Thursday, September 01, 2022, 10:34
The coated container was wrapped in three Ta foil heatshields.
Target temperature on OMEGA= 1850-1900 C
OMEGA slope:= 0.990
Target time at max temperature = 4 hours
Final Current TBHT= 230A
Final TGHT current= ~420A (adjustable)
Heating autoramp starged at 2A/min on both TGHT and TBHT to 40A
Then at 1A/min on both heaters to 120A.
Good vacuum = 5.0 e-05 Torr
Bad vacuum = 5.0E-04 Torr
Thursday, September 01, 2022, 12:39
Has been stabilizing at 40A on both heaters.
Starting 1A/min autoramp to 80A
A discrepancy between setpoint and readback currents was observed for both TGHT and TBHT. The difference is substancial and warrants investigation. This process will be paused until further notice
Tuesday, September 06, 2022, 14:45
Controls has been troubleshooting EVAP2. In the process TBHT has been damaged. Arthur will take a look at it ASAP and his group will try and fix it tomorrow.
Regarding our initial problem, it appears that when an electrical safety box was installed, the copper water lines connected to output terminals of the power supply, were moved so that they were in contact with the evaporator cage. See the figure below.
Thursday, September 08, 2022, 12:47
Target has been removed and a new test target (HP-FEBIAD) has been placed inside. System left to generate enough vacuum and then testing will be performed.
Friday, September 09, 2022, 15:58
System was tested and all seems good. This coat/sintering will continue after conditioning of graphite material
Saturday, September 24, 2022, 09:13
Continuation of process.
IGP1= 4.3e-07 Torr
ramping @ 1A/min to 230 A on both TGHt and TBHT
Saturday, September 24, 2022, 16:28
ramped to 430A, 7.2V on TGHT and 233A, 4.2V on TBHT. Will leave until 7 pm.
Saturday, September 24, 2022, 19:44
Starting rampdown @-2A/min TGHT -1A/min TBHT
camera offline
IGP1= 1.2e-6 Torr
Monday, September 26, 2022, 09:41
IGP1=2.2e-07 Torr. Shutting off TBHT and TGHT.
Thursday, September 29, 2022, 09:53
Final notes: coating looks good . Probably 3 hours at final temperature is better to prevent material degradation. |