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Direct x-ray response of self-scanning photodiode arrays

Description: Self-scanning photodiode arrays were tested for their ability to measure the spatial distribution of low-energy x rays in a wavelength-dispersive spectrometer. X-ray spectral sensitivity was measured with a calibrated dc source of nearly-monochromatic characteristic-x rays with photon energies in the range of 1.5 to 8 keV. Photodiode response was found to be linear with x-ray flux. Exposure to large doses of copper radiation did not affect sensitivity. A mathematical model that describes the experimental data is presented. It was found that spatial resolving power was lowered by the dispersal of photogenerated charges. This effect was investigated with collimated beams and is described with a formula that predicts the loss of diode signals. (auth)
Date: August 13, 1975
Creator: Koppel, L. N.
Partner: UNT Libraries Government Documents Department

Charged-particle magnetic-quadrupole spectrometer for neutron induced reactions

Description: A spectrometer has been developed for measuring the charged particle production cross sections and spectra in neutron-induced reactions. The spectrometer consists of a magnetic quadrupole doublet which focuses the charged particles onto a silicon surface barrier detector telescope which is 2 meters or more from the irradiated sample. Collimators, shielding, and the large source-to- detector distance reduce the background enough to use the spectrometer with a 14- MeV neutron source producing 4 . 10$sup 12$ n/s. The spectrometer has been used in investigations of proton, deuteron, and alpha particle production by 14-MeV neutrons incident on various materials. Protons with energies as low as 1.1 MeV have been measured. The good resolution of the detectors has also made possible an improved measurement of the neutron- neutron scattering length from the 0$sup 0$ proton spectrum from deuteron breakup by 14-MeV neutrons. (auth)
Date: December 10, 1975
Creator: Haight, R. C.; Grimes, S. M.; Tuckey, B. J. & Anderson, J. D.
Partner: UNT Libraries Government Documents Department

Fast calibration of large Si(Li) electron detectors from 511.0 to 4564.0 keV using double-escape peaks and Compton edges from $sup 66$Ga

Description: Double-escape peaks and Compton edges from the gamma -rays of 9 5-h / sup 66/Ga were used for the fast, precise calibration of Si(Li) electron detectors. They allow a direct calibration up to 4564.0 keV, and the calibration curve is linear enough that it can probably be extrapolated safely to even higher energies. (auth)
Date: January 1, 1973
Creator: Firestone, R.B.; Warner, R.A.; McHarris, W.C. & Kelly, W.H.
Partner: UNT Libraries Government Documents Department

Studies with a passive Ge(Li) assay system

Description: From joint meeting of the American Nuclear Society and the Atomic Industrial Forurm and Nuclear Energy Exhibition; San Francisco, California, USA (11 Nov 1973). The use of passive Ge(Li) gamma-ray waste/scrap assay systems for material accountability at Rocky Flats is briefly discussed. (WHK)
Date: January 1, 1973
Creator: Martin, H. R. & Chanda, R. N.
Partner: UNT Libraries Government Documents Department

Preliminary neutron foil dosimetry characterization of the BLIP neutron facility

Description: The Brookhaven Linac Isotope Producer (BLIP) produces neutrons from 200 MeV proton bombardment of a transparent (relative to 200 MeV protons) Be target. Threshold foil dosimetry techniques were utilized to characterize the BLIP neutron spectra which includes neutrons with energies greater than 15 MeV. Some operational characteristics of spallation neutron sources were also determined. The derived BLIP neutron spectrum has a hard component (neutrons between 6 to q2 MeV which peaks at 8 to 9 MeV) and a soft component characteristic of neutron scattering. Between 10 and 30% of the neutrons have energies below 0.25 MeV and less than 0.1% of the neutrons have energy in excess of 15 MeV. The derived neutron flux is 8.0 plus or minus 3 x 10/sup 9/ n/cm/sup 2/ mu C. (auth)
Date: August 29, 1973
Creator: Parkin, D.M.; Dudey, N.D.; Heinrich, R.R. & Fluss, M.J.
Partner: UNT Libraries Government Documents Department

Alpha pulse height analysis of 32 samples simultaneously using a minicomputer

Description: From 19th annual analytical chemistry conference; Jackson Hole, Wyoming, USA (3 Sep 1973). An alpha spectroscopy system for analysis of environmental samples at Rocky Flats is described. The system consists of 16 silicon detectors and associated electronics (preamplifiers, amplifiers, multiplier/router, analog- to-digital convcrter, pulseheight analyzer) for input in a NOVA 1200 minicomputer with 24 K, 16 bit memory. Software is briefly discussed. (WHK)
Date: January 1, 1973
Creator: Allen, I. B. & West, J. R.
Partner: UNT Libraries Government Documents Department