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.

Tuesday, October 08, 2019, 14:14: Remove Flex line HS. 

HS: 42752-1

Waterlines not open yet.

Tuesday, October 08, 2019, 14:15: roughing.

Tuesday, October 08, 2019, 14:24: Turbo pump on. 

Tuesday, October 08, 2019, 14:32: TP @ speed. 

Wednesday, October 09, 2019, 13:24 

The initial pressure was 3.25e-7 Torr

The current was manually increased to 25 A on both TBHT and TGHT  at a rate of 1 A each 30 s for both heaters.

Wednesday, October 09, 2019, 13:33

At 1 pm an additional ram was made to TGHT 350 A and TBHT 200 at same rate.

 HS 42752-5 - Setup for Temperature mapping.

Friday, November 15, 2019, 13:26: Roughing. 

Friday, November 15, 2019, 13:36: Turbo pump on. 

Monday, November 18, 2019, 07:46: Waterlines opened. Vacuum ok @ 3.56e-07T.

Monday, November 18, 2019, 07:48: PS on.

Monday, November 18, 2019, 09:21: PS off. Vacuum slowly spiked to 1.23e-06T. Indicative of a small water leak. 

Monday, November 18, 2019, 09:24: HS waterlines purged. vacuum dropped to 5.54e-07T. 

Monday, November 18, 2019, 09:27: Valves closed. TP off. BP off.

Monday, November 18, 2019, 10:27: Venting.

Monday, November 18, 2019, 11:06: Gaskets checked / replaced. Roughing. 

Monday, November 18, 2019, 11:14: turbo pump on. 

Monday, November 18, 2019, 14:19: Waterlines opened. 

Monday, November 18, 2019, 14:23: Response on vacuum. Leak is still present & a higher rate (Has an immediate response). Turbos off. 

Monday, November 18, 2019, 14:28: Venting. 

Monday, November 18, 2019, 14:49: turbo pump on. 

Tuesday, November 19, 2019, 07:07: Waterlines opened. Leak is present.  Turbo pump off. 

Tuesday, November 19, 2019, 11:24: After venting, changed 1 gasket. Setup LD & completed a leak check with the lines pressurized to 75 PSI of He. 

Tuesday, November 19, 2019, 11:25: Roughing. 

Tuesday, November 19, 2019, 11:33: Turbo pump on. 

Wednesday, November 20, 2019, 08:59: Waterlines opened. Leak is present.  Turbo pump off.  

Wednesday, November 20, 2019, 11:26: FEBIAD Removed. U-Line installed to check Evap 2 Connection. FEBIAD examined outside. 

Wednesday, November 20, 2019, 11:34: Turbo pump on. 

Wednesday, November 20, 2019, 13:05: HPA off (Was running through HS line still. Vac @ 5.54e-06T).  

Wednesday, November 20, 2019, 13:07: Open waterline. Vacuum @ 3.88e-06T & dropping steadily.  

Wednesday, November 20, 2019, 13:12: Vacuum @ 3.69e-06T & dropping. No leak detected via Vac. 

Wednesday, November 20, 2019, 13:14: Waterline Closed / purged. Turbo pumps off. 

Wednesday, November 20, 2019, 13:58: Turbo pump on. 

Wednesday, November 20, 2019, 13:50: Cleaned seal / FEBIAD re-installed. Roughing.

Thursday, November 21, 2019, 08:06: Waterlines opened. Vacuum ok @ 4.10e-07T. 

Notes:

1) The FEBIAD left cooling line was the culprit for the leaks. A fine copper build up was noted on the gasket /  sealing face. Images included. 

2) Evap 2 was leak checked separately as well & is OK.

 Thursday, November 21, 2019, 08:09: PS on. Leak issue resolved (Evap 2 Elog 466). Vacuum @ 4.10e-07T.

Thursday, November 21, 2019, 08:15: Auto-ramping TGHT / TBHT @ 2 A per min to 300 / 150 A. 

 Friday, November 22, 2019, 18:18:

Friday, November 22, 2019, 18:18: Roughing

Friday, November 22, 2019, 18:23: Turbo on .

Friday, November 22, 2019, 18:32: Turbo at speed 

12.3

Saturday, November 23, 2019, 14:00

Container coated with TaC and wrapped with 3 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 Friday November 22; however.

No leaks were observed when turning water lines on.

IGP1= 4.6e-07 Torr

 Saturday, November 23, 2019, 15:30

autoramp at 0.5A /min up to 50A for both TGHT and TBHT and maintained for 1 hour.

Saturday, November 23, 2019, 16:15

IGP1= 1.1e-06 Torr

Auto Ramp to 450 A on THGT and 230A on TBHT at 0.5A/min

Saturday, November 23, 2019, 23:44

IGP1= 5.2e-06 Torr

TGHT = 248A, 2.9V  TBHT= 233A 2.9V

Increased ramp step to 1A/min to 620 A

Sunday, November 24, 2019, 00:14

IGP1=1.9e-06 Torr

TGHT = 274.3, 3.3V   TBHT= 233A, 2.9V

Sunday, November 24, 2019, 07:33

IGP1=3.2e-06 Torr

OMEGA= 1490C

TGHT = 619 A, 9.1V   TBHT=233A, 2.9V

Continue ramping THGT at 1A/min to 700 A

Sunday, November 24, 2019, 10:05

IGP1= 2.1 e-05 Torr

OMEGA= 1676 C

TGHT= 700A, 10.6V   TBHT= 233A, 2.0V

Start autoramp to 780A as per regression in attachment

Sunday, November 24, 2019, 13:22

Autoramp to 795A  for TGHT

Sunday, November 24, 2019, 21:16

OMEGA= 1854 C

TGHT= 789.6A, 12.27V  TBHT= 233.A, 2.9V

IGP1= 2.0e-05

Will allow pressure to stabilize lower.

Sunday, November 24, 2019, 22:16

TGHTT= 789.6A, 12.3V TBHT=233.3A, 2.9V

OMEGA=1855C

IGP1 = 6.9e-06Torr

Start cooling TGHT at 2A/min and TBHT at 1A/min

Tuesday, November 26, 2019, 14:53

Total number of foils: 504

Total length packed 17.4 cm

container has 3 Ta heat shields.

No endcaps inserted to facilitate out-gassing

Two TaC coated Ta wire springs inserted at either end.

Initially to ramp TGHT and TBHT to 50A at 1A/min

Then heat manually to OMEGA ~1400 C , ramping TGHT manually and automatically  to reach 530A A (Omega slope set = 0.990)

Then temperature= (Correected to 1800C) 1900 C, Omega Slope set = 0.990, manually and automatically ramp to 700A, TGHT will be tapped up accordingly to reach desired Temp.

TBHT will be set fixed at 230 A (max).  TBHT heated manually and automatically to max.

Good vac at 3.00 e -5 Torr

Bad vac at 5.00 e-5 Torr

System experienced some vacuum issues due to cooling water leak in a heatshield line. 

Evaluation discs not included because no space.

Total Green disc mass measured = 58.250 g

Tuesday, November 26, 2019, 15:00

IGP1= 7.4e-06 Torr.  No leak issues found after last fix (Anders will add details).

Tuesday, November 26, 2019, 15:33

TGHT= 52.7A, .22V   TBHT= 49.3A, .52V

IGP1= 7.202 e-06 Torr (trending up so will allow to stabilize).

Wednesday, November 27, 2019, 06:09

left with autoramp waiting for vac to drop but no advance overnight.

Pressure did not seem to drop back below 3e-5 Torr magnitude, therefore not much advance in current ramp.

Thursday, November 28, 2019, 11:15

Continued ramping manually 

OMEGA = 1429 C  (0.99 slope), TGHT = 542A, 7.8V

With slope = 1.08 OMEGA = 1724 C, therefore staying at 0.99 slope

TaC coating sintering  plot suggests 753A to reach 1800C (See attachment 1)

Windows a little bit coated but not enough to disturb laser. 

Thursday, November 28, 2019, 12:17

TGHT =753A, 11.8V since 12:00 noon. 

TBHT= 233.4A, 3.3V

OMEGA= 1735 C (0.99 slope)

 Thursday, November 28, 2019, 13:01

OMEGA = 1860C (1.08 slope)

 Thursday, November 28, 2019, 14:38

OMEGA temperature began to creep up to ~1880.  Tapped TGHT current down to 733.5A, 11.4V

Thursday, November 28, 2019, 15:12

Checked windows and no significant additional buildup of obstructive material.

Temperature creeping up again.  Tap down TGHT current to 729 A, 11.2 V

OMEGA = 1870C at slope 1.08

 Thursday, November 28, 2019, 16:03

Temperature increase to 1880C

Tap down TGHT current to 715A, 10.9V

OMEGA= 1870 C (slope = 1.08)

Thursday, November 28, 2019, 16:22

Temperature creep to 1880 C

Tap down TGHT to 700A, 10.8V

OMEGA= 1845C

IGP1=2.2e-06 Torr

Thursday, November 28, 2019, 16:37

IGP1= 1.9e-06 Torr

OMEGA = 1850C (1.08 slope)

TGHT = 692A, 10.5V  TBHT= 233A, 3.2V

Initiating pressure ramp at -2A/min on TGHT and -1A/min on TBHT

Thursday, November 28, 2019, 16:45

IGP1= 1.28e-06 Torr

OMEGA= 1770 C (1.08 slope)

TGHT = 650A, 9.8V

ramp TGHT at -3.5A/min maintain TBHT at -1A/m in

 Thursday, November 28, 2019, 17:11

IGP1= 1.14e-06 Torr

OMEGA = 1730 C (1.08 slope)

ramp TGHT at -5A/min maintain TBHT at -1A/m

Thursday, November 28, 2019, 17:20

IGP1- 8.9e-07 Torr

OMEGA=1636C

ramp TGHT at -6A/min maintain TBHT at -1A/min

 Thursday, November 28, 2019, 17:34

IGP1= 7e-07 Torr

OMEGA= 1500 C (1.08 slope)

ramp TGHT at -8A/min maintain TBHT at -1A/min

TBHT = 183A

 OMEGA 1180C

TGHT =300 A

TBHT = 155A

Initiated -15A/min TGHT and -4A/min TBHT

IGP1= 5.2e-07 Torr

OMEGA below 1000C

begin manual tapdown

Thursday, November 28, 2019, 19:42

Target was dismounted after cooling.  Two graphite discs and end caps inserted.

This morning, the vacuum responded to shutting of the water of the heat shield circuit (leak rate without pumping leveling out). The vacuum chamber was vented and the heat shield with flexible lines was replaced with another heat shield with fixed lines. The chamber was again pumped down and water opened at ~150 mTorr to test the leak up rate without pumping. No leaks apparent, so continued pumping down with turbo pump. At a vacuum of about 1E-6 Torr the water was again supplied to the heat shield circuit and an increase in vacuum could be observed. Stopped the turbo pump and prepared to vent. Two new heat shield lines were brazed in the machine shop and fitted by Maico after lunch. During this time one of the old lines (from heat shield to feedthrough in box) was leak tested and a leak found at a location just above the VCR. The line had been twisted and due to the twist developed a leak. With the two lines replaced, the vacuum was pumped down again and water could be supplied without any increase in vacuum pressure at 1E-6 Torr. To facilitate the new copper tubing, the restraining bracket for the heat shield VCRs was not mounted. It will have to be fitted later. Until then, please contact Anders for help in removing the heat shield to prevent any damage to the new lines.

Darwin Ortiz Rosales wrote:

Tuesday, November 26, 2019, 14:53 Total number of foils: 504 Total length packed 17.4 cm container has 3 Ta heat shields. No endcaps inserted to facilitate out-gassing Two TaC coated Ta wire springs inserted at either end. Initially to ramp TGHT and TBHT to 50A at 1A/min Then heat manually to OMEGA ~1400 C , ramping TGHT manually and automatically  to reach 530A A (Omega slope set = 0.990) Then temperature= 1900 C (Correction = 1800 C, NOT 1900 - JW), Omega Slope set = 0.990 (use 1.08, check temp, JW), manually and automatically ramp to 700A (check temp to see if it's matching with the 1.08 slope), TGHT will be tapped up accordingly to reach desired Temp. TBHT will be set fixed at 230 A (max).  TBHT heated manually and automatically to max. Good vac at 3.00 e -5 Torr Bad vac at 5.00 e-5 Torr System experienced some vacuum issues due to cooling water leak in a heatshield line.  Evaluation discs not included because no space. Total Green disc mass measured = 58.250 g   Tuesday, November 26, 2019, 15:00 IGP1= 7.4e-06 Torr.  No leak issues found after last fix (Anders will add details). Tuesday, November 26, 2019, 15:33 TGHT= 52.7A, .22V   TBHT= 49.3A, .52V IGP1= 7.202 e-06 Torr (trending up so will allow to stabilize).

 Wednesday, November 27, 2019, 17:44

I'll take over from here to step up the target heater, and I'll coordinate it with Darwin. 

 Wednesday, November 27, 2019, 20:36

Note: Sintering temp should be at 1800 C, NOT 1900.  Use Omega slope 1.08 and check temperature.  Correction made on elog #471.

Continue to step up TGHT and TBHT, keeping vacuum below 1.5 e-5 Torr. 

 Thursday, November 28, 2019, 03:06

TGHT reached to 400A/5.29V, TBHT at 230A/3.13V. 

Vacuum coming down from 1.3 e-5 Torr.

OMEGA = 1105 C (slope at 0.99).

Instructions for Darwin:

1.  Confirm temperature - check the temp plot from the TaC coating step. 

2.  Change OMEGA slop to 1.08 - check to see if this matches the temp plot.  If not, bring it back to 0.99.

3.  Continue to step up TGHT, check temp at 1400C (change slop 1.08 and check), 1500 C, 1600 C (check windows for coating - if any coating, then OMEGA is no longer useful hereon)

4.  Use the temp plot and continue to tap up TGHT to reach 1800 C and hold it for at least 4 hours or until the vacuum goes below 1 e-6 Torr then proceed with cooling down.

5.  Use the auto cooling program for TGHT (-2A/min) and TBHT (-1A/min)

Note:  For ramping up TGHT, keep vacuum below 1.5 e-4 Torr and keep tapping up to reach 1800 C.  Above 1100 C, this should be a quick step to get to 1800 C; should take < 2 hrs to get there.  

See the striptool or the attachment below to see how I did it. 

Once the chamber is cool down, take out a few samples for SEM analysis. 

Good luck!

Tuesday, March 09, 2021, 11:54 

 Container coated with TaC and wrapped with 3 Ta heat shields.

Desired temperature= 1900 C, Omega Slope set = 0.990, Auto TGHT at 0.2A/min to reach 400A, TGHT will be increased  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

Wednesday, March 10, 2021, 08:32

IGP1 = 2.6 e -07 Torr

Start autoramp @ 1A/min to 40 A on both TGHT and TBHT

***Autoramp aborted due to work on EF12 affecting EVAP2***

Will have to resume Thursday or Friday

Saturday, March 13, 2021, 7:54

  IGP1= 3.8e-07 Torr

Initiate heating @ 0.5A/min TBHT and TGHT to 60 A

Saturday, March 13, 2021, 23:01

IGP1 = 2.7e-07Torr

TGHT = 60.5A, 0.7V

TBHT= 60.0A, 0.7V

Initiate ramp @ 1 a/min to 400 A on TGHT and 230A on TBHT

Sunday, March 14, 2021, 08:45

IGP1= 8.2e-07 Torr

TGHT = 400A, 5.6V

TBHT = 232.9A, 3.0V 

OMEGA = 1142 C

Continue ramping to 460 A on TGHT at 1a/min

 Sunday, March 14, 2021, 10:11

IGP1 = 1.0 e-06 Torr

TGHT= 460.4 A, 6.5 V

TBHT = 232.9 A, 3.0 V

OMEGA = 1239 C

Will ramp up to 500 A at 1a/min on TGHT

Sunday, March 14, 2021, 10:53

 IGP1 = 1.3 e-06 Torr

TGHT= 495 A, 7.2 V

TBHT = 232.9 A, 3.0 V

OMEGA = 1316 C

Will ramp up to 600 A at 1a/min on TGHT

Sunday, March 14, 2021, 12:45

IGP1 = 3.0 e-06 Torr

TGHT= 604 A, 9.1 V

TBHT = 232.9 A, 3.1 V

OMEGA = 1610 C

Will ramp up to 660 A at 1a/min on TGHT 

Sunday, March 14, 2021, 17:01

IGP1= 2.4e-06 Torr

TGHT =  664 A, 10V

TBHT = 232.9 A, 3.1V

OMEGA = 1733 C

tapping TGHT to 740 A

OMEGA = 1883 C

 Sunday, March 14, 2021, 21:45

IGP1= 3.1e-06 Torr

TGHT =  744A, 11.5V

TBHT = 232.9 A, 3.2V

OMEGA = 1875 C

Start cooling TGHT @-3A/min and TBHT @-1A/min

Thursday, February 10, 2022, 08:52 

Total number of foils: 528 ( including 10 analysis discs)

Weight without springs = 1521.9 g (includes heatshields and T bar)

Total length packed 18.1 cm (including 10 analysis discs that will be removed)

container has 3 Ta heat shields.

No endcaps inserted to facilitate out-gassing

Ta coated spring at  ends

Initially to ramp TGHT and TBHT to 50A at0.5 A/min

Then heat automatically heat to OMEGA ~1400 C , then continue to max 530A on TGHT and 230A on TBHT (Omega slope set = 0.990)

Then temperature = 1800C

TBHT will be set fixed at 230 A (max).  TBHT heated manually and automatically to max.

Good vac at 3.00 e -4 Torr

Bad vac at 5.00 e-2 Torr

 IGP1= 1.0 e-06 Torr at start of initial ramp

IGP1 = 5.7 e-06 Torr

TGHT = 50.0 A, 0.6 V

TBHT = 50.0A, 0.5 V

continue to ramp up at 0.5A/min to 200A

Friday, February 11, 2022, 07:59 

IGP1=3.0e-07 Torr and stable

TGHT= 201A, 2.8V

TBHT = 201A, 2.6V

continue autoramp at 1A/min to 230A on TBHT and 450A on TGHT

Friday, February 11, 2022, 12:41

IGP1= 6.6e-05 Torr

TGHT= 450A, 6.5V

TBHT= 232A, 3.1V

OMEGA = 1258C

Allowing pressure to drop.  Will continue ramp up when [pressure around 9-e-6 Torr

Friday, February 11, 2022, 13:59

IGP1= 2.4e-05 Torr

Will ramp up at 1A/min to 550A on TGHT

Friday, February 11, 2022, 15:54  

IGP1= 2.4e-05 Torr

TGHT= 551.0A, 8.3V

TBHT=232A, 3.2V

OMEGA= 1426 C

ramp to 600 A @ 2A/min

Friday, February 11, 2022, 16:23

TGHT= 600.1A, 9.3V

TBHT= 232A, 3.2V

OMEGA = 1612C

ramp to 689 @2A/min to 1800 C as projected in regression plot attached 

Friday, February 11, 2022, 21:20 

Evap has been at 1800 +/- 20 C for 4 hours and 10 minutes

OMEGA 1802 C

TGHT = 689 A, 11.0V

TBHT=232.8 A, 3.26V

IGP1= 1.3e-05 Torr and stabilizing.  

will start cool down at -2A/min TGHT and -1A/min TBHT