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.

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.

Laura Lambert wrote:

Wednesday, August 17, 2016, 17:30 Container coated with TaC using 'flushing technique', cleaned ionizer tube with acetone, so no coating inside ionizer tube Wrapped with 3 x Ta heat shields, incl center block Currently pumping down in evap2 Thursday, August 18, 2016, 10:14  HS water valves opened...leak detected  see attachment for photo from archives Vented and opened up. Anders performed leak check, nothing found. Replaced all seals with blue seals. Pumping down now  Thursday, August 18, 2016, 16:12 HS water valves opened...leak detected again  see attachment for photo of striptool Vented and opened up. working with Anders on finding leak...  Monday, August 22, 2016, 10:38 leaks FIXED! HS water valves opened, NO leaks detected! Tapped up manually to 70A Vacuum stable, IGP1 = 2.5e-6 Torr Initiating auto ramp for TGHT @ 0.2A/min to a max setpoint of 350A Initiating auto ramp for TBHT @ 0.1A/min to a max setpoint of 230A Once max setpoints achieved, will tap up manually to final desired temperature of 1900C  Monday, August 22, 2016, 14:58 TGHT = 115A, 1.3V TBHT = 89A, 0.97V IGP1 = 4.1e-7 Torr. Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.  Monday, August 22, 2016, 16:01 IGP1 = 1.25e-6 torr TGHT = 174A, 2.2V TBHT = 118A, 1.4V Lowering ramping rate to 0.2A/min and 0.1A/min for the TGHT and TBHT respectively for overnight ramping.

 Tuesday, August 23, 2016, 12:14

Initiate TGHT autoramping to 400A at 2A/min.  Vac 3.5e-7 Torr. 

 Tuesday, August 23, 2016, 14:48

TGHt tapped up to 420A/7.01V.  Local temp read at ~1900C.  Will sinter at this temp for a few hours before cooling down.

 Tuesday, August 23, 2016, 17:20

TGHT at been at 420A/7.01V for over 4 hours.  Vac at 4.8e-7 Torr.

Cooling TGHT and TBHT at 1A/min.

 Wednesday, August 24, 2016, 10:35

TGHT/TBHT at 0A.

Venting chamber.

Container looks good.

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.

 Wednesday, September 07, 2016, 14:45

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

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

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

 Thursday, September 08, 2016, 18:14

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

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

Will remain at this TGHT current over night

Vac at 3.0e-6 Torr and coming down.

Friday, September 09, 2016, 11:01 

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

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

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

Pressure at 1.07e-6 Torr. 

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

Continue to capture the cooling down process. 

 Friday, September 09, 2016, 15:17

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

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

John Wong wrote:

Wednesday, September 07, 2016, 14:45 Container was previously coated with TaC solution and wrapped with 1-full length layer of Ta- heat shield around the fins.   Chamber is being pumped down.  Vac at 5.6e-7 Torr before HS water valves were open; no leaks were detected.  Sintering Temperature 1900C (Omega slope @ 0.98); expected TGHT ~765A/11.90V, TGHT max at 230A.  Thursday, September 08, 2016, 18:14 At about 1600C, it was observed that the coating inside the tube seems to chip off (see attachment 1). TGHT was ramped up to 745A/11.85V and TBHT to 230A/3.25V.  Temperature measured on OMEGA/Mikron = 1914C/1881C; both instruments slopes set at 0.98. Will remain at this TGHT current over night Vac at 3.0e-6 Torr and coming down. Friday, September 09, 2016, 11:01  Target has been heated at the stable temperature at 1914C (for OMEGA) and 1881C (for Mikron) with current at 745A/11.94V (see attachment 2) for almost 19 hours.  No fluctuation in p/s current or temperature was observed.  The ramping up process is captured and can be view from the link below: https://www.dropbox.com/sh/9lgtin54o17ds6j/AABn1-XjvK44mm74TjqTAmvta?dl=0 Pressure at 1.07e-6 Torr.  Cooling down TGHT at 2A/min and TBHT at 1A/min.  Continue to capture the cooling down process.   Friday, September 09, 2016, 15:17  While the target container was cooling down, the chip-like particle began obvious (see attachment 3).   Will inspect the container.. TGHT currently at 260A.

 Monday, September 12, 2016, 16:54

The TaC coating chipped off from the surface and didn't get sintered with the container.  (See attachment1). 

There are a few possible reasons why this happened:

1.  The coating was too think.  This may cause the TaC  layer to curl up while the heater was ramped up. 

2.  The coated material got brittle.  The container was flushed with TaC (probably a few weeks ago?) before it went through the sintering process.  Prolong exposure to air/light usually degrade the polymers viscoelasticity.

3.  TaC solution has got bad.  The particles can agglomerate over time and this can cause uneven surface.

4.  Combination of all... ???

Anyway, the chipped off TaC layer was gently scraped off with a stainless steel rod.  Then using kimwipes, i was able to remove most of the chipped off coating; it was not easy - especially trying to remove it from the inner tube.

Instead of "flushing" the tube with TaC, I decided to spray it with thin layer.  And using the air supply, I could quickly dry the coating and installed it back to the evaporator for 2nd Round sintering as we are approaching the deadline!

.                         

John Wong wrote:

John Wong wrote:  Wednesday, September 07, 2016, 14:45 Container was previously coated with TaC solution and wrapped with 1-full length layer of Ta- heat shield around the fins.   Chamber is being pumped down.  Vac at 5.6e-7 Torr before HS water valves were open; no leaks were detected.  Sintering Temperature 1900C (Omega slope @ 0.98); expected TGHT ~765A/11.90V, TGHT max at 230A.  Thursday, September 08, 2016, 18:14 At about 1600C, it was observed that the coating inside the tube seems to chip off (see attachment 1). TGHT was ramped up to 745A/11.85V and TBHT to 230A/3.25V.  Temperature measured on OMEGA/Mikron = 1914C/1881C; both instruments slopes set at 0.98. Will remain at this TGHT current over night Vac at 3.0e-6 Torr and coming down. Friday, September 09, 2016, 11:01  Target has been heated at the stable temperature at 1914C (for OMEGA) and 1881C (for Mikron) with current at 745A/11.94V (see attachment 2) for almost 19 hours.  No fluctuation in p/s current or temperature was observed.  The ramping up process is captured and can be view from the link below: https://www.dropbox.com/sh/9lgtin54o17ds6j/AABn1-XjvK44mm74TjqTAmvta?dl=0 Pressure at 1.07e-6 Torr.  Cooling down TGHT at 2A/min and TBHT at 1A/min.  Continue to capture the cooling down process.   Friday, September 09, 2016, 15:17  While the target container was cooling down, the chip-like particle began obvious (see attachment 3).   Will inspect the container.. TGHT currently at 260A.    Monday, September 12, 2016, 16:54 The TaC coating chipped off from the surface and didn't get sintered with the container.  (See attachment1).  There are a few possible reasons why this happened: 1.  The coating was too think.  This may cause the TaC  layer to curl up while the heater was ramped up.  2.  The coated material got brittle.  The container was flushed with TaC (probably a few weeks ago?) before it went through the sintering process.  Prolong exposure to air/light usually degrade the polymers viscoelasticity. 3.  TaC solution has got bad.  The particles can agglomerate over time and this can cause uneven surface. 4.  Combination of all... ??? Anyway, the chipped off TaC layer was gently scraped off with a stainless steel rod.  Then using kimwipes, i was able to remove most of the chipped off coating; it was not easy - especially trying to remove it from the inner tube. Instead of "flushing" the tube with TaC, I decided to spray it with thin layer.  And using the air supply, I could quickly dry the coating and installed it back to the evaporator for 2nd Round sintering as we are approaching the deadline! .

 Monday, September 12, 2016, 17:24

Chamber was pumped down to low 10e-6 Torr before HS water valves were open - no leaks detected.

TGHT/TBHT auto ramped at 2A/min to 600A/230A.

Will continue to monitor..

 Wednesday, September 14, 2016, 17:04

TGHT was stepped up to 700A and temp 1851C (OMEGA), 1930C(Mikron).  (see attachment 1).  The container was heated over night before it was cool down at 2A/min. 

Target container seems to properly sintered with TaC (see attachment 2); it will be used for SiC#35. 

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.  

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) 

Laura Lambert wrote:

Friday, October 07, 2016, 16:40 Target consists of 470 discs. Total packed length 3.4cm [exactly 7.8cm space on both sides] Total mass g [Incl foils + Ta wire on 6 packs] Note: Target consists of 350 single discs and 6x20 packs of Ta discs 3x Ta Heat shields. No endcaps inserted, no Rh foil inserted. Chamber currently pumping down. TBHT will be ramped up to 230A at 1.0A/min. TGHT will be ramped up to 300A at 2.0A/min. Final desired temperature = 1900C  Tuesday, October 11, 2016, 10:02   HS water valves opened, no leaks detected   Tapped up manually to 35A   Vacuum stable, IGP1 = 2e-7 Torr   Initiating auto-ramp.   OMEGA slope = 0.98  Wednesday, October 12, 2016, 16:15 Tapped up to 1900C? [see attached link for data concerning temperature readings] TGHT = 450A, 7.16V TBHT = 230A, 4.1V OMEGA = 1748C IGP1 = 6.1e-7 Torr

 Wednesday, October 12, 2016, 21:14

Current status before cooling down:

TGHT at 450A/7.32V; TBHT at 230A/4.10V; OMEGA at 1747C

Vacuum at 4.05 e-7 Torr.

Initiate auto-rampping at 2A/min for TGHT and 1A/min for TBHT

Monday, October 24, 2016, 17:43

Two samples were prepared and loaded into the target boat with 1 layer of heat-shied as shown in the attachment#1.

Ingredients used: np-SiC and very small about of 5% PVA to hold the powder together. 

Samples were dried in the oven at 110C before loaded in Evap#2. 

After dried:

Sample #1 (larger graphite boat, mass =0.3779) = 0.4259g (PVA mass unknown due to solution leaking out from the boat)

Sample #2 = 0.2306g (with 5% PVA of 0.4111g)

Test temperature at 1600C, expect TGHT to be around 400A. 

Monday, October 24, 2016, 17:50

Ramping up TGHT to 300A at 0.5A/min. Vac at 2.3e-6 Torr. 

 Tuesday, October 25, 2016, 12:59

TGHT reached to 300A and stabilized for 10 hours.  OMEGA temp reader at 1150C

Continue to ramp up TGHT

 Wednesday, October 26, 2016, 15:49

TGHT was ramped up to 450A/7.91V; the temp readers on MIKON and OMEGA were 1489 and 1535, respectively (see attachment).

The temperature was much lower than the previous two tests (see elog #296 and #335).  Not sure why... 

Will do composition analysis on the sample... 

Cooling down at 2A/min.

Tuesday, November 15, 2016, 16:48

Three samples were prepared  (see my logbook#1 page 3, preparing for carbonization).

One layer of Ta foil was used to wrap around the target boat. 

Chamber is currently being pumped down

 Wednesday, November 16, 2016, 11:04

Ramping up TGHT at 2A/min, set at 350A.

Desired temperature, ~1530C (similar heating condition as raw npSiC heat treatment, elog ID335)

 Thursday, November 17, 2016, 10:09

TGHT reached to 350A/5.80V, stayed for over 20 hours.  Temp measured at 1276 C (Mikon) and 1270 (Omega), vac at 6.07e-7 Torr. 

Stepping up TGHT to reach the desired temp.

Laura Lambert wrote:

John Wong wrote: Tuesday, November 15, 2016, 16:48 Three samples were prepared  (see my logbook#1 page 3, preparing for carbonization). One layer of Ta foil was used to wrap around the target boat.  Chamber is currently being pumped down  Wednesday, November 16, 2016, 11:04 Ramping up TGHT at 2A/min, set at 350A. Desired temperature, ~1530C (similar heating condition as raw npSiC heat treatment, elog ID335)  Thursday, November 17, 2016, 10:09 TGHT reached to 350A/5.80V, stayed for over 20 hours.  Temp measured at 1276 C (Mikon) and 1270 (Omega), vac at 6.07e-7 Torr.  Stepping up TGHT to reach the desired temp.    Thursday, November 17, 2016, 11:13 TGHT = 400A, 6.73V IGP1 = 8.2e-7 Torr OMEGA = 1385C MIKRON = 1389C Tapping up manually to 1500C or a max setpoint of 450A Thursday, November 17, 2016, 11:56 TGHT = 450A, 7.85V IGP1 = 1.7e-6 Torr OMEGA = 1502C MIKRON = 1510C  Friday, November 18, 2016, 10:08 IGP1 = 5.3e-7 Torr TGHT = 450A, 7.9V OMEGA = 1510C MIKRON = 1515C Evap2 has remained at max setpoints for 23hrs. Initiating auto-cool at 2.0A/min

 Friday, November 18, 2016, 17:27

The heat treatment of the fiber mats is done. 

Analyzing steps...

Thursday, February 09, 2017, 23:26

There are two types of samples being test for thermal stability:

1.  SiC-SiO2-Lys nanofiber mats

2.  SiC pellets

(see Lab Book for more info)

Desired temperature: ~1500C

One-Ta heat shield is used, est. TGHT 450A.

 Thursday, February 09, 2017, 23:38

TGHT currently at 322A/5.28V, OMEGA 1204C.

Vac 2.9e-6 Torr.

 Friday, February 10, 2017, 08:58

TGHT at 400A, temp at 1425C for 8 hours.

Decided to cool down for analysis.  Check for carboreduction for SiO2 at 1400C.  Then continue to ramp up to 1500C. 

Ramping down at 2A/min

 Friday, February 10, 2017, 10:47

Rapid out-gas (2.7e-6 to 3.8e-6 Torr) from TGHT 330A until current stopped at 400A (see attachment).  Could be the evolution of O2 from SiO2... 

Friday, March 10, 2017, 17:29

Three B3 pellets are loaded into the container for thermo test. 

(see lab book1 Pg 26, 28-30 for more detail about the materials)

Desired temp ~1500C; one long-sheet of Ta foil is used, est 400A. 

Auto ramping 0.5A/min to 300A first.  Check later...

 Saturday, March 11, 2017, 11:58

Increased TGHT from 300A to 350A last night at ramping rate of 0.5A/min.

Tapped up further from 350A to 400A, 6.92V (2.8kW), Temp measured at ~1550C. 

Pressure peaked at 1.5e-6 Torr and coming down when ramping TGHT from 350A to 400A. (see attachment1)

Will remain at the current.  Continue monitoring..

 Monday, March 13, 2017, 01:14

Temp was held at 1550C for about 1.5days. Vac stabilized at 3.08e-7 torr.  TGHT 400A/6.94V.

Initiated cooling at 1A/min. 

Next, Materials inspection.

 Monday, March 13, 2017, 11:24

Target has been at room temp for about 4 hours.  Venting chamber.

Friday, March 31, 2017, 12:21

Two compressed pellets loaded into the target boat and wrapped with Ta foil.  (see lab book p32 for details).

Chamber is pumping down.

Desired temp 1550C, TGHT expected to be around 400A.

 Friday, March 31, 2017, 16:31

Auto-ramp at 0.5A/min to reach 350A.

 Saturday, April 01, 2017, 12:30

TGHT reached to 350A/5.7V, temp around 1200C - notice voltage is much lower than previous process (ID 351), possible target/heat shield shorted therefore lower temp observed. (This should not cause any damage to the container.) 

Continue to ramp up to 400A.  Notice some evolution of gasses similar to the previous process (ID351) during ramping up of TGHT around 220A . (see attachment1)

 Saturday, April 01, 2017, 13:52

TGHT reached to 400A/6.7V; temp stabilized at 1400C. 

Tap up to 1550, TGHT 456A/8.08V (3.7KW, about 1KW higher than before).

Pressure coming down (see attachment 2)

Hold temp for several days.

 Saturday, April 01, 2017, 17:22

Temp went up by 10C. Lowered TGHT to 450A.

Thursday, April 20, 2017, 12:38

3 samples are loaded into the Ta boat and wrapped with heat shield (1 long piece, 3 rounds):  2x of B3-92Mpa pellets and 10% pure PAN pellet as control.  See lab book page 32 for more details.

The B3-92Mpa pellets were previously heated to 1550C (TGHT 400A/6.94V), see elog#351

Attempting to heat samples up to 1800C to determine the weight loss and shrinkage. 

Est. TGHT 480A.

OK to auto ramp to 400A at 1A/min.  Check for coating on the window. 

Chamber is currently being pumped down.

 Thursday, April 20, 2017, 14:28

Pressure 3.14e-6 Torr.  Auto ramp TGHT at 1A/min to reach 400A. 

 Friday, April 21, 2017, 10:56

TGHT at 400A/6.75V, temp at 1475C (75C/0.19V lower). 

Tapping up TGHT

 Friday, April 21, 2017, 12:32

TGHT ramped up to 530A/9.85V, temp at 1800C. 

 Friday, April 21, 2017, 15:38

TGHT dropped slightly, no coating on windows. 

Checked with Mikron, agreed with the dropped temp. 

Tapped up TGHt to 545A/10.1V to reach 1800C.  Will keep at that temp for several days.

 Wednesday, April 26, 2017, 17:06

Samples have been heated at 1800C (-25C) for 7 days now (see attachment for archiver). 

Cooling down TGHT at 1A/min.

Monday, July 10, 2017, 17:28

Two np-SiC fibrous pellets with different applied pressure:

1) 200MPa, 2)  335 MPa (see logbook pg 36 for more details). 

Desired heating temperature: 1550C (Previous setting: TGHT 400A/6.94V)

Two layers of Ta foils wrapped around the target boat.

Chamber is pumping down...

 Tuesday, July 11, 2017, 11:11

Pressured came down to 1.0e-6 Torr. 

Tapping up TGHT.

 Tuesday, July 11, 2017, 11:24

Tapped TGHT up to 45A - pressure stabilized at around 3.0e-5 Torr. 

Auto ramp 1.0A/min to reach 350A before tapping up further.

 Wednesday, July 12, 2017, 10:59

TGHT reached to 350A/5.5V, temp @ 1270C - much lower than expected; could be a short between the target container and the heat shield.  I actually had a had time adjusting the target legs to avoid shorting the cu-heat shield. 

Tapped TGHT further up to 375A/6.07V, Omega Temp at 1340C.  Holding current for about 50 mins, re-measured with pyrometer - temperature matches.

Wednesday, July 12, 2017, 14:49 

TGHT set at 450A/7.7A.  Temp at ~1550C.  See attachment for temp plot

Holding at temp for 5 days before cooling down on Monday July 17.

 Thursday, July 13, 2017, 17:52

TGHT tripped off due to bad IEVAP2:WFB1 water flow.  Not sure what was the cause.  Will leave the heater off for now and investigate this tomorrow.

 Friday, July 14, 2017, 11:48

Investigated the bad water flow situation.  It was due to a faulty water flow sensor.  The paddle wheel stopped turning until I gave it a tab.  We had a similar problem before with the water sensor, see elog ID 109.  It is probably the time to replace all the water sensors. 

Monday, August 21, 2017, 17:09

Two pellets of sol-gel SiO2+CNT were produced.  See lab book pg 44-46 for details. 

Samples were loaded in Ta boat, wrapped with heat shield (1 layer)

Synthesis temperature = 1600C.  TGHT ~ 460A/8.0V

Vacuum at 7.5 e-6 Torr.

TGHt Auto-ramp at 01A/min to reach 350A. 

 Thursday, August 24, 2017, 00:28

TGHT reached to 350A/5.9V, temp @ 1230C (in-line with the last measurement see elog 378).

Increase TGHT to 430, ramp at 0.1A/min.

 Thursday, August 24, 2017, 23:42

TGHT reached to 430A/7.87V, temp at 1410C. Outgassing pressure reached to peak at 430A before TGHT stabilized.  (Evolution of SiO(g)???)

Ramp up to 460A at 0.1A/min.

 Friday, August 25, 2017, 10:30

TGHT reached to 460A/8.6V, temp at 1520C.  More outgassing was observed as temp was increased.

Tapping up TGHT to reach 1600c.

Friday, August 25, 2017, 15:17

Temp reached to 1600C; TGHT at 492 A/9.3 V.  Temperature was held for 3 hours.  Due to a problem with the backing pump, the cooling down process was initiated. 

Sample will be taken out next Monday for evaluation.