Monday, March 16, 2020, 13:47
Target material characteristics: Graphite cast of 0.965g/cm3, 287 D-shaped discs, disc area 0.969cm2, total mass of 9.972g, length 10.657cm.
The target material is loaded in a graphite cartridge.
The graphite cartridge is placed in a tantalum boat previously coated with TaC,
the Ta boat was wrapped with two used Ta heat shields.
The system is currently pumping down.
Tuesday, March 17, 2020, 08:11
IGP1 = 3.18e-7 Torr
Current will be increased manually to 10 A, and then it will be autoramp to 500 A
During the input of the 10 A there was no anomaly with the pressure and the autoramp was set to:
1 A each 10 s with a good vacuum of 3e-2 Torr and a bad vacuum 5e-2 Torr
Tuesday, March 17, 2020, 09:03
After 30 min:
TGHT: 98.1 A, 1.48 V (the voltage is increasing)
IGP1 = 3e-4 Torr
The autoramp is set to 2 A each 10 s to 500 A
Tuesday, March 17, 2020, 09:52
At 500 A the temperature was ~1243 C
So, the autoramp was re started 2 A each 10 s to 520 A
Tuesday, March 17, 2020, 09:56
TGHT= 510 A, 9.18 V
IGP1= 8.2e-5 Torr
Pressure decreasing.
Temperature register in iR2C: 1272 C
The target will stay at 520 A for 15 min to account for thermal equilibrium, and then the current will be increased to go to 1800 C
Tuesday, March 17, 2020, 10:11
The temperature stayed at 1270 C,
The autoramp is re started: 2 A each 10 s to 600 A
Tuesday, March 17, 2020, 10:24
TGHT: 10.693 V, 588.5 A
IGP1 max 7.4e-5 Torr
Temperature after 3 min at 588.5 A: 1368 C
Tuesday, March 17, 2020, 10:34
The autoramp is re started: 2 A each 10 s to 650 A
Tuesday, March 17, 2020, 10:46
TGHT=11.99 V, 637.6 A
IGP1=5.5e-5 Torr (8e-5 Torr max)
Temperature 1459 C
The current and voltage drop 10 A and 0.3 V respectively when the autoramp is stopped
Tuesday, March 17, 2020, 10:53
The autoramp is re started: 2 A each 10 s to 700A
Tuesday, March 17, 2020, 11:04
TGHT: 13 V, 686.59 A
IGP1: 6.2e-5 Torr (Max 8.7e-5Torr)
Temperature: 1507 C
Tuesday, March 17, 2020, 11:05
The autoramp is re started: 2 A each 10 s to 800A
Tuesday, March 17, 2020, 11:16
TGHT=14.29 V, 759 A
IGP1: 8.6e-5 Torr (Max 1e-4 Torr)
Temperature 1527 C
There is a current discrepancy in EPICs (see current discrepancy picture),
the autoramp stopped at 761 A because EPICS? reads 800 A
Increasing current manually.
Increasing the current manually did not work, because set current is at fake maximum
Tuesday, March 17, 2020, 13:43
The temperature stabilized to 1567 C. The current however was not stable ( look at the CarbonTarget - Max current)
an autoramp is set to -2 A each 10 s to 0A
The set current is going down but not the epics reading current neither the temperature. I assume the current will star going down when the set and the reading current from epics are the same.
Tuesday, March 17, 2020, 13:50
Autoramp was stopped, and current was reduced manually, at around 652 A (set current) the reading current started going down (639.5 A)
Autoramp is set to -2 A each 10s to 0 A
The tantalum boat deformed and the graphite cartridge rim broke |