Tuesday, September 04, 2018, 16:58

Container is coated with TaC and wrapped with Ta heat-shield ( 3 layers)

Desired temp = 1900 C (expected TGHT ~445A/7.5V), TBHT will be set fixed at 230A (max).

Good vac at 3.00-5 Torr

Bad vac at 5.0e-5 Torr.

Chamber is currently being pumped down

 Wednesday, September 05, 2018, 10:53

Pressure at 9.5-7 Torr. 

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

 Wednesday, September 05, 2018, 17:52

Problem with TGHT readback vs setpoint.  TGHT ramped up to 400A, temp measured at 1830C.  However, the setup remained at 228A (see attachment).  The autoramping program only sees the readback; in this case, the TGHT would continue to keep ramping up until the target breaks.  The autoramping program has stopped just in time. 

TGHT stepped down to 400A (setpoint), readback at 206A/6.59V.  TGHT at 230A/4.16V.  Temperature holding at 1783C. 

Control has been informed.

 Thursday, September 06, 2018, 10:54

Target temp holding at 1773C.  Pressure at 8.5e-7 Torr. 

Ramping down TGHT and TBHT, and inspect the container later. 

Problem with the TGHT readback/setpoint will need to be investigated.

 Friday, September 07, 2018, 16:03

Target container is nicely sintered.

Awaiting for Control group to investigate with the problem on TGHT readback/setpoint.