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Title: Fission foil detector calibrations with high energy protons

Fission foil detectors (FFD`s) are passive devices composed of heavy metal foils in contact with muscovite mica films. The heavy metal nuclei have significant cross sections for fission when irradiated with neutrons and protons. Each isotope is characterized by threshold energies for the fission reactions and particular energy-dependent cross sections. In the FFD`s, fission fragments produced by the reactions are emitted from the foils and create latent particle tracks in the adjacent mica films. When the films are processed surface tracks are formed which can be optically counted. The track densities are indications of the fluences and spectra of neutrons and/or protons. In the past, detection efficiencies have been calculated using the low energy neutron calibrated dosimeters and published fission cross sections for neutrons and protons. The problem is that the addition of a large kinetic energy to the (n,nucleus) or (p,nucleus) reaction could increase the energies and ranges of emitted fission fragments and increase the detector sensitivity as compared with lower energy neutron calibrations. High energy calibrations are the only method of resolving the uncertainties in detector efficiencies. At high energies, either proton or neutron calibrations are sufficient since the cross section data show that the proton and neutronmore » fission cross sections are approximately equal. High energy proton beams have been utilized (1.8 and 4.9 GeV, 80 and 140 MeV) for measuring the tracks of fission fragments emitted backward and forward.« less
Authors:
;
Publication Date:
OSTI Identifier:
64252
Report Number(s):
N-95-25911; NASA-CR-197694; NAS-1.26:197694
TRN: 9525924
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Mar 1995; Related Information: Is Part Of High LET, passive space radiation dosimetry and spectrometry; Benton, E.V.; Frank, A.L.; Benton, E.R.; Keegan, R.P.; Frigo, L.A.; Sanner, D.; Rowe, V.; PB: 356 p.
Research Org:
San Francisco Univ., CA (United States)
Country of Publication:
United States
Language:
English
Subject:
44 INSTRUMENTATION, INCLUDING NUCLEAR AND PARTICLE DETECTORS; FISSION FOIL DETECTORS; CALIBRATION; PROTON BEAMS; DOSEMETERS; GEV RANGE 01-10; MEV RANGE 100-1000