Friday, October 04, 2013, 15:37
A LP target container is coated with TaC. The container is wrapped with 3 layers to heat shield.
This container will be used for the graphite tube test.
Chamber is being pumped down.
The HS cooling water valves are open and no leaks are detected.
TGHT will be ramped up to 580A at 0.2A/min
TBHT will be ramped up to 230A at 0.2A/min.
The temperature will be monitored and measured.
Sunday, October 06, 2013, 19:55
TGHT and TBHT have reached to 580A/230A, respectively. And the target has been heated for about 5 hours.
The temperature inside the tube is measure at 1000C; this is much lower than expected as to previously measured at 1700C.
The temperature outside the container is at 1400C.
I'm suspecting the thermocouple inside the tube could be shorted.
Cooling down the heaters down to zero at 2A/min for TGHT and 1A/min for TBHT.
Tomorrow, the chamber will be vented and the target will be inspected.
I like to re-adjust the thermocouple again, and re-heat the target back up, hoping to reach 1700C at TGHT = 580A.
Monday, October 07, 2013, 15:24
The sintering of the TaC coating is complete.
The chamber was vented this morning. Apparently, there was a short in the thermocouple so the temperature measure was recorded much lower.
The thermocouples are adjusted, and the chamber is pumped down.
Vac currently at 1.17e-6 Torr.
TGHT and TBHT will be ramped up to 580A/230A at 2A/min.
Continue monitoring the temperature...
Monday, October 07, 2013, 16:13
TGHT and TBHT were ramped up to 90A. Temperature inside the tube was measure just at 75C and the outside surface was at 207C.
Maybe the thermocouple is F up; will replace with a new one tomorrow.
Cooling down the target down...
Tuesday, October 22, 2013, 16:49
The target was heated up to 580A and the temperature inside the tube was measured to be ~1800C and the outside surface was ~1400C.
The target was cooled down. Then the graphite tube was inserted.
There are two thermcouples inserted inside the tube on both ends.
Chamber has been pumped down to 4.33 e-7 Torr. No leaks were detected.
Target will be heated up again to TGHT @ 580A / TBHT @ 230A at 0.2A/min.
The temperatures will be monitored.
T1 = left (floating)
T2 = right (toughing C-grv tube)
(wtf ionizer pointing into the page).
Thursday, October 24, 2013, 16:35
TGHT/TBHT reached to 580A/230A.
T1 = 1642C
T2 = Error?? Reading goes on/off intermittently, showing 900 - 1900C
Thursday, October 24, 2013, 16:45
Ramping up TGHT to 680A to see if T1 can reach 1700C.
IG1 currently at 5.2e-7 Torr.
Friday, October 25, 2013, 12:30
TGHT was ramped up to 632A (stopped due to voltage limiting).
T1 was measured at 1960C. Vac went up as it was heated up. (see attachment #2)
Target was cooled down at 5A/min, now at 0A.
The chamber will be vented and the target will be inspected.
This run is complete.
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