John Wong wrote:

Laura Lambert wrote: John Wong wrote:   Laura Lambert wrote:  Thursday, June 09, 2016, 15:39 First target using beta-SiC material! Target container contains 450 discs of SiC [4 x 5 packs + 430 single discs] Target packed length = 16cm.  Mass of 533 discs SiC(green)  = 53.8758g Container is wrapped with 3 heatshields; no end caps are inserted yet - coated spring inserted both sides to hold discs in place. Sintering temp = 1800C, TGHT will be set accordingly.  TBHT max at 230A.  Chamber is currently being pumped down.  Friday, June 10, 2016, 13:24 HS water valves opened, no leaks detected. Tapping up manually to 70A... Auto ramp will be set for TGHT = 0.2A/min to a final setpoint of 520A Auto-ramp for TBHT = 0.1A/min to a final setpoint of 230A.      Friday, June 10, 2016, 16:27 TGHT stepped up to 70A/0.55V.  TGHT at 50A/0.62V.  Pressure stabilized at 5.5e-5 Torr. Initiated auto ramping.  TGHT at 0.2A/min --> 520A.  TBHT at 0.1A/min --> 230A.    Monday, June 13, 2016, 09:51 TGHT = 425A, 5.65V TBHT = 225A, 3.7V IGP1 = 8.7e-6 Torr. Increasing ramping rate to 1.0A/min...  Monday, June 13, 2016, 15:56 Tapped up manually from 520A to 1800C Extrapolated data on graph to determine correct current required to reach desired max temperature. Will remain at 1800C for ~48hrs See attachements for excel sheet and screenshot of striptool.    Wednesday, June 15, 2016, 17:54 TGHT at 710A, 11.35V.  TBHT at 230A/3.86V.  Omega reading droppd to 1130C due to coating on windows.  Ionizer tube was measured (center) at around 1900C Cooling down at 2A/min for TGHT, 1A/min for TBHT.  Samples will be collected prior to cleaning the windows. NEXT:  Conditioning.

Thursday, June 16, 2016, 09:29

vented in air and opened up this morning.

took some samples to be tested.

 Thursday, June 16, 2016, 10:59

Previously sintered over weekend [see elog i.d 306]

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.

Conditioning temp = 1800C.

TGHT max = 710A according to sintering data.  TBHT max = 230A. 

Chamber is currently being pumped down. 

 Thursday, June 16, 2016, 15:43

Target was not removed from evap2 after sintering, vented and cleaned windows only.

HS water valves already open.

Stepped up manually to 70A, vacuum stable.

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

TGHT = 118A, 0.9V

TBHT = 90A, 1.1V

IGP1 = 7.3e-7 Torr

 Friday, June 17, 2016, 12:14

TGHT has been tapped up manually to reach max desired temperature of 1800C

TGHT = 690A, 10.85V

TBHT = 230A, 3.88V

IGP1 = 4.9e-7 Torr

This is a lower current than the current required to reach 1800C during the sintering process.

For sintering, the max current was determined via extrapolation of trendline from raw data due to interference of coating on window and unable to take reliable readings from OMEGA.

For this conditioning process ~1800C is reached on the OMEGA since the window is still ~un-coated.

Will remain at 690A, ~1800C for several days to maximize conditioning process.

See attachment for raw data.

 Monday, June 20, 2016, 09:01

At the end of the day on friday 17th, OMEGA read ~1750C - no change in the current or voltage, vacuum was stable, this was the max setpoints used to reach 1800C.

This morning OMEGA = 2040C

TGHT = 690A, 10.95V

vacuum stable at IGP1 = 1.8e-7 Torr.

Slightly more noticeable coating on window port, looks like a thin ink layer, still relatively thin coating [ see attached image]

Also attached is archive from over wknd to show vacuum stable, current unchanged and voltage negligibly changed [only gone up by ~0.1V]

 Friday, June 24, 2016, 13:52

Container has remained at max setpoints for 7 days.

Initiating auto-cool for TGHT @ 2.0A/min and for TBHT @ 1.0A/min.

Will vent chamber and remove from evap2 to pass off for assembly monday morning.

See attachment for updated excel on temperature readings for the conditioning process.

 Monday, June 27, 2016, 08:28

vented in air and removed this morning.

target looks good!

all discs remained nicely alligned.

discs expanded outwards ~1cm, pushed back in to keep target length at 16cm

no visible yellow crystals like previous SiC targets 

endcaps inserted and expanded.

Rh foil inserted.

Ta heat shield foils removed, fins look good.

see photos attached for pictures of target - post conditioning.

coating on window very hard to remove. looked like a light sharpy pen coating on window. ended up scratching off with acetone and screw driver. couldn't remove all of it...

 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.

 Monday, August 08, 2016, 15:19

Previously sintered over weekend [see elog i.d 311]

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

Target packed length = 16cm. 

Mass of 533 discs 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.

Conditioning temp = 1800C.

TGHT max = 450A.  TBHT max = 230A. 

Chamber is currently being pumped down. 

 Monday, August 08, 2016, 16:38

Target was not removed from evap2 after sintering, vented and cleaned windows only.

IGP1 = 5.5e-6 Torr

Stepped up manually to 80A, vacuum stable.

IGP1 = 3.2e-6 Torr

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

 Thursday, August 11, 2016, 14:14

Tues the TGHT reached ~280A via auto-ramp

Evap2 was then tapped up manually to 480A/ ~1800C

Temperature readings on OMEGA have fluctuated up and down during conditioning process which was also observed for SiC#33

Also consistent with SiC#33, a lower current was required to reach 1800C during the conditioning process compared to the sintering process.

See attached link for data.

 Tuesday, August 16, 2016, 16:25

TGHT remained at 480A, 9.2V for ~7 days.

IGP1 = 6.5e-6 Torr

OMEGA = 1470C [with window coating, so temperature reading compromised]

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

Wednesday, August 17, 2016, 13:40

Vented in air and opened this morning.

Target broke  

Target clearly heated to high.

See attached snapshot of striptool from conditioning process.

Will update later with photos of broken container

Wednesday, August 24, 2016, 17:05

Target container was previously coated with TaC and sintered up to 1900C at 420A/7.01V

Container is loaded with beta-SiC 432 discs at 16cm in length. 

Container is wrapped with Ta-heat shield; no end-caps are used at this time.

Chamber is being pumped down.

 Thursday, August 25, 2016, 12:04

Chamber has been pumped down overnight.  Pressure at 5.9e-7 Torr.

HS water valve opened; no leaks were detected.

Sintering temperature 1800C. TGHT will be set accordingly to get the desired temperature.  TBHT max at 230A.

Thursday, August 25, 2016, 12:12

Tapped up TGHT/TBHT to 40A.  Vac at 7e-6 and slowly going up  but still below limit.

 Monday, August 29, 2016, 11:04

TGHT and TBHT reached to 250A (3.65V)//230A(3.02V), respectively, and kept stable over the weekend. 

Temp measured at 1372C with slope set at 1.04 (1230C at slope 0.98). 

No visible coating on windows. 

Setting up TGHT to reach 1800C; monitoring locally

 Monday, August 29, 2016, 14:35

Stepped up TGHT to 390A/6.54V; light coating was observed on the windows.  The temperature should be around 1800C which should be in line with the power (current) deposited in the container during the TaC coat sintering process (1900A at 420A); however, with the light coating the reading may be off.  

Mikron was used to measured inside of the tube (away from the discs); temperature was measured at ~1800C, (see attachment)  [adjusted slope at 1.00 to compensate the SiC disc and Ta]  

Omega was used to measured the temperature of the discs.  It is difficult to know what's the temperature inside the tube, so this measurement  is only taken as a guideline.  Slope changed from 1.04 to 1.15 to match Mikron's reading.  

After heated at  390A for 30 mins, the windows are now coated.  Temp reading is no longer reliable.  The temperature could be above 1800C.  Keeping a close monitor!!!

No blockage inside the tube was observed.  

Will remain heating at 390A/6.44V for overnight before proceeding with the re-conditioning. 

 Tuesday, August 30, 2016, 10:41

Target was heated at 390A  for over 10 hours and then cool down at 1A/min (see attachment#2).  Windows were fully coated and Omega couldn't register any reading. 

Chamber will be vented and target will be inspected before proceeding with the re-conditioning step.

Tuesday, August 30, 2016, 12:13  

Target was inspected; no visible damage was observed (see attachment)

Material coated on the windows and the cu heat shields;  all parts were wiped off with acetone. 

No visible material build up inside the container. 

Chamber is now being pumped down for re-conditiing.  

 Tuesday, August 30, 2016, 13:05

HS water valves open; no leaks detected.  

Vac at 3.6 e-6 Torr.  

Ready to set up TGHT/TBHT

 Tuesday, August 30, 2016, 16:41

TGHT/TBHT stepped up to 340A (5.40V) /230A (3.1V), respectively. 

Temperature was measured at 1835C at TGHT of 340A.  Omega, Mikron and analogue pyrometer were all reading ~1800C inside the tube (not on the SiC surface).  For that reason, I decided to stop the current at 340A, instead of 390A.  

TGHT voltage is running stable.  

No visible coating or blockage inside the tube was observed.  

Wednesday, August 31, 2016, 11:53

A thin layer of coating is observed on both the side windows (see attachment 5).  The temp reading is no longer reliable.

TGHT remains at 340A/5.45V.  P/S voltage is performing steadily.  

No clogging inside the tube is observed. 

Setting up another Omega reader to measure temperature from the front window since this window is clear and won't get coated (see attachment #6).

Temperature measurement from the front window is ~1140C; this corresponds to the measurement from the analogue pyrometer with the correction of e=~0.2 for tantalum at 1100C.

Note:  The temperature measurements should be taken as relative.  Since the reading from the side windows isn't reliable any longer, the centre window will give some information how stable the temperature is holding during the reconditioning process.  Continue to monitor.

 Wednesday, August 31, 2016, 16:24

About two hours ago, I increased TGHT to 350A and stayed there for a few mins (see attachment 7).  No change in temp was observed - that's mainly due to the coating on the windows.  As for the temp measurement from the center window, a more power current input would require to see the change as heat is slowly propagating through the layers of Ta heatshields.

Local inspection on the target: no clogging inside the tube. Voltage/Current is stable at 340A/5.45V.  Vac at 1.43e-7 Torr.

 Wednesday, August 31, 2016, 23:00

Strange observation:  Temperature readers on both omega have gone up. (see attachment 8).

I'm not sure if the temperature is reiiable.  I actually saw the increase in temperature ~1850C  last night around the same time; no change in TGHT current/voltage.  By the next morning, it went back down to 1400C with significant coating on the windows.

 Wednesday, August 31, 2016, 23:28

I had ISAC Op (Justin) to help me go into the Hotlab and take a look at the reading on Mikron.  Indeed, it is reading about 2000C which is close to the Omega reading.  He also looked into the tube through Mikron scope and found no clogging inside the tube.

To be safe, I am going to lower the TGHT heater down to reach ~1800C.

Wednesday, August 31, 2016, 23:41

Lower TGHT to 305A/4.81V; OMEGA reading at 1830C.  Vac at 1.27e-7 Torr.  Will remain at this current over night. 

 Thursday, September 01, 2016, 12:16

Checked on the target.  

Temperature readings, right windows (omega)= 1726C, centre = 1100C (omega), left (Mikron) = 1720C.  

No blockage inside the tube.  

TGHT stabilizes at 305A/4.79V.  Vac at 1.09e-7 Torr.  

 Thursday, September 01, 2016, 16:32

 About an hour ago, the temp dropped to 1660C with no change in TGHT current/voltage (see attachment 9).

Vac is a 1.06e-7 Torr. 

After consulting with Friedhelm, we decided to cool the target down and inspect it tomorrow.

Ramping TGHT/TBHT at 2A/min.

 Wednesday, September 07, 2016, 15:13

The target was removed from the Evap and inspected. 

Some spots on both ends and ionizer tube were crystalized.  (see attachment 10). 

No blockage inside the tube was observed. 

End caps were inserted.

The target was assembled and tested - All seems fine. 

Laura Lambert wrote:

Monday, August 08, 2016, 15:19 Previously sintered over weekend [see elog i.d 311] Target container contains 471 discs of SiC [6 x 5 packs + 441 single discs] Target packed length = 16cm.  Mass of 533 discs 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. Conditioning temp = 1800C. TGHT max = 450A.  TBHT max = 230A.  Chamber is currently being pumped down.   Monday, August 08, 2016, 16:38 Target was not removed from evap2 after sintering, vented and cleaned windows only. IGP1 = 5.5e-6 Torr Stepped up manually to 80A, vacuum stable. IGP1 = 3.2e-6 Torr Initiating auto-ramp at 0.2A/min for the TGHT and 0.1A/min for the TBHT.  Thursday, August 11, 2016, 14:14 Tues the TGHT reached ~280A via auto-ramp Evap2 was then tapped up manually to 480A/ ~1800C Temperature readings on OMEGA have fluctuated up and down during conditioning process which was also observed for SiC#33 Also consistent with SiC#33, a lower current was required to reach 1800C during the conditioning process compared to the sintering process. See attached link for data.  Tuesday, August 16, 2016, 16:25 TGHT remained at 480A, 9.2V for ~7 days. IGP1 = 6.5e-6 Torr OMEGA = 1470C [with window coating, so temperature reading compromised] Initiating auto cool at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively. Wednesday, August 17, 2016, 13:40 Vented in air and opened this morning. Target broke   Target clearly heated to high. See attached snapshot of striptool from conditioning process. Will update later with photos of broken container

 Tuesday, August 30, 2016, 15:17

A better look at the p/s voltage over the course of the constant heating at 480A.  (see attachment).

The striptool shows the voltage was not giving a stable output.  There were multiple occasions that the voltage dropped and then recovered; the obvious was on Aug 16.  This indicates that  the target was breaking up.

Finally on Aug 17, the voltage dropped and never recovered again - that indicates the target was broken.

 Thursday, September 15, 2016, 16:23

Target container contains 487 discs of SiC 

Target packed length = 16cm. 

Mass of SiC(green)  = 58.8795g

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

Sintering temp = 1800C

Chamber is currently being pumped down. 

 Friday, September 16, 2016, 10:50

Tapped up manually to 50A

Waited ~1hr , vacuum stable.

IGP1 = 1.24e-5 Torr

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

TGHT max = 500A.  TBHT max at 230A. 

Slope on OMEGA = 1.15

 Monday, September 19, 2016, 10:53

OMEGA = 1230C

TGHT = 360A, 4.75V

TBHT = 204A, 2.68V

IGP1 = 5.3e-6 Torr

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

 Monday, September 19, 2016, 11:57

OMEGA = ~1300C

TBHT = 230A, 3.16V

TGHT = 409A, 5.55V

Lowering ramping rate to 0.2A/min while vaccum high

IGP1 = 3.05e-5 Torr

 Monday, September 19, 2016, 13:22

OMEGA = 1350C

TGHT = 425A, 5.82V

IGP1 = 1.97e-5 Torr

Stepping ramping rate back up to 1.0A/min

Laura Lambert wrote:

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

 Monday, September 19, 2016, 18:24

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

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

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

John Wong wrote:

Laura Lambert wrote:  Thursday, September 15, 2016, 16:23 Target container contains 487 discs of SiC  Target packed length = 16cm.  Mass of SiC(green)  = 58.8795g Container is wrapped with 1x heatshield around each side of cooling fins; no end caps are inserted yet - coated spring inserted both sides to hold discs in place. Sintering temp = 1800C Chamber is currently being pumped down.   Friday, September 16, 2016, 10:50 Tapped up manually to 50A Waited ~1hr , vacuum stable. IGP1 = 1.24e-5 Torr Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. TGHT max = 500A.  TBHT max at 230A.  Slope on OMEGA = 1.15  Monday, September 19, 2016, 10:53 OMEGA = 1230C TGHT = 360A, 4.75V TBHT = 204A, 2.68V IGP1 = 5.3e-6 Torr Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.  Monday, September 19, 2016, 11:57 OMEGA = ~1300C TBHT = 230A, 3.16V TGHT = 409A, 5.55V Lowering ramping rate to 0.2A/min while vaccum high IGP1 = 3.05e-5 Torr  Monday, September 19, 2016, 13:22 OMEGA = 1350C TGHT = 425A, 5.82V IGP1 = 1.97e-5 Torr Stepping ramping rate back up to 1.0A/min    Monday, September 19, 2016, 18:24 Measuring the temperature on the SiC is difficult due to the changing in emissivity as the temperature goes up.  So, I will use the MIKRON to measure the temperature on the Ta surface near the end of the tube and OMEGA for measuring the inside.   Using the analogue pyrometer, the temperature on the Ta surface at the end of the tube was measured at around ~1450C; this temperature match the temperature on the Mikron at slope 0.98 (as usual).  To match it with OMEGA, I changed the slope to 1.04 since this measurement is taking readings on the  inside of the tube and on the SiC material.    Note:  The measurements are NOT the absolute temperature.  These are relative temperature measurements  which give some guideline where the target current should be at for the sintering process.  Please plot the temp vs current as the TGHT is being ramped up.  At some point, the windows will get coated and the measurement is no longer reliable.   The plot will be used to give an estimation of the current for 1800C.

 Tuesday, September 20, 2016, 15:18

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

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

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

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

see attachment for raw data

 Wednesday, September 21, 2016, 11:34

temperatures dropped a small amount overnight.

tapped up manually to 625A/ 1810C

still no coating on window.

see attachment for updated raw data

Laura Lambert wrote:

John Wong wrote: Laura Lambert wrote:  Thursday, September 15, 2016, 16:23 Target container contains 487 discs of SiC  Target packed length = 16cm.  Mass of SiC(green)  = 58.8795g Container is wrapped with 1x heatshield around each side of cooling fins; no end caps are inserted yet - coated spring inserted both sides to hold discs in place. Sintering temp = 1800C Chamber is currently being pumped down.   Friday, September 16, 2016, 10:50 Tapped up manually to 50A Waited ~1hr , vacuum stable. IGP1 = 1.24e-5 Torr Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. TGHT max = 500A.  TBHT max at 230A.  Slope on OMEGA = 1.15  Monday, September 19, 2016, 10:53 OMEGA = 1230C TGHT = 360A, 4.75V TBHT = 204A, 2.68V IGP1 = 5.3e-6 Torr Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.  Monday, September 19, 2016, 11:57 OMEGA = ~1300C TBHT = 230A, 3.16V TGHT = 409A, 5.55V Lowering ramping rate to 0.2A/min while vaccum high IGP1 = 3.05e-5 Torr  Monday, September 19, 2016, 13:22 OMEGA = 1350C TGHT = 425A, 5.82V IGP1 = 1.97e-5 Torr Stepping ramping rate back up to 1.0A/min    Monday, September 19, 2016, 18:24 Measuring the temperature on the SiC is difficult due to the changing in emissivity as the temperature goes up.  So, I will use the MIKRON to measure the temperature on the Ta surface near the end of the tube and OMEGA for measuring the inside.   Using the analogue pyrometer, the temperature on the Ta surface at the end of the tube was measured at around ~1450C; this temperature match the temperature on the Mikron at slope 0.98 (as usual).  To match it with OMEGA, I changed the slope to 1.04 since this measurement is taking readings on the  inside of the tube and on the SiC material.    Note:  The measurements are NOT the absolute temperature.  These are relative temperature measurements  which give some guideline where the target current should be at for the sintering process.  Please plot the temp vs current as the TGHT is being ramped up.  At some point, the windows will get coated and the measurement is no longer reliable.   The plot will be used to give an estimation of the current for 1800C.        Tuesday, September 20, 2016, 15:18 there was a temperature fluctuation resulting in the MIKRON no longer matching the readout on the OMEGA this prompted another change in the slope on the OMEGA to 1.08 TGHT was then tapped up manually to 600A/ 1800C will remain at this max setpoint for a few days before ramping down see attachment for raw data  Wednesday, September 21, 2016, 11:34 temperatures dropped a small amount overnight. tapped up manually to 625A/ 1810C still no coating on window. see attachment for updated raw data

 Thursday, September 22, 2016, 12:07

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

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

Continue to monitor… (see dropbox for captured photos) 

John Wong wrote:

Laura Lambert wrote: John Wong wrote: Laura Lambert wrote:  Thursday, September 15, 2016, 16:23 Target container contains 487 discs of SiC  Target packed length = 16cm.  Mass of SiC(green)  = 58.8795g Container is wrapped with 1x heatshield around each side of cooling fins; no end caps are inserted yet - coated spring inserted both sides to hold discs in place. Sintering temp = 1800C Chamber is currently being pumped down.   Friday, September 16, 2016, 10:50 Tapped up manually to 50A Waited ~1hr , vacuum stable. IGP1 = 1.24e-5 Torr Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. TGHT max = 500A.  TBHT max at 230A.  Slope on OMEGA = 1.15  Monday, September 19, 2016, 10:53 OMEGA = 1230C TGHT = 360A, 4.75V TBHT = 204A, 2.68V IGP1 = 5.3e-6 Torr Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.  Monday, September 19, 2016, 11:57 OMEGA = ~1300C TBHT = 230A, 3.16V TGHT = 409A, 5.55V Lowering ramping rate to 0.2A/min while vaccum high IGP1 = 3.05e-5 Torr  Monday, September 19, 2016, 13:22 OMEGA = 1350C TGHT = 425A, 5.82V IGP1 = 1.97e-5 Torr Stepping ramping rate back up to 1.0A/min    Monday, September 19, 2016, 18:24 Measuring the temperature on the SiC is difficult due to the changing in emissivity as the temperature goes up.  So, I will use the MIKRON to measure the temperature on the Ta surface near the end of the tube and OMEGA for measuring the inside.   Using the analogue pyrometer, the temperature on the Ta surface at the end of the tube was measured at around ~1450C; this temperature match the temperature on the Mikron at slope 0.98 (as usual).  To match it with OMEGA, I changed the slope to 1.04 since this measurement is taking readings on the  inside of the tube and on the SiC material.    Note:  The measurements are NOT the absolute temperature.  These are relative temperature measurements  which give some guideline where the target current should be at for the sintering process.  Please plot the temp vs current as the TGHT is being ramped up.  At some point, the windows will get coated and the measurement is no longer reliable.   The plot will be used to give an estimation of the current for 1800C.        Tuesday, September 20, 2016, 15:18 there was a temperature fluctuation resulting in the MIKRON no longer matching the readout on the OMEGA this prompted another change in the slope on the OMEGA to 1.08 TGHT was then tapped up manually to 600A/ 1800C will remain at this max setpoint for a few days before ramping down see attachment for raw data  Wednesday, September 21, 2016, 11:34 temperatures dropped a small amount overnight. tapped up manually to 625A/ 1810C still no coating on window. see attachment for updated raw data    Thursday, September 22, 2016, 12:07 Temperature reader on OMEGA dropped slightly to 1785C overnight.  The temperature on the leg remained at 1800C (MIKRON).  No coating on windows.   Increased TGHT to 635A/10.12V (local 10.40V).  OMEGA reads 1800C, MIKRON ~1817C.   Continue to monitor… (see dropbox for captured photos)

 Monday, September 26, 2016, 13:24

Temperature decreased over weekend.

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

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

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

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

See attached picture showing these details

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

Windows remain un-coated.

Current and voltage readings remain un-changed.

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

 Wednesday, September 28, 2016, 17:05

Vented in air, target taken out today.

Target looks good!

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

Will update tomorrow with photos

Endcaps inserted.

 Thursday, April 13, 2017, 12:01

Pellets made this morning and weighed.

Placed in a graphite boat which is placed inside a previously TaC coated boat.

Boat is wrapped with 3x Ta heat shields.

Loaded into evap2.

Chamber currently pumping down.

 Tuesday, April 18, 2017, 13:53

HS water valves were opened this morning, no leaks detected.

Tapped up manually to 100A, 1.28V

Vacuum stable.

IGP1 = 3.63e-6 Torr.

Initiating auto ramp at a rate of 1.0A/min to 150A

Final desired temperature of 1100C

 Tuesday, April 18, 2017, 14:57

TGHT = 150A, 2.08V

Still no temperature reading on OMEGA.

Vacuum stable, IGP1 = 1.16e-6 Torr.

Initiating auto ramp at the same rate of 1.0A/min up to 200A.

 Tuesday, April 18, 2017, 15:56

TGHT = 200A, 2.91V

OMEGA = 990C

IGP1 = 8.59e-7 Torr

Tapping up manually to 1100C...

 Wednesday, April 19, 2017, 08:34

TGHT = 235A, 3.47V

OMEGA = 1090C

IGP1 = 1.6e-7 Torr.

Has remained at ~1100C since 16:30 yesterday.

Intitiating auto-cool at 2.0A/min

 Thursday, April 20, 2017, 08:40

Vented in air and taken out yesterday.

Pellets look good.

No obvious colour change.

 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

 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.

 Wednesday, June 14, 2017, 15:49

Pellets previously made by Marla and weighed.

Pellets are placed inside a small graphite sample tube.

Graphite sample tube loaded with pellets is loaded into a previously TaC coated boat.

Boat is wrapped with 3x Ta heat shields.

Loaded into evap2.

Chamber currently pumping down.

 Thursday, June 15, 2017, 11:24

HS water valves were opened this morning, no leaks detected.

Tapped up manually to 50A, 0.44V

Vacuum currently rising starting to settle.

IGP1 = 1.51e-6 Torr.

One vacuum stabilizes will initiate auto ramp at a rate of 1.0 A/min up to a final set point of 150 A.

Final desired temperature of 1800C.

Laura Lambert wrote:

Wednesday, June 14, 2017, 15:49 Pellets previously made by Marla and weighed. Pellets are placed inside a small graphite sample tube. Graphite sample tube loaded with pellets is loaded into a previously TaC coated boat. Boat is wrapped with 3x Ta heat shields. Loaded into evap2. Chamber currently pumping down.  Thursday, June 15, 2017, 11:24 HS water valves were opened this morning, no leaks detected. Tapped up manually to 50A, 0.44V Vacuum currently rising starting to settle. IGP1 = 1.51e-6 Torr. One vacuum stabilizes will initiate auto ramp at a rate of 1.0 A/min up to a final set point of 150 A. Final desired temperature of 1800C.

 Friday, June 16, 2017, 10:37

IGP1 = 7.91e-7 torr.

TGHT = 167 A, 2.3 V.

Tapped up manually to 350A yesterday, remained there overnight.

IGP1 = 4.55e-7 torr

TGHT=350 A, 5.6 V,

Changed slope to 0.98

Checked temperature readings with mikron to confirm slope

Mikron LS = 1260C, RS=1290C

OMEGA= 1295C

Initiating auto ramp at 1.0A/min to a final set point of 450A.

Final desired temperature of 1600C (no longer need to go to 1800C).

*note: graphite sample tube has graphite endcaps inserted