Measurement of Outgassing Rates of Polyester and Polyimide Films for Vacuum Thermal Insulation

Abstract

Multilayer insulation (MLI) is wellknown as a means of minimizing heat leakage into the cryogenic system. In this study, outgassing rates of thirteen kinds of MLI samples made of commercially available polyester and polyimide have been measured as a function of pumping time at a room temperature of 20°C, using an UHV system. Typical values of outgassing rates are on the order of 10-4Pa.m33/s.m2after 1 h and 10-8Pa-m3/s-m2after 72 h, respectively. The measured results are also compared with reference data reported by other investigators. © 1994, The Vacuum Society of Japan. All rights reserved.