Friday, March 05, 2021, 10:47

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

Initial weight including heat-shields = 431.0 g

Desired temperature = 1900 C (expected TGHT ~430 A), TBHT will be set fixed at 230A (max).

Evap 2 will be pumped down over night.

Good vacuum = 3.00 e-5 Torr

Bad vacuum = 5.00 e-5 Torr

 Saturday, March 06, 2021, 10:29

IGP1= 2.7 e-07 Torr and stable

AutoRamp at 1A/min to 40 A on TGHT and TBHT

Saturday, March 06, 2021, 22:36

IGP1= 2.2e-07 Torr

TGHT = 40.3 A, .46V

TBHT = 38.48 A, .48 V  (set to 40 A)

Start Autoramp at 0.5A/min to 400 A on TGHT and 230A on TBHT

Sunday, March 07, 2021, 07:48

IGP1=8.5e-7 Torr

TGHT = 287 A, 4.6V

TBHT = 232 A, 4.0 V

OMEGA = 1493C

 Increase ramp speed on TGHT to 2A/min to 400A

Sunday, March 07, 2021, 08:36 

 IGP1=1.7 e-06 Torr

TGHT = 373.7 A, 6.3V

TBHT = 232.9 A, 4.1 V

OMEGA = 1752 C

Sunday, March 07, 2021, 08:53

 IGP1= 1.7e-06 Torr

TGHT = 400 A, 6.8 V

TBHT = 232.8 A, 4.1 V

OMEGA= 1842

Ramp TGHT @ 2A/min to 420 A as per attached current approximation

Sunday, March 07, 2021, 09:25

OMEGA=1915 C

TGHT = 420A, 7.2V

TBHT= 232.8 A, 4.1V

IGP1= 1.6 e-06 Torr

Tap down manually to approx 1900 C

TGHT = 412.9 A, 7.0 V and OMEGA=1900 C

Will leave for about 4 hours at this temperature

Sunday, March 07, 2021, 13:05

IGP1= 1.1 e-06 Torr

TGHT = 415 A, 7.2 V

TBHT = 232.8 A, 4.1 V

OMEGA = 1880C

Start cool down at -2A/min on TGHT and -1A/min TBHT