Nikita Bernier wrote:

Friday, August 10, 2012, 19:54   Target boat with TaC coating, inside covered with a 0.002 inches thick Ta foil, wrapped with a 0.002 inches thick Ta foil, contains a Ta foil with TaO coating. See John's Ipad for their recipes. Evaporator #2 is now auto-ramping overnight at 0.2 A/min, up to 830 A, with the maximum voltage limited at 14 V, between 2.00e-05 (Good vacuum) and 3.00e-05 Torr (Bad vacuum).

 Saturday, August 11, 2012, 19:15

Heating process was going smoothly up to 400 A. See Attachment 1.

Around 420 A, vacuum went up again and the voltage increased more quickly. It seems like resistance is building up. After reaching 530 A, the current was tapped down to 420 A in an effort to save the Ta boat. See Attachment 2.

The current will stay at 420 A for the weekend until John takes a look at this.

Nikita Bernier wrote:

Nikita Bernier wrote:  Friday, August 10, 2012, 19:54   Target boat with TaC coating, inside covered with a 0.002 inches thick Ta foil, wrapped with a 0.002 inches thick Ta foil, contains a Ta foil with TaO coating. See John's Ipad for their recipes. Evaporator #2 is now auto-ramping overnight at 0.2 A/min, up to 830 A, with the maximum voltage limited at 14 V, between 2.00e-05 (Good vacuum) and 3.00e-05 Torr (Bad vacuum).    Saturday, August 11, 2012, 19:15 Heating process was going smoothly up to 400 A. See Attachment 1. Around 420 A, vacuum went up again and the voltage increased more quickly. It seems like resistance is building up. After reaching 530 A, the current was tapped down to 420 A in an effort to save the Ta boat. See Attachment 2. The current will stay at 420 A for the weekend until John takes a look at this.

 Monday, August 13, 2012, 13:46

 TGHT was ramped down at 2 A/min and then tapped down to 0A. See Attachment 1.  The target boat will be cooled down for about an hour before turning off the chiller.

 Monday, September 24, 2012, 15:01

The target boat with TaC coating is being used again. The inside of the boat is covered with a 0.002 inches thick Ta foil with TaC coating, wrapped with a 0.002 inches thick Ta foil.

Chamber was pumped down to 6e-6 Torr before the Heat Shield cooling water valve was opened. A small vacuum bump was detected (See attachment #1). It is not clear if it was caused by a water leak or not.

After consulting with Peter, I will wait for the vacuum to be below e-07 Torr before turning the target heater on.

Nikita Bernier wrote:

Monday, September 24, 2012, 15:01 The target boat with TaC coating is being used again. The inside of the boat is covered with a 0.002 inches thick Ta foil with TaC coating, wrapped with a 0.002 inches thick Ta foil. Chamber was pumped down to 6e-6 Torr before the Heat Shield cooling water valve was opened. A small vacuum bump was detected (See attachment #1). It is not clear if it was caused by a water leak or not. After consulting with Peter, I will wait for the vacuum to be below e-07 Torr before turning the target heater on.

 Monday, September 24, 2012, 18:02

The vacuum was stable until 1e-06 Torr. The target heater was turned on and tapped up to 60 A (0.8 V). 

Evaporator #2 is now auto-ramping overnight at 0.2 A/min, up to 800-850 A, with the maximum voltage limited at 14 V, between 2.00e-05 (Good vacuum) and 3.00e-05 Torr (Bad vacuum). 

 Tuesday, September 25, 2012, 15:11

Sintering process is going smoothly. See Attachment 1. The auto-ramping was increased to 1 A/min up to 800-850 A.

Tuesday, September 25, 2012, 16:11 

And the voltage limit was increased to 18 V ! See Attachment 2.

 Tuesday, September 25, 2012, 19:13

Around 806 A (readback), voltage increased more quickly than the current. It seems like resistance is building up. After reaching 836 A (readback), the current was tapped down to 800 A (readback)/ 816 A (setting) in an effort to save the Ta boat. See Attachment 3. The current will stay at 800 A for ~4 hours before ramping down.

Nikita Bernier wrote:

Nikita Bernier wrote:  Monday, September 24, 2012, 15:01 The target boat with TaC coating is being used again. The inside of the boat is covered with a 0.002 inches thick Ta foil with TaC coating, wrapped with a 0.002 inches thick Ta foil. Chamber was pumped down to 6e-6 Torr before the Heat Shield cooling water valve was opened. A small vacuum bump was detected (See attachment #1). It is not clear if it was caused by a water leak or not. After consulting with Peter, I will wait for the vacuum to be below e-07 Torr before turning the target heater on.        Monday, September 24, 2012, 18:02 The vacuum was stable until 1e-06 Torr. The target heater was turned on and tapped up to 60 A (0.8 V).  Evaporator #2 is now auto-ramping overnight at 0.2 A/min, up to 800-850 A, with the maximum voltage limited at 14 V, between 2.00e-05 (Good vacuum) and 3.00e-05 Torr (Bad vacuum).     Tuesday, September 25, 2012, 15:11 Sintering process is going smoothly. See Attachment 1. The auto-ramping was increased to 1 A/min up to 800-850 A.     Tuesday, September 25, 2012, 16:11  And the voltage limit was increased to 18 V ! See Attachment 2.    Tuesday, September 25, 2012, 19:13 Around 806 A (readback), voltage increased more quickly than the current. It seems like resistance is building up. After reaching 836 A (readback), the current was tapped down to 800 A (readback)/ 816 A (setting) in an effort to save the Ta boat. See Attachment 3. The current will stay at 800 A for ~4 hours before ramping down.

 Wednesday, September 26, 2012, 14:31

The current was tapped down twice as resistance was building up. After 4 hours at ~800 A, the TGHT was ramped down at 2 A/min. See Attachment 1. The target boat was cooled down for 4 hours before the chiller was turned off.

Also I had trouble measuring the temperature. I was unable to get a clear picture with the pyrometer. Therefore the exact temperature remains unknown, but from previous experiments, 800 A was about 1400°C.

The TaC coated Ta foil is very brittle. There is a lot of crystallisation on the Ta boat. See attachment 2. It is unlikely that the boat would survive many more sintering. Therefore it will be used for BeO pellets tests. 

When John gets back, I suggest we use a new boat coated with TaC, without additional layers. (See message #15 when this target boat was sintered up to 900A (local 893A/16.88V), Measured temp @ 1500°C)

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, 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

 Tuesday, May 16, 2017, 10:56

Target container contains 460 discs of SiC 

Target packed length = 17cm. 

Mass of SiC(green)  = 55.5152g

Consists of 4 packs of 5 and 440 singles.

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. 

 Tuesday, May 16, 2017, 15:27

HS water valves turned on, no leaks detected.

Tapped up manually to 30A

Waited ~30min , vacuum stable.

IGP1 = 8.25e-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 = 1.09 [see elog i.d. # 370 for reasoning behind OMEGA slope choice]

 Friday, May 19, 2017, 10:13

TGHT = 250A, 3.11V     DR = 248A, 3.3V

TBHT = 137A, 1.68V     DR = 140A, 1.73V

OMEGA = 1100C

IGP1= 6.9e-6 Torr     DR = 1e-5mbar

IGP2 = 5.9e-6 Torr     DR = 6.45e-6 Torr

Vacuum stable.

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

 Friday, May 19, 2017, 10:33

Change in plan and switching ramping rate to 0.5A/min and 0.2A/min for the TBHT and TGHT respectively.

 Friday, May 19, 2017, 14:49

TGHT = 400A, 5.46

TBHT = 200A, 2.66

IGP1 = 2.7e-5 Torr

IGP2 = 2.2e-5 Torr

OMEGA = 1200C

Increasing max setpoint for TGHT to 550A

Decreasing ramping rate to 0.2A/min and 0.1A/min for over the weekend.

 Tuesday, May 23, 2017, 09:23

TGHT = 550A, 8.37

TBHT = 230A, 3.14

IGP1 = 1.6e-7 Torr

IGP2 = 1.6e-7 Torr

OMEGA = 1570C

Increasing max setpoint for TGHT to 600A at rate to 0.5A/min

 Tuesday, May 23, 2017, 11:45

TGHT = 600A, 9.36

IGP1 = 3.5e-7 Torr

IGP2 = 3.8e-7 Torr

OMEGA = 1675C

Increasing max setpoint for TGHT to 625A at rate to 0.5A/min

 Tuesday, May 23, 2017, 13:03

TGHT = 625A, 9.80V

IGP1 = 5.2e-7 Torr

IGP2 = 5.7e-7 Torr

OMEGA = 1715C

OMEGA no longer valid around 640A as temperature drops instantly after tapping up.

Could be due to target movement at high temperature.

No obvious window coating.

Tapped up manually to 660A, 10.49V.

Will remain at max setpoint overnight.

 Wednesday, May 24, 2017, 11:13

TGHT = 660A, 10.74V

TGHT power supply = 662A, 11.00V

TBHT = 230A, 3.16V

TBHT power supply = 232A, 3.25V

IGP1 = 4.2e-7 Torr

IGP1 direct readout = 5.9e-7 mbar

IGP2 = 4.6e-8 Torr

IGP2 direct readout = 5e-7 Torr

Evap2 reached max setpoint yesterday afternoon.

Window has thiny coating - see attached photo.

OMEGA = 1800

MIKRON = ~1800

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

 Wednesday, May 24, 2017, 11:36

Change of plan.

TGHT = 620A, TBHT = 210A

Ramping back-up to max setpoints and will remain at those points until vacuum starts to decrease more.

 Friday, May 26, 2017, 15:24

IGP1 = 2.1e-7 Torr

IGP2 = 2.2e-7 Torr

TGHT = 660A, 10.72V

TBHT = 230A, 3.21V

All windows coated.

Remained at max setpoints for ~3.5days.

Conditioning process complete.

Initiating auto-cool at 2A/min and 1A/min for the TGHT and TBHT respectively.

 Tuesday, May 30, 2017, 14:41

Target vented in air and removed from evap2

Looks good!

Endcaps inserted and expanded.

See photos attached.

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.  

 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

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, August 02, 2016, 13:41

Target container contains 471 discs of SiC [6 x 5 packs + 441 single discs]

Target packed length = 16cm. 

Mass of SiC(green)  = 52.7172g

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

Sintering temp = 1800C

TGHT max = 350A.  TBHT max at 230A. 

Chamber is currently being pumped down. 

Slope on OMEGA = 1.04

Tuesday, August 02, 2016, 16:00

Tapped up manually to 30A - vacuum to high, lowered down to 20A to be able to initiate auto-ramp.

IGP1 = 2.3e-5 Torr

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

 Friday, August 05, 2016, 11:57

Evap2 has reached TGHT = 350A, 5.33V

TBHT = 187A, 2.31V and still climbing...

OMEGA = 1365C

IGP1 = 7.88e-7 Torr

Increased max setpoint for TGHT to 400A.

 Friday, August 05, 2016, 13:33

TGHT = 380A, 5.97V

TBHT = 197A, 2.45V

OMEGA = 1396C

IGP1 = 8.75e-7 Torr

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

New final setpoint for the TGHT = 450A

 Friday, August 05, 2016, 14:17

TBHT = 230A, 2.97V

TGHT = 450A, 7.4V

OMEGA = 1572C

IGP1 = 3.2e-6 Torr

Increasing max setpoint for TGHT to 500A and re-initiating auto-ramp.

 Friday, August 05, 2016, 15:18

At TGHT = 480A, OMEGA temperature dropped to 1400C due to coating on window.

Last reading was ~1600C

Tapped up manually to TGHT = 500A, 8.61V

Window fully coated therefore OMEGA reading is negligible at this point

Attempted to take temperature reading with other OMEGA from behind evaporator or using handheld manual temperature reader - all windows have a coating, therefore unsuccessful.

IGP1 = 1.75e-6 Torr

Reduced max voltage set for TGHT to 9.0V to minimize possibly voltage 'creep'

Will remain at these setpoints over wknd and ramp down monday morning.

 Monday, August 08, 2016, 08:45

TGHT = 500A on the 'current set' and 466A on the readout, 8.74V

TBHT = 230A, 2.99V

IGP1 = 6.6e-8 Torr

OMEGA = 1460C [reading through coating on window port]

Evap2 has been at these setpoints for the wknd.

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

 Monday, August 08, 2016, 10:38

Quick observational note:

while ramping down OMEGA readings have slowly increased.

At ~350A OMEGA = ~1500C

At ~300A, OMEGA = ~1750C

Currently at 280A, OMEGA = ~2800C

Coating on window has affected the OMEGA readings in a weird way...

 Monday, August 08, 2016, 15:17

Vented in air and opened up this afternoon.

Cleaned windows but left target loaded in evap2 for conditioning process.

 Thursday, June 09, 2016, 15:39

First target using beta-SiC material!

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

Target packed length = 16cm. 

Mass of 533 discs SiC(green)  = 53.8758g

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

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

Chamber is currently being pumped down. 

Friday, June 10, 2016, 13:24

HS water valves opened, no leaks detected.

Tapping up manually to 70A...

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

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

 Friday, June 10, 2016, 16:27

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

Pressure stabilized at 5.5e-5 Torr.

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

John Wong wrote:

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

 Monday, June 13, 2016, 09:51

TGHT = 425A, 5.65V

TBHT = 225A, 3.7V

IGP1 = 8.7e-6 Torr.

Increasing ramping rate to 1.0A/min...

 Monday, June 13, 2016, 15:56

Tapped up manually from 520A to 1800C

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

Will remain at 1800C for ~48hrs

See attachements for excel sheet and screenshot of striptool.