drift-diffusion model of H{sup -} beam in Xe gas has been used to calculate the neutralization times for the following scenarios: (a) a region initially cleared of Xe+ ions with an electric field but partially neutralized outside, (b) a region within and outside the chopper which is initially partially neutralized.
Date: March 1, 2010
Creator: Tan, Cheng-Yan
Partner: UNT Libraries Government Documents Department

Radioxenons: Their role in monitoring a Comprehensive Test Ban Treaty

Description: Monitoring for xenon radionuclides which are produced in a nuclear detonation can provide a strong deterrent to the violation of a Comprehensive nuclear Test Ban Treaty (CTBT). There are 18 known radioactive xenon isotopes produced in nuclear fission with half-lives ranging from less than one second to 11.9 days. However, only four of these remain in significant amounts more than a day after a detonation. In order for radioxenon monitoring to be practical, it was necessary to develop an automated measurement system which could operate unattended for periods of months, measure the entire spectrum of radioxenons, and provide hundreds of times better sensitivities than current laboratory procedures. This capability was developed at the US Department of Energy`s Pacific Northwest National Laboratory based on rapid separation of atmospheric xenon coupled with a unique high sensitivity measurement device for the radioxenons. A fieldable prototype analyzer is scheduled for testing in August 1996 with commercial availability planned by 1998.
Date: June 1996
Creator: Perkins, R. W. & Casey, L. A.
Partner: UNT Libraries Government Documents Department

Production of Xe¹³¹, Xe¹³⁵, Kr⁸⁵m and Kr⁸⁵ From Plated-Out U²³⁵ in the MTR Core

Description: This report discusses details of the release of Xe¹³¹, Xe¹³⁵, Kr⁸⁵m and Kr⁸⁵ into the process water system of the MTR along with the development of high process water radioactivity. It is suggested that this release followed the fissioning of U²³⁵. Equations that produce the rate of release of fission products is given and approximate rate of release is represented in a graph.
Date: January 14, 1955
Creator: Grimaud, Adrian V.
Partner: UNT Libraries Government Documents Department