Aurelia Laxdal wrote:

Started Ta#47 heating at Evap2 using the autoramp program. The TGHT current is setup to go to 300A (for now) and the TBHT to 230A (final value).

 Monday, March 14, 2016, 09:20

One thermocouple was not welded on correctly and is not working. 

Cooling evap2 back down, to remove target and re-weld thermocouple.

Once thermocouple replaced, will ramp back up and continue with tests/ conditioning of target.

Laura Lambert wrote:

Aurelia Laxdal wrote: Started Ta#47 heating at Evap2 using the autoramp program. The TGHT current is setup to go to 300A (for now) and the TBHT to 230A (final value).  Monday, March 14, 2016, 09:20 One thermocouple was not welded on correctly and is not working.  Cooling evap2 back down, to remove target and re-weld thermocouple. Once thermocouple replaced, will ramp back up and continue with tests/ conditioning of target.

 Monday, March 14, 2016, 13:12: Stopped turbo pump

Anders Mjos wrote:

Laura Lambert wrote: Aurelia Laxdal wrote: Started Ta#47 heating at Evap2 using the autoramp program. The TGHT current is setup to go to 300A (for now) and the TBHT to 230A (final value).  Monday, March 14, 2016, 09:20 One thermocouple was not welded on correctly and is not working.  Cooling evap2 back down, to remove target and re-weld thermocouple. Once thermocouple replaced, will ramp back up and continue with tests/ conditioning of target.    Monday, March 14, 2016, 13:12: Stopped turbo pump

 After EVAP2 was vented the thermocouple problem was fixed: it was the wire at on connector inside the box not making proper contact. The lid of the heat shield was also replaced since the one initially mounted had no holes, so one couldn't see the center block. Restarted pumping down at 4:30pm. Just started again the autoramp program: TGHT set to 300A (for the time being) and TBHT to 230A. Temperature measurements will resume tomorrow morning.

Aurelia Laxdal wrote:

Anders Mjos wrote: Laura Lambert wrote: Aurelia Laxdal wrote: Started Ta#47 heating at Evap2 using the autoramp program. The TGHT current is setup to go to 300A (for now) and the TBHT to 230A (final value).  Monday, March 14, 2016, 09:20 One thermocouple was not welded on correctly and is not working.  Cooling evap2 back down, to remove target and re-weld thermocouple. Once thermocouple replaced, will ramp back up and continue with tests/ conditioning of target.    Monday, March 14, 2016, 13:12: Stopped turbo pump  After EVAP2 was vented the thermocouple problem was fixed: it was the wire at on connector inside the box not making proper contact. The lid of the heat shield was also replaced since the one initially mounted had no holes, so one couldn't see the center block. Restarted pumping down at 4:30pm. Just started again the autoramp program: TGHT set to 300A (for the time being) and TBHT to 230A. Temperature measurements will resume tomorrow morning.

 Raised the TGHT at 620A. The TBHT was already set at 230A. The temperature is at 1902 deg C. As per John's instructions the target will condition at these setpoints over the week-end.

Aurelia Laxdal wrote:

Aurelia Laxdal wrote: Anders Mjos wrote: Laura Lambert wrote: Aurelia Laxdal wrote: Started Ta#47 heating at Evap2 using the autoramp program. The TGHT current is setup to go to 300A (for now) and the TBHT to 230A (final value).  Monday, March 14, 2016, 09:20 One thermocouple was not welded on correctly and is not working.  Cooling evap2 back down, to remove target and re-weld thermocouple. Once thermocouple replaced, will ramp back up and continue with tests/ conditioning of target.    Monday, March 14, 2016, 13:12: Stopped turbo pump  After EVAP2 was vented the thermocouple problem was fixed: it was the wire at on connector inside the box not making proper contact. The lid of the heat shield was also replaced since the one initially mounted had no holes, so one couldn't see the center block. Restarted pumping down at 4:30pm. Just started again the autoramp program: TGHT set to 300A (for the time being) and TBHT to 230A. Temperature measurements will resume tomorrow morning.  Raised the TGHT at 620A. The TBHT was already set at 230A. The temperature is at 1902 deg C. As per John's instructions the target will condition at these setpoints over the week-end.

Today, lowered the TGHT from 620A (at 1894 deg C) to 300A.  TBHT is still at 230A.

Aurelia Laxdal wrote:

Aurelia Laxdal wrote: Aurelia Laxdal wrote: Anders Mjos wrote: Laura Lambert wrote: Aurelia Laxdal wrote: Started Ta#47 heating at Evap2 using the autoramp program. The TGHT current is setup to go to 300A (for now) and the TBHT to 230A (final value).  Monday, March 14, 2016, 09:20 One thermocouple was not welded on correctly and is not working.  Cooling evap2 back down, to remove target and re-weld thermocouple. Once thermocouple replaced, will ramp back up and continue with tests/ conditioning of target.    Monday, March 14, 2016, 13:12: Stopped turbo pump  After EVAP2 was vented the thermocouple problem was fixed: it was the wire at on connector inside the box not making proper contact. The lid of the heat shield was also replaced since the one initially mounted had no holes, so one couldn't see the center block. Restarted pumping down at 4:30pm. Just started again the autoramp program: TGHT set to 300A (for the time being) and TBHT to 230A. Temperature measurements will resume tomorrow morning.  Raised the TGHT at 620A. The TBHT was already set at 230A. The temperature is at 1902 deg C. As per John's instructions the target will condition at these setpoints over the week-end. Today, lowered the TGHT from 620A (at 1894 deg C) to 300A.  TBHT is still at 230A.

 Cooling down the target.

 Wednesday, May 04, 2016, 13:28

Target boat has a layer of niobium foil on the bottom of the boat.

A niobium foil has been made with slots to hold samples [similar to when sintering endcaps] *See attached photos

Larger niobium samples are placed in the slots, holding in place, to avoid warping; smaller niobium sample sitting inside the boat by itself.

Smaller sample closest to OMEGA IR reading [right side]

Boat is wrapped with 1 large layer of Ta foil, wrapped around the boat 3x, careful to avoid touching samples.

Loaded into evap2 yesterday.

Vacuum pump bearings gone - pump replaced this morning by vacuum group.

Pumping down now...

 Friday, May 06, 2016, 13:36

HS water valves opened, no leaks detected.

Tapped up manually to 35A.

IGP1 = 2.4e-7 Torr

Setting auto-ramp rate at 0.2A/min to 250A over the weekend.

Will tap up manually monday to final desired temperature of 1400C.

 Monday, May 09, 2016, 09:38

OMEGA = 1128C

IGP1 = 1.3e-7 Torr

TGHT = 250A, 3.7V

Tapping up manually to 1400C...

 Monday, May 09, 2016, 14:05

Evap2 has reached ~1405C

TGHT = 341A, 5.34V

IGP1 = 1.9e-7 Torr

Will remain at max setpoints for min 4hrs then initiate cool down.

Laura Lambert wrote:

Wednesday, May 04, 2016, 13:28 Target boat has a layer of niobium foil on the bottom of the boat. A niobium foil has been made with slots to hold samples [similar to when sintering endcaps] *See attached photos Larger niobium samples are placed in the slots, holding in place, to avoid warping; smaller niobium sample sitting inside the boat by itself. Smaller sample closest to OMEGA IR reading [right side] Boat is wrapped with 1 large layer of Ta foil, wrapped around the boat 3x, careful to avoid touching samples. Loaded into evap2 yesterday. Vacuum pump bearings gone - pump replaced this morning by vacuum group. Pumping down now...  Friday, May 06, 2016, 13:36 HS water valves opened, no leaks detected. Tapped up manually to 35A. IGP1 = 2.4e-7 Torr Setting auto-ramp rate at 0.2A/min to 250A over the weekend. Will tap up manually monday to final desired temperature of 1400C.  Monday, May 09, 2016, 09:38 OMEGA = 1128C IGP1 = 1.3e-7 Torr TGHT = 250A, 3.7V Tapping up manually to 1400C...  Monday, May 09, 2016, 14:05 Evap2 has reached ~1405C TGHT = 341A, 5.34V IGP1 = 1.9e-7 Torr Will remain at max setpoints for min 4hrs then initiate cool down.

 Monday, May 09, 2016, 18:18

TGHT at 341A/5.34V for over 4 hours.  Vac stables at 1.78e-7 Torr.

Cooling down at 2A/min

The purpose of this experiment is to determined the limiting operating temperature for Beta-SiC.  To do so, samples will be heated in sequence to observe any volatile Si coated on the window.  The coating is observed above 1400C for the conventional SiC (mixuture of alpha and beta) and this coating leads to HV shorting problem. 

Thursday, May 19, 2016, 14:26

Beta-SiC (size ~1um) slurry was prepared and casted on a graphite foil. 

Discs are cut into D-shape

Average thickness (including graphite foil) = 0.349mm

Graphite foil = 0.13mm

Actual SiC thickness = 0.219mm (close to normal SiC thickness)

Samples are loaded into a target boat.

Total discs = 120

Total mass = 14.3507g

Thursday, May 19, 2016, 14:32

Omega slope set to = 1.04

Heat-treatment #1: 1400C

 Thursday, May 19, 2016, 17:04

TGHT ramping up to 250A at 0.5A/min

John Wong wrote:

The purpose of this experiment is to determined the limiting operating temperature for Beta-SiC.  To do so, samples will be heated in sequence to observe any volatile Si coated on the window.  The coating is observed above 1400C for the conventional SiC (mixuture of alpha and beta) and this coating leads to HV shorting problem.  Thursday, May 19, 2016, 14:26 Beta-SiC (size ~1um) slurry was prepared and casted on a graphite foil.  Discs are cut into D-shape Average thickness (including graphite foil) = 0.349mm Graphite foil = 0.13mm Actual SiC thickness = 0.219mm (close to normal SiC thickness) Samples are loaded into a target boat. Total discs = 120 Total mass = 14.3507g Thursday, May 19, 2016, 14:32 Omega slope set to = 1.04 Heat-treatment #1: 1400C  Thursday, May 19, 2016, 17:04 TGHT ramping up to 250A at 0.5A/min

 Friday, May 20, 2016, 08:53

IGP1 = 9.2e-6 Torr.

Increasing ramping rate to 1.0A/min up to 250A

 Friday, May 20, 2016, 09:17

IGP1 = 2.1e-5 Torr

TGHT = 215A, 3.1V

OMEGA = 1035C

Stopping auto-ramp and tapping up manually...

 Friday, May 20, 2016, 12:26

OMEGA slope changed to 1.04

OMEGA reached ~1430C and kept there for ~1hr.

no change. no coating on window observed

tapped up manually to OMEGA =1500C

TGHT = 350A, 5.8V

 Friday, May 20, 2016, 14:17

Not much change to window.

Might be beginning of light dusting, hard to tell.

Will be better observed after longer period of time at 1500C

Will remain at 1500C over weekend.

Laura Lambert wrote:

John Wong wrote: The purpose of this experiment is to determined the limiting operating temperature for Beta-SiC.  To do so, samples will be heated in sequence to observe any volatile Si coated on the window.  The coating is observed above 1400C for the conventional SiC (mixuture of alpha and beta) and this coating leads to HV shorting problem.  Thursday, May 19, 2016, 14:26 Beta-SiC (size ~1um) slurry was prepared and casted on a graphite foil.  Discs are cut into D-shape Average thickness (including graphite foil) = 0.349mm Graphite foil = 0.13mm Actual SiC thickness = 0.219mm (close to normal SiC thickness) Samples are loaded into a target boat. Total discs = 120 Total mass = 14.3507g Thursday, May 19, 2016, 14:32 Omega slope set to = 1.04 Heat-treatment #1: 1400C  Thursday, May 19, 2016, 17:04 TGHT ramping up to 250A at 0.5A/min    Friday, May 20, 2016, 08:53 IGP1 = 9.2e-6 Torr. Increasing ramping rate to 1.0A/min up to 250A  Friday, May 20, 2016, 09:17 IGP1 = 2.1e-5 Torr TGHT = 215A, 3.1V OMEGA = 1035C Stopping auto-ramp and tapping up manually...  Friday, May 20, 2016, 12:26 OMEGA slope changed to 1.04 OMEGA reached ~1430C and kept there for ~1hr. no change. no coating on window observed tapped up manually to OMEGA =1500C TGHT = 350A, 5.8V  Friday, May 20, 2016, 14:17 Not much change to window. Might be beginning of light dusting, hard to tell. Will be better observed after longer period of time at 1500C Will remain at 1500C over weekend.

 Tuesday, May 24, 2016, 11:15

Sample has been heated over the long weekend.  Temp dropped to 1400C.  TGHT at 350A/5.78V.  Vac at 1.5e-7 Torr.

It is hard to tell if there is any coating on the window.  Will increase temperature to 1800C

 Tuesday, May 24, 2016, 11:43

Temp at 1620C. TGHT at 440A/7.7V. 

At this temperature, the coating would have been seen for the conventional SiC target material.  But, no much of change on the window since the TGHT was tapped up from 1400C.

Continue to increase TGHT to reach 1800C

 Tuesday, May 24, 2016, 11:58

Temp at 1680C/TGHT 470A/8.4C - a very light film on the window was observed.  Not sure if this film was left from previous processes; it is just that the target container is getting very bright and hard to see.

 Tuesday, May 24, 2016, 12:15

TGHT at 510A/9.16V - Observed coating on window.  Omega got interfered, therefore temp is unknown.  But it was read at ~1720C before the window was getting coated and temp started to dropped.

Will leave at this stage for now...

 Tuesday, May 24, 2016, 16:57

Window is fully coated.  Based on the heating curve, at 500A, the temp should be at ~1900C (wrapped with a layer of heat shield).  Temperature reader dropped to1340C due to the coating interference. 

Cooling down TGHT at 2A/min. And will exam the materials tomorrow... 

 Wednesday, May 25, 2016, 11:37

Container coated with TaC using 'flushing technique' [cleaned ionizer tube with acetone, so no coating inside ionizer tube]

Wrapped with 2 x Ta heat shields - one full height of Ta foil wrapped around cooling fins twice

Currently pumping down in evap2

 Thursday, May 26, 2016, 09:28

Tapped up manually to 40A

IGP1 = 6.6e-7 Torr

Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively.

Final setpoints for TGHT = 650A and TBHT = 230A

Once max setpoints reached will continue to tap up manually while monitoring temperature to 1900C

 Thursday, June 09, 2016, 15:39

First target using beta-SiC material!

Target container contains 450 discs of SiC [4 x 5 packs + 430 single discs]

Target packed length = 16cm. 

Mass of 533 discs SiC(green)  = 53.8758g

Container is wrapped with 3 heatshields; no end caps are inserted yet - coated spring inserted both sides to hold discs in place.

Sintering temp = 1800C, TGHT will be set accordingly.  TBHT max at 230A. 

Chamber is currently being pumped down. 

Friday, June 10, 2016, 13:24

HS water valves opened, no leaks detected.

Tapping up manually to 70A...

Auto ramp will be set for TGHT = 0.2A/min to a final setpoint of 520A

Auto-ramp for TBHT = 0.1A/min to a final setpoint of 230A.

 Friday, June 10, 2016, 16:27

TGHT stepped up to 70A/0.55V.  TGHT at 50A/0.62V. 

Pressure stabilized at 5.5e-5 Torr.

Initiated auto ramping.  TGHT at 0.2A/min --> 520A.  TBHT at 0.1A/min --> 230A.

John Wong wrote:

Laura Lambert wrote:  Thursday, June 09, 2016, 15:39 First target using beta-SiC material! Target container contains 450 discs of SiC [4 x 5 packs + 430 single discs] Target packed length = 16cm.  Mass of 533 discs SiC(green)  = 53.8758g Container is wrapped with 3 heatshields; no end caps are inserted yet - coated spring inserted both sides to hold discs in place. Sintering temp = 1800C, TGHT will be set accordingly.  TBHT max at 230A.  Chamber is currently being pumped down.  Friday, June 10, 2016, 13:24 HS water valves opened, no leaks detected. Tapping up manually to 70A... Auto ramp will be set for TGHT = 0.2A/min to a final setpoint of 520A Auto-ramp for TBHT = 0.1A/min to a final setpoint of 230A.      Friday, June 10, 2016, 16:27 TGHT stepped up to 70A/0.55V.  TGHT at 50A/0.62V.  Pressure stabilized at 5.5e-5 Torr. Initiated auto ramping.  TGHT at 0.2A/min --> 520A.  TBHT at 0.1A/min --> 230A.

 Monday, June 13, 2016, 09:51

TGHT = 425A, 5.65V

TBHT = 225A, 3.7V

IGP1 = 8.7e-6 Torr.

Increasing ramping rate to 1.0A/min...

 Monday, June 13, 2016, 15:56

Tapped up manually from 520A to 1800C

Extrapolated data on graph to determine correct current required to reach desired max temperature.

Will remain at 1800C for ~48hrs

See attachements for excel sheet and screenshot of striptool.

Laura Lambert wrote:

John Wong wrote:   Laura Lambert wrote:  Thursday, June 09, 2016, 15:39 First target using beta-SiC material! Target container contains 450 discs of SiC [4 x 5 packs + 430 single discs] Target packed length = 16cm.  Mass of 533 discs SiC(green)  = 53.8758g Container is wrapped with 3 heatshields; no end caps are inserted yet - coated spring inserted both sides to hold discs in place. Sintering temp = 1800C, TGHT will be set accordingly.  TBHT max at 230A.  Chamber is currently being pumped down.  Friday, June 10, 2016, 13:24 HS water valves opened, no leaks detected. Tapping up manually to 70A... Auto ramp will be set for TGHT = 0.2A/min to a final setpoint of 520A Auto-ramp for TBHT = 0.1A/min to a final setpoint of 230A.      Friday, June 10, 2016, 16:27 TGHT stepped up to 70A/0.55V.  TGHT at 50A/0.62V.  Pressure stabilized at 5.5e-5 Torr. Initiated auto ramping.  TGHT at 0.2A/min --> 520A.  TBHT at 0.1A/min --> 230A.    Monday, June 13, 2016, 09:51 TGHT = 425A, 5.65V TBHT = 225A, 3.7V IGP1 = 8.7e-6 Torr. Increasing ramping rate to 1.0A/min...  Monday, June 13, 2016, 15:56 Tapped up manually from 520A to 1800C Extrapolated data on graph to determine correct current required to reach desired max temperature. Will remain at 1800C for ~48hrs See attachements for excel sheet and screenshot of striptool.

 Wednesday, June 15, 2016, 17:54

TGHT at 710A, 11.35V.  TBHT at 230A/3.86V. 

Omega reading droppd to 1130C due to coating on windows. 

Ionizer tube was measured (center) at around 1900C

Cooling down at 2A/min for TGHT, 1A/min for TBHT. 

Samples will be collected prior to cleaning the windows.

NEXT:  Conditioning.

 Wednesday, August 17, 2016, 17:30

Container coated with TaC using 'flushing technique', cleaned ionizer tube with acetone, so no coating inside ionizer tube

Wrapped with 3 x Ta heat shields, incl center block

Currently pumping down in evap2

Thursday, August 18, 2016, 10:14 

HS water valves opened...leak detected  see attachment for photo from archives

Vented and opened up.

Anders performed leak check, nothing found.

Replaced all seals with blue seals.

Pumping down now

 Thursday, August 18, 2016, 16:12

HS water valves opened...leak detected again  see attachment for photo of striptool

Vented and opened up.

working with Anders on finding leak...

 Monday, August 22, 2016, 10:38

leaks FIXED!

HS water valves opened, NO leaks detected!

Tapped up manually to 70A

Vacuum stable, IGP1 = 2.5e-6 Torr

Initiating auto ramp for TGHT @ 0.2A/min to a max setpoint of 350A

Initiating auto ramp for TBHT @ 0.1A/min to a max setpoint of 230A

Once max setpoints achieved, will tap up manually to final desired temperature of 1900C

 Monday, August 22, 2016, 14:58

TGHT = 115A, 1.3V

TBHT = 89A, 0.97V

IGP1 = 4.1e-7 Torr.

Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.

 Monday, August 22, 2016, 16:01

IGP1 = 1.25e-6 torr

TGHT = 174A, 2.2V

TBHT = 118A, 1.4V

Lowering ramping rate to 0.2A/min and 0.1A/min for the TGHT and TBHT respectively for overnight ramping.

 Wednesday, September 07, 2016, 14:45

Container was previously coated with TaC solution and wrapped with 1-full length layer of Ta- heat shield around the fins.  

Chamber is being pumped down.  Vac at 5.6e-7 Torr before HS water valves were open; no leaks were detected. 

Sintering Temperature 1900C (Omega slope @ 0.98); expected TGHT ~765A/11.90V, TGHT max at 230A.

 Thursday, September 08, 2016, 18:14

At about 1600C, it was observed that the coating inside the tube seems to chip off (see attachment 1).

TGHT was ramped up to 745A/11.85V and TBHT to 230A/3.25V.  Temperature measured on OMEGA/Mikron = 1914C/1881C; both instruments slopes set at 0.98.

Will remain at this TGHT current over night

Vac at 3.0e-6 Torr and coming down.

Friday, September 09, 2016, 11:01 

Target has been heated at the stable temperature at 1914C (for OMEGA) and 1881C (for Mikron) with current at 745A/11.94V (see attachment 2) for almost 19 hours. 

No fluctuation in p/s current or temperature was observed.  The ramping up process is captured and can be view from the link below:

https://www.dropbox.com/sh/9lgtin54o17ds6j/AABn1-XjvK44mm74TjqTAmvta?dl=0

Pressure at 1.07e-6 Torr. 

Cooling down TGHT at 2A/min and TBHT at 1A/min. 

Continue to capture the cooling down process. 

 Friday, September 09, 2016, 15:17

 While the target container was cooling down, the chip-like particle began obvious (see attachment 3).  

Will inspect the container.. TGHT currently at 260A.

 Thursday, September 15, 2016, 16:23

Target container contains 487 discs of SiC 

Target packed length = 16cm. 

Mass of SiC(green)  = 58.8795g

Container is wrapped with 1x heatshield around each side of cooling fins; no end caps are inserted yet - coated spring inserted both sides to hold discs in place.

Sintering temp = 1800C

Chamber is currently being pumped down. 

 Friday, September 16, 2016, 10:50

Tapped up manually to 50A

Waited ~1hr , vacuum stable.

IGP1 = 1.24e-5 Torr

Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively.

TGHT max = 500A.  TBHT max at 230A. 

Slope on OMEGA = 1.15

 Monday, September 19, 2016, 10:53

OMEGA = 1230C

TGHT = 360A, 4.75V

TBHT = 204A, 2.68V

IGP1 = 5.3e-6 Torr

Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.

 Monday, September 19, 2016, 11:57

OMEGA = ~1300C

TBHT = 230A, 3.16V

TGHT = 409A, 5.55V

Lowering ramping rate to 0.2A/min while vaccum high

IGP1 = 3.05e-5 Torr

 Monday, September 19, 2016, 13:22

OMEGA = 1350C

TGHT = 425A, 5.82V

IGP1 = 1.97e-5 Torr

Stepping ramping rate back up to 1.0A/min

Laura Lambert wrote:

Thursday, September 15, 2016, 16:23 Target container contains 487 discs of SiC  Target packed length = 16cm.  Mass of SiC(green)  = 58.8795g Container is wrapped with 1x heatshield around each side of cooling fins; no end caps are inserted yet - coated spring inserted both sides to hold discs in place. Sintering temp = 1800C Chamber is currently being pumped down.   Friday, September 16, 2016, 10:50 Tapped up manually to 50A Waited ~1hr , vacuum stable. IGP1 = 1.24e-5 Torr Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. TGHT max = 500A.  TBHT max at 230A.  Slope on OMEGA = 1.15  Monday, September 19, 2016, 10:53 OMEGA = 1230C TGHT = 360A, 4.75V TBHT = 204A, 2.68V IGP1 = 5.3e-6 Torr Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.  Monday, September 19, 2016, 11:57 OMEGA = ~1300C TBHT = 230A, 3.16V TGHT = 409A, 5.55V Lowering ramping rate to 0.2A/min while vaccum high IGP1 = 3.05e-5 Torr  Monday, September 19, 2016, 13:22 OMEGA = 1350C TGHT = 425A, 5.82V IGP1 = 1.97e-5 Torr Stepping ramping rate back up to 1.0A/min

 Monday, September 19, 2016, 18:24

Measuring the temperature on the SiC is difficult due to the changing in emissivity as the temperature goes up.  So, I will use the MIKRON to measure the temperature on the Ta surface near the end of the tube and OMEGA for measuring the inside.  

Using the analogue pyrometer, the temperature on the Ta surface at the end of the tube was measured at around ~1450C; this temperature match the temperature on the Mikron at slope 0.98 (as usual).  To match it with OMEGA, I changed the slope to 1.04 since this measurement is taking readings on the  inside of the tube and on the SiC material.   

Note:  The measurements are NOT the absolute temperature.  These are relative temperature measurements  which give some guideline where the target current should be at for the sintering process.  Please plot the temp vs current as the TGHT is being ramped up.  At some point, the windows will get coated and the measurement is no longer reliable.   The plot will be used to give an estimation of the current for 1800C.