A Multiple Radiation Effects Facility for the Study of Structural and Flexible Materials Exposed to the Space Environment
A radiation effects facility is described which utilizes multiple radiation sources, vacuum chambers and thermal control to simulate the space environment. Use of the facility for eight months' continuous testing of thin film flexible materials is discussed and summary results, primarily from in-situ testing, are presented.
Effect of Neutron and Proton Irradiation on Some Properties of Kapton
Photoacoustic, dielectric and surface-morphological properties of Kapton* were studied after exposing sheets (25 μm thick) separately to fast reactor neutrons (E>0.1 MeV) and to 250 keV protons up to doses 1.2×1018 (maximum)and 7.0×1015 cm−2, respectively. The photoacoustic spectrum (PAS) of the maximum neutron dose irradiated sample shows the red-shift of the absorption peak from 450 nm to 470 nm, whereas in the proton irradiated (7×1015 cm−2) sample, a new flattened absorption peak appears at λ ≃ 515 nm. There is a net enhancement in the D.C. dielectric constant of about 13% after the maximum neutron dose. It is attributed to the enhanced water absorptivity of the material due to neutron induced radiation damage.
Electron backscatter measurements for perpendicular and non-perpendicular incidence at 1.0 MeV bombarding energy
Abstract Total energy spectra of backscattered electrons for 1.0-MeV electrons with perpendicular incidence on targets of saturation thicknesses of Al, Fe, Sn and Au are shown. The variation of the shape of the energy distributions with angle observed for Al and Fe is illustrated. Total backscatter coefficients of 0.08, 0.22, 0.37, and 0.51 were obtained for Al, Fe, Sn, and Au. Mapping of electrons backscattered from a saturation thickness of Al for an angle of incidence of 30° from the target plane was also carried out at 1.0 MeV. Angular distributions as a function of two angles and typical energy distributions are included.