John Wong wrote:

Laura Lambert wrote: John Wong wrote: Laura Lambert wrote: John Wong wrote:  Wednesday, January 15, 2014, 17:30 Target container is coated with TaC.  No Ta-heat shields are used. TGHT will be ramped up to 580A at 0.2A/min.  TBHT will be ramped up to 230A at 0.2A/min.    Chamber is currently being pumped.  Tomorrow, the HS water valve can be opened to test for leaks.   Notes:  If everything is fine, TGHT/TBHT can be stepped up to 30A-50A.  Watch for the vacuum; once it's stable the auto ramping program can be initiated.   Once TGHT/TBHT reached above 200A, the ramping rate for TGHT can be increased up to 2A/min.  (This step is to speed up the process; however it's not mandatory)     Thursday, January 16, 2014, 11:35 Chamber was pumped down overnight to 10-7 Torr. HS water valve was opened and no leak in vacuum was observed. TGHT and TBHT were stepped up to 35A. Waited ~30min, current stabilized and vacuum starting to drop. Initiating auto-ramping: Good Vac = 2.0e-5 Torr, Bad Vac = 3.0e-5 Torr.    Friday, January 17, 2014, 09:28 TGHT/TBHT @ 300/200A.  TBHT voltage is limited at 3A.   TGHT ramping rate increased to 2A/min.  Pressure @ 4.5e-7 Torr.      Friday, January 17, 2014, 10:14 TBHT stopped at 200A with voltage limit sitting at 3V. Aborted auto-ramp, changed the voltage limit to 5V and increased ramping rate to 2A/min. Re-started auto-ramp. IGP1 @ 5.0e-7 Torr  Friday, January 17, 2014, 12:45 TGHT voltage limiting at 9.9V, and  current stayed at 560A.  Increased the TGHT voltage to 10.5V and continued ramping the heater up. TGHT/TBHT stabilized at 850A (~10V) and 230A(3.6V).  Pressure at 1.03e-6 Torr and coming down...  Target will be heated until 5pm (4hrs) before cooling down at the ramping rate of 2A/min.  Chamber will be vented in air, next week.  Friday, January 17, 2014, 16:51 Auto-cooling initiated at 2A/min. Vac @ 5.3e-7 Torr.