Laura Lambert wrote:

John Wong wrote: Tuesday, September 01, 2015, 17:16 Target container contains 533 discs of SiC with packed length of 17cm.  Mass of 533 discs SiC(green)  = 57.8979g Total mass SiC(green) + target container = 1455g Container is wrapped with 3 heatshields; no end caps are inserted yet. Sintering temp at 1800C - TGHT will be set accordingly.  TBHT max at 230A.  Chamber is currently being pumped down.     Wednesday, September 02, 2015, 09:11 HS water valves opened, no leaks detected. IGP1 = 1.15e-6 Torr Tapped up manually to 40A. Waited ~1hr40 for vacuum to stabilize. IGP1 = 3.6e-6 Torr. Max setpoints set to TGHT = 630A and TBHT = 230A, ~1400C Initiating auto ramp at a rate of 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. Once max setpoints achieved, will tap up manually until window port becomes coated [as previously observed] Once window port becomes coated will leave at set temp for ~4hrs to continue with outgassing, then cool down, clean window and ramp back up. If LS port still clean, will continue to ramp up to final desired temperature of 1800C.  Wednesday, September 02, 2015, 14:23 IGP1 = 4.0e-5 Torr. Vacuum too high, stopped auto-ramp and tapped down manually. Dropped TGHT down from 80A to 50A Dropped TBHT down from 55A to 50A Wednesday, September 02, 2015, 15:29 Vacuum down to IGP1 = 1.2e-5 Torr. Re-initiating auto-ramp...  Tuesday, September 08, 2015, 10:04 IGP1 = 4.5e-7 Torr. TGHT = 630A, 9.6V TBHT = 230A, 3.2V DV = 0.22V OMEGA RS = 1476C OMEGA LS = 1450C see attached photo for screenshot. will tap up manually with a visual on both window ports...

 Tuesday, September 08, 2015, 15:44

TGHT has stepped up to 820A.  Coating on both windows is becoming obvious and it's interfering the temp readers; however, the left window (see attachment, which is further away from the target) is lightly coated than the right.  See attachment for The Temp (and Power) vs current plots.

Target will remained heated at the current and will be cooled down later today. 

The target will be re-conditioned up to 820A and temp and mass will be re-measured.

Plans:

The chamber will be vented tomorrow and the target will be taken out to weigh for mass change. 

The chamber windows will need to be clean.

A piece of Ta foil will be cover in front of the ionizer to trap any loss material (if any).

 Tuesday, September 08, 2015, 17:37

TGHT was at 800A for 2 hours before ramping up 820A for another 2 hours heating.  More coating on the right window is observed and temp reading came down to 1340C.  The left window remains the same and temp reads at 1646C.  

Ramping TGHT/TBHT to 0A at 2A/min and 1A/min, respectively.  

 Wednesday, September 09, 2015, 12:27

Result after the sintering process:

No yellow crystal formed (compared to previously observed SiC targets that heated up above 1900C). 

Total green mass = 57.90g 

mass of graphite foil = 0.035g x 533 discs = 18.7g 

mass of green SiC = 39.30g 

Target container with SiC before sintered = 1455g 

Target container after sintered = 1450g 

mass loss ~ 5.0g ~ 13% organic mass, as expected!  

The target will undergo the re-condition stage, and the temperature will be measured from 600A to 820A. 

John Wong wrote:

Laura Lambert wrote: John Wong wrote: Tuesday, September 01, 2015, 17:16 Target container contains 533 discs of SiC with packed length of 17cm.  Mass of 533 discs SiC(green)  = 57.8979g Total mass SiC(green) + target container = 1455g Container is wrapped with 3 heatshields; no end caps are inserted yet. Sintering temp at 1800C - TGHT will be set accordingly.  TBHT max at 230A.  Chamber is currently being pumped down.     Wednesday, September 02, 2015, 09:11 HS water valves opened, no leaks detected. IGP1 = 1.15e-6 Torr Tapped up manually to 40A. Waited ~1hr40 for vacuum to stabilize. IGP1 = 3.6e-6 Torr. Max setpoints set to TGHT = 630A and TBHT = 230A, ~1400C Initiating auto ramp at a rate of 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. Once max setpoints achieved, will tap up manually until window port becomes coated [as previously observed] Once window port becomes coated will leave at set temp for ~4hrs to continue with outgassing, then cool down, clean window and ramp back up. If LS port still clean, will continue to ramp up to final desired temperature of 1800C.  Wednesday, September 02, 2015, 14:23 IGP1 = 4.0e-5 Torr. Vacuum too high, stopped auto-ramp and tapped down manually. Dropped TGHT down from 80A to 50A Dropped TBHT down from 55A to 50A Wednesday, September 02, 2015, 15:29 Vacuum down to IGP1 = 1.2e-5 Torr. Re-initiating auto-ramp...  Tuesday, September 08, 2015, 10:04 IGP1 = 4.5e-7 Torr. TGHT = 630A, 9.6V TBHT = 230A, 3.2V DV = 0.22V OMEGA RS = 1476C OMEGA LS = 1450C see attached photo for screenshot. will tap up manually with a visual on both window ports...    Tuesday, September 08, 2015, 15:44 TGHT has stepped up to 820A.  Coating on both windows is becoming obvious and it's interfering the temp readers; however, the left window (see attachment, which is further away from the target) is lightly coated than the right.  See attachment for The Temp (and Power) vs current plots. Target will remained heated at the current and will be cooled down later today.    The target will be re-conditioned up to 820A and temp and mass will be re-measured. Plans: The chamber will be vented tomorrow and the target will be taken out to weigh for mass change.  The chamber windows will need to be clean. A piece of Ta foil will be cover in front of the ionizer to trap any loss material (if any).  Tuesday, September 08, 2015, 17:37 TGHT was at 800A for 2 hours before ramping up 820A for another 2 hours heating.  More coating on the right window is observed and temp reading came down to 1340C.  The left window remains the same and temp reads at 1646C.   Ramping TGHT/TBHT to 0A at 2A/min and 1A/min, respectively.    Wednesday, September 09, 2015, 12:27 Result after the sintering process: No yellow crystal formed (compared to previously observed SiC targets that heated up above 1900C).  Total green mass = 57.90g  mass of graphite foil = 0.035g x 533 discs = 18.7g  mass of green SiC = 39.30g  Target container with SiC before sintered = 1455g  Target container after sintered = 1450g  mass loss ~ 5.0g ~ 13% organic mass, as expected!   The target will undergo the re-condition stage, and the temperature will be measured from 600A to 820A.

 Wednesday, September 09, 2015, 17:39

Both end-caps are inserted onto the targets.  The total mass (Target, Sintered SiC, end caps, 4x 19"round graphite foils) = 1453g.

Target is wrapped with 3 layers of heat shields.  

The extraction electrode is wrapped with Ta-foil (see attachment).  This is to trap any lose particle, if any.  

Chamber is currently being pumped down, currently at 1.2e-5 Torr.  

John Wong wrote:

John Wong wrote: Laura Lambert wrote: John Wong wrote: Tuesday, September 01, 2015, 17:16 Target container contains 533 discs of SiC with packed length of 17cm.  Mass of 533 discs SiC(green)  = 57.8979g Total mass SiC(green) + target container = 1455g Container is wrapped with 3 heatshields; no end caps are inserted yet. Sintering temp at 1800C - TGHT will be set accordingly.  TBHT max at 230A.  Chamber is currently being pumped down.     Wednesday, September 02, 2015, 09:11 HS water valves opened, no leaks detected. IGP1 = 1.15e-6 Torr Tapped up manually to 40A. Waited ~1hr40 for vacuum to stabilize. IGP1 = 3.6e-6 Torr. Max setpoints set to TGHT = 630A and TBHT = 230A, ~1400C Initiating auto ramp at a rate of 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. Once max setpoints achieved, will tap up manually until window port becomes coated [as previously observed] Once window port becomes coated will leave at set temp for ~4hrs to continue with outgassing, then cool down, clean window and ramp back up. If LS port still clean, will continue to ramp up to final desired temperature of 1800C.  Wednesday, September 02, 2015, 14:23 IGP1 = 4.0e-5 Torr. Vacuum too high, stopped auto-ramp and tapped down manually. Dropped TGHT down from 80A to 50A Dropped TBHT down from 55A to 50A Wednesday, September 02, 2015, 15:29 Vacuum down to IGP1 = 1.2e-5 Torr. Re-initiating auto-ramp...  Tuesday, September 08, 2015, 10:04 IGP1 = 4.5e-7 Torr. TGHT = 630A, 9.6V TBHT = 230A, 3.2V DV = 0.22V OMEGA RS = 1476C OMEGA LS = 1450C see attached photo for screenshot. will tap up manually with a visual on both window ports...    Tuesday, September 08, 2015, 15:44 TGHT has stepped up to 820A.  Coating on both windows is becoming obvious and it's interfering the temp readers; however, the left window (see attachment, which is further away from the target) is lightly coated than the right.  See attachment for The Temp (and Power) vs current plots. Target will remained heated at the current and will be cooled down later today.    The target will be re-conditioned up to 820A and temp and mass will be re-measured. Plans: The chamber will be vented tomorrow and the target will be taken out to weigh for mass change.  The chamber windows will need to be clean. A piece of Ta foil will be cover in front of the ionizer to trap any loss material (if any).  Tuesday, September 08, 2015, 17:37 TGHT was at 800A for 2 hours before ramping up 820A for another 2 hours heating.  More coating on the right window is observed and temp reading came down to 1340C.  The left window remains the same and temp reads at 1646C.   Ramping TGHT/TBHT to 0A at 2A/min and 1A/min, respectively.    Wednesday, September 09, 2015, 12:27 Result after the sintering process: No yellow crystal formed (compared to previously observed SiC targets that heated up above 1900C).  Total green mass = 57.90g  mass of graphite foil = 0.035g x 533 discs = 18.7g  mass of green SiC = 39.30g  Target container with SiC before sintered = 1455g  Target container after sintered = 1450g  mass loss ~ 5.0g ~ 13% organic mass, as expected!   The target will undergo the re-condition stage, and the temperature will be measured from 600A to 820A.     Wednesday, September 09, 2015, 17:39 Both end-caps are inserted onto the targets.  The total mass (Target, Sintered SiC, end caps, 4x 19"round graphite foils) = 1453g. Target is wrapped with 3 layers of heat shields.   The extraction electrode is wrapped with Ta-foil (see attachment).  This is to trap any lose particle, if any.   Chamber is currently being pumped down, currently at 1.2e-5 Torr.

 Thursday, September 10, 2015, 09:55

HS water valves opened this morning, no leaks detected.

TGHT and TBHT tapped up manually to 35A.

IGP1 = 4.4e-7 Torr, vacuum stable.

Initiating auto-ramp at 1.0A/min and 0.5A/min for the TGHT and TBHT respectively with final setpoints of 600A and 230A.

Laura Lambert wrote:

John Wong wrote: John Wong wrote: Laura Lambert wrote: John Wong wrote: Tuesday, September 01, 2015, 17:16 Target container contains 533 discs of SiC with packed length of 17cm.  Mass of 533 discs SiC(green)  = 57.8979g Total mass SiC(green) + target container = 1455g Container is wrapped with 3 heatshields; no end caps are inserted yet. Sintering temp at 1800C - TGHT will be set accordingly.  TBHT max at 230A.  Chamber is currently being pumped down.     Wednesday, September 02, 2015, 09:11 HS water valves opened, no leaks detected. IGP1 = 1.15e-6 Torr Tapped up manually to 40A. Waited ~1hr40 for vacuum to stabilize. IGP1 = 3.6e-6 Torr. Max setpoints set to TGHT = 630A and TBHT = 230A, ~1400C Initiating auto ramp at a rate of 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. Once max setpoints achieved, will tap up manually until window port becomes coated [as previously observed] Once window port becomes coated will leave at set temp for ~4hrs to continue with outgassing, then cool down, clean window and ramp back up. If LS port still clean, will continue to ramp up to final desired temperature of 1800C.  Wednesday, September 02, 2015, 14:23 IGP1 = 4.0e-5 Torr. Vacuum too high, stopped auto-ramp and tapped down manually. Dropped TGHT down from 80A to 50A Dropped TBHT down from 55A to 50A Wednesday, September 02, 2015, 15:29 Vacuum down to IGP1 = 1.2e-5 Torr. Re-initiating auto-ramp...  Tuesday, September 08, 2015, 10:04 IGP1 = 4.5e-7 Torr. TGHT = 630A, 9.6V TBHT = 230A, 3.2V DV = 0.22V OMEGA RS = 1476C OMEGA LS = 1450C see attached photo for screenshot. will tap up manually with a visual on both window ports...    Tuesday, September 08, 2015, 15:44 TGHT has stepped up to 820A.  Coating on both windows is becoming obvious and it's interfering the temp readers; however, the left window (see attachment, which is further away from the target) is lightly coated than the right.  See attachment for The Temp (and Power) vs current plots. Target will remained heated at the current and will be cooled down later today.    The target will be re-conditioned up to 820A and temp and mass will be re-measured. Plans: The chamber will be vented tomorrow and the target will be taken out to weigh for mass change.  The chamber windows will need to be clean. A piece of Ta foil will be cover in front of the ionizer to trap any loss material (if any).  Tuesday, September 08, 2015, 17:37 TGHT was at 800A for 2 hours before ramping up 820A for another 2 hours heating.  More coating on the right window is observed and temp reading came down to 1340C.  The left window remains the same and temp reads at 1646C.   Ramping TGHT/TBHT to 0A at 2A/min and 1A/min, respectively.    Wednesday, September 09, 2015, 12:27 Result after the sintering process: No yellow crystal formed (compared to previously observed SiC targets that heated up above 1900C).  Total green mass = 57.90g  mass of graphite foil = 0.035g x 533 discs = 18.7g  mass of green SiC = 39.30g  Target container with SiC before sintered = 1455g  Target container after sintered = 1450g  mass loss ~ 5.0g ~ 13% organic mass, as expected!   The target will undergo the re-condition stage, and the temperature will be measured from 600A to 820A.     Wednesday, September 09, 2015, 17:39 Both end-caps are inserted onto the targets.  The total mass (Target, Sintered SiC, end caps, 4x 19"round graphite foils) = 1453g. Target is wrapped with 3 layers of heat shields.   The extraction electrode is wrapped with Ta-foil (see attachment).  This is to trap any lose particle, if any.   Chamber is currently being pumped down, currently at 1.2e-5 Torr.      Thursday, September 10, 2015, 09:55 HS water valves opened this morning, no leaks detected. TGHT and TBHT tapped up manually to 35A. IGP1 = 4.4e-7 Torr, vacuum stable. Initiating auto-ramp at 1.0A/min and 0.5A/min for the TGHT and TBHT respectively with final setpoints of 600A and 230A.

Thursday, September 10, 2015, 12:05  

Changed TGHT to 2A/min and TGHT remains at 1A/min.  Vacuum is table at 1.0e-6 Torr. 

Friday, September 11, 2015, 11:34  

TGHT was at 600A for almost 20 hours.  Vac at 5.2 e-7 Torr.   L-temp at 1490C, R-temp at 1685 (odd?).   Using pyrometer to measure - Right end does seem brighter than the L end.  

Continue to ramp up TGHT.  Date is collected, will be posted later.  

 Friday, September 11, 2015, 11:53

L/R-temp measurements just don't seem normal.  

Ramped up to 220A- temp reads L = 1522C, R = 1722C.  

Ramping down TBHT doesn't change the temp.  

Will cool TGHT/TBHT to 0A at 2A/min & 1A/min, respectively.  

Will vent the chamber on Monday and inspect for any wrong.

 Monday, September 14, 2015, 12:13

The target has taken out for inspection.  No visible damage/problem was observed.  The Ta-foil for loss particle capture only showed some heat marking but no material was trapped. 

Target was weighted, no mass loss was observed.

Try expending the end caps to get a good thermal conductivity and will re-conditiong again.  

 Tuesday, September 15, 2015, 12:31

The end caps have been expended. 

New Ta foils are used for the heat shields.  The foils are cut in 3 1/4" x 12" and wrapped around the target.  (see attachment).  This is to see if the heat is evenly distributed.  

Both omega optical lens are aligned properly.  

Target is installed but the chamber is NOT yet being pumped down.  Awaiting for the fume hood work in B2 level to be complete before the evaporator can be started. 

 Wednesday, September 16, 2015, 17:57

The work in the B2 level is done; the nuclear ventilation for the evaporators is now operational. 

Chamber is currently being pumped down.

 Thursday, September 17, 2015, 12:19

Chamber has been pump down overnight and pressure is currently at 5.8e-7 Torr.

HS valves are opened and no leaks are detected.

Ramping up TGHT/TBHT to 600A at 2A/min and 230A at 1A/min, respectively.

 Thursday, September 17, 2015, 17:58

TGHT has reached to 600A/9.14V.  Both the L and R temperatures are measured at 1710C and 1760C, respectively.  At 600A, the temperature now is about 300C higher compared to that during the sintering process. 

The difference in the temperature could be from Ta surface vs SiC surface.  (But the 2-color IR temp reader shouldn't matter what color it's measuring?!! I don't know!)

Note: 

Both temperature readings are fairly close.  Could this be improved from the new Ta-foils?  Possible!

It is still unclear what is the absolute temperature.  A more systematic student needs to be done. 

Using a thermocouple couple to measurement the endcaps at 600A and compared with the Omage reader may help to understand more. 

After discussing with Friedhelm, it is decided to stay the target at 600A for the conditioning process. 

 Friday, September 18, 2015, 09:10

Target has been heated at 600A at stable temperature at 1716C (LS) and 1769C (RS), see attachment. 

 Friday, September 18, 2015, 11:45

Initiated cooling down at 2A/min for TGHT, and 1A/min TBHT. 

Currently vac at 5.48e-7 Torr.

 Thursday, September 24, 2015, 11:31

Target was inspected after the 2nd conditioning, up to 1700C at 600A for overnight. 

No solid particle was observed that might have extracted from the ionizer tube.  

The heat shields have been removed and the target is ready for assembly. 

Monday, November 23, 2015, 14:29

No heat shields.

Container empty.

Loaded into evap2 and currently pumping down.

 Tuesday, November 24, 2015, 09:36

HS water valves opened this morning, no leaks detected.

IGP1 = 4.5e-7 Torr.

Changed slope of OMEGA IR to 0.98 for empty container.

Tapped up manually to 35A.

IGP1 = 4.7e-7 Torr.

Vacuum stable, initiating auto-ramp at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.

Final setpoints: TBHT = 230A, TGHT = 300A

Will tap up manually to 2000C

 Tuesday, November 24, 2015, 14:00

TGHT = 300A, 3.75V

TBHT = 230A, 3.08V

IGP1 = 4.7e-7 Torr

No reading yet on the OMEGA.

Re-initiating auto-ramp to final setpoint TGHT = 450A

 Wednesday, November 25, 2015, 09:11

IGP1 = 3.0e-7Torr.

TGHT = 450A, 6.37V

Tapping up manually to 2000C

 Wednesday, November 25, 2015, 15:31

container was tapped up manually to 650A, slope/emissivity settings were checked.

ramped back down to 450A and tapped up manually while recording data up to 1800C [legs = 2000C]

once reached 1800C, tapped TBHT down manually to see relation of TBHT to temperature/ TGHT

remained at 1800C for ~1hr [while tapping down TBHT] before initiating auto-cool at 2.0A/min for the TGHT

see attachment for raw data.

 Thursday, November 26, 2015, 10:08

Vented in air and took out this morning.

 Monday, November 30, 2015, 15:37

No heat shields.

Container empty.

Loaded into evap2 and currently pumping down.

Tuesday, December 01, 2015, 10:07 

HS water valves opened this morning, no leaks detected.

IGP1 = 4.3e-7 Torr.

Slope of OMEGA = 0.98

Tapped up manually to 35A.

Vacuum stable, initiating auto-ramp at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.

Final setpoints: TBHT = 90A, TGHT = 360A

Once final setpoints reached, will tap up manually to max 1800C [legs = 2000C]

 Monday, December 07, 2015, 09:06

Container was tapped up manually with emissivity measurements taken every 50A starting at 360A.

The final measurement was taken at 640A.

Container was ramped down for the weekend.

See attachment for raw data.

 Monday, December 07, 2015, 09:04

No heat shields.

Container empty.

IGP1 = 1.1e-7 Torr.

Slope of OMEGA = 0.98

Tapped up manually to 35A.

Vacuum stable, initiating auto-ramp at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.

Final setpoints: TBHT = 90A, TGHT = 360A

Will tap up with the same parameters as last round to confirm results.

 Friday, December 11, 2015, 11:44

Took out of evap2 yesterday.

Aurelia took many emissivity measurements to compare with previous data - which matched up.

The dip in emissivity before going up again around ~560A could be due to oxidation of the materials.

 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.  

John Wong wrote:

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.

 Tuesday, September 20, 2016, 15:18

there was a temperature fluctuation resulting in the MIKRON no longer matching the readout on the OMEGA

this prompted another change in the slope on the OMEGA to 1.08

TGHT was then tapped up manually to 600A/ 1800C

will remain at this max setpoint for a few days before ramping down

see attachment for raw data

 Wednesday, September 21, 2016, 11:34

temperatures dropped a small amount overnight.

tapped up manually to 625A/ 1810C

still no coating on window.

see attachment for updated raw data

Laura Lambert wrote:

John Wong wrote: 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.        Tuesday, September 20, 2016, 15:18 there was a temperature fluctuation resulting in the MIKRON no longer matching the readout on the OMEGA this prompted another change in the slope on the OMEGA to 1.08 TGHT was then tapped up manually to 600A/ 1800C will remain at this max setpoint for a few days before ramping down see attachment for raw data  Wednesday, September 21, 2016, 11:34 temperatures dropped a small amount overnight. tapped up manually to 625A/ 1810C still no coating on window. see attachment for updated raw data

 Thursday, September 22, 2016, 12:07

Temperature reader on OMEGA dropped slightly to 1785C overnight.  The temperature on the leg remained at 1800C (MIKRON).  No coating on windows.  

Increased TGHT to 635A/10.12V (local 10.40V).  OMEGA reads 1800C, MIKRON ~1817C.  

Continue to monitor… (see dropbox for captured photos) 

John Wong wrote:

Laura Lambert wrote: John Wong wrote: 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.        Tuesday, September 20, 2016, 15:18 there was a temperature fluctuation resulting in the MIKRON no longer matching the readout on the OMEGA this prompted another change in the slope on the OMEGA to 1.08 TGHT was then tapped up manually to 600A/ 1800C will remain at this max setpoint for a few days before ramping down see attachment for raw data  Wednesday, September 21, 2016, 11:34 temperatures dropped a small amount overnight. tapped up manually to 625A/ 1810C still no coating on window. see attachment for updated raw data    Thursday, September 22, 2016, 12:07 Temperature reader on OMEGA dropped slightly to 1785C overnight.  The temperature on the leg remained at 1800C (MIKRON).  No coating on windows.   Increased TGHT to 635A/10.12V (local 10.40V).  OMEGA reads 1800C, MIKRON ~1817C.   Continue to monitor… (see dropbox for captured photos)

 Monday, September 26, 2016, 13:24

Temperature decreased over weekend.

MIKRON dropped from ~1800C to ~1670C, OMEGA on right side remained ~1800C

Comparing screen shots of temperature readings and camera looking at target from left side, changes can be seen:

-darker area on top edge of target tube, above inside tube, grows larger when temperature drops - indicating 'cooler area' has grown

-initially darker area covers top above target materials on tube, when drops to ~1670C darker area extends down sides of target tube and reaches past target material area

See attached picture showing these details

Target has remained at this max setpoint for ~4-5 days

Windows remain un-coated.

Current and voltage readings remain un-changed.

Initiating auto-cool at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.

 Wednesday, September 28, 2016, 17:05

Vented in air, target taken out today.

Target looks good!

A small amount of material was removed from the windows in evap2, very thin layer of coating.

Will update tomorrow with photos

Endcaps inserted.

 Tuesday, January 31, 2017, 13:43

Container coated with TaC using new method: Ends taped off,  with liquid poured in and swirled around entire container, then poured back out - 'flushing technique'

Container is wrapped with 3 x Ta heat shields, not incl center block.

Loaded into EVAP2 and currently pumping down.

Tuesday, January 31, 2017, 16:02 

IGP1 = 3.9e-6 Torr.

HS water valves opened.

No leaks detected.

Tapped up manually to 35A.

Vacuum stable.

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

Final setpoints for TGHT = 450A and TBHT = 230A, with final desired temp of 1900C

OMEGA slope = 0.98

 Wednesday, February 01, 2017, 10:01

IGP1 = 5.7e-7 Torr.

TGHT = 254A, 3.0V

TBHT = 142A, 1.8V

Increasing ramping rate to 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.

 Wednesday, February 01, 2017, 11:48

IGP1 = 1.7e-6 Torr.

TGHT = 450A, 6.27V

TBHT = 230A, 3.14V

OMEGA = 1176C

Increasing max setpoint of TGHT = 600A

 Wednesday, February 01, 2017, 13:09

IGP1 = 3.7e-6 Torr.

TGHT = 600A, 9.0V

TBHT = 230A, 3.18V

OMEGA = 1480C

Increasing max setpoint of TGHT = 700A

 Wednesday, February 01, 2017, 14:08

IGP1 = 3.8e-6 Torr.

TGHT = 700A, 10.96V

TBHT = 230A, 3.2V

OMEGA = 1705C

Increasing max setpoint of TGHT = 750A

 Wednesday, February 01, 2017, 15:02

IGP1 = 5.1e-6 Torr.

TGHT = 750A, 11.87V

TBHT = 230A, 3.2V

OMEGA = 1808C

Increasing max setpoint of TGHT = 800A

 Wednesday, February 01, 2017, 15:30

IGP1 = 6.6e-6 Torr.

TGHT = 800A, 12.86V

TBHT = 230A, 3.2V

OMEGA = 1903C

Will remain at max setpoints overnight.

 Thursday, February 02, 2017, 09:16

Remained at max setpoints for ~18hrs.

IGP1 = 9.5e-7 Torr.

OMEGA =1914C

TGHT = 800A, 12.83V

TBHT = 230A, 3.22V

Initiating auto-cool at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.

 Friday, February 03, 2017, 14:24

Vented in air and opened up this morning

Coating looks good.

See photos attached.

 Thursday, April 27, 2017, 14:01

Target container contains 470 discs of SiC 

Target packed length = 16cm. 

Mass of SiC(green)  = 52.13g

Discs in target are arranged as follows: 5singles / 1pack / 65singles / 1pack / 75singles / 1pack / 75singles / 2packs / 75singles / 1pack / 75singles / 1pack / 55singles / 1pack / 5singles

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, April 28, 2017, 13:06

HS water valves turned on this morning, no leaks detected.

Tapped up manually to 40A

Waited ~3hrs , vacuum stable.

IGP1 = 4.13e-6 Torr

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

TGHT max = 400A.  TBHT max at 230A. 

Slope on OMEGA = 1.08 [see elog i.d. # 326 for reasoning behind OMEGA slope choice]

 Tuesday, May 02, 2017, 09:24

IGP1 = 2.34e-6 Torr

TBHT = 230A, 3.15V

TGHT = 298A, 3.96V

OMEGA = 1030C

Vacuum stable, increasing ramping rate up to 0.5A/min

 Tuesday, May 02, 2017, 13:20

IGP1 = 1.3e-5 Torr

TGHT = 400A, 5.6V

OMEGA = 1175C

Increasing max setpoint to 500A

Laura Lambert wrote:

Thursday, April 27, 2017, 14:01 Target container contains 470 discs of SiC  Target packed length = 16cm.  Mass of SiC(green)  = 52.13g Discs in target are arranged as follows: 5singles / 1pack / 65singles / 1pack / 75singles / 1pack / 75singles / 2packs / 75singles / 1pack / 75singles / 1pack / 55singles / 1pack / 5singles 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, April 28, 2017, 13:06 HS water valves turned on this morning, no leaks detected. Tapped up manually to 40A Waited ~3hrs , vacuum stable. IGP1 = 4.13e-6 Torr Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. TGHT max = 400A.  TBHT max at 230A.  Slope on OMEGA = 1.08 [see elog i.d. # 326 for reasoning behind OMEGA slope choice]  Tuesday, May 02, 2017, 09:24 IGP1 = 2.34e-6 Torr TBHT = 230A, 3.15V TGHT = 298A, 3.96V OMEGA = 1030C Vacuum stable, increasing ramping rate up to 0.5A/min  Tuesday, May 02, 2017, 13:20 IGP1 = 1.3e-5 Torr TGHT = 400A, 5.6V OMEGA = 1175C Increasing max setpoint to 500A

  Wednesday, May 03, 2017, 13:33

TGHT had remained at 500A for 16hrs, vacuum had initially come down nicely.

Vacuum was starting to creep up when i came in this morning before 8am,  IGP1 was at 1.2e-5 Torr

TGHT = 500A, 7.77V

OMEGA = 1440C

Around 8:30 vacuum started to spike, so the TGHT was tapped down rapidly to 450A

Tapping the TGHT down made no difference to the vacuum.

By the time 450A was hit, it was too late and the spike in vacuum caused the evaporator to trip off.

Turbo pump in epics showed on, turbo pump showed on according to TP direct controls.

Everything was shut off and the venting tapped, this made it obvious the turbo pump was already off as there was no ramping down noises from the turbo pump.

TP control box turned off then on again, at this point the controls showed a 'fail' message.

Turns out the turbo pump control box was fried and that's what had caused the turbo pump to fail with no notice in epics causing the vacuum to spontaneously spike.

Waiting on a new one from vacuum group...

See photos attached of striptool screenshots.

 Wednesday, May 03, 2017, 15:03

New TP control boxed installed.

Turbo pump turned on, everything pumped down.

Vacuum good, IGP1 = 6.92e-7 Torr.

IGP2 still not working, won't turn on via epics.

Tried unplugging and plugging back in...still appears red with 'fail' message...

Laura Lambert wrote:

Laura Lambert wrote:  Thursday, April 27, 2017, 14:01 Target container contains 470 discs of SiC  Target packed length = 16cm.  Mass of SiC(green)  = 52.13g Discs in target are arranged as follows: 5singles / 1pack / 65singles / 1pack / 75singles / 1pack / 75singles / 2packs / 75singles / 1pack / 75singles / 1pack / 55singles / 1pack / 5singles 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, April 28, 2017, 13:06 HS water valves turned on this morning, no leaks detected. Tapped up manually to 40A Waited ~3hrs , vacuum stable. IGP1 = 4.13e-6 Torr Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. TGHT max = 400A.  TBHT max at 230A.  Slope on OMEGA = 1.08 [see elog i.d. # 326 for reasoning behind OMEGA slope choice]  Tuesday, May 02, 2017, 09:24 IGP1 = 2.34e-6 Torr TBHT = 230A, 3.15V TGHT = 298A, 3.96V OMEGA = 1030C Vacuum stable, increasing ramping rate up to 0.5A/min  Tuesday, May 02, 2017, 13:20 IGP1 = 1.3e-5 Torr TGHT = 400A, 5.6V OMEGA = 1175C Increasing max setpoint to 500A     Wednesday, May 03, 2017, 13:33 TGHT had remained at 500A for 16hrs, vacuum had initially come down nicely. Vacuum was starting to creep up when i came in this morning before 8am,  IGP1 was at 1.2e-5 Torr TGHT = 500A, 7.77V OMEGA = 1440C Around 8:30 vacuum started to spike, so the TGHT was tapped down rapidly to 450A Tapping the TGHT down made no difference to the vacuum. By the time 450A was hit, it was too late and the spike in vacuum caused the evaporator to trip off. Turbo pump in epics showed on, turbo pump showed on according to TP direct controls. Everything was shut off and the venting tapped, this made it obvious the turbo pump was already off as there was no ramping down noises from the turbo pump. TP control box turned off then on again, at this point the controls showed a 'fail' message. Turns out the turbo pump control box was fried and that's what had caused the turbo pump to fail with no notice in epics causing the vacuum to spontaneously spike. Waiting on a new one from vacuum group... See photos attached of striptool screenshots.  Wednesday, May 03, 2017, 15:03 New TP control boxed installed. Turbo pump turned on, everything pumped down. Vacuum good, IGP1 = 6.92e-7 Torr. IGP2 still not working, won't turn on via epics. Tried unplugging and plugging back in...still appears red with 'fail' message...

 Wednesday, May 03, 2017, 16:07

Unplugging and plugging back in seemed to work now that evap2 under vacuum

IGP2 works again.

Will look into replacement ion gauge...

Laura Lambert wrote:

Laura Lambert wrote: Laura Lambert wrote:  Thursday, April 27, 2017, 14:01 Target container contains 470 discs of SiC  Target packed length = 16cm.  Mass of SiC(green)  = 52.13g Discs in target are arranged as follows: 5singles / 1pack / 65singles / 1pack / 75singles / 1pack / 75singles / 2packs / 75singles / 1pack / 75singles / 1pack / 55singles / 1pack / 5singles 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, April 28, 2017, 13:06 HS water valves turned on this morning, no leaks detected. Tapped up manually to 40A Waited ~3hrs , vacuum stable. IGP1 = 4.13e-6 Torr Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. TGHT max = 400A.  TBHT max at 230A.  Slope on OMEGA = 1.08 [see elog i.d. # 326 for reasoning behind OMEGA slope choice]  Tuesday, May 02, 2017, 09:24 IGP1 = 2.34e-6 Torr TBHT = 230A, 3.15V TGHT = 298A, 3.96V OMEGA = 1030C Vacuum stable, increasing ramping rate up to 0.5A/min  Tuesday, May 02, 2017, 13:20 IGP1 = 1.3e-5 Torr TGHT = 400A, 5.6V OMEGA = 1175C Increasing max setpoint to 500A     Wednesday, May 03, 2017, 13:33 TGHT had remained at 500A for 16hrs, vacuum had initially come down nicely. Vacuum was starting to creep up when i came in this morning before 8am,  IGP1 was at 1.2e-5 Torr TGHT = 500A, 7.77V OMEGA = 1440C Around 8:30 vacuum started to spike, so the TGHT was tapped down rapidly to 450A Tapping the TGHT down made no difference to the vacuum. By the time 450A was hit, it was too late and the spike in vacuum caused the evaporator to trip off. Turbo pump in epics showed on, turbo pump showed on according to TP direct controls. Everything was shut off and the venting tapped, this made it obvious the turbo pump was already off as there was no ramping down noises from the turbo pump. TP control box turned off then on again, at this point the controls showed a 'fail' message. Turns out the turbo pump control box was fried and that's what had caused the turbo pump to fail with no notice in epics causing the vacuum to spontaneously spike. Waiting on a new one from vacuum group... See photos attached of striptool screenshots.  Wednesday, May 03, 2017, 15:03 New TP control boxed installed. Turbo pump turned on, everything pumped down. Vacuum good, IGP1 = 6.92e-7 Torr. IGP2 still not working, won't turn on via epics. Tried unplugging and plugging back in...still appears red with 'fail' message...    Wednesday, May 03, 2017, 16:07 Unplugging and plugging back in seemed to work now that evap2 under vacuum IGP2 works again. Will look into replacement ion gauge...

 Wednesday, May 03, 2017, 16:09

HS water valves opened, no leaks detected.

Tapped up manually to 40A.

Vacuum stable.

IGP1 = 3.6e-7 Torr

Initiated auto-ramp at 1.0A/min and 0.5A/min to 300A and 230A for the TGHT and TBHT respectively.

 Thursday, May 04, 2017, 08:41

Reached 300A, 230A 10hrs ago.

IGP1 = 1.5e-7 Torr

OMEGA = 1070C

Increasing max setpoint to 500A at a rate of 0.5A/min for TGHT

 Thursday, May 04, 2017, 14:58

Back up to max setpoint that was reached before evap2 tripped off.

TGHT = 500A, 7.65V

IGP1 = 9.3e-7 Torr

OMEGA = 1450C

Increasing max setpoint to 550A, ramping up at a lower rate of 0.2A/min since this will be done overnight.

 Friday, May 05, 2017, 08:53

TGHT = 550A, 8.64V

IGP1 = 2.8e-7 Torr

OMEGA = 1560C

Increasing max setpoint to 600A at a ramping rate of 0.5A/min

 Friday, May 05, 2017, 11:09

TGHT = 600A, 9.58V

IGP1 = 7.3e-7 Torr

OMEGA = 1670C

Increasing max setpoint to 625A at a ramping rate of 0.5A/min

 Friday, May 05, 2017, 12:05

TGHT = 625A, 10.05V

IGP1 = 9.9e-7 Torr

OMEGA = 1710C

Increasing max setpoint to 650A at a ramping rate of 0.5A/min

 Friday, May 05, 2017, 13:13

TGHT = 650A, 10.57V

IGP1 = 1.1e-6 Torr

OMEGA  = 1740C

Mikron through left side windown on outside bottom left edge on container = 1750C

Tapping up manually to 1800C

 Friday, May 05, 2017, 13:42

Adjusted slope to 1.09 so same spot on leg using MIKRON = OMEGA

TGHT = 680A, 11.08V

IGP1 = 1.6e-6 Torr

OMEGA = 1795C

MIKRON = 1795C

Plotting a temperature curve, the predicted required current to reach 1800C was 670A using a slope of 1.08

Currently sitting 10A above predicted required current.

After several minutes, temperature dropped a few degrees to 1790C

Window remains clear and uncoated.

Tapped up to TGHT = 685A, 11.2V

OMEGA = 1795C

Will remain at this setpoint over the weekend.

 Monday, May 08, 2017, 08:59

TGHT = 685A, 11.08V

TBHT = 230A, 3.24V

IGP1 = 1.98e-7 Torr

OMEGA has lowered to 1342C

Evap2 sat at max setpoints over the wknd.

Will check window port before cooling...

*UPDATE ON TRIP-OFF*

A closer look into the details using archives [see photos attached]:

TP tripped off TBHT and TGHT at ~8e-5Torr

Anything in the evaporator requires ~1hr to cool before turning things off.

In this scenario, the target was @ ~1440C. so ~30min post TP trip, the target may still be at ~1000C.

Anything above 0.02Torr could be close enough to atmopheric pressure that this would be cooling too fast and could lead to breaking the target/ cracking the Ta metal.

As one can see in the screenshots attached, the vacuum lingered around 0.005Torr for ~2hrs before anything was done.

This provided enough time for the target to cool before it was introduced to atmospheric pressure when the BV was closed when trying to figure out the problem.

In summary, the target 'should' be OK...will inspect target further when removed from the evaporator.

 Tuesday, May 09, 2017, 09:16

TGHT = 685A, 11.04V

TGHT power supply = 686A, 11.31V

TBHT = 230A, 3.24V

TBHT power supply = 236A, 3.32V

IGP1 = 1.6e-7 Torr

IGP1 direct readout = 2.3e-7 mbar

IGP2 = 6.8e-8 Torr

IGP2 direct readout = 8.46e-8 Torr

Evap2 reached max setpoint friday afternoon.

Window clearly coated - see attached photo.

Initiating auto cool at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.

 Wednesday, May 10, 2017, 09:18

Vented in air and opened up this morning.

Inspected container carefully for any cracks/ marks due to TP tripping off at 1450C

Target looks good! 

One sample disc removed for SEM.

When removing disc for sample, the SiC came off the graphite backing and just SiC flake came out - see photo

Photos attached showing inside container with no Si crystal formation/ good clear path all the way through target and sample removed for tests

Laura Lambert wrote:

Laura Lambert wrote: Laura Lambert wrote: Laura Lambert wrote:  Thursday, April 27, 2017, 14:01 Target container contains 470 discs of SiC  Target packed length = 16cm.  Mass of SiC(green)  = 52.13g Discs in target are arranged as follows: 5singles / 1pack / 65singles / 1pack / 75singles / 1pack / 75singles / 2packs / 75singles / 1pack / 75singles / 1pack / 55singles / 1pack / 5singles 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, April 28, 2017, 13:06 HS water valves turned on this morning, no leaks detected. Tapped up manually to 40A Waited ~3hrs , vacuum stable. IGP1 = 4.13e-6 Torr Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. TGHT max = 400A.  TBHT max at 230A.  Slope on OMEGA = 1.08 [see elog i.d. # 326 for reasoning behind OMEGA slope choice]  Tuesday, May 02, 2017, 09:24 IGP1 = 2.34e-6 Torr TBHT = 230A, 3.15V TGHT = 298A, 3.96V OMEGA = 1030C Vacuum stable, increasing ramping rate up to 0.5A/min  Tuesday, May 02, 2017, 13:20 IGP1 = 1.3e-5 Torr TGHT = 400A, 5.6V OMEGA = 1175C Increasing max setpoint to 500A     Wednesday, May 03, 2017, 13:33 TGHT had remained at 500A for 16hrs, vacuum had initially come down nicely. Vacuum was starting to creep up when i came in this morning before 8am,  IGP1 was at 1.2e-5 Torr TGHT = 500A, 7.77V OMEGA = 1440C Around 8:30 vacuum started to spike, so the TGHT was tapped down rapidly to 450A Tapping the TGHT down made no difference to the vacuum. By the time 450A was hit, it was too late and the spike in vacuum caused the evaporator to trip off. Turbo pump in epics showed on, turbo pump showed on according to TP direct controls. Everything was shut off and the venting tapped, this made it obvious the turbo pump was already off as there was no ramping down noises from the turbo pump. TP control box turned off then on again, at this point the controls showed a 'fail' message. Turns out the turbo pump control box was fried and that's what had caused the turbo pump to fail with no notice in epics causing the vacuum to spontaneously spike. Waiting on a new one from vacuum group... See photos attached of striptool screenshots.  Wednesday, May 03, 2017, 15:03 New TP control boxed installed. Turbo pump turned on, everything pumped down. Vacuum good, IGP1 = 6.92e-7 Torr. IGP2 still not working, won't turn on via epics. Tried unplugging and plugging back in...still appears red with 'fail' message...    Wednesday, May 03, 2017, 16:07 Unplugging and plugging back in seemed to work now that evap2 under vacuum IGP2 works again. Will look into replacement ion gauge...    Wednesday, May 03, 2017, 16:09 HS water valves opened, no leaks detected. Tapped up manually to 40A. Vacuum stable. IGP1 = 3.6e-7 Torr Initiated auto-ramp at 1.0A/min and 0.5A/min to 300A and 230A for the TGHT and TBHT respectively.  Thursday, May 04, 2017, 08:41 Reached 300A, 230A 10hrs ago. IGP1 = 1.5e-7 Torr OMEGA = 1070C Increasing max setpoint to 500A at a rate of 0.5A/min for TGHT  Thursday, May 04, 2017, 14:58 Back up to max setpoint that was reached before evap2 tripped off. TGHT = 500A, 7.65V IGP1 = 9.3e-7 Torr OMEGA = 1450C Increasing max setpoint to 550A, ramping up at a lower rate of 0.2A/min since this will be done overnight.  Friday, May 05, 2017, 08:53 TGHT = 550A, 8.64V IGP1 = 2.8e-7 Torr OMEGA = 1560C Increasing max setpoint to 600A at a ramping rate of 0.5A/min  Friday, May 05, 2017, 11:09 TGHT = 600A, 9.58V IGP1 = 7.3e-7 Torr OMEGA = 1670C Increasing max setpoint to 625A at a ramping rate of 0.5A/min  Friday, May 05, 2017, 12:05 TGHT = 625A, 10.05V IGP1 = 9.9e-7 Torr OMEGA = 1710C Increasing max setpoint to 650A at a ramping rate of 0.5A/min  Friday, May 05, 2017, 13:13 TGHT = 650A, 10.57V IGP1 = 1.1e-6 Torr OMEGA  = 1740C Mikron through left side windown on outside bottom left edge on container = 1750C Tapping up manually to 1800C  Friday, May 05, 2017, 13:42 Adjusted slope to 1.09 so same spot on leg using MIKRON = OMEGA TGHT = 680A, 11.08V IGP1 = 1.6e-6 Torr OMEGA = 1795C MIKRON = 1795C Plotting a temperature curve, the predicted required current to reach 1800C was 670A using a slope of 1.08 Currently sitting 10A above predicted required current. After several minutes, temperature dropped a few degrees to 1790C Window remains clear and uncoated. Tapped up to TGHT = 685A, 11.2V OMEGA = 1795C Will remain at this setpoint over the weekend.  Monday, May 08, 2017, 08:59 TGHT = 685A, 11.08V TBHT = 230A, 3.24V IGP1 = 1.98e-7 Torr OMEGA has lowered to 1342C Evap2 sat at max setpoints over the wknd. Will check window port before cooling...   *UPDATE ON TRIP-OFF* A closer look into the details using archives [see photos attached]: TP tripped off TBHT and TGHT at ~8e-5Torr Anything in the evaporator requires ~1hr to cool before turning things off. In this scenario, the target was @ ~1440C. so ~30min post TP trip, the target may still be at ~1000C. Anything above 0.02Torr could be close enough to atmopheric pressure that this would be cooling too fast and could lead to breaking the target/ cracking the Ta metal. As one can see in the screenshots attached, the vacuum lingered around 0.005Torr for ~2hrs before anything was done. This provided enough time for the target to cool before it was introduced to atmospheric pressure when the BV was closed when trying to figure out the problem. In summary, the target 'should' be OK...will inspect target further when removed from the evaporator.  Tuesday, May 09, 2017, 09:16 TGHT = 685A, 11.04V TGHT power supply = 686A, 11.31V TBHT = 230A, 3.24V TBHT power supply = 236A, 3.32V IGP1 = 1.6e-7 Torr IGP1 direct readout = 2.3e-7 mbar IGP2 = 6.8e-8 Torr IGP2 direct readout = 8.46e-8 Torr Evap2 reached max setpoint friday afternoon. Window clearly coated - see attached photo. Initiating auto cool at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.  Wednesday, May 10, 2017, 09:18 Vented in air and opened up this morning. Inspected container carefully for any cracks/ marks due to TP tripping off at 1450C Target looks good!  One sample disc removed for SEM. When removing disc for sample, the SiC came off the graphite backing and just SiC flake came out - see photo Photos attached showing inside container with no Si crystal formation/ good clear path all the way through target and sample removed for tests

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

Monday, June 24, 2019, 08:24

Total number of foils: 484

Total mass in  including container = 1495 grams

Total length packed 17.28 cm

container has 3 Ta heat shields.

No endcaps inserted to facilitate outgassing

Two TaC coated Ta wire springs inserted at either end.

Initially will heat via autoramp to OMEGA 1400 C , ramping TGHT at  0.1 A/min to reach 530A A (Omega slope set = 0.990)

Then temperature= (Correction to 1800C) 1900 C, Omega Slope set = 0.990, Auto TGHT at 0.2A/min to reach 700A, TGHT will be tapped up accordingly to reach desired Temp.

TBHT will be set fixed at 230 A (max).  TBHT at 0.1 A/min.

Good vac at 3.00 e -5 Torr

Bad vac at 5.00 e-5 Torr

System was pumped down on Friday June 24th, 2019.

IGP1= 3.3 e-07 Torr

(EPICS was down this morning and came back up around 930 a.m.)

Will proceed to manually tap up TGHT and TBHT to 40A as soon as EPICS stability confirmed

Mondayy, June 24, 2019, 15:30

TBHT = 39 A, 0.4V

TGHT=40 A, 0.1V

IGP1= 4.3 e-06 Torr and trending down

Autoramp increments to 0.1 A/min , to 400A on TGHT and 230A on TBHT

Tuesday, June 25, 2019, 08:40

Current has only increased to 53 A and pressure limit reached.  Lowered current back to 51 A on TGHT and TBHT.  Waiting for pressure to stabilize.

Tuesday, June 25, 2019, 12:16

TGHT 51.3 A, 0.39 V

TBHT 51.1 A, 0.58 V

IGP1 = 1.91 e-05 Torr

Starting autoramp with  increments to 0.1 A/min , to 400A on TGHT and 230A on TBHT

 Saturday, June 29, 2019, 22:45

Autoramp increments for TGHT set to 0.2 A/min

 IGP1=2.4 e-06 Torr

 Sunday, June 30, 2019, 07:46

Autoramp incrementsTGHT set to 0.1 A/min to prevent pressure spike. 

IGP1= 1.5 e-05 Torr

 Sunday, June 30, 2019, 08:26

Set autoramp increments on TGHT back to 0.2 A/min

Sunday, June 30, 2019, 15:47

Set autoramp max on TGHT to 500 A

Sunday, June 30, 2019, 21:15

OMEGA = 1240C

TGHT= 465A, 7.0V

TBHT = 233A, 3.2V

IGP1= 1.6 e-05 Torr

Set autoramp max on TGHT to 600A

Monday, July 01, 2019, 09:48

OMEGA = 1605 C

TGHT = 599A, 9.7V

TBHT = 233A, 3.2V

IGP1= 1.3 e-06 Torr

Set autoramp max on TGHT to 650A

Monday, July 01, 2019, 18:21

OMEGA = 1630 C

TGHT = 650 A, 10.6V

TBHT = 233A, 3.2V

IGP1 = 9.7 e-07 Torr

Set utoramp max on TGHT to 700A

Monday, July 01, 2019, 22:07

OMEGA = 1663 C

TGHT = 682A, 11.4V

TBHT = 233A, 3.2V

IGP1= 1.5 e-06 Torr

Set autoramp max on TGHT to 730A

Tuesday, July 02, 2019, 08:15

OMEGA =1700 C

TGHT = 730A, 12.0V

TBHT = 233A, 3.2V

IGP1= 1.1 e-06 Torr

Set autoramp max on TGHT to 750A and increments to 0.4A/min

Tuesday, July 02, 2019, 09:49

Temperature on OMEGA began dropping.  Changed OMEGA slope to 1.09 (Elog 371) and temperature reading = 1884 C.  Aborted autoramp and lowered TGHT current to 740A.

Tuesday, July 02, 2019, 12:14

Temperature and pressure have dropped at a consistent rate. 

IGP1= 9.6 e-07 Torr

OMEGA = 1715 C

Will tap up manually to 750A on TGHT

No appreciable increase in pressure will tap back down to 745A on TGHT

Tuesday, July 02, 2019, 13:11

OMEGA = 1675 C

TGHT = 745A, 12.4V

TBHT = 233A, 3.2V

IGP1 = 1.03 e-06Torr

 Will start to ramp- down TGHT @ -2.0A/min

OMEGA = 1354 C

TGHT = 495A, 7.01V

TBHT = 233.2A, 3.2V

IGP1= 2.2 e-07 Torr

Continue ramp-down TGHT @ -2.0A/min

Tuesday, July 02, 2019, 17:14

TGHT = 285.5A, 3.4V

TBHT = 232A, 3.1V

IGP1= 1.4 e-07 Torr

Start TBHT ramp-down at -1.0 A/min

Wednesday, July 03, 2019, 08:37

Turned off TGHT and TBHT

IGP1 = 7.8 e-08 Torr

Wednesday, July 03, 2019, 13:18

Final total weight of Target = 1489.5 g

Removed 18 discs after weighing.