PERFORMANCE OF VACUUM COMPONENTS OPERATING AT 1X10-11 TORR

The Intersecting Storage Accelerator (ISABELLE) consists of two rings having a circumference of 3. 8 km each. The vacuum system uses an 8. 8-cm circular chamber maintained at 1 multiplied by 10** minus **1**1 Torr by a combination of Ti sublimation and 30-lsec** minus **1 ion pumps placed at 5-m intervals. Several experimental setups which simulate sections of ISABELLE have been constructed to study the behavior of stainless steel, aluminum, H//2-Ti system, and ion pumps at low pressures ( less than equivalent to 1 multiplied by 10** minus **1**1 Torr). In this paper we will summarize the results of our measurements on (1) total outgassing of 304 stainless and 6061 aluminum, (2) hydrogen pumping speed, ultimate pressure, and sorbing capacity of titanium films as a function of surface coverage, H//2 input flux and surface preparation, (3) hydrogen, methane, helium, and argon pumping speeds of ion pumps as a function of pressure, and (4) reemission of gases from ion pumps.