Summary of LET spectra and dose measurements on ten STS missions

Technical Report · Wed Mar 01 04:00:00 EST 1995

OSTI ID:64243

A comparison of linear energy transfer (LET) spectra measurements made with plastic nuclear track detectors (PNTD`s) from area passive dosimeters (APD`s), was made for ten different STS missions under similar shielding. The results show that integral flux, dose rate and equivalent dose rate values follow a general increase with respect to increasing orbital inclination and altitude but that there are large variations from a simple relationship. This is to be expected since it has been shown that Shuttle attitude variations, combined with the anisotropic particle flux at the South Atlantic Anomaly (SAA), can result in differences of a factor of 2 in dose rate inside the Shuttle (Badhwar et al.). Solar cycle and shielding differences also result in variations in radiation dose between STS missions. Spaceflight dosimeters from the STS missions are also being used in the development of a method for increasing LET spectra measurement accuracy by extending LET measurements to particle tracks of ranges 10-80 microns. Refinements in processing and measurement techniques for the flight PNTD`s have yielded increased detection efficiencies for the short tracks when LET spectra determined by using the standard and refined methods were intercompared.

• Research Organization: San Francisco Univ., CA (United States)
• OSTI ID: 64243
• Report Number(s): N--95-25911; NASA-CR--197694; NAS--1.26:197694
• Country of Publication: United States
• Language: English

Related Subjects

56 BIOLOGY AND MEDICINE
APPLIED STUDIES
ALTITUDE
DOSEMETERS
LET
PARTICLE TRACKS
RADIATION DOSES
SPACE SHUTTLES