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Wednesday, June 06, 2012, 16:55
The UO2/C green was prepared on June 04, 2012.
UO2 powder used = 50.26g
C-grv used = 10.14g.
Dry UO2/C green mass = 61.71g.
The green was rolled and wrapped in a piece of graphite sheet.
The target boat was wrapped with 3 Ta-heat shield and installed in the Evap#1.
The chamber is currently being pumped down.
Tuesday, June 12, 2012, 11:42
Currently, IEVAPIG1= 1.83e-6 Torr, IEVAP:CG2= 48 mTorr.
Backing line pressure is slightly high. Will get Edi to look into this.
Tuesday, June 12, 2012, 14:38
The backing pump oil was changed (ISAC WP#2012-06-12-1). IEVAP:CG2 is currently reading 27mTorr and IEVAPIG1 at 1.66e-6 Torr.
Tuesday, June 12, 2012, 16:06
TGHT was tabbed up to 50A and stayed for 1.5 hrs. Not much change in the pressure, currently at 1.8e-6 Torr, BP @ 25mTorr.
Keep stepping up TGHT current...
Tuesday, June 12, 2012, 16:37
TGHT at 65A. Pressure is starting to rise.
Tuesday, June 12, 2012, 16:46
Pressure at 6.8e-6 Torr and going up slowly.
Initiated TGHT auto-ramping:
Max current = 525A, rate @ 0.1A/min (see attachment #1)
Wednesday, June 13, 2012, 13:22
TGHT has almost reached to 80A. Pressure is limiting at 4.5e-6 Torr. (see attachment#2)
Thursday, June 14, 2012, 17:11
TGHT has reached to 95.40A, local @ 92A & 0.48V. Pressure is still limiting at 4e-6 Torr. (see attachment #3)
The TGHT current can not go up above 232A because it's voltage limiting at 1.953V (see attachment#4). The carbon thermal-reduction process stops and the vacuum is going down to low 10e-6 Torr.
The voltage can not be increased on EPICS; it has to be adjusted locally.
Auto-ramping aborted.
The TGHT current setpoint was lowered down to 228A.
Sunday, June 17, 2012, 12:03
Asked ISAC Ops (Ed Parton) to help me increase the voltage locally. The voltage nob was turned 1/4 clockwise, and the current was tapped up from 228 to 231A, and it was responding. The voltage nob was further turned to 3/4 clockwise.
Initiated auto-ramping.
Currently, TGHT setpoint at 234.90A, local 231A/1.95V.
Vacuum is responding and it's slowly going up (currently at 2.8e-6 Torr) - The carbon thermal reduction process continues...
Monday, June 18, 2012, 00:20
TGHT is going up slowly, currently at 285A. The pressure is limiting as the carbonization process is under way (see attachment 5).
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