Monday, July 18, 2011, 15:53: Target oven was coated with TaC and let dry over the weekend. The target is now installed in the evaporator and currently being pumped down. No Ta-heat shields are required for LP target ovens.
Wednesday, July 20, 2011, 11:42: Evaporator had to be vented to remove the target because Ta-heat shields were actually required for UCx target at 2uA p+. Target heater was never turned on. After removing the target oven, it was rolled around Ta wire; this prevent the Ta foil to stick on the oven. Then 3 Ta-heat shields were wrapped around it, plus 2 shields on the back block. The evaporator has been pumped down over night, currently vac @ 1.30e-6 Torr.
Wednesday, July 20, 2011, 12:35: TGHT stepped up to 110A, pressure began to increase exponentially. Brought THGT down to 100A. Will being auto cooling soon.
Wednesday, July 20, 2011, 12:48: Auto heating beings. 2A/min, max current @ 520A.
Wednesday, July 20, 2011, 17:49: TGHT reached to 520A. Increased heater to 570A according to last year UCx procedures.
Wednesday, July 20, 2011, 19:46: TGHT held at 570A for about 2 hours. Cooling down has begun. Set rate at 0.5A/min for slow cool down.
Thursday, July 21, 2011, 12:20 : TGHT cooling rate increased to 2A/min at about 10:25 am. At 10:55am, TGHT p/s tripped off, and the water valve was closed. Not sure what was the reason. Rest p/s and water valve, and turned back the p/s and continue to cool down from 74A. (see attachment#1: striptool)
Thursday, July 21, 2011, 14:45 : TGHT off, chamber about to be vented into atmosphere. |