Wednesday, March 18, 2020, 07:10
Ta tube was coated with TaC and wrapped with Ta heat-shields (3 layers)
Desired temperature= 1900 C (expected TGHT ~430 A), TBHT will be set fixed at 230A (max).
Evap 2 was pumped down on the previous night.
Good vacuum= 3.00 e-5 Torr
Bad vacuum = 5.00 e-5 Torr
Ramped TGHT and TBHT to 40A at 0.5A/min
Initial pressure IGP1 = 4.8e-7Torr
Wednesday, March 18, 2020, 09:29
After an hour pressure reduced to 5.45e-6 Torr
TGHT; 0.518 V, 40.5 A
TBHT: 0.41 V, 38.6 A
Autoramp TGHT and TBHT at 1A/min to 400A and 230A respectively.
Wednesday, March 18, 2020, 18:29
TGHT = 400A, 6.6V, TBHT= 232.9, 3.9V
OMEGA = 1240 C, this is 500 degC lower than previous LP-SIS at same conditions
https://elog.triumf.ca/TIS/Evaporator_2/464
Start autoramp to 460A on TGHT at 1A/min
Wednesday, March 18, 2020, 20:51
TGHT: 464 A, 7.75 V
Temperature 1328, I won't increase the temperature because there is a chance that the reading is 500 degC off and the target is sitting at 1828 degC instead of 1328 degC
Wednesday, March 18, 2020, 23:17
After ~4 hours at 1317 degC according to the pyrometer:
TGHT = 7.7 V, 457.8 A,
TBHT = 3.9 V, 232.9 A,
IGP1 = 1.16e-6
Commence cooling at -2A/min for TGHT and -1A/min for TBHT
Thursday, March 19, 2020, 15:53
Venting and dismounting.
The coating does not have the quality to be used online, another LP-SIS will be coated and sinter |