Monday, April 01, 2019, 16:35

Container was coated with TaC and a roll of graphite inserted inside the tube.   A couple of TaC coated Ta springs inside to keep graphite pressed against walls of cylinder.

Container 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.

Good vac at 3.00-5 Torr

Bad vac at 5.0e-5 Torr.

Chamber is currently being pumped down.  Sintering will proceed tomorrow.

Tuesday, April 02, 2019, 06:27

IGP1 = 4.37e-7 Torr

Current is manually tapped to 40 A

Tuesday, April 02, 2019, 08:12 

Pressure increased to IGP1 = 1.15e-5 Torr

and it stabilized to IGP1 = 2.32e-6 Torr after ~1.5 hrs

Autoramp is set to 1 A/min to 400 A

Tuesday, April 02, 2019, 08:45

Autoramp stopped momentarily, to stop current reduction

When pressure reduced to ~4e-5Torr, current was tapped manually to 50 A

Autoramp is set again, the conditions are

IGP1 = 2.5e-5 Torr

TGHT = 58.87 A, 0.36 V

Tuesday, April 02, 2019, 09:31

Autoramp stopped momentarily, to avoid current reduction

When pressure reduced, autoramp is set again,

the conditions are:

IGP1 = 2.9e-5 Torr, TGHT = 0.52 V, 71.5 A 

 Tuesday, April 02, 2019, 15:32

 Autoramp stopped momentarily, to avoid current reduction

conditions: IGP1=4.99e-5 Torr, TGHT = 0.78 V, 85.9 A

When pressure reduced, autoramp is set again,

 Tuesday, April 02, 2019, 22:37

Camera conexion was lost

Autoramp reached 400 A

the current was manually raise to 425 A to allow the completation of the process

Wednesday, April 03, 2019, 00:27

Camera connection still off

The current was reduced to 410 A to match with the estimated temperature 

Wednesday, April 03, 2019, 06:56

Camera connection is back, temperature reading is 1786 C

IGP1  5.01e- Torr

TGHT = 6.93 V, 412.22 A

Autoramp was set to -1A/min to 0A

Wednesday, April 03, 2019, 11:01

IGP1 = 1.67e-7 Torr

TGHT = 2.25 V, 179.53 A

Autoramp changed to -2 A/min 

Wednesday, April 03, 2019, 16:54

The tube was removed from the EVAP2,

The coating has a different color than regular coatings, but it doe not seem like the graphite adhered as expected.