Induced radioactivity of LDEF materials and structural components

Radiat Meas. 1996 Nov;26(6):863-80. doi: 10.1016/s1350-4487(96)00094-7.

Abstract

We present an overview of the Long Duration Exposure Facility (LDEF) induced activation measurements. The LDEF, which was gravity-gradient stabilized, was exposed to the low Earth orbit (LEO) radiation environment over a 5.8 year period. Retrieved activation samples and structural components from the spacecraft were analyzed with low and ultra-low background HPGe gamma spectrometry at several national facilities. This allowed a very sensitive measurement of long-lived radionuclides produced by proton- and neutron-induced reactions in the time-dependent, non-isotropic LEO environment. A summary of major findings from this study is given that consists of directionally dependent activation, depth profiles, thermal neutron activation, and surface beryllium-7 deposition from the upper atmosphere. We also describe a database of these measurements that has been prepared for use in testing radiation environmental models and spacecraft design.

MeSH terms

  • Aluminum / radiation effects
  • Anisotropy
  • Beryllium*
  • Databases, Factual
  • Extraterrestrial Environment
  • Metals, Heavy
  • Neutron Activation Analysis
  • Neutrons*
  • Protons*
  • Radioactivity
  • Radioisotopes*
  • Research
  • Solar Activity
  • Space Flight / instrumentation*
  • Spacecraft / instrumentation*
  • Spectrometry, Gamma / methods

Substances

  • Metals, Heavy
  • Protons
  • Radioisotopes
  • Aluminum
  • Beryllium