An In-Vacuum BR/TDF Measurement Apparatus

Abstract

An in-vacuum BR /TDF measurement apparatus has just been assembled as part of a larger space environmental effects facility. The sample stage and detector assemblies are mounted within and the requisite optics train and light sources external to a 48 -in. diameter vacuum chamber.The chopped and field stopped f /60 incident beam enters the chamber through a window of appropriate material. Argon ion, helium neon, and CO2 lasers, as well as a xenon arc lamp, are used as light sources.Beam size on the sample is about 1 -cm diameter with the detectors mounted on a 60 -cm arm.The detectors can be rotated from within about 2° of the incident beam to directly facing the incident beam and can measure reflectance of a normally incident beam to about 83° and transmittance from 150° to 180 °.