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in subjects: "440200"

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Charge trapping and breakdown in N{sub 2}O oxides

Nitrided gate oxides have been fabricated by furnace oxidation in N{sub 2}O with and without prior oxidation in O{sub 2}. SIMS nitrogen profiles show a sharp peak at the Si-insulator interface for both processes. Improved breakdown characteristics and reduced oxide damage after irradiation and charge injection are obtained.

Date: December 1, 1993

Creator: Saks, N. S.; Ma, D. I. & Fleetwood, D. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Characterization of wafer charging mechanisms and oxide survival prediction methodology

Unipolar, EEPROM-based peak potential sensors and current sensors have been used to characterize the I-V relationship of charging transients which devices normally experience during the course of ion implantation. The results indicate that the charging sources may appear to behave like current-sources or voltage-sources, depending on the impedance of the load. This behavior may be understood in terms of plasma concepts. The ability to empirically characterize the I-V characteristics of charging… more

Date: April 1, 1994

Creator: Lukaszek, W.; Dixon, W.; Vella, M.; Messick, C.; Reno, S. & Shideler, J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Vulnerability assessment of a space based weapon platform electronic system exposed to a thermonuclear weapon detonation

Rapidly changing world events, the increased number of nations with inter-continental ballistic missile capability, and the proliferation of nuclear weapon technology will increase the number of nuclear threats facing the world today. Monitoring these nation`s activities and providing an early warning and/or intercept system via reconnaissance and surveillance satellites and space based weapon platforms is a viable deterrent against a surprise nuclear attack. However, the deployment of satellit… more

Date: March 1, 1994

Creator: Perez, C. L. & Johnson, J. O.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Neutron fluence calculations for the SDC detector and the results of codes comparison

CALOR89, A Monte Carlo particle physics code package in conjunction with ISAJET, a high energy particle collision code, has been successfully used to evaluate the radiation environment of a high energy physics collider detector. We found that for a collider luminosity of 10{sup 33} cm{sup {minus}2sec{minus}1}, the neutron fluences can be significant at certain detector locations.

Date: April 1994

Creator: Job, P. K.; Handler, T.; Gabriel, T. A.; Slater, C. O.; Waters, L. S.; Palounek, A. P. T. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Determination of the Fermi level position for neutron irradiated high resistivity silicon detectors and materials using the transient charge technique (TChT)

The transient charge technique (TChT) has been used in this work to study the electrical properties in both space charge region (SCR) and electrical neutral bulk (ENB) of neutron irradiated high resistivity (4--6 k{Omega}-cm) silicon particle detectors. Detectors irradiated to various neutron fluences were measured by TChT at various biases and temperatures below the room temperature. The Fermi level, obtained from the Arrhenius plot of the time constant of the slow component of the charge shap… more

Date: February 1, 1994

Creator: Eremin, V. & Li, Z.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Relaxation of radiation damages in silicon planar detectors

The behaviour of radiation induced carbon related defects in high resistivity silicon detectors has been investigated. The defects were introduced by {alpha}-particle irradiation and the measurements were carried out by the DLTS-technique. The unusual defect behaviour consists in low temperature annealing, including self annealing at room temperature, of the interstitial carbon C{sub i} with the simultaneous increase of the (C{sub i}-O{sub i})-complex concentration. The kinetic parameters of th… more

Date: December 1, 1993

Creator: Eremin, V.; Ivanov, A.; Storkan, N.; Verbitskaya, E.; Li, Zheng & Schmidt, B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Experimental comparisons among various models for the reverse annealing of the effective concentration of ionized space charges (N{sub eff}) of neutron irradiated silicon detectors

Experimental data of the reverse annealing of the effective concentration of ionized space charges (N{sub eff}, also called effective doping or impurity concentration) of neutron irradiated high resistivity silicon detectors has been compared with various models: compensation model (first order), cluster model of the first order, neutral to acceptor model (first order), and cluster model of the second order. Detectors irradiated to various neutron fluences have been annealed at 80{degree}C for … more

Date: March 1, 1994

Creator: Li, Zheng

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Resistivity measurements on the neutron irradiated detector grade silicon materials

Resistivity measurements under the condition of no or low electrical field (electrical neutral bulk or ENB condition) have been made on various device configurations on detector grade silicon materials after neutron irradiation. Results of the measurements have shown that the ENB resistivity increases with neutron fluence ({Phi}{sub n}) at low {phi}{sub n} (<10{sup 13} n/cm{sup 2}) and saturates at a value between 300 and 400 k{Omega}-cm at {phi}{sub n} {approximately}10{sup 13} n/cm{sup 2}. Me… more

Date: November 1, 1993

Creator: Li, Zheng

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Radiation and EMI effects in the NIF environment

In order to determine the magnitude of the noise problem in the target chamber area of the National Ignition Facility, a literature search was conducted to determine the sensitivities of various components that would be exposed to the radiation and electro magnetic interference fields in the target chamber area. Additionally, Test Program experience and data were also used in determining some of these sensitivities. Using the predicted fluences, it was found that there will be significant effec… more

Date: July 1, 1994

Creator: Stathis, P.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Investigation on the long-term radiation hardness of low resistivity starting silicon materials for RT silicon detectors in high energy physics

Relatively low resistivity (200 to 1000 {Omega}-cm) starting silicon materials have been studied in the search of room temperature neutron radiation-hard silicon detectors. It has been found that, moderate resistivity (300-700 {Omega}-cm) silicon detectors, after being irradiated to 5.0 {times} 10{sup 13} to 2.0 {times} 10{sup 14} n/cm{sup 2}, are extremely stable in terms of the detector full depletion voltage (V{sub d}) or the net effective concentration of ionized space charges (N{sub eff} -… more

Date: February 1, 1994

Creator: Li, Z.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

[Effects of ionizing radiation on scintillators and other particle detectors]. Conference summary

It is my task to summarise the great variety of topics (covering a refreshing mix of physics, chemistry and technology) presented at this conference, which has focused on the effects of ionising radiation on scintillators and other particle detectors. One of the reasons and the central interest of many of the participants was the use of such detectors in experiments at two future large hadron colliders: the Superconducting Super Collider to be operating outside of Dallas in the United States by… more

Date: September 1, 1992

Creator: Proudfoot, J.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Target area acquisition and control system survivability for the National Ignition Facility

The hardening of instruments to survive NIF target emission environments presents a significant challenge. Neutron flux is predicted to be as much as six orders of magnitude greater than the highest achieved neutron flux on NOVA. Not withstanding the high prompt radiation fields, the specifications for the instruments are demanding; requiring high resolution imaging and sub nanosecond transient measurements. We present an analysis of the sensitivity of the proposed NIF instrumentation design to… more

Date: June 1, 1994

Creator: Hagans, K.; Stathis, P.; Wiedwald, J. & Campbell, D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Innovative use of DSP technology in space: FORTE event classifier

The Fast On-Orbit Recording of Transient Events (FORTE) small satellite will field a digital signal processor (DSP) experiment for the purpose of classifying radio-frequency (rf) transient signals propagating through the earth`s ionosphere. Designated the Event Classifier experiment, this DSP experiment uses a single Texas Instruments` SMJ320C30 DSP to execute preprocessing, feature extraction, and classification algorithms on down-converted, digitized, and buffered rf transient signals in the … more

Date: August 1, 1994

Creator: Briles, S.; Moore, K. Jones, R.; Klingner, P.; Neagley, D.; Caffrey, M.; Henneke, K. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Summary of the radiation damage studies of the SDC dopants in polystyrene

Approximately 80 commercially available fluorescent organic compounds were studied as dopants in a polystyrene matrix for possible use in wavelength shifting (WLS) fibers. The goal was to find a new green- emitting WLS fiber which would outperform in light yield and decay time the currently available fiber doped with K-27. Therefore the fluorescent compounds of interest should exhibit the following spectroscopic characteristics in polystyrene: {lambda}{sub abs} = 400--450 nm,{lambda}{sub em} = … more

Date: December 22, 1993

Creator: Pla-Dalmau, A.; Foster, G. W. & Zhang, G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Radiation effects in polymers for plastic scintillation detectors

Radiation damage studies were performed on polystyrene and poly(vinyltoluene) samples containing different concentrations of either an antioxidant (A O-2) or a plasticizer (PP-4). In addition, parallel studies were carried out utilizing samples of these polymers prepared in the presence of cross-linking agents such as NPG, HDA, and DVB. The samples were irradiated using a {sup 60} Co source to total doses of 1 and 10 Mrad, at a dose rate of approximately 1 Mrad/h. Transmittance measurements wer… more

Date: April 20, 1994

Creator: Pla-Dalmau, A.; Bross, A. D.; Hurlbut, C. R. & Moser, S. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

A historical perspective on fifteen years of laser damage thresholds at LLNL

We have completed a fifteen year, referenced and documented compilation of more than 15,000 measurements of laser-induced damage thresholds (LIDT) conducted at the Lawrence Livermore National Laboratory (LLNL). These measurements cover the spectrum from 248 to 1064 nm with pulse durations ranging from < 1 ns to 65 ns and at pulse-repetition frequencies (PRF) from single shots to 6.3 kHz. We emphasize the changes in LIDTs during the past two years since we last summarized our database. We relate… more

Date: December 21, 1993

Creator: Rainer, F.; De Marco, F. P.; Staggs, M. C.; Kozlowski, M. R.; Atherton, L. J. & Sheehan, L. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Elevated temperature annealing of the neutron induced leakage current and corresponding defect levels in low and high resistivity silicon detectors

The leakage current (I{sub L}) annealing at the elevated temperatures and the corresponding changes of the DLTS spectra of defects for fast neutron irradiated Silicon detectors, fabricated on high (4--6 k{Omega}-cm), moderate (0.5--1.0 k{Omega}-cm), and low(<100 {Omega}-cm) resistivity silicon material, have been investigated. For all the resistivities, three annealing stages have been observed: (1) The transformation of carbon related defects at 72{degree}C; (2) slight decrease of the peak E{s… more

Date: March 1, 1994

Creator: Eremin, V.; Ivanov, A.; Verbitskaya, E.; Li, Z. & Kraner, H. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Secondary particle in background levels and effects on detectors at future hadron colliders

The next generation of hadron colliders, the Superconducting Super Collider (SSC) and the Large Hadron Collider (LHC), will operate at high center-of-mass energies and luminosities. Namely, for the SSC (LHC) {radical}s = 40 TeV ({radical}s = 16 TeV) and L = 10{sup 33} cm{sup {minus}2}s{sup {minus}1} (L = 3 {times} 10{sup 34} cm{sup {minus}2}s{sup {minus}1}). These conditions will result in the production of large backgrounds as well as radiation environments. Ascertaining the backgrounds, in te… more

Date: June 1, 1993

Creator: Pal, T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Estimates of the neutron fluence for the SDC detector

The high energy and high luminosity of SSC cause radiation problems to detectors. Almost all the radiation in the SDC detector comes from the 20 TeV on 20 Tev pp collisions. The design luminosity corresponds to 10{sup 8} collisions per second. This luminosity is maintained for 10{sup 7} seconds (one SSC year). It is important to know the radiation fields experienced by the tracking volume, calorimeter, electronics and the phototubes. The loss of light due to the radiation damage to the scintill… more

Date: November 20, 1992

Creator: Job, P. K.; Price, L. E.; Handler, T. & Gabriel, T. A.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

JFET monolithic preamplifier with outstanding noise behaviour and radiation hardness characteristics

A second series of monolithic preamplifiers based on epitaxial channel JFETs and intended for calorimetry at hadron colliders has been realized. The employed buried layer process has been upgraded, resulting in a lower pinch-off voltage and a reduced power dissipation. Results will be presented on noise, dynamic behavior and radiation damage. New versions of the preamplifier have been designed for both large capacitance detectors and for low capacitance pre-shower detectors.

Date: October 1, 1992

Creator: Radeka, V.; Rescia, S.; Manfredi, P. F.; Speziali, V. & Svelto, F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Electromagnetic pulse (EMP) survey of the FEMA Region X Federal Regional Center, Bothell, Washington

The purpose of this report is to develop an engineering design package to protect the Federal Emergency Management Agency (FEMA) National Radio System (FNARS) facilities against the effects of high-altitude electromagnetic pulses (HEMPS). This report refers to the FEMA Federal Regional Center (FRC) in Bothell, Washington. It is highly probably that there will be a heavy dependence upon high-frequency (hf) radio communications for long-haul communications following a nuclear attack on the contin… more

Date: November 1, 1991

Creator: Crutcher, R. I.; Buchanan, M. E. & Jones, R. W.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Ion damage studies in GaAs/Al{sub 0.6}Ga{sub 0.4}As/GaAs heterostructures

Development of damage structure produced in (100) GaAs/Al{sub 0.6}Ga{sub 0.4}As/GaAs by 1 MeV Kr{sup +} ion irradiation at 77 and 293 K was investigated by RBS channeling and cross-sectional high-resolution TEM techniques. Following an implantation to a dose of 10{sup 14} ions CM{sup {minus}2} at 77 K, RBS channeling spectra indicate that the Al{sub 0.6}Ga{sub 0.4}AS layer contained a high defect density and was possibly amorphous. Warming to room temperature resulted in a change in the channel… more

Date: December 1, 1993

Creator: Turkot, B. A.; Forbes, D. V.; Xiao, H.; Robertson, I. M.; Coleman, J. J.; Kirk, M. A. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Development of radiation resistant electrical cable insulations

Two new polyethylene cable insulations have been formulated for nuclear applications, and have been tested under gamma radiation. Both insulations are based on low density polyethylene, one with PbO and the other with Sb{sub 2}O{sub 3} as additives. The test results show that the concept of using inorganic antioxidants to retard radiation initiated oxidation (RIO) is viable. PbO is more effective than Sb{sub 2}O{sub 3} in minimizing RIO.

Date: December 31, 1993

Creator: Lee, B. S.; Soo, P. & MacKenzie, D. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

ANL/WSU radiation damage studies

We report preliminary results for the radiation hardness of (polystryrene) plastic scintillator stacks using a spectrum of energy hardened neutrons from a MARK-III TRIGA reactor. The total dose ranged from 100 KRad to 3MRad. The corresponding fluence was 3.8 {times} 10{sup 13} to 3.8 {times} 10{sup 14} (n/cm/cm) with the gamma contribution on the order 2--3% (of fluence). The measurements used Li-6, Li-7 Thermo-luminescence dosimeters. Radiochromic/GaF- Chromic film, and activated foils simulta… more

Date: December 31, 1993

Creator: Jankowski, D. J.; Lopiano, D.; Proudfoot, J.; Underwood, D.; Miles, L.; Neidiger, J. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department