UHV TECHNIQUE FOR INTER-VACUUM SAMPLE TRANSFER

An alternative to the modern UHV multiport surface analytic system is a transfer technique for intervacuum sample transfer which maintains the sample at UHV ( less than 10** minus **9 Torr) at all times. Major advantages are (1) economical use of available facilities by a number of experimentalists (2) instrument and surface standardization (3) complementary experiments by remote specialized laboratories (4) preparation of samples in specialized facilities (e. g. , space shuttle or thermonuclear reactor) followed by a transfer to surface analytic facility. Such a transfer system has been built and tested. Transfers currently take three to four hours between nearby stations. Intercontinental transfers are feasible using a battery operated ion pump during transport. For a transfer a UHV system must have a suitable gate valve (35-mm bore, 10** minus **1**3 ls** minus **1 helium closed conductance) and a platform capable of accepting a standard 22. 8-mm-diam ring, which carries the sample itself.