Monday, July 13, 2015, 11:53

A Ta foil is placed in the target boat with separate slots for each endcap [same as elog 200]

The target boat is wrapped with 3-layers of Ta-heat shield.

The boat is installed in EVAP2, chamber is currently being pumped down.

 Monday, July 13, 2015, 15:00

Opened HS water valves, no leaks detected.

IGP1 = 2.7e-6 Torr.

Tapping up manually.

 Monday, July 13, 2015, 15:41

Tapped up manually to 30A

TGHT = 30A, 0.05V

IGP1 = 7e-6 Torr.

Initiating auto-ramp at 0.2A/min up to 480A with a final desired temperature of 1800C

 Tuesday, July 14, 2015, 09:12

IGP1 = 7.8e-7 Torr

TGHT = 241A, 3.3V

OMEGA = 1010C

Increasing auto-ramp to 2.0A/min

 Tuesday, July 14, 2015, 11:12

Reached final setpoint of TGHT = 480A, 8.43V

OMEGA = 1667C

IGP1 = 3.3e-6 Torr.

Tapping up manually to reach final desired temperature of 1800C.

 Tuesday, July 14, 2015, 11:33

Reached TGHT = 500A, 8.8V by tapping up manually.

OMEGA = 1714V

IGP1= 3.5e-6 Torr.

Re-initiating auto-ramp at 2.0A/min with a final setpoint of 580A.

New final desired temperature min of 1900C

 Tuesday, July 14, 2015, 13:16

TGHT = 577A, 10.74V

OMEGA = 1938C

IGP1 = 3.2e-6 Torr

Endcaps have been at this temperature for just over an hour.

Spikes in vacuum started ~430A - this is due to the green TaC coating reacting with the Ta foil, the carbide is reacting directly with the Ta foil [see picture]

Stopping sintering early before endcaps break -> initiating auto-cool at 2.0A/min.

 Wednesday, July 15, 2015, 11:33

Vented in air and took out this morning.

Endcaps sintered on top side but not fully sintered on inner edge.

Inner edge is peeling off and unsintered green TaC.

The coating peeling off did not shrink, as seen with previous tests done, one would expect a shrinkage in the coating when heated.

The peeling is most likely due to the way to endcaps were placed  in the slots of the Ta foil.

This may have cause the foil to be hotter than the inside of the endcaps and subsequently the Ta foil and TaC coating on the inside reacted - with the Ta foil extracting the carbide from the coating.

This would cause the outer edges of the inside of the endcap to peel/curl inwards as it was heated [like a cast, as the cast dries the outer edges curl inwards].

See photos attached for clarification.

Endcaps will be re-coated and sintered again via a different procedure.

John Wong wrote:

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.

 Monday, July 06, 2015, 16:28

Container has been re-coated with TaC.

Target container is wrapped with a single 15.5cm x 8.5cm Ta foil heat shield on each side of the center block, spaced with Ta wire coil.

Chamber is currently being pumped down.

 Tuesday, July 07, 2015, 09:36

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

IGP1 = 6e-7 Torr.

Tapped up manually to 30A.

Waited ~1hr.

Vacuum stable, IGP1 = 1.9e-6 Torr.

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

 Target container reached max setpoints of 520A/230A and 1950C ~6hrs ago.

IGP1 = 7.6e-7 Torr.

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

 Friday, July 10, 2015, 11:16

Vented in air and removed from evap2.

Again, edges not fully sintered [see photos]

Inside of container looks better, fully coated.

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. 

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]

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.

 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.

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

 Thursday, June 25, 2015, 16:14

Total number of foils: 422 discs

Total mass of materials [incl graphite foils]: 

Total length packed: 12.0cm

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.

John Wong wrote:

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.

 Thursday, June 25, 2015, 16:09

Vented in air and took out this afternoon.

Target looks good [see photos]

Window for OMEGA fully coated from outgassing of target materials

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. 

John Wong wrote:

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, 10:17

vented in air and opened up this morning.

coating looks good.

loading container now...

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 16, 2015

An Extraction Insulator ITD0381 made from a different grade of AiN was installed in Evaporator 2 for testing purposes. The sub assembly included the SIS Restraint Housing ITD0389, New Extraction Insulator ITD0381, Repeller Electrode ITD0377, Extraction Electrode ITD0374 with fingerstock mounted.

The standoff insulator ITD0400 was found to be swelled up and broken. It was replaced with and glazed alumina insulator.

The tube heater Insulator ITD0342 - central support helicoil was repaired.

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!

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: 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:  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.

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

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:  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.