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AbstractAbstract
[en] The summary and viewgraphs of work presented at the Long Duration Exposure Facility (LDEF) materials workshop are given. Experimental data for erosion depths and rates for polymers measured on LDEF are given. In general, agreement is reasonably good between erosion rates from the University of Alabama in Huntsville (UAH) LDEF experiment and prior data obtained at much lower mission fluences. Agreement is particularly satisfying in the case of Kapton where the prior data base is large. In spite of the known presence of silicaceous contamination on LDEF surfaces, the erosion rates of the highly erodible materials are hardly affected, if at all. Graphs showing changes in optical properties (reflectance and transmittance) of metal films are included
Primary Subject
Secondary Subject
Source
Gregory, J.C.; Alabama Univ., Huntsville, AL (United States); [10 p.]; Feb 1992; p. 22; NTIS HC A03/MF A01; CASI HC A03/MF A01; INIS
Record Type
Report
Report Number
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Gregory, J.C.
Alabama Univ., Huntsville (USA)1987
Alabama Univ., Huntsville (USA)1987
AbstractAbstract
[en] Work on the MSFC emulsion laboratory microscopes in which mechanical modifications previously made were verified is reviewed, as is a design study of a large area hybrid electronic/emulsion chamber balloon flight detector system. This design is built upon the experience obtained with the highly successful MSFC/UAH hybrid instrument flown by the JACEE consortium. The design included overall system design and specification, design and fabrication of a prototype large light diffusion for Cerenkov charge detector or scintillator, design of a multiwire proportional counter array and design of the gondola or flight support system
Source
Feb 1987; 29 p; NASA-CR--179086; NAS--1.26:179086; Available from NTIS, PC A03/MF A01
Record Type
Report
Report Number
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Gregory, J.C.
Alabama Univ., Huntsville (USA). School of Graduate Studies and Research1973
Alabama Univ., Huntsville (USA). School of Graduate Studies and Research1973
AbstractAbstract
No abstract available
Source
Apr 1973; 40 p; NASA-CR--124271
Record Type
Report
Report Number
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Gregory, J.C.
Alabama Univ., Huntsville, AL (United States)1991
Alabama Univ., Huntsville, AL (United States)1991
AbstractAbstract
[en] During the contract period, work concentrated on four main components. Data from the UAH silver pin hole camera was analyzed for determination of the mean Long Duration Exposure Facility (LDEF) satellite attitude and stability in orbit, to include pitch and yaw. Chemical testing performed on the AO-114 hot plate determined the form and locus of absorption of cosmogenic beryllium-7. Reaction rates of atomic oxygen with Kapton and other polymeric solids integrated over the whole LDEF orbital lifetime were analyzed. These rates were compared with the JSC estimated values for Space Station exposures. Metal and polymer films exposed on A0114 (C-9 and C-3 plates) were also analyzed
Primary Subject
Secondary Subject
Source
1991; 34 p; NASA-CR--193826; NAS--1.26:193826; NAS8-36645; Also available from CASI HC A03/MF A01
Record Type
Report
Literature Type
Progress Report
Report Number
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Gregory, J.C.
Alabama Univ., Huntsville (USA)1986
Alabama Univ., Huntsville (USA)1986
AbstractAbstract
[en] Instrument design and data analysis expertise was provided in support of several space radiation monitoring programs. The Verification of Flight Instrumentation (VFI) program at NASA included both the Active Radiation Detector (ARD) and the Nuclear Radiation Monitor (NRM). Design, partial fabrication, calibration and partial data analysis capability to the ARD program was provided, as well as detector head design and fabrication, software development and partial data analysis capability to the NRM program. The ARD flew on Spacelab-1 in 1983, performed flawlessly and was returned to MSFC after flight with unchanged calibration factors. The NRM, flown on Spacelab-2 in 1985, also performed without fault, not only recording the ambient gamma ray background on the Spacelab, but also recording radiation events of astrophysical significance
Source
1986; 56 p; NASA-CR--179037; NAS--1.26:179037; Available from NTIS, PC A04/MF A01
Record Type
Report
Report Number
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Gregory, J.C.
Alabama Univ., Huntsville (USA)1982
Alabama Univ., Huntsville (USA)1982
AbstractAbstract
[en] The Nuclear Radiation Monitor (NRM) is flying on the Spacelab 2 vehicle as part of a set of instrumentation designed to measure the ambient physical environment on Spacelab in orbit. The NRM measures the natural and induced gamma ray activity. The instrument is constituted of a 25 sq in (NaI (T1)) crystal viewed with a single phototube and surrounded by a plastic anticoincidence shield. It is mounted on a pedestal and placed, with its electronics, on the Spacelab pallet. The detector head was designed and a development model fabricated and tested. Extensive software studies for on board and GSE microprocessors for use with the NRM were also made
Secondary Subject
Source
Jun 1982; 39 p; NASA-CR--162047; Available from NTIS, PC A03/MF A01
Record Type
Report
Report Number
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Gregory, J.C.
Alabama Univ., Huntsville, AL (United States)1992
Alabama Univ., Huntsville, AL (United States)1992
AbstractAbstract
[en] Analysis of surfaces from the Long Duration Exposure Facility (LDEF) continued during the reporting period. Work has continued on profilometry measurements of eroded and corroded sample surfaces, optical transmission measurements, analysis of the pinhole camera, and x-ray photoelectron spectroscopy (XPS) analysis of some samples. Papers that have appeared or have been accepted for publications are listed. Several of these papers and an abstact are included
Primary Subject
Secondary Subject
Source
Feb 1992; 49 p; NASA-CR--190596; NAS--1.26:190596; CONTRACT NAG1-1228; NTIS HC A03/MF A01; CASI HC A03/MF A01; INIS
Record Type
Report
Report Number
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Gregory, J.C.
Alabama Univ., Huntsville (USA). School of Graduate Studies and Research1976
Alabama Univ., Huntsville (USA). School of Graduate Studies and Research1976
AbstractAbstract
[en] The use and sensitivity of the multiwire proportional counter to detect Kr-85 in ambient air are examined. Data also cover monitoring beta and x-ray emitting radio nuclides at low activity levels. Results show the counter to have excellent properties for monitoring Kr-85 down to 0.0004 pCi cu/cm
Source
Feb 1976; 16 p; NASA-CR--144205; SAR--1976; Available from NTIS. $3.50.
Record Type
Report
Literature Type
Progress Report
Report Number
Country of publication
BETA DECAY RADIOISOTOPES, BETA-MINUS DECAY RADIOISOTOPES, CHARGED PARTICLE DETECTION, EVEN-ODD NUCLEI, HOURS LIVING RADIOISOTOPES, INTERMEDIATE MASS NUCLEI, ISOMERIC TRANSITION ISOTOPES, ISOTOPES, KRYPTON ISOTOPES, MEASURING INSTRUMENTS, MONITORING, NUCLEI, PROPORTIONAL COUNTERS, RADIATION DETECTION, RADIATION DETECTORS, RADIOISOTOPES, YEARS LIVING RADIOISOTOPES
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
AbstractAbstract
No abstract available
Source
Nuclear science symposium; San Francisco, Calif; 3 Nov 1971
Record Type
Journal Article
Literature Type
Conference
Journal
IEEE (Inst. Elec. Electron. Eng.), Trans. Nucl. Sci; v. NS-19(1); p. 224-232
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
Paciesas, W.S.; Gregory, J.C.; Fishman, G.J.
National Aeronautics and Space Administration, Huntsville, AL (USA). George C. Marshall Space Flight Center1988
National Aeronautics and Space Administration, Huntsville, AL (USA). George C. Marshall Space Flight Center1988
AbstractAbstract
[en] A Nuclear Radiation Monitor incorporating a NaI(Tl) scintillation detector was flown as part of the verification flight instrumentation on the Spacelab 2 mission, July 29 to August 6, 1985. Gamma-ray spectra were measured with better than 20 s resolution throughout most of the mission in the energy range 0.1 to 30 MeV. Knowledge of the decay characteristics and the geomagnetic dependence of the counting rates enable measurement of the various components of the Spacelab gamma-ray background: prompt secondary radiation, Earth albedo, and delayed induced radioactivity. The status of the data analysis and present relevant examples of typical background behavior are covered
Primary Subject
Source
1988; 10 p; NASA-CR--183782; NAS--1.26:183782; NTIS, PC A02/MF A01
Record Type
Report
Literature Type
Numerical Data; Progress Report
Report Number
Country of publication
Reference NumberReference Number
INIS VolumeINIS Volume
INIS IssueINIS Issue
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