Thursday, February 21, 2019, 09:01

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

Desired temperature= 1900 C, Omega Slope set = 0.990, Auto TGHT at 0.2A/min to reach 400A, TGHT will be tapped up accordingly to reach desired Temp.

TBHT will be set fixed at 230 A (max). 

Good vac at 3.00e -5 Torr

Bad vac at 5.00e-5 Torr

Chamber pump down was started on Wednesday February 20th; however, this morning IEVAP2:TP1 and IEVAP2:BV1 were found in the OFF position.

There are no abnormal sounds from the roughing pump.

IGP1= 5.6e-2 Torr

Will turn on IEVAP2:BV1 and IEVAP:TP1 from the hot lab and listen for anything out of the ordinary.

 Friday, February 22, 2019, 09:56

Pumped down to IGP1=2.1 e-07

Will tap up TGHT and TBHTmanually and monitor the pressure.

Friday, February 22, 2019, 11:20

Manually tapped up TGHT (V~ 0.90) and TBHT(V ~0.99) to 90A

maximum pressure reached ~7.4e-06 Torr and trended down

Friday, February 22, 2019, 11:25

Initiating Autoramp @ 0.2 A/min for TGHT to reach 450A and TBHT to reach 230A

Estimated temperature for TGHT ~1200 C
 

 Friday, February 22, 2019, 15:42

TGHT @ 145 A and TBHT @ 138A

Changed Autoramp to 0.1 A/min  so that it will take over the weekend to reach 450A and 230A for TGHT and TBHT respectively.

Monday, February 25, 2019, 08:29

IGP1=1.1e-07 Torr, TGHT= 451.4 A, 6.7 V, TBHT = 233.1 A, 3.1 V

Omega T = 1197 C

Will manually tap up by increasing TGHT current by ~1A/min monitoring pressure.   Will allow system to stabilize ~1400 C.

 Monday, February 25, 2019, 11:14

 Trend forcast 1400 C at TGHT= 566.75 A (Line plot attached)

Actual but not stable ~1445-1452 C at 566 A

Will continue to manually increase current monitoring pressure

 Monday, February 25, 2019, 12:33

Omega T= 1679 C , TGHT = 657.7A, 10.52 V, TBHT = 233.2 A, 3.2 V

IGP1 = 1.4e-05 Torr slightly trending up.

Autoramp @ 1 A/min to a maximum of TGHT 780 A. 

Monday, February 25, 2019, 14:43

IGP1= 3.7e-06 Torr trending down slightly, TGHT = 780.3 A, 12.9 V

Omega T = 1931 C

Monday, February 25, 2019, 15:14

manually tap up to TGHT to 790 A

Monday, February 25, 2019, 15:36

IGP1= 2.9e-6 Torr trending down

TGHT = 784.3 A, 13.01 V

TGHT current set to 790 A

Omega T = 1940 C

Will leave over-night

 Tuesday, February 26, 2019, 08:23

IGP1= 7.85e-07 Torr Stable

TGHT = 784.32 A, 12.54 V

TBHT = 233.3 A, 3.2 V

OMEGA T = 1948 C

Initiating Auto-cool ramp at 2.0A/min and 1.0A/min for TGHT and TBHT respectively.

Wednesday, February 27, 2019, 08:10

IGP1 = 3.3 e-08 Torr Stable

TGHT = 0A, 0.05V

TBHT = 0.02A, 0. V

Will begin vacuum release