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Commercial and Cost Effective Production of Two-Dimensional Read-Out Boards for Sub-Atomic Particle Detectors

Description: We report results from research aimed at developing and demonstrating production of 2-D readout structures for GEM (Gas Electron Multiplier) charged particle tracking chambers at Tech-Etch. Readout boards of two types, bi-planar and single plane, were fabricated and evaluated. The results show that Tech-Etch can produce suitable boards of either type however the single plane board has a number of advantages both in production and use that will likely make it the preferred choice for GEM tracking chambers.
Date: October 22, 2010
Creator: Crary, David & Majka, Richard
Partner: UNT Libraries Government Documents Department

Large-Area Liquid Scintillation Detector Slab

Description: A low-cost detector 18' x 2' x 5" has been developed for an underground cosmic ray neutrino experiment. The liquid employed is a high-clarity mineral oil-based mixture, and light is guided to the ends of the detector by total internal reflection at the surface of the Lucite container. Signals from 2 five-inch photomultipliers at each end give energy and event location for single penetrating particles, with relatively good discrimination against natural radioactivity by virtue of the substantial thickness. Data are presented on the response function of the tank, energy resolution, rates and thresholds. A number of modifications that have been tried are also described.
Date: March 1, 1966
Creator: Crouch, M. F.; Gurr, H. S.; Hruschka, A. A.; Jenkins, T. L.; Kropp, W.; Reines, F. et al.
Partner: UNT Libraries Government Documents Department

Instrument Qualification of Custom Fabricated Water Activity Meter for Hot Cell Use

Description: This report describes a custom fabricated water activity meter and the results of the qualification of this meter as described in the laboratory test plan LAB-PLN-11-00012, Testing and Validation of an Enhanced Acquisition and Control System. It was calibrated against several NaOH solutions of varying concentrations to quantify the accuracy and precision of the instrument at 20 °C and 60 °C. Also, a schematic and parts list of the equipment used to make the water activity meter will be presented in this report.
Date: January 22, 2014
Creator: McCoskey, Jacob K.
Partner: UNT Libraries Government Documents Department

GAMMA-RAY DETECTION WITH PbO GLASS CONVERTERS IN MWPC: ELECTRON CONVERSION EFFICIENCY AND TIME RESOLUTION

Description: The development of glass tubing converters for efficient gamma-ray detection in multiwire proportional chambers (MWPC) has led to an investigation on the improvement of conductivity on glass surfaces and to an investigation of gas mixtures which will improve on the electron conversion efficiency and electron transit time within the tubes. Efforts to establish uniform electric field lines within small diameter tubes has resulted in an improved H{sub 2} reducing treatment. For a 0.91 mm I.D., 1.10 mm O.D., 2 cm thick converter the electron conversion efficiency {epsilon} was measured to be 9.0% and 10.4% at 511 keV, using Ar mixtures containing 10% CF{sub 4} and 30% isobutane, respectively. The effects of gas mixtures on {epsilon} and on {tau}, the mean transit time on conversion electrons within the converter, and the projection of these results on the performance of a modified MWPC positron camera will be presented.
Date: June 1, 1980
Creator: Lum, G.K.; Perez-Mendez, V. & Sleaford, B.
Partner: UNT Libraries Government Documents Department

THE HANFORD CRITICAL RADIATION DOSIMETER

Description: The Hanford critical radiation dosimeter, developed for measuring neutron dose and spectrum distribution from nuclear radiation, has been modified to incorporate new dosimetry techniques and to correct assembly errors. Modifications to the dosimeter package are 1) inclusion of {sup 6}LiF and {sup 7}LiF thermoluminescent dosimeter (TLD) chips in the foil holder at the lower end of the dosimeter "candle" for measurement of neutron and garrrna dose, 2) removal of the indium foil in the foil holder at the lower end of the dosimeter candle, to reduce gamma dose to the TLD chips due to activation of the indium foil, 3) inclusion of a {sup 7}LiF TLD chip for measuring gamma dose and removal of glass rod dosimeters from the foil holder at the top of the dosimeter candle, and 4) correction of an assembly error by moving the copper foil inside the cadmium shields. Neutron spectrum measurements will still yield five energy groups, and the dose measurement will give the single-collision neutron dose over a wide range of neutron energies with an accuracy of {+-}15% within the range of a few rads to several thousand rads. Measurement of gamma dose between 0.1 and 10,000 rads is provided by the {sup 7}LiF TLD chips placed in the top and bottom of the dosimeter candle.
Date: November 1, 1977
Creator: RD. Glenn, PE. Bramson
Partner: UNT Libraries Government Documents Department

Chalcogenide Glass Radiation Sensor; Materials Development, Design and Device Testing

Description: For many decades, various radiation detecting material have been extensively researched, to find a better material or mechanism for radiation sensing. Recently, there is a growing need for a smaller and effective material or device that can perform similar functions of bulkier Geiger counters and other measurement options, which fail the requirement for easy, cheap and accurate radiation dose measurement. Here arises the use of thin film chalcogenide glass, which has unique properties of high thermal stability along with high sensitivity towards short wavelength radiation. The unique properties of chalcogenide glasses are attributed to the lone pair p-shell electrons, which provide some distinctive optical properties when compared to crystalline material. These qualities are derived from the energy band diagram and the presence of localized states in the band gap. Chalcogenide glasses have band tail states and localized states, along with the two band states. These extra states are primarily due to the lone pair electrons as well as the amorphous structure of the glasses. The localized states between the conductance band (CB) and valence band (VB) are primarily due to the presence of the lone pair electrons, while the band tail states are attributed to the Van der Waal’s forces between layers of atoms [1]. Localized states are trap locations within the band gap where electrons from the valence band can hop into, in their path towards the conduction band. Tail states on the other hand are locations near the band gap edges and are known as Urbach tail states (Eu). These states are occupied with many electrons that can participate in the various transformations due to interaction with photons. According to Y. Utsugi et. al.[2], the electron-phonon interactions are responsible for the generation of the Urbach tails. These states are responsible for setting the absorption edge for these glasses ...
Date: April 30, 2013
Creator: Mitkova, Maria; Butt, Darryl; Kozicki, Michael & Barnaby, Hugo
Partner: UNT Libraries Government Documents Department

Development of A Self Biased High Efficiency Solid-State Neutron Detector for MPACT Applications

Description: Neutron detection is an important aspect of materials protection, accounting, and control for transmutation (MPACT). Currently He-3 filled thermal neutron detectors are utilized in many applications; these detectors require high-voltage bias for operation, which complicates the system when multiple detectors are used. In addition, due to recent increase in homeland security activity and the nuclear renaissance, there is a shortage of He-3, and these detectors become more expensive. Instead, cheap solid-state detectors that can be mass produced like any other computer chips will be developed. The new detector does not require a bias for operation, has low gamma sensitivity, and a fast response. The detection system is based on a honeycomb-like silicon device, which is filled with B-10 as the neutron converter; while a silicon p-n diode (i.e., solar cell type device) formed on the thin silicon wall of the honeycomb structure detects the energetic charged particles emitted from the B-10 conversion layer. Such a detector has ~40% calculated thermal neutron detection efficiency with an overall detector thickness of about 200 ?m. Stacking of these devices allows over 90% thermal neutron detection efficiency. The goal of the proposed research is to develop a high-efficiency, low-noise, self-powered solid-state neutron detector system based on the promising results of the existing research program. A prototype of this solid-state neutron detector system with sufficient detector size (up to 8-inch diam., but still portable and inexpensive) and integrated with interface electronics (e.g., preamplifier) will be designed, fabricated, and tested as a coincidence counter for MPACT applications. All fabrications proposed are based on silicon-compatible processing; thus, an extremely cheap detector system could be massively produced like any other silicon chips. Such detectors will revolutionize current neutron detection systems by providing a solid-state alternative to traditional gas-based neutron detectors.
Date: September 3, 2013
Creator: Danon, Yaron; Bhat, Ishwara & Jian-Qiang Lu, James
Partner: UNT Libraries Government Documents Department

Microscope-Quantitative Luminescence Imaging System (M-Qlis) Description and User's Manual

Description: A Microscope Quantitative Luminescence Imaging System (M-QLIS} has been designed and constructed. The M-QLIS is designed for use in studies of chemiluminescent phenomena associated with absorption of radio-frequency radiation. The system consists of a radio-frequency waveguide/sample holder, microscope, intensified video camera, radiometric calibration source and optics, and computer-based image processor with radiometric analysis software. The system operation, hardware, software, and radiometric procedures are described.
Date: October 1, 1991
Creator: Stahl, K. A.
Partner: UNT Libraries Government Documents Department

A Fixed Filter Paper Alpha Air Monitor

Description: An instrument has been developed for the detection of uranium dust in the atmosphere. The principle feature of this device is its ability to indicate a gross release of alpha radiation within a few minutes of its occurrence. The unit will sound an alarm when either the indicated level or the rate of increase exceeds preset values above normal background variations. (auth)
Date: March 23, 1964
Creator: Seaborn, B. G.
Partner: UNT Libraries Government Documents Department

Dual-Readout Calorimetry for High-Quality Energy Measurements. Final Report

Description: This document constitutes the final report on the project Dual-Readout Calorimetry for High-Quality Energy Measurements. The project was carried out by a consortium of US and Italian physicists, led by Dr. Richard Wigmans (Texas tech University). This consortium built several particle detectors and tested these at the European Center for Nuclear Research (CERN) in Geneva, Switzerland. The idea arose to use scintillating crystals as dual-readout calorimeters. Such crystals were of course already known to provide excellent energy resolution for the detection of particles developing electromagnetic (em) showers. The efforts to separate the signals from scintillating crystals into scintillation and Cerenkov components led to four different methods by which this could be accomplished. These methods are based on a) the directionality, b) spectral differences, c) the time structure, and d) the polarization of the signals.
Date: September 1, 2013
Creator: Wigmans, Richard & Nural, Akchurin
Partner: UNT Libraries Government Documents Department

Large Cryogenic Germanium Detector. Final Report

Description: The goal of this project was to investigate possible ways of increasing the size of cryogenic Ge detectors. This project identified two possible approaches to increasing the individual cryogenic Ge detector size. The first approach relies on using the existing technology for growing detector-grade (high-purity) germanium crystals of dislocation density 100-7000 cm{sup -2}. The second approach is to consider dislocation-free Ge crystals.
Date: February 13, 2013
Creator: Mandic, Vuk
Partner: UNT Libraries Government Documents Department

Selective Filtration of Gadolinium Trichloride for Use in Neutron Detection in Large Water Cherenkov Detectors

Description: Water Cherenkov detectors have been used for many years as inexpensive, effective detectors for neutrino interactions and nucleon decay searches. While many important measurements have been made with these detectors a major drawback has been their inability to detect the absorption of thermal neutrons. We believe an inexpensive, effective technique could be developed to overcome this situation via the addition to water of a solute with a large neutron cross section and energetic gamma daughters which would make neutrons detectable. Gadolinium seems an excellent candidate especially since in recent years it has become very inexpensive, now less than $8 per kilogram in the form of commercially-available gadolinium trichloride, GdCl{sub 3}. This non-toxic, non-reactive substance is highly soluble in water. Neutron capture on gadolinium yields a gamma cascade which would be easily seen in detectors like Super-Kamiokande. We have been investigating the use of GdCl{sub 3} as a possible upgrade for the Super-Kamiokande detector with a view toward improving its performance as a detector for atmospheric neutrinos, supernova neutrinos, wrong-sign solar neutrinos, reactor neutrinos, proton decay, and also as a target for the coming T2K long-baseline neutrino experiment. This focused study of selective water filtration and GdCl{sub 3} extraction techniques, conducted at UC Irvine, followed up on highly promising benchtop-scale and kiloton-scale work previously carried out with the assistance of 2003 and 2005 Advanced Detector Research Program grants.
Date: April 10, 2013
Creator: Vagins, Mark R.
Partner: UNT Libraries Government Documents Department