Wednesday, October 27, 2021, 11:07

Monday, October 25, 2021, 11:52

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

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

Evap 2 will be pumped down over previous night

Good vacuum = 3.00 e-3 Torr

Bad vacuum = 5.00 e-2 Torr

Initial total weight = 464.8 g

Final weight after sintering = 

 Thursday, October 28, 2021, 07:46

IGP1= 7.4e-07 Torr

Initiating autoramp to 40 A on both TGHT and TBHT

ramp rate = 1 A/min

Will keep at 40A for approximately 1 hour or until pressure below 1e-05 Torr

 Thursday, October 28, 2021, 09:41

IGP1= 1.9e-06 Torr TGHT = 40.3 A, 0.48 V TBHT = 39.0 A, 0.48V

Autoramp @ 1A/min to 100A on both TGHT and TBHT

 Thursday, October 28, 2021, 12:57

IGP1= 1.1e-06 Torr

TGHT = 100 A, 1.3 V

TBHT = 100 A, 1.2 V

Start autoramp at 2A/min to 400 for TGHT and 230 for TBHT

The current from the plot (below) required to reach 1900 C seems too high.

Will take to 430 A as previous.  The slope was chequed previously.  Need to check OMEGA.

Thursday, October 28, 2021, 20:08

IGP1=  3.34 e-06 Torr

TGHT = 430A , 7.2 V

TBHT = 233A, 4.1V

OMEGA  = 1628C

Start ramp down at -2A/min for TGHT and -1A/min for TBHT

	44691-3 TaC coating
		TGHT		TBHT			Temperature (C)	Current (A)
	Temperature ( C )	Voltage (V)	Current (A)	Voltage (V)	Current  (A)		1900	512.88
	1250	3.90	255.0				1700	434.06
	1302	4.30	279.0				1800	473.47
	1343	4.60	294.0
	1423	5.10	325.0
	1484	5.7	348.0
	1555	6.2	377.0
										Slope	2.537
										Y intercept	598.66
										R2	0.999