Tuesday, January 15, 2018, 17:30

Tantalum tube was coated with TaC and wrapped with Ta heat-shield (3 layers)

Desired temp = 1900 C (expected TGHT ~445A/7.5V), TBHT will be set fixed at 230A (max).

EVAP2 currently pumping down.

 Pressure at IGP1 4.71 -7 Torr. 

Tapped up TGHT manually to 40 A

Waited ~1 hr for vacuum to stabilize.

IGP1 = 9.96-7 Torr

Good vac at 3.00e-5 Torr

Bad vac at 5.00e-5 Torr.

Initiating auto ramp for TGHT @ 1 A/min to a max set point of 350 A

Once max set points achieved, will tap up manually to final desired temperature of 1900 C

 Thursday, January 17, 2019, 15:31

The tube remained at ~1900 C for 6 hours.

IGP1=5.8e-7 Torr

TGHT = 427 A, 7.23 V

Min Temperature = 1890 C

Thursday, January 17, 2019, 15:33

 Auto-ramp set to TGHT 0 A @ -2 A/min.