Thursday, February 23, 2023, 18:20

Ta HP-FEBIAD was coated with TaC and wrapped with Ta heat-shields (3 layers) and 1 under layer that doesn't cover the middle section.

Desired temperature = 1800 C , TBHT will be set fixed at 230A (max).

Evap 2 will be pumped down to 5e-06 Torr range

OMEGA slope= 0.990

Good vacuum = 5.00 e-4 Torr

Bad vacuum = 5.00 e-2 Torr

IGP1=2.5 e-06 Torr

Start autoramp @1A/min to 80 A then autoramp heat @1A/min to 150 A.  Then autoramp TGHT to approx 675A and TBHT to 230A.1

Friday, February 24, 2023, 09:10

heated overnight @0.5 A/min to 400 A.  Then started heating at 1A/min to 600 A while taking readings for current/Temp regression.

regression so far points to 682A to get to 1800C.  Will continue taking readings and possible heat to 1850 C. 

Friday, February 24, 2023, 09:43

autoramping to 690A at 1A/min

Friday, February 24, 2023, 11:24

ramping manually to 690A from 650A

Friday, February 24, 2023, 11:32

4 hours at 330pm

TGHT 492A, 10.6V

TBHT = 230A, 3.2V

IGP1=5.11e-06 Torr

OMEGA =1840 C

Friday, February 24, 2023, 15:36

TGHT = 692A, 10.6V

TBHT = 230 A, 3.2V

OMEGA = 1835 C

IGP1= 2.4e-06 Torr

Starting rampdown at -2A/min TGHT and -1A/min TBHT