Laura Lambert wrote:

John Wong wrote: Laura Lambert wrote:  Thursday, June 04, 2015, 9:07 Container was sprayed with TaC and let dry. Container has 3x Ta heat shields including center block. Container was loaded into EVAP2 yesterday and pumped down overnight. HS water valves were opened up this morning, no leaks detected. IGP1 = 4.6e-7 Torr. Tapped up manually to 40A. Waited ~25min, Vacuum stable. IGP1 = 5.0e-7 Torr. Initiating auto-ramp. TGHT will be ramped to reach 2000C  Friday, June 05, 2015, 10:01 IGP1 = 4.5e-7 Torr. TGHT = 313A, 4.47V OMEGA = 1444C Increasing ramping rate to 1.0A/min  Friday, June 05, 2015, 11:31 IGP1 = 1.2e-6 Torr. Increasing ramping rate to 2.0A/min    Friday, June 05, 2015, 12:01 TGHT reached to 465A/7.56V, temp is stable at 2000C. Current vac at 1.2e-6 Torr and coming down Cooling down process can be initiated after 4 hours.     Friday, June 05, 2015, 13:21 OMEGA = 1995C Increasing TGHT to 470A to achieve desired max temperature of 2000C Friday, June 05, 2015, 15:59 TGHT sat at max desired temperature of 2000C for ~4hrs. TGHT = 470A, 7.7V Initiating auto-cool at 1.0A/min.  Monday, June 08, 2015, 11:31 Vented in air and opened up this morning. Target container mostly sintered, two tiny patches near both ends not fully sintered. Will re-install and re-sinter next week as another container with priority needs to be sintered first.  Tuesday, June 09, 2015, 10:45 See attachements for 'not-fully-sintered' photos

 Wednesday, June 10, 2015, 12:06

After inspecting the target container,  the inner tube surface has "dark" patches, which may not be evenly coated or the coating layer was too think.  

See link for photos:  https://www.dropbox.com/sh/m94mjuuodwhz5jb/AADEBv_Kha_p_1An40eftWNHa?dl=0 

Attempt to re-spray the container and re-sinter.  

Laura Lambert wrote:

Tuesday, June 09, 2015, 9:16 Target container is coated with TaC. No Ta-heat shields are used. TGHT will be ramped up to 580A at 0.2A/min. TBHT will be ramped up to 230A at 01A/min. Chamber is currently being pumped down.  Tuesday, June 09, 2015, 15:37 HS water valves were opened. no leaks detected. Tapped up manually to 35A. Once vacuum stabilized after ~45min, initiated auto-ramp.  Wednesday, June 10, 2015, 08:02 IGP1 = 5.3e-7 Torr. TGHT = 250A and TBHT = 140A. Increasing auto ramp to 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.

 Wednesday, June 10, 2015, 16:32

TGHT/TBHT are at 580A/230A for almost 6 hours, temp at 1728C.

Vac at 8.5e-7 Torr. 

Cooling down initiated at 1A/min.

Target container should be inspected once the chamber is vented.

Laura Lambert wrote:

John Wong wrote: Laura Lambert wrote: John Wong wrote: Laura Lambert wrote:  Thursday, June 04, 2015, 9:07 Container was sprayed with TaC and let dry. Container has 3x Ta heat shields including center block. Container was loaded into EVAP2 yesterday and pumped down overnight. HS water valves were opened up this morning, no leaks detected. IGP1 = 4.6e-7 Torr. Tapped up manually to 40A. Waited ~25min, Vacuum stable. IGP1 = 5.0e-7 Torr. Initiating auto-ramp. TGHT will be ramped to reach 2000C  Friday, June 05, 2015, 10:01 IGP1 = 4.5e-7 Torr. TGHT = 313A, 4.47V OMEGA = 1444C Increasing ramping rate to 1.0A/min  Friday, June 05, 2015, 11:31 IGP1 = 1.2e-6 Torr. Increasing ramping rate to 2.0A/min    Friday, June 05, 2015, 12:01 TGHT reached to 465A/7.56V, temp is stable at 2000C. Current vac at 1.2e-6 Torr and coming down Cooling down process can be initiated after 4 hours.     Friday, June 05, 2015, 13:21 OMEGA = 1995C Increasing TGHT to 470A to achieve desired max temperature of 2000C Friday, June 05, 2015, 15:59 TGHT sat at max desired temperature of 2000C for ~4hrs. TGHT = 470A, 7.7V Initiating auto-cool at 1.0A/min.  Monday, June 08, 2015, 11:31 Vented in air and opened up this morning. Target container mostly sintered, two tiny patches near both ends not fully sintered. Will re-install and re-sinter next week as another container with priority needs to be sintered first.  Tuesday, June 09, 2015, 10:45 See attachements for 'not-fully-sintered' photos    Wednesday, June 10, 2015, 12:06 After inspecting the target container,  the inner tube surface has "dark" patches, which may not be evenly coated or the coating layer was too think.   See link for photos:  https://www.dropbox.com/sh/m94mjuuodwhz5jb/AADEBv_Kha_p_1An40eftWNHa?dl=0  Attempt to re-spray the container and re-sinter.        Friday, June 12, 2015, 14:58 re-sprayed with second layer of TaC spray this morning. re-loaded into evap2. HS water valves opened, no leaks detected. will ramp-up over weekend.

 Friday, June 12, 2015, 16:07

Vacuum comes down to 6.1e-6 Torr.

Initiated auto-ramping at 0.2A/min for 300A first. 

John Wong wrote:

Laura Lambert wrote: John Wong wrote: Laura Lambert wrote: John Wong wrote: Laura Lambert wrote:  Thursday, June 04, 2015, 9:07 Container was sprayed with TaC and let dry. Container has 3x Ta heat shields including center block. Container was loaded into EVAP2 yesterday and pumped down overnight. HS water valves were opened up this morning, no leaks detected. IGP1 = 4.6e-7 Torr. Tapped up manually to 40A. Waited ~25min, Vacuum stable. IGP1 = 5.0e-7 Torr. Initiating auto-ramp. TGHT will be ramped to reach 2000C  Friday, June 05, 2015, 10:01 IGP1 = 4.5e-7 Torr. TGHT = 313A, 4.47V OMEGA = 1444C Increasing ramping rate to 1.0A/min  Friday, June 05, 2015, 11:31 IGP1 = 1.2e-6 Torr. Increasing ramping rate to 2.0A/min    Friday, June 05, 2015, 12:01 TGHT reached to 465A/7.56V, temp is stable at 2000C. Current vac at 1.2e-6 Torr and coming down Cooling down process can be initiated after 4 hours.     Friday, June 05, 2015, 13:21 OMEGA = 1995C Increasing TGHT to 470A to achieve desired max temperature of 2000C Friday, June 05, 2015, 15:59 TGHT sat at max desired temperature of 2000C for ~4hrs. TGHT = 470A, 7.7V Initiating auto-cool at 1.0A/min.  Monday, June 08, 2015, 11:31 Vented in air and opened up this morning. Target container mostly sintered, two tiny patches near both ends not fully sintered. Will re-install and re-sinter next week as another container with priority needs to be sintered first.  Tuesday, June 09, 2015, 10:45 See attachements for 'not-fully-sintered' photos    Wednesday, June 10, 2015, 12:06 After inspecting the target container,  the inner tube surface has "dark" patches, which may not be evenly coated or the coating layer was too think.   See link for photos:  https://www.dropbox.com/sh/m94mjuuodwhz5jb/AADEBv_Kha_p_1An40eftWNHa?dl=0  Attempt to re-spray the container and re-sinter.        Friday, June 12, 2015, 14:58 re-sprayed with second layer of TaC spray this morning. re-loaded into evap2. HS water valves opened, no leaks detected. will ramp-up over weekend.  Friday, June 12, 2015, 16:07 Vacuum comes down to 6.1e-6 Torr. Initiated auto-ramping at 0.2A/min for 300A first.

Sunday, June 14, 2015, 09:37  

TGHT at 254.2A/3.5V3, DV = 1.614V Temp at 1177C. 

Vacuum is stable at 3.2e-7 Torr.  

Increase ramping rate at 2A/min until TGHT reached 300A. 

Sunday, June 14, 2015, 10:04  

TGHT reached 300A, temp 1368C.

Tapping up to ~1800C

Sunday, June 14, 2015, 11:26 

TGHT at 425A/6.84V, DV 3.59V, temp at 1814C, 

Vacuum coming down, currently at 7.5e-7 Torr. 

Will remain at that current for at least 4 hours before cooling down

Sunday, June 14, 2015, 17:15  

Target container has been sintered with TiC for over 6 hours at 1823C, with TGHT at 425A/6.84V, DV at 3.584V. 

Vac at 4.9e-7 Torr.  

Cooling initiated.  

Chamber can be vented tomorrow and target container can be taken out for inspection. 

 Monday, June 15, 2015, 11:38

Target container was taken out for inspection.  

It's observed that the coated/sintered TaC surface is improved.  The sintered temperature was only gone up just above 1800C, so there still some area near the ends that is still somewhat "brownish", fully sintered shows a

smooth .  (see attachment) 

Spraying into a cylinder tube can be challenging.  It was observed that the coating was dispersed out from the end cap to the centre tube.  For that reason, the container isn't has much protective layer;vthe Ta surface can

react with carbides and the container eventually breaks.  Take the endcap process for example,  the caps are evenly coated with TaC and can be sintered up to 2000C (see e-log Evap ID 202).

Suggestions:  

Using a spray ball nozzle or some sort so that the inner tube can be evenly coated. 

Under investigating...

Laura Lambert wrote:

John Wong wrote: Laura Lambert wrote:  Tuesday, June 09, 2015, 9:16 Target container is coated with TaC. No Ta-heat shields are used. TGHT will be ramped up to 580A at 0.2A/min. TBHT will be ramped up to 230A at 01A/min. Chamber is currently being pumped down.  Tuesday, June 09, 2015, 15:37 HS water valves were opened. no leaks detected. Tapped up manually to 35A. Once vacuum stabilized after ~45min, initiated auto-ramp.  Wednesday, June 10, 2015, 08:02 IGP1 = 5.3e-7 Torr. TGHT = 250A and TBHT = 140A. Increasing auto ramp to 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.    Wednesday, June 10, 2015, 16:32 TGHT/TBHT are at 580A/230A for almost 6 hours, temp at 1728C. Vac at 8.5e-7 Torr.  Cooling down initiated at 1A/min. Target container should be inspected once the chamber is vented.    Thursday, June 11, 2015, 10:55 Vented in air and opened up this morning. Same as last container sintered in evap2 [IG-LIS for UCx#13] - ends not quite fully sintered and coating not very good. most likely due to old TaC spray. See link for photos. https://www.dropbox.com/sh/75o43x8y2z16e7j/AABc8Z1fTTaTRtJ5_Jr1eacWa?dl=0

 Monday, June 15, 2015, 15:24

Same problem also found for the LP-IG-LIS container, WO#40860-1, see elog id#215.  After re-coating and sintering, it seems better. 

For this container, it is re-coated and will undergo the sintering process one more time. 

Will try to go up to 1900C for the sintering process.

Target container is temporarily wrapped with 6.2cm of Ta foil as a layer for heat shield on each side of the tube, excluding the centre block.  The shield will be removed once the process is done.  

Target current will be controlled accordingly. 

Chamber is being pumped down. 

 Monday, June 15, 2015, 16:17

HS water valves open; no leaks detected. 

IGP1 at 6.8e-6 Torr and coming down.

 Monday, June 15, 2015, 17:21

Stepping up TGHT/TBHT to 60A, pressure seems pretty stable at 7.2e-6 Torr and coming down. 

Setting TGHT to 400A and TBHT to 230A, auto-ramping initiated.   Will setup up current to reach 1900C, if necessary. 

 Monday, June 15, 2015, 20:28

TGHT and TBHT reached 400A/230A, Temp at 1552C.  Vac at 2.7e-6 Torr.

Stepping TGHT

Monday, June 15, 2015, 21:16  

TGHT at 520A/9.06 V to achieve 1900C.  DV at 5.09V.  

Vac at 4.2e-6 Torr.  

Will continue the sintering process at this temperature for another 3-4 hours. 

 Tuesday, June 16, 2015, 00:15

Target container has been heated at 1900C for over 3 hours.  

Vacuum is coming down to 1.4e-6 Torr.  

Initiated cooling process at 2A/min

Chamber can be vented tomorrow and container should be inspected

 Friday, June 26, 2015, 16:04

Container looks good!

Monday, June 22, 2015, 13:00

Containers is coated with TaC. Wrapped with 3 layers of Ta heat-shield.  Air blown to for quick dry.

Installed, and pumped down, vac currently at 6.7e-6 Torr. 

HS water valve open, no leaks detected. 

Stepping up TGHT/TBTH:  50A.

 Monday, June 22, 2015, 14:22

Pressure is coming down, currently at 1.75e-5 Torr.

auto-ramping initiated: TGHT = 820A; TBHT = 230A, rate at 2A/min.

 Tuesday, June 23, 2015, 00:50

Target container has reached to 1860C and has been heated for almost 4 hours, with TGHT at 800A/12.60V, DV = 6.28. TBHT at 230A/3.8V.  

Vac at 3e-6 Torr.  

Cooling down at 2A/min.  

Chamber can be vented tomorrow and SiC can be loaded in for the sintering process. 

Tuesday, June 23, 2015, 12:21

Target container is loaded with 485 discs of SiC with packed length of 17.4cm. 

Container is wrapped with 3 Ta-heat shields and previously coated/sintered with TaC.

Chamber is currently being pumped down

TGHT will be ramped up to 800A, ~1800C, and TBHT is limited to 230A max.

 Tuesday, June 23, 2015, 15:53

HS valves are open, no leaks detected.

TGHT stepped up to 70A, pressure is currently at 4.17e-5 torr and coming up. 

Initiated auto-ramping at 0.5A/min for both TGHT and TBHT: good vac at 3.0e-5, bad vac at 4.0e-5 Torr.

 Wednesday, June 24, 2015, 00:03

Stopped auto-ramping about 2 hours ago.  

Manual stepped up TGHT to 73A.  Vac is stabilizing at 5e-8 Torr.  Will keep it at that current over night.

 Wednesday, June 24, 2015, 07:41

Vac has come down to 3.6e-6 Torr.

Continue to step up TGHT...

 Wednesday, June 24, 2015, 23:52

It has been a super long day operating the evaporator and finally the target is up to 1800C.  Vac is coming down from 2.e-5 Torr. 

TGHT is at 790A/12.61V, DV at 6.60V, TBHT at 230A/3.57V.  Omega temp reader is at 1680C - that's due to the window being coated with SiC, as expected. 

Target will continue heated at that current for over night, and will start the cooling process next AM. 

Thursday, June 25, 2015, 06:18  

Target is holding pretty well over night.  Vac is coming down to 1.6e-6 Torr. 

Initiated cooling down at 2A/min. 

Laura Lambert wrote:

Thursday, June 25, 2015, 16:14 Total number of foils: 422 discs Total mass of materials [incl graphite foils]:  Total length packed: 13.2cm Container has one Ta heat shield. No endcaps inserted to allow outgassing Two TaC coated Ta wires formed into a spring inserted either end to avoid ZrC expansion of materials. Currently being pumped down.  Friday, June 26, 2015, 11:44 HS water valves opened. No leaks detected. Initiating ramp up.  Friday, June 26, 2015, 14:44 EVAP2 was tapped up manually to 50A. Vacuum tripped evap off. Tapping back up manually now...  Friday, June 26, 2015, 15:53 Tapped up manually to 45A for both TGHT and TBHT IGP1 = 4.8e-5 Torr Will initiate auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively once vacuum settled down and stable. Max setpoints set to 520A and 230A for the TGHT and TBHT respectively. Good Vacuum = 3.0e-5 Torr. Bad Vacuum = 4.0e-5 Torr.

 Monday, June 29, 2015, 06:57

TGHT has been at 520A/9.80V, DV 5.80V for 7 hours, temperature measured at 1800C.  Vac is coming down to 9.18e-6 Torr.  However, TGHT voltage is slightly going up over the 7 hours of heating, See screenshot attachment. (Can't make further comments until target is inspected.)

Initiated cooling down at 2A/min for TGHT and 1A/min for TBHT.

Chamber can be vented later today.

 Monday, June 29, 2015, 14:58

Target has been inspected.

Slightly crystallization on the outer tube of the container can be observed. 

Overall, the container looks a lot better than before. 

Rn foiled inserted. Salt added - Ready for test-stand

Laura Lambert wrote:

Monday, June 29, 2015, 16:17 Target container is coated with TaC. No Ta-heat shields are used. TGHT will be ramped up to 580A at 0.2A/min. TBHT will be ramped up to 230A at 01A/min. Chamber is currently being pumped down.

 Monday, June 29, 2015, 23:37

Opened the HS valves around 5pm.  Small leaks or just a vibration in the pipe line caused a rise in vacuum.  Leak rate is small, so allow the chamber to continue to pump down over night.

Sintering process can begin tomorrow if vacuum is allowed.

Laura Lambert wrote:

John Wong wrote: Laura Lambert wrote:  Monday, June 29, 2015, 16:17 Target container is coated with TaC. No Ta-heat shields are used. TGHT will be ramped up to 580A at 0.2A/min. TBHT will be ramped up to 230A at 01A/min. Chamber is currently being pumped down.    Monday, June 29, 2015, 23:37 Opened the HS valves around 5pm.  Small leaks or just a vibration in the pipe line caused a rise in vacuum.  Leak rate is small, so allow the chamber to continue to pump down over night. Sintering process can begin tomorrow if vacuum is allowed.    Tuesday, June 30, 2015, 08:22 IGP1 = 3.6e-7 Torr. Tapped up manually to 40A. Vacuum looks good. IGP1 = 6.9e-7 Torr. Inititating auto-ramp...  Thursday, July 02, 2015, 09:56 IGP1 = 8.9e-7 Torr. OMEGA = 1728C TGHT and TBHT = 580A and 230A respectively. Tapping up manually to 1800C.  Thursday, July 02, 2015, 11:02 TGHT = 615A, 10.9V OMEGA = 1800C IGP1 = 1.1e-6 Torr. Will continue to heat for 4hrs.  Thursday, July 02, 2015, 15:43 Target container remained at 1800C for 4hrs50min. Initiating auto-cool for TGHT = 2A/min and TBHT = 1A/min.  Friday, July 03, 2015, 08:24 Vented in air and opened up this morning. Edge of container on both ends not fully sintered [see photos]

 Monday, July 06, 2015, 11:54

Inner tube surface isn't homogeneously sintered with TaC (see attachment).  

A second coating may help.  

For the re-sintering process, the target container will be wrapped with 6.2cm Ta (width) foil as a layer for heat shield on each side of the tube,  excluding the centre block - just like the same process was done last time, see e-log ID#217.  

The Ta-foil and the target tube will be spaced with Ta wire coiled around it.  

TGHT can be ramped up about 520A/9.1V to achieve 1900C.  Heating time for 3-4 hours until vacuum comes down to low 10-6 Torr. 

 Thursday, July 30, 2015, 17:02

EVAP1 cooling system is now on the NALCW.  The city water has been removed from the system.  

Tested all the cooling system interlocks by shutting off each individual valve, and the main supply valve to the lab -  All Passed!  

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. 

 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.     

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.

 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.

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.    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.    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.

 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.

 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…. 

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.

 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.  

Tuesday, September 01, 2015, 17:16

Target container contains 533 discs of SiC with packed length of 17cm. 

Mass of 533 discs SiC(green)  = 57.8979g

Total mass SiC(green) + target container = 1455g

Container is wrapped with 3 heatshields; no end caps are inserted yet.

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

Chamber is currently being pumped down. 

Laura Lambert wrote:

John Wong wrote: Tuesday, September 01, 2015, 17:16 Target container contains 533 discs of SiC with packed length of 17cm.  Mass of 533 discs SiC(green)  = 57.8979g Total mass SiC(green) + target container = 1455g Container is wrapped with 3 heatshields; no end caps are inserted yet. Sintering temp at 1800C - TGHT will be set accordingly.  TBHT max at 230A.  Chamber is currently being pumped down.     Wednesday, September 02, 2015, 09:11 HS water valves opened, no leaks detected. IGP1 = 1.15e-6 Torr Tapped up manually to 40A. Waited ~1hr40 for vacuum to stabilize. IGP1 = 3.6e-6 Torr. Max setpoints set to TGHT = 630A and TBHT = 230A, ~1400C Initiating auto ramp at a rate of 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. Once max setpoints achieved, will tap up manually until window port becomes coated [as previously observed] Once window port becomes coated will leave at set temp for ~4hrs to continue with outgassing, then cool down, clean window and ramp back up. If LS port still clean, will continue to ramp up to final desired temperature of 1800C.  Wednesday, September 02, 2015, 14:23 IGP1 = 4.0e-5 Torr. Vacuum too high, stopped auto-ramp and tapped down manually. Dropped TGHT down from 80A to 50A Dropped TBHT down from 55A to 50A Wednesday, September 02, 2015, 15:29 Vacuum down to IGP1 = 1.2e-5 Torr. Re-initiating auto-ramp...  Tuesday, September 08, 2015, 10:04 IGP1 = 4.5e-7 Torr. TGHT = 630A, 9.6V TBHT = 230A, 3.2V DV = 0.22V OMEGA RS = 1476C OMEGA LS = 1450C see attached photo for screenshot. will tap up manually with a visual on both window ports...

 Tuesday, September 08, 2015, 15:44

TGHT has stepped up to 820A.  Coating on both windows is becoming obvious and it's interfering the temp readers; however, the left window (see attachment, which is further away from the target) is lightly coated than the right.  See attachment for The Temp (and Power) vs current plots.

Target will remained heated at the current and will be cooled down later today. 

The target will be re-conditioned up to 820A and temp and mass will be re-measured.

Plans:

The chamber will be vented tomorrow and the target will be taken out to weigh for mass change. 

The chamber windows will need to be clean.

A piece of Ta foil will be cover in front of the ionizer to trap any loss material (if any).

 Tuesday, September 08, 2015, 17:37

TGHT was at 800A for 2 hours before ramping up 820A for another 2 hours heating.  More coating on the right window is observed and temp reading came down to 1340C.  The left window remains the same and temp reads at 1646C.  

Ramping TGHT/TBHT to 0A at 2A/min and 1A/min, respectively.  

 Wednesday, September 09, 2015, 12:27

Result after the sintering process:

No yellow crystal formed (compared to previously observed SiC targets that heated up above 1900C). 

Total green mass = 57.90g 

mass of graphite foil = 0.035g x 533 discs = 18.7g 

mass of green SiC = 39.30g 

Target container with SiC before sintered = 1455g 

Target container after sintered = 1450g 

mass loss ~ 5.0g ~ 13% organic mass, as expected!  

The target will undergo the re-condition stage, and the temperature will be measured from 600A to 820A. 

John Wong wrote:

Laura Lambert wrote: John Wong wrote: Tuesday, September 01, 2015, 17:16 Target container contains 533 discs of SiC with packed length of 17cm.  Mass of 533 discs SiC(green)  = 57.8979g Total mass SiC(green) + target container = 1455g Container is wrapped with 3 heatshields; no end caps are inserted yet. Sintering temp at 1800C - TGHT will be set accordingly.  TBHT max at 230A.  Chamber is currently being pumped down.     Wednesday, September 02, 2015, 09:11 HS water valves opened, no leaks detected. IGP1 = 1.15e-6 Torr Tapped up manually to 40A. Waited ~1hr40 for vacuum to stabilize. IGP1 = 3.6e-6 Torr. Max setpoints set to TGHT = 630A and TBHT = 230A, ~1400C Initiating auto ramp at a rate of 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. Once max setpoints achieved, will tap up manually until window port becomes coated [as previously observed] Once window port becomes coated will leave at set temp for ~4hrs to continue with outgassing, then cool down, clean window and ramp back up. If LS port still clean, will continue to ramp up to final desired temperature of 1800C.  Wednesday, September 02, 2015, 14:23 IGP1 = 4.0e-5 Torr. Vacuum too high, stopped auto-ramp and tapped down manually. Dropped TGHT down from 80A to 50A Dropped TBHT down from 55A to 50A Wednesday, September 02, 2015, 15:29 Vacuum down to IGP1 = 1.2e-5 Torr. Re-initiating auto-ramp...  Tuesday, September 08, 2015, 10:04 IGP1 = 4.5e-7 Torr. TGHT = 630A, 9.6V TBHT = 230A, 3.2V DV = 0.22V OMEGA RS = 1476C OMEGA LS = 1450C see attached photo for screenshot. will tap up manually with a visual on both window ports...    Tuesday, September 08, 2015, 15:44 TGHT has stepped up to 820A.  Coating on both windows is becoming obvious and it's interfering the temp readers; however, the left window (see attachment, which is further away from the target) is lightly coated than the right.  See attachment for The Temp (and Power) vs current plots. Target will remained heated at the current and will be cooled down later today.    The target will be re-conditioned up to 820A and temp and mass will be re-measured. Plans: The chamber will be vented tomorrow and the target will be taken out to weigh for mass change.  The chamber windows will need to be clean. A piece of Ta foil will be cover in front of the ionizer to trap any loss material (if any).  Tuesday, September 08, 2015, 17:37 TGHT was at 800A for 2 hours before ramping up 820A for another 2 hours heating.  More coating on the right window is observed and temp reading came down to 1340C.  The left window remains the same and temp reads at 1646C.   Ramping TGHT/TBHT to 0A at 2A/min and 1A/min, respectively.    Wednesday, September 09, 2015, 12:27 Result after the sintering process: No yellow crystal formed (compared to previously observed SiC targets that heated up above 1900C).  Total green mass = 57.90g  mass of graphite foil = 0.035g x 533 discs = 18.7g  mass of green SiC = 39.30g  Target container with SiC before sintered = 1455g  Target container after sintered = 1450g  mass loss ~ 5.0g ~ 13% organic mass, as expected!   The target will undergo the re-condition stage, and the temperature will be measured from 600A to 820A.

 Wednesday, September 09, 2015, 17:39

Both end-caps are inserted onto the targets.  The total mass (Target, Sintered SiC, end caps, 4x 19"round graphite foils) = 1453g.

Target is wrapped with 3 layers of heat shields.  

The extraction electrode is wrapped with Ta-foil (see attachment).  This is to trap any lose particle, if any.  

Chamber is currently being pumped down, currently at 1.2e-5 Torr.