Contribution of proton-induced short range secondaries to the LET spectra on LDEF

Conference · Wed Feb 01 04:00:00 EST 1995

OSTI ID:42743

Benton, E R; Csige, I; Benton, E V; Frigo, L A

The contribution to the LET (linear energy transfer) spectrum from proton-induced short range secondaries was investigated by making measurements of total track density and LET spectra in CR-39 Plastic Nuclear Track Detectors (PNTD`s) at varying shielding depths in the A0015 West-side stack. Proton-induced short range secondaries were found to make a significant contribution to the LET spectra, especially in the region above 100 keV/micron. At present, calculational models do not include this component. Total track density was measured at five shielding depths and was seen to increase as a function of shielding. LET spectra were measured under two shielding depths (2.6 and 9.2 g/cm(exp 2)) and stayed fairly constant as a function of shielding. Prerecovery estimates of LET spectra dropped off rapidly in the 100-300 keV/micron region, while the measured LET spectra extended to higher LET`s. Track density and LET spectra measurements of secondaries were made in a CR-39 PNTD stack exposed to 154 MeV accelerator protons. Similarities in LET spectra measured in the A0015 experiment and in the 154 MeV accelerator proton stack demonstrate that a useful first step in modeling the contribution to the LET spectra of secondaries induced by the spectrum of trapped protons would be to model a mono-energetic proton beam being transported through a one-dimensional geometry.

• Research Organization: National Aeronautics and Space Administration, Hampton, VA (United States). Langley Research Center
• OSTI ID: 42743
• Report Number(s): N--95-23796; NASA-CP--3275-PT-1; L--17430A-PT-1; NAS--1.55:3275-PT-1; CONF-9311137--; CNN: NAS8-38610
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
ENERGY SPECTRA
LET
PROTONS
RADIATION EFFECTS
SECONDARY EMISSION
SPACE FLIGHT