Tuesday, April 30, 2019, 09:33

Container was coated with TaC and wrapped with 2 Ta heat shields.

Desired temp = 1900 C, Omega slope set = 0.990, Auto ramping TGHT at 1A/min to reach 400A, TGHT will be tapped up accordingly to reach desired Temp.

TBHT will be set fixed at 230A (max). TBHT at 1A/min to reach 230A.

Good vac at 3.0e-5 Torr

Bad vac at 5.0e-5 Torr.

Chamber is currently being pumped down (since yesterday evening).

Tuesday, April 30, 2019, 10:25 

Current pressure at IGP1 = 5.17e-7 Torr

Manual tapping to 40A on TBHT and TGHT

TBHT 38.59A, 0.43V

TGHT43.69, 0.23V

waiting for pressure to stabilize.

 Tuesday, April 30, 2019, 15:15

Current pressure IGP1= 5.29e-07 Torr

Auto ramping TGHT at 1A/min to reach 400A, and TBHT at 1A/min to reach 230A.

Wednesday, May 01, 2019, 08:41

Target current of 400A reached around 00:19 am

Will tap up to 444A on TGHT as projected from plot of temperature vs current (attachment 1)

Current IGP1=5.91e-07 Torr

Wednesday, May 01, 2019, 09:54

At 444A 1900C not reached.  Continue tapping to 1900C (attachment 2)

1900 C reached at 459 A on THGT.

will leave at 1900C for 4 hours.

 Wednesday, May 01, 2019, 14:21

IGP1= 6.7e-7 Torr

After 4.5  hours, TGHT was ramped down @ 2A/min and TBHT @1A/min overnight

Thursday, May 02, 2019, 10:46

 Vented Evap 2 and removed the target container.