Tuesday, June 06, 2023, 09:11

A Ta container tube was wrapped with 4 Ta heatshields.  Note final container is 45220-6

272 graphite discs were loaded.

a TaC coated Ta spring at the front end.

The system was left to establish vacuum over previous night.

Good vacuum set to5e-04Torr

Bad vacuum was set to 5e-2 Torr

Total weight of system including spring= 253.94 g

OMEGA slope = 0.99

The target will be heated to ~2000 C, held there for 10 hours. 

Initial ramp at 1A/min to 200A

Then ramp at 0.5A/min while taking temperature readings periodically unti l250A.

At 250 A will let pressure stabilize and then ramp at 1A/min to 2000C or 480A.  Will use read back current

Will hold at target Temperature or Current for 10 hours before starting ramp-down.

Tuesday, June 06, 2023, 09:14

 Starting ramt at 1A/min

initial IGP1= 8.2e-07

Tuesday, June 06, 2023, 21:25

@480 A on readback, 1823C on OMEGA.  ramping to 510A set point which should be around 490 RD.  (see heating profile for details)

Tuesday, June 06, 2023, 22:02

ramped to 516 on RD 527 on set.  Will leave for 10 hours

OMEGA =1930 C

Wednesday, June 07, 2023, 06:32

OMEGA at 1950 C this morning.  Will continue heating.  Lowered to 1940 C as in experiment 1 this was the top temperature.

Wednesday, June 07, 2023, 07:40

OMEGA= 1940 C

IGP1=1.7-6 Torr

TGHT= 513A, 9.4V

starting ramp down at -2A/min