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.

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.

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.

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.

 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]

-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]

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.

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.

 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.     

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. 

 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!  

 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...