Friday, July 31, 2015, 15:10, John Wong, , , , Maintenance, Installed leftside port
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Friday, July 31, 2015, 15:09
The left side port was installed on the evaporator #2. Leak check was performed and no leak was detected.
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Friday, July 31, 2015, 15:51, John Wong, Ta, , TARGET BOAT, In progress, Test for homogeneity: Sintering TaC coating on a Ta tube
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Friday, July 31, 2015, 15:39
A Ta tube was coated with TaC. The inner of the tube was filled with TaC solution and the excess was drained out to give a homogenous coating. The outer layer of the tube was brushed with TaC.
The tube is installed in a target boat and wrapped with 3 layers of heat shields.
Chamber is currently pumped down and the target heater will be ramped up after the long weekend (Tue)
A new window port is installed (see photo). TGHT will need to be ramped up slowly to make sure the new window can sustain the heat shine from the target - local check on the Evap is required to make sure it's safe to keep ramping up the heater.
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Tuesday, August 04, 2015, 12:04, Laura Lambert, Ta, , TARGET BOAT, Done, Test for homogeneity: Sintering TaC coating on a Ta tube
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John Wong wrote: |
Friday, July 31, 2015, 15:39
A Ta tube was coated with TaC. The inner of the tube was filled with TaC solution and the excess was drained out to give a homogenous coating. The outer layer of the tube was brushed with TaC.
The tube is installed in a target boat and wrapped with 3 layers of heat shields.
Chamber is currently pumped down and the target heater will be ramped up after the long weekend (Tue)
A new window port is installed (see photo). TGHT will need to be ramped up slowly to make sure the new window can sustain the heat shine from the target - local check on the Evap is required to make sure it's safe to keep ramping up the heater.
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Tuesday, August 04, 2015, 11:26
HS water valves opened, no leaks detected.
IGP1 = 2.2e-7 Torr.
Tapped up manually to 30A.
IGP1 = 2.7e-7 Torr.
Initiating auto-ramp at 0.2A/min with a final value of 350A.
Tuesday, August 04, 2015, 15:30
IGP1 = 2.8e-6 Torr.
TGHT = 79A.
Increasing ramping rate to 0.5A/min
Wednesday, August 05, 2015, 15:25
EVAP2 reached 350A this morning, OMEGA = 1414C
Temperature measurements were taken using the FLUKE IR camera of the new window port to be used for the second OMEGA camera.
Measurements were taken of both the Cu seal on the inside of the window and in the centre of the window [the hottest point].
TGHT was ramped up at 2.0A/min from 1414C --> 1800C with auto ramp paused at each measurement reading taken.
See attachment for raw data.
TGHT remained at 500A/1800C for 4hrs and will be cooled down at a rate of 2.0A/min.
Thursday, August 06, 2015, 15:32
Vented and opened today.
New window port passed inspection, max temperature reached = 32.4C
Coating on tube looks good, partial sintering. Internal sintered better than outside of tube.
See attached photos.
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Thursday, August 06, 2015, 15:45, Laura Lambert, Endcaps, , TARGET BOAT, Done, Sintering TaC coating on Ta endcaps
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Thursday, August 06, 2015, 15:36
The endcaps are stacked together with a punched out disc of graphite foil placed in between each endcap for separation so endcaps won't fuse together.
The end caps are further wrapped in a larger piece of graphite foil to hold together as a tube [same method used in elogID # 158]
There are two separate tubes in the target boat:
1) endcaps coated with TaC coating - never been sintered
2) previously sintered [but not fully] endcaps with a second coating done on the one side of each endcap
The boat is wrapped with 3-layers of Ta heatshields.
Chamber is currently being pumped down.
Friday, August 07, 2015, 08:45
HS water valves opened, no leaks detected.
IGP1 = 3.6e-7 Torr.
Tapped up manually to 30A.
Friday, August 07, 2015, 11:23
IGP1 = 2.2e-6 Torr.
Vacuum stable.
Initiating auto-ramp at 0.2A/min with a final setpoint of 480A.
Will ramp up over the weekend, confirm temperature readings on monday and tap up to final desired temperature of 1800C manually.
Friday, August 07, 2015, 13:04
Vacuum climbed quite fast.
IGP1 = 6.3e-6 Torr.
Stopped auto-ramp to allow vacuum to settle.
Waited ~1hr.
IGP1 = 4.3e-6 Torr.
Re-initiating auto-ramp.
Monday, August 10, 2015, 09:22
TGHT reached 480A, 8.2V on the weekend.
OMEGA = 1708C
IGP1 = 3.8e-7 Torr.
Tapped up manually to 1803C, 520A, 9.0V
IGP1 = 5.9e-7 Torr.
Monday, August 10, 2015, 14:50
EVAP2 remained at 1800C for 4.5hours.
Internal temperature taken at new window port read 1800C using the mikron.
Initiating auto-cool at 2.0A/min.
Tuesday, August 11, 2015, 09:23
Vented in air and opened up this morning.
The following observations were noted:
1) single round sintered endcaps:
-Batch of green endcaps, single round of sintering look good. fully sintered.
-however when applying a scratch test, excess TaC scrapes off.
[see single round sintering photos]
2) Re-sintering of batch from july 14th
-Outside of endcap [concave side] was re-coated, Inside of endcap had good first coating - therefore no second coating applied [see photos from elog ID#230]
-A few endcaps almost heated too long and started to appear brittle/ further crystallization on inside of endcap - the side that did not have a second coating applied.
-Outside of endcap looks good/ fully sintered - the side that had a second round of TaC coating
-further tests confirm this batch should still be okay to use
[see round2 batch photos]
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Tuesday, August 18, 2015, 16:02, Laura Lambert, Ta, , HP-SIS, In progress, Conditioning Ta#46 Target
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Tuesday, August 18, 2015, 15:53
Target consists of 505 discs.
Total packed length 3.4cm.
Total mass 75.2772g.
Re foil inserted.
3x Ta Heat shields.
No endcaps inserted.
Chamber currently pumping down.
TBHT will be ramped up to 230A at 1.0A/min.
TGHT will be ramped up to 1800C, auto ramp to 600A at 2.0A/min [estimated final value of 720A according to elog ID 184]
*Note: Turbo Pump is on low speed
Wednesday, August 19, 2015, 10:15
IGP1 = 8.3e-7 Torr.
Tapped up manually to 35A.
Initiating auto-ramp.
Wednesday, August 19, 2015, 15:55
IGP1 = 3.3e-6 Torr.
TBHT reached max setpoint of 230A
TGHT reached max setpoint of 600A
OMEGA = 1554C
Increasing final setpoint of TGHT to 700A and re-initiating auto-ramp.
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Wednesday, August 19, 2015, 17:26, John Wong, Ta, , HP-SIS, In progress, Conditioning Ta#46 Target
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Laura Lambert wrote: |
Tuesday, August 18, 2015, 15:53
Target consists of 505 discs.
Total packed length 3.4cm.
Total mass 75.2772g.
Re foil inserted.
3x Ta Heat shields.
No endcaps inserted.
Chamber currently pumping down.
TBHT will be ramped up to 230A at 1.0A/min.
TGHT will be ramped up to 1800C, auto ramp to 600A at 2.0A/min [estimated final value of 720A according to elog ID 184]
*Note: Turbo Pump is on low speed
Wednesday, August 19, 2015, 10:15
IGP1 = 8.3e-7 Torr.
Tapped up manually to 35A.
Initiating auto-ramp.
Wednesday, August 19, 2015, 15:55
IGP1 = 3.3e-6 Torr.
TBHT reached max setpoint of 230A
TGHT reached max setpoint of 600A
OMEGA = 1554C
Increasing final setpoint of TGHT to 700A and re-initiating auto-ramp.
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Wednesday, August 19, 2015, 17:13
TGHT reached to 700A/10.5V, direct voltage at 5.2V, and temp measured at both ends at 1755C. Vac is coming down from 4.2e-6 Torr.
Stepping up TGHT to reach 1800C
Wednesday, August 19, 2015, 17:22
Increased TGHT to 722A/11.3V (direct voltage at 5.48V) to reach 1800C (consistant with the heating curve as for the previous HPTa target, elog 184)
Will continue to condition the target at this temperature for overnight.
Cooling down can be initiated tomorrow morning at 2A/min --- Please measure the target temperature from the new window port before cooling it down.
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Thursday, August 20, 2015, 10:07, Laura Lambert, Ta, , HP-SIS, In progress, Conditioning Ta#46 Target
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John Wong wrote: |
Laura Lambert wrote: |
Tuesday, August 18, 2015, 15:53
Target consists of 505 discs.
Total packed length 3.4cm.
Total mass 75.2772g.
Re foil inserted.
3x Ta Heat shields.
No endcaps inserted.
Chamber currently pumping down.
TBHT will be ramped up to 230A at 1.0A/min.
TGHT will be ramped up to 1800C, auto ramp to 600A at 2.0A/min [estimated final value of 720A according to elog ID 184]
*Note: Turbo Pump is on low speed
Wednesday, August 19, 2015, 10:15
IGP1 = 8.3e-7 Torr.
Tapped up manually to 35A.
Initiating auto-ramp.
Wednesday, August 19, 2015, 15:55
IGP1 = 3.3e-6 Torr.
TBHT reached max setpoint of 230A
TGHT reached max setpoint of 600A
OMEGA = 1554C
Increasing final setpoint of TGHT to 700A and re-initiating auto-ramp.
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Wednesday, August 19, 2015, 17:13
TGHT reached to 700A/10.5V, direct voltage at 5.2V, and temp measured at both ends at 1755C. Vac is coming down from 4.2e-6 Torr.
Stepping up TGHT to reach 1800C
Wednesday, August 19, 2015, 17:22
Increased TGHT to 722A/11.3V (direct voltage at 5.48V) to reach 1800C (consistant with the heating curve as for the previous HPTa target, elog 184)
Will continue to condition the target at this temperature for overnight.
Cooling down can be initiated tomorrow morning at 2A/min --- Please measure the target temperature from the new window port before cooling it down.
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Thursday, August 20, 2015, 08:27
OMEGA = 1830C
Internal temperature using Mikron taken from the second 'new' view port: Hottest point on target leg = 2250C; hottest point on target material discs inside container = 1830C.
IGP1 = 1.5e-6 Torr.
EVAP2 has been sitting at max setpoints for ~15hours.
Initiated auto-cool at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.
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Thursday, August 20, 2015, 17:15, John Wong, Ta, , HP-SIS, Done, Conditioning Ta#46 Target
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Laura Lambert wrote: |
John Wong wrote: |
Laura Lambert wrote: |
Tuesday, August 18, 2015, 15:53
Target consists of 505 discs.
Total packed length 3.4cm.
Total mass 75.2772g.
Re foil inserted.
3x Ta Heat shields.
No endcaps inserted.
Chamber currently pumping down.
TBHT will be ramped up to 230A at 1.0A/min.
TGHT will be ramped up to 1800C, auto ramp to 600A at 2.0A/min [estimated final value of 720A according to elog ID 184]
*Note: Turbo Pump is on low speed
Wednesday, August 19, 2015, 10:15
IGP1 = 8.3e-7 Torr.
Tapped up manually to 35A.
Initiating auto-ramp.
Wednesday, August 19, 2015, 15:55
IGP1 = 3.3e-6 Torr.
TBHT reached max setpoint of 230A
TGHT reached max setpoint of 600A
OMEGA = 1554C
Increasing final setpoint of TGHT to 700A and re-initiating auto-ramp.
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Wednesday, August 19, 2015, 17:13
TGHT reached to 700A/10.5V, direct voltage at 5.2V, and temp measured at both ends at 1755C. Vac is coming down from 4.2e-6 Torr.
Stepping up TGHT to reach 1800C
Wednesday, August 19, 2015, 17:22
Increased TGHT to 722A/11.3V (direct voltage at 5.48V) to reach 1800C (consistant with the heating curve as for the previous HPTa target, elog 184)
Will continue to condition the target at this temperature for overnight.
Cooling down can be initiated tomorrow morning at 2A/min --- Please measure the target temperature from the new window port before cooling it down.
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Thursday, August 20, 2015, 08:27
OMEGA = 1830C
Internal temperature using Mikron taken from the second 'new' view port: Hottest point on target leg = 2250C; hottest point on target material discs inside container = 1830C.
IGP1 = 1.5e-6 Torr.
EVAP2 has been sitting at max setpoints for ~15hours.
Initiated auto-cool at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.
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Thursday, August 20, 2015, 17:14
Target was removed the the evaporator and inspected. It looks good!
Ta-heat shields are removed.
End caps are inserted but need to be expended.
Ready for assembly.
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Monday, August 24, 2015, 12:58, John Wong, , , , Maintenance, Replacing turbo pump, IEVAP2TP1
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Monday, August 24, 2015, 12:54
The turbo pump was found to be faulty. The pump couldn't get on full speed and eventually timed out. Vacuum group inspected the pump and it is time for a service.
A new pump has been installed. Leak check was performed and no leaks were detected.
Pump is now fully operational.
Back in business….
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Tuesday, August 25, 2015, 11:54, Laura Lambert, Empty, , HP-FEBIAD, In progress, Sintering TaC coating container for SiC Target
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Tuesday, August 25, 2015, 11:50
Container coated with TaC using new method: Ends tapped off, with liquid poured in and swirled around entire container, then poured back out - 'flushing technique'
Container is wrapped with 3 x Ta heat shields, not incl center block.
Loaded into EVAP2 and currently pumping down.
Tuesday, August 25, 2015, 13:52
IGP1 = 2.2e-6 Torr.
HS water valves opened.
No leaks detected.
Tapped up manually to 35A.
Vacuum stable.
Initiated auto ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively.
Final setpoints for TGHT = 720A and TBHT = 230A, with final desired temp of 1800C
Wednesday, August 26, 2015, 09:56
IGP1 = 8.8e-7 Torr.
TGHT = 260A, 3.0V
TBHT = 145A, 1.8V
Increasing ramping rate to 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.
Wednesday, August 26, 2015, 14:15
IGP1 = 3.5e-6 Torr.
TGHT = 720A, 11.3V
TBHT = 230A, 3.2V
DV = 5.48V
OMEGA RS [right side-old port] = 1745C
OMEGA LS [left side-new port] = 1880C
Tapping up manually to achieve 1800C on OMEGA RS
Wednesday, August 26, 2015, 14:44
IGP1 = 3.7e-6 Torr.
TGHT = 748A, 11.9V
DV = 5.78V
OMEGA RS = 1803C
OMEGA LS = 1935C
Thursday, August 27, 2015, 07:31
Remained at max setpoints for ~17hrs.
IGP1 = 1.3e-6 Torr.
DV = 5.79V
OMEGA RS = 1862 [this reading may not be correct due to the laser being moved at max setpoint - this temperature reading may be taken from a different location then the last reading]
OMEGA LS = 1955
Initiating auto-cool at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.
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Thursday, August 27, 2015, 16:37, John Wong, Empty, , HP-FEBIAD, Done, Sintering TaC coating container for SiC Target
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Laura Lambert wrote: |
Tuesday, August 25, 2015, 11:50
Container coated with TaC using new method: Ends tapped off, with liquid poured in and swirled around entire container, then poured back out - 'flushing technique'
Container is wrapped with 3 x Ta heat shields, not incl center block.
Loaded into EVAP2 and currently pumping down.
Tuesday, August 25, 2015, 13:52
IGP1 = 2.2e-6 Torr.
HS water valves opened.
No leaks detected.
Tapped up manually to 35A.
Vacuum stable.
Initiated auto ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively.
Final setpoints for TGHT = 720A and TBHT = 230A, with final desired temp of 1800C
Wednesday, August 26, 2015, 09:56
IGP1 = 8.8e-7 Torr.
TGHT = 260A, 3.0V
TBHT = 145A, 1.8V
Increasing ramping rate to 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.
Wednesday, August 26, 2015, 14:15
IGP1 = 3.5e-6 Torr.
TGHT = 720A, 11.3V
TBHT = 230A, 3.2V
DV = 5.48V
OMEGA RS [right side-old port] = 1745C
OMEGA LS [left side-new port] = 1880C
Tapping up manually to achieve 1800C on OMEGA RS
Wednesday, August 26, 2015, 14:44
IGP1 = 3.7e-6 Torr.
TGHT = 748A, 11.9V
DV = 5.78V
OMEGA RS = 1803C
OMEGA LS = 1935C
Thursday, August 27, 2015, 07:31
Remained at max setpoints for ~17hrs.
IGP1 = 1.3e-6 Torr.
DV = 5.79V
OMEGA RS = 1862 [this reading may not be correct due to the laser being moved at max setpoint - this temperature reading may be taken from a different location then the last reading]
OMEGA LS = 1955
Initiating auto-cool at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.
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Thursday, August 27, 2015, 16:34
Target is removed from the evaporator and inspected.
The "flushing technique" has a much better result. The inner coated surface is sintered well.
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Thursday, January 14, 2016, 11:48, Laura Lambert, , , , Maintenance, Backing Pump Replaced
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Thursday, January 14, 2016, 11:47
Backing pump was making very loud high pitched noises during last couple processes in the evaporator.
Replaced with a new one this morning.
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Wednesday, February 24, 2016, 17:40, John Wong, Nb, , LP-SIS, Done, Bob/Tobi Nb samples
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Thursday, February 25, 2016, 18:04 Wednesday, February 24, 2016, 17:29
Heat treatment of 2 bullet-shaped Nb samples in a LP-SIS container; it is just that we don't have a target boat.
Container is wrapped with 12" in total length. A strip of Nb foil is used as an underlayer for the samples to sit on top.
Chamber has been pumped down and current vacuum at 1e-6 Torr.
HS water check - good.
Target temperature 1400C
Ramping up to 250A; this should get to ~1300C. Will let it heat for over night and step up to 1400C tomorrow.
Wednesday, February 24, 2016, 17:59
I'm stopping the heating process because the camera is not working. I can't monitor the temperature. Tried to fit the camera; don't now why it fails to connect to the server.
Will look in to it tomorrow...
Thursday, February 25, 2016, 08:17
Initiated auto ramping TGHT at 2A/min.
Thursday, February 25, 2016, 17:33
Finally the camera is fixed.
Current temperature is at 1126C, TGHT at 250A. Will step up to reach 1400C.
Thursday, February 25, 2016, 18:04
TGHT stepped up to 335A to reach 1400C. (see attachment)
Will heat this for few hours and cool it at around 11pm tonight.
Thursday, February 25, 2016, 22:19
Samples have been heated over 4.5 hours.
Initiated cool down at 1A/min.
Friday, February 26, 2016, 15:43
done! all good.
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Friday, February 26, 2016, 16:02, John Wong, np-SiC, , TARGET BOAT, Done, Test#2: Carbonizing sol-gel TEOS + Pan nanofibers
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Friday, February 26, 2016, 15:44
5 samples were prepared at UBC MTRL using Sol-gel tetraethyl orthosilicate (TEOS) coated on electrospun polyacrylonitrate (PAN).
Each sample is sandwiched in between graphite foils.
Sample labeling:
Direct, 0.2358g
Mix, 0.3486g
3X, 0.2273g
5x, 0.2079g
7x, 0.1735g
All samples are loaded in the target boat, stacking on each other. The Container is wrapped with 2X- Ta shields.
Chamber is pumping down.
Step#1 Carbonization temperature: 1600C
Saturday, February 27, 2016, 10:07
Vac at 2.5e-7 torr.
Ramping up TGHT to 300A at 1A/min. monitoring temp.
Saturday, February 27, 2016, 17:38
TGHT at 400A, temp at 1600C. Vac 1.34e-6 Torr.
Monday, February 29, 2016, 13:04
Samples have been heated at 1635C for almost 2 days.
Pressure at 2.1e-7 Torr.
Initiated cooling at 2A/min.
Thursday, March 24, 2016, 11:26
Samples were analyzed for Si using EDX. Unfortunately, no Si was found. The vapour pressure of SiO was too high for it to react with PAN to carbonize in a vacuum environment.
Will look into a different technique.
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Thursday, March 24, 2016, 12:05, John Wong, SiC, , TARGET BOAT, Done, Test#3: E-spin SiC with PAN
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Thursday, March 24, 2016, 11:37
SiC powder (<1um) [10%] was mixed with PAN solution [10%]. Solution was sonicated before e-spinning.
Fiber mat was binded to graphite foil and heat treated to 250C in air for 1 hour.
Samples were cut in pieces and rolled up and inserted in Ta target container (TaC coated). Heat shield was added.
Heat Treatment #1:
Temperature: 1600C (~350A)
Ramping up TGHT to 300A at 1A/min.
Tuesday, March 29, 2016, 11:11
TGHT was maintained at 410A for 1600C for 2 days (see attachment 1). However at around 22:30 on March 28, there was a sudden increase in voltage.
Temperature raised up to 1750C. Not sure there was a fault with the control system and it was caused by the Ta-heat shield. (see attachment #2).
Target was cooled down around 2am on March 29.
Samples will be removed from the chamber.
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Thursday, April 07, 2016, 15:23, John Wong, SiC, , TARGET BOAT, Done, E-spun SiC/PAN thermal treatment
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Thursday, April 07, 2016, 15:18
E-spun SiC/PAN fiber mats were produced at UBC.
12%PAN solution; 50% SiC to weight of PAN.
Materials used:
1.2g PAN, 8.8g DMF, 0.6g SiC, SDS ~0.1% to SiC
Fiber mats were heat treated at 250C in air. Then cut into 18" discs and loaded into Ta target boat with heatshield wrapped.
3 temperature treatments will carry out: 1200C, 1400C and 1600C
Chamber is being pumped down
Friday, April 08, 2016, 10:02
TGHT at 285A, Temp at ~1200C. Will remain at this temp for a few hours before cooling down.
Some samples will be taken out for analysis.
Next week, temperature treatment will continue at 1400C
Friday, April 08, 2016, 14:26
Samples have been heated at 1200C for just over 4 hours.
Initiated auto-cooling at 2A/min
Tuesday, April 12, 2016, 17:51
Heat treatment #2 - 1400C.
Initial mass after 1200C = 0.0312g
Monday, April 18, 2016, 12:55
Samples was heated at 1400C (TGHT maintained at ~370A) for 4 days (see attachment 1).
Chamber is vented; samples will be inspected.
Tuesday, April 19, 2016, 17:49
Results
Sample mass after 1200C = 0.0312g
Sample mass after 1400C = 0.0294g
~5.78% mass loss.
Tuesday, April 19, 2016, 17:57
Heat Treatment#3: 1600C
sample mass before heating = 0.0238g (this sample is taken from the batch after it was heated at 1400C)
Chamber is being pumped.
Thursday, April 21, 2016, 11:07
TGHT stepped up to 330A, temp measured at 1422C.
Thursday, April 21, 2016, 12:05
TGHT at 415A/7.16V; temp at 1610C
Thursday, April 21, 2016, 17:49
Temp dropped to 1590. Increased TGHT to 425A; temp reads 1602A.
Friday, April 22, 2016, 10:57
Voltage increased to 7.33V, TGHT stepped down to 418A, temp maintained at 1610A.
Monday, April 25, 2016, 12:08
Sample was heat treated for almost 4 days. Temperature dropped to 1578C, TGHT at 418/7.26V. (see attachment #2)
Ramping down TGHT 2A/min.
Monday, April 25, 2016, 16:00
Result:
Mass after 1600C = 0.0104g, 5.63% mass loss.
Will do XRD/EDX
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Tuesday, May 03, 2016, 14:44, Laura Lambert, , , , , VACUUM PUMP REPLACEMENT
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Tuesday, May 03, 2016, 14:29
Turned vacuum pump on this morning, sounded awful: loud grinding bad noises.
Called vacuum group, will replace pump tomorrow morning.
Sounds like materials coming out from all the out-gassing during sintering processes has ruined the bearings.
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Wednesday, May 11, 2016, 17:24, John Wong, np-SiC, , TARGET BOAT, Done, Temperature Treament of Nanofiber SiC/PAN
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Wednesday, May 11, 2016, 17:15
Nanofiber SiC (~50nm grain size)/PAN was prepared at UBC.
SiC 0.50g, DMF 9.0g, PAN 1.0g, tiny bit of SDS.
The fiber mat was stabilized in air at 250C and then cut into discs, initial mass = 0.1072g
Discs were then bounded with PVA on 9 pieces of rounded graphite foil (green mass gained to 0.6031g)
The stack of naofiber SiC/PAN was loaded on to Ta boated (coated) and wrapped with Ta heat shield.
Chamber is currently being pumped down.
Friday, May 13, 2016, 15:00
TGHT at 390A/6.966V. Temp measured at 1615C.
Will keep at that temperature for a few days.
Monday, May 16, 2016, 15:44
Sample has been heated at ~1600C for 4 days. TGHT at 400A/7.02V.
Cooling down at 2A/min
Tuesday, May 17, 2016, 11:18
Chamber vented. Inspecting samples.
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Thursday, May 19, 2016, 14:38, John Wong, SiC, , TARGET BOAT, In progress, Heat-treatment: Beta-SiC (1um) target discs
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The purpose of this experiment is to determined the limiting operating temperature for Beta-SiC. To do so, samples will be heated in sequence to observe any volatile Si coated on the window. The coating is observed above 1400C for the conventional SiC (mixuture of alpha and beta) and this coating leads to HV shorting problem.
Thursday, May 19, 2016, 14:26
Beta-SiC (size ~1um) slurry was prepared and casted on a graphite foil.
Discs are cut into D-shape
Average thickness (including graphite foil) = 0.349mm
Graphite foil = 0.13mm
Actual SiC thickness = 0.219mm (close to normal SiC thickness)
Samples are loaded into a target boat.
Total discs = 120
Total mass = 14.3507g
Thursday, May 19, 2016, 14:32
Omega slope set to = 1.04
Heat-treatment #1: 1400C
Thursday, May 19, 2016, 17:04
TGHT ramping up to 250A at 0.5A/min
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Friday, May 20, 2016, 08:54, Laura Lambert, SiC, , TARGET BOAT, In progress, Heat-treatment: Beta-SiC (1um) target discs
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John Wong wrote: |
The purpose of this experiment is to determined the limiting operating temperature for Beta-SiC. To do so, samples will be heated in sequence to observe any volatile Si coated on the window. The coating is observed above 1400C for the conventional SiC (mixuture of alpha and beta) and this coating leads to HV shorting problem.
Thursday, May 19, 2016, 14:26
Beta-SiC (size ~1um) slurry was prepared and casted on a graphite foil.
Discs are cut into D-shape
Average thickness (including graphite foil) = 0.349mm
Graphite foil = 0.13mm
Actual SiC thickness = 0.219mm (close to normal SiC thickness)
Samples are loaded into a target boat.
Total discs = 120
Total mass = 14.3507g
Thursday, May 19, 2016, 14:32
Omega slope set to = 1.04
Heat-treatment #1: 1400C
Thursday, May 19, 2016, 17:04
TGHT ramping up to 250A at 0.5A/min
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Friday, May 20, 2016, 08:53
IGP1 = 9.2e-6 Torr.
Increasing ramping rate to 1.0A/min up to 250A
Friday, May 20, 2016, 09:17
IGP1 = 2.1e-5 Torr
TGHT = 215A, 3.1V
OMEGA = 1035C
Stopping auto-ramp and tapping up manually...
Friday, May 20, 2016, 12:26
OMEGA slope changed to 1.04
OMEGA reached ~1430C and kept there for ~1hr.
no change. no coating on window observed
tapped up manually to OMEGA =1500C
TGHT = 350A, 5.8V
Friday, May 20, 2016, 14:17
Not much change to window.
Might be beginning of light dusting, hard to tell.
Will be better observed after longer period of time at 1500C
Will remain at 1500C over weekend.
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