The purpose of this experiment is to improve the TaC coating mixed with other metals as additives.  The coating solution will be sprayed on Ta metal (0.015" thick, same thickness as the target container).

The samples will be sintered at ~ 1800C.  Once the process is completed, a graphite tube will be inserted into the tube, and then re-heated it up to 1800C. 

This test will show how good the protective layer to prevent the graphite to react with the Ta metal.

Wednesday, November 06, 2013, 17:11

Step #1

Two samples: 

1.  A short tube (same diameter as the usual container)

2.  A cross section of the tube.

Both samples are coated with the TaC matrix spray: 

0.05 moles TaC

0.005 moles of Mo2C, VC, Cr3C2, NbC 

A Rh foil is used as a protective under layer.

see links for pictures:  https://www.dropbox.com/sh/866zsp44nnjeg2z/LqCThu-G_0

The target boat is wrapped with 3 layers of heat shields. 

Samples will be heated up to 600A ~1800C

Chamber is currently being pumped down.

 Friday, November 08, 2013, 17:13

Chamber was pumped down to ~2e-6 Torr.  HS water valve is opened and no leaks were detected. 

TGHT will be ramped up to 580A at 1A/min. 

Monday, November 11, 2013, 08:10  

TGHT has reached to 580A; samples has been heated at that current for over the weekend. 

IGP2 currently at 3.5e-7 Torr.

Auto cooling initiated, ramping rate at -2.0A/min.

 Step 2:

The coated tube is sintered with TaC-matrix.

The graphite tube is inserted in the tube and will be heated back up; see link for details:

https://www.dropbox.com/sh/ji0rhlj0v1tfj1w/cRv1I3VJXE

Chamber is currently pumped down to 1.8e-6 Torr.

TGHT will first be ramped up to 450A (1A/min) to see how the reaction behaves, then a caution ramp up to 600A will take place. 

 Friday, November 15, 2013, 11:04

TGHT reached to 450A.  Cooling down to 0A.  Chamber will be vented for inspection.

 Monday, November 18, 2013, 17:22

Continue Step#2:

The sample looks ok after heating at 450A.

Re-heating it to 500A. 

Chamber has been pumped down to 4.0e-6 Torr. 

Initiated auto-ramping...

 Wednesday, January 15, 2014, 17:30

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 0.2A/min.  

 Chamber is currently being pumped.  Tomorrow, the HS water valve can be opened to test for leaks.  

Notes: 

If everything is fine, TGHT/TBHT can be stepped up to 30A-50A.  Watch for the vacuum; once it's stable the auto ramping program can be initiated.  

Once TGHT/TBHT reached above 200A, the ramping rate for TGHT can be increased up to 2A/min.  (This step is to speed up the process; however it's not mandatory) 

Laura Lambert wrote:

John Wong wrote:  Wednesday, January 15, 2014, 17:30 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 0.2A/min.    Chamber is currently being pumped.  Tomorrow, the HS water valve can be opened to test for leaks.   Notes:  If everything is fine, TGHT/TBHT can be stepped up to 30A-50A.  Watch for the vacuum; once it's stable the auto ramping program can be initiated.   Once TGHT/TBHT reached above 200A, the ramping rate for TGHT can be increased up to 2A/min.  (This step is to speed up the process; however it's not mandatory)     Thursday, January 16, 2014, 11:35 Chamber was pumped down overnight to 10-7 Torr. HS water valve was opened and no leak in vacuum was observed. TGHT and TBHT were stepped up to 35A. Waited ~30min, current stabilized and vacuum starting to drop. Initiating auto-ramping: Good Vac = 2.0e-5 Torr, Bad Vac = 3.0e-5 Torr.

 Friday, January 17, 2014, 09:28

TGHT/TBHT @ 300/200A.  TBHT voltage is limited at 3A.  

TGHT ramping rate increased to 2A/min.  Pressure @ 4.5e-7 Torr.  

Laura Lambert wrote:

John Wong wrote: Laura Lambert wrote: John Wong wrote:  Wednesday, January 15, 2014, 17:30 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 0.2A/min.    Chamber is currently being pumped.  Tomorrow, the HS water valve can be opened to test for leaks.   Notes:  If everything is fine, TGHT/TBHT can be stepped up to 30A-50A.  Watch for the vacuum; once it's stable the auto ramping program can be initiated.   Once TGHT/TBHT reached above 200A, the ramping rate for TGHT can be increased up to 2A/min.  (This step is to speed up the process; however it's not mandatory)     Thursday, January 16, 2014, 11:35 Chamber was pumped down overnight to 10-7 Torr. HS water valve was opened and no leak in vacuum was observed. TGHT and TBHT were stepped up to 35A. Waited ~30min, current stabilized and vacuum starting to drop. Initiating auto-ramping: Good Vac = 2.0e-5 Torr, Bad Vac = 3.0e-5 Torr.    Friday, January 17, 2014, 09:28 TGHT/TBHT @ 300/200A.  TBHT voltage is limited at 3A.   TGHT ramping rate increased to 2A/min.  Pressure @ 4.5e-7 Torr.      Friday, January 17, 2014, 10:14 TBHT stopped at 200A with voltage limit sitting at 3V. Aborted auto-ramp, changed the voltage limit to 5V and increased ramping rate to 2A/min. Re-started auto-ramp. IGP1 @ 5.0e-7 Torr

 Friday, January 17, 2014, 12:45

TGHT voltage limiting at 9.9V, and  current stayed at 560A.  Increased the TGHT voltage to 10.5V and continued ramping the heater up.

TGHT/TBHT stabilized at 580A (~10V) and 230A(3.6V). 

Pressure at 1.03e-6 Torr and coming down... 

Target will be heated until 5pm (4hrs) before cooling down at the ramping rate of 2A/min. 

Chamber will be vented in air, next week.

 Friday, January 17, 2014, 16:51

Auto-cooling initiated at 2A/min.

Vac @ 5.3e-7 Torr.

Laura Lambert wrote:

Laura Lambert wrote: Laura Lambert wrote: Laura Lambert wrote: Laura Lambert wrote:  Monday, January 20, 2014, 16:32 A new target boat was sprayed with TaC coating and let dry this morning. The target boat is NOT wrapped with Ta-heat shield. The boat was installed in Evap#2, chamber is currently being pumped down overnight.    Tuesday, January 21, 2014, 11:10 Chamber was pumped down to ~2e-7 Torr. HS cooling water valves were opened, no leaks detected. TGHT was stepped up to 35A, voltage max set at 13V. TBHT currently @ 0A. Waited ~20min, current stabilized, vacuum started to drop, auto-ramp initiated at 2.0A/min and max setpoint to 700A. Good vacuum: 3.00e-5 Torr, Bad vacuum 4.00e-5 Torr.    Tuesday, January 21, 2014, 11:51 Vacuum was grumpy and was well on it's way to tripping off [reached 5e-5 Torr], auto ramping was stopped at ~95A and quickly stepped down to 90A to avoid tripping it off. Allowed vacuum to settle back down to 2.3e-6 Torr. Auto ramping changed to 0.2A/min and re-started.  close-call!    Wednesday, January 22, 2014, 09:46 TGHT has been slowly ramping up overnight at a rate of 0.2A/min. IGP1 = 2.9e-7 Torr, TGHT = 342A; stepping ramping rate up to 2.0A/min.    Wednesday, January 22, 2014, 13:43 TGHT is sitting at 693A, IGP1 = 1.3e-6 Torr. Stepping up TGHT voltage up to 14V from 13.05V to reach the max current of 700A.

 Wednesday, January 22, 2014, 15:09

TGHT reached to 700A/12.83V.  Local temperature on the boat surface was measured at ~1500C.

Note: This is the "old" design boat.  The new design boat was able to heat up to 900A/16.88 - the temperature was measured at about 1500C.  (see elog: https://elog.triumf.ca/TIS/Evaporator_2/15)

Target will be heated for a few hours and will be cooled down later tonight.

The chamber will be vented tomorrow and the boat will be inspected.

John Wong wrote:

Laura Lambert wrote: Laura Lambert wrote: Laura Lambert wrote: Laura Lambert wrote: Laura Lambert wrote:  Monday, January 20, 2014, 16:32 A new target boat was sprayed with TaC coating and let dry this morning. The target boat is NOT wrapped with Ta-heat shield. The boat was installed in Evap#2, chamber is currently being pumped down overnight.    Tuesday, January 21, 2014, 11:10 Chamber was pumped down to ~2e-7 Torr. HS cooling water valves were opened, no leaks detected. TGHT was stepped up to 35A, voltage max set at 13V. TBHT currently @ 0A. Waited ~20min, current stabilized, vacuum started to drop, auto-ramp initiated at 2.0A/min and max setpoint to 700A. Good vacuum: 3.00e-5 Torr, Bad vacuum 4.00e-5 Torr.    Tuesday, January 21, 2014, 11:51 Vacuum was grumpy and was well on it's way to tripping off [reached 5e-5 Torr], auto ramping was stopped at ~95A and quickly stepped down to 90A to avoid tripping it off. Allowed vacuum to settle back down to 2.3e-6 Torr. Auto ramping changed to 0.2A/min and re-started.  close-call!    Wednesday, January 22, 2014, 09:46 TGHT has been slowly ramping up overnight at a rate of 0.2A/min. IGP1 = 2.9e-7 Torr, TGHT = 342A; stepping ramping rate up to 2.0A/min.    Wednesday, January 22, 2014, 13:43 TGHT is sitting at 693A, IGP1 = 1.3e-6 Torr. Stepping up TGHT voltage up to 14V from 13.05V to reach the max current of 700A.    Wednesday, January 22, 2014, 15:09 TGHT reached to 700A/12.83V.  Local temperature on the boat surface was measured at ~1500C. Target will be heated for a few hours and will be cooled down later tonight. The chamber will be vented tomorrow and the boat will be inspected.

 Wednesday, January 22, 2014, 18:09

After the boat was heated for ~4hrs, TGHT tripped off on IEVAP2:TBHT2 (see attachment #1, #2). 

Tried clearing the water interlock via EPICS - failed to clear.  Checked the local water valves - ALL VALVES are OPEN 

Tried closing and re-opening the IEVAP2:TBHT2 valves, interlock cleared after a few minutes. 

Maybe a fault in the water signal.  If it happens again, the water signal should be replaced.

Turned back on the power supply - TGHT current/voltage are holding.  Target boat may be OK!

Chamber is a bit warm now.  Will allow time to cool down.

Will vent the chamber tomorrow and the boat will be inspected. 

Laura Lambert wrote:

Friday, March 07, 2014, 11:41 The target container end-caps were sintered previously, but did not fully complete the sintering process [See elog entry # 119 EVAP2] The caps are inserted in the target boat wrapped in graphite foils with 3 x Ta-heat shields. The chamber was pumped down overnight. IGP1 = 2e-7 Torr HS cooling water valves were opened; no leaks detected. TGHT was stepped up to 35A, voltage max set at 9.05V. TBHT currently at 0A.  Friday, March 07, 2014, 11:52 Waited ~20min, current stabilized, vacuum started to drop, auto-ramp initiated at 0.5A/min and max setpoint to 500A. Will ramp to 500A due to last failed round of end caps breaking with 3-ta heat shields at 580A. Good vacuum: 3.00e-5 Torr; Bad vacuum: 4.00e-5 Torr.  Friday, March 07, 2014, 13:21 IGP1 = 8e-7 Torr. TGHT = 72A Vacuum stable; therefore, increasing ramping rate up to 1.0A/min  Friday, March 07, 2014, 14:20 IGP1 = 9.8e-7 Torr TGHT = 130A Vacuum stable; therefore, increasing ramping rate up to 2.0A/min

Friday, March 07, 2014, 22:22  

Target current was at 500A before it tripped off on the chiller.   Tried to reset the chiller but to no avail.  Don't know what is going on yet. 

The TGHT/TBHT cooling water is still on, and this should OK while the HOT target boat is cooling down at the moment. 

Will leave it for now and further investigate on Monday

Monday, March 10, 2014, 11:44

Rick replaced the backing pump hose from 1.5" to 2.0" for better flow.  And the HEPA filter was checked - it looks OK.

Monday, March 10, 2014, 11:45

The chiller tripped off on March 7, 2014.

• Water is not flowing into the chiller; paddle wheel shows no signal.
• Tried turning on the chiller locally; a few seconds later, it tripped off. 
• Motor is not responding;
• EPICS is not responding;
• All other water flow signals to TGHT, TBHT, HS, are responding;

Continue investigating...

 Monday, March 10, 2014, 14:36

The water line to the chiller is disconnected, and is re-connected straight to the TGHT power supply.  The paddle wheel is responding - the cooling line in the power supply is not blocked.

It is confirmed the chiller is broken. 

Will discuss if we can use the Evaporator without a chiller but with the DI water connected directly to the TGHT power supply....

Friday, March 14, 2014, 14:50  

The chiller was replaced with a "new" one.  

Checked the chiller interlock - It's working.  

The evaporator is now operational. 

 Friday, March 21, 2014, 16:19

Note about Auto-ramping program.

Previously the auto-rampiong program takes the Chiller as part of the reference to the interlocks.  Because the New chiller is not connected to EPICS; all the references to the Chiller on the auto-ramping program has been removed in order for it to function. 

 Friday, March 21, 2014, 16:09

Target container is loaded with 360 Discs of TiC.  

Target length = 11.7cm.  

Total green mass = 40.945g 

Container is wrapped with 3 Ta-heat shields, and have been pumped down in the chamber. 

For the sintering process: 

TGHT ramp up to 820A, and TGHT to 300A at 0.1A/min. 

Friday, March 21, 2014, 16:15

TGHT/TBHT were manually stepped up to 40A.  

Vac stabilizes at 1.7e-6 Torr.  

Initiate auto-ramping... 

Laura Lambert wrote:

John Wong wrote:  Friday, March 21, 2014, 16:09 Target container is loaded with 360 Discs of TiC.   Target length = 11.7cm.   Total green mass = 40.945g  Container is wrapped with 3 Ta-heat shields, and have been pumped down in the chamber.  For the sintering process:  TGHT ramp up to 820A, and TGHT to 300A at 0.1A/min.  Friday, March 21, 2014, 16:15 TGHT/TBHT were manually stepped up to 40A.   Vac stabilizes at 1.7e-6 Torr.   Initiate auto-ramping...     Wednesday, March 26, 2014, 11:05 TBHT reached max desired current of 300A IGP1 = 1.4e-6 Torr TGHT = 543A Increasing TGHT auto-ramp to 2.0A/min

 Wednesday, March 26, 2014, 18:18

TGHT has reached to 820A\13.4V and target has been heated at that current for 4.5 hours.

Vac is coming down to 1.1e-6 Torr.

See link for RGA results: https://www.dropbox.com/sh/08dcxskux21aqap/1SF_dTJB4l

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

 Thursday, March 27, 2014, 11:14

Target is cooled down.  TGHT/TBHT have reached to 0A. 

All pumps off; chamber will be vented soon. 

 Friday, March 28, 2014, 15:00

Target has been assembled.  Heat shield WO#39956-10

Thursday, March 27, 2014, 17:38

TEST #1

WC slurry was prepared in non-aqueous environment (see lab book for procedures).  The solution was dripped on two Ta plates (3.1cm2) and let dry. 

Another Ta plate (3.1 cm2) was sprayed with TaC coating (for comparison).

All 3 coated Ta plates are put in a target boat and the boat is wrapped with 3 layers of Ta-heat shields.

HS water valves open; no leaks detected.

TGHT will be ramped up to 700A at 2.0A/min.

RGA is running and gases are being monitored.  See link:

https://www.dropbox.com/sh/625xl7zgepbybmu/GQJTlMo-5a

 Friday, March 28, 2014, 09:13

TGHT reached to 700A and samples were heated up over night. 

Cooling down Evap at 4A/min. 

 Tuesday, April 01, 2014, 17:37

Previous samples, namely WC#1, #2, TC#1 were fully sinterred.  See above link for photos.

TEST#2

Samples WC#3, #4, #5 are sprayed coated with WC solution.  Grains were pre-treated at 400RPM.

These 3 new samples are loaded in a boat, wrapped with 3 layers of Ta-heat shields.

Chamber is pumped down; no water leaks are detected.

TGHT will be ramped up to 700A at 2.0A/min

RGA is running.

Samples were analyzed with SEM/EDX.  The results are inconclusive because W and Ta peaks are very close together.  And WC coated layer may be even too thin to analyze. 

 Monday, April 14, 2014, 16:32

Test#3:  Coated WC on Endcap.  Total mass WC ~350mg.

Sintered at 500A/9.5V; measure temperature on actual sample surface ~1700C.  Sample heated >24hr.

Cooling down TGHT at 2A/min.  IG currently at 3.1e-7 Torr.

 Thursday, April 24, 2014, 17:25

The purpose of this experiment is to see if the carbon mesh is suitable for coating and sintering with uranium carbide.  For this test, the mesh is coated with WC slurry (previously prepared).

 The carbon mesh disks are bought from ERG aerospace corporation; the specifications of the mesh can be found on the link:  http://www.ergaerospace.com/RVC-properties.htm

Photos, EDX, SEM, RGA, etc... and be found on this link:  https://www.dropbox.com/sh/6ic932wu8yl9ad2/7rHFTiSzLY

Thursday, April 24, 2014, 17:51 

TEST #1:  Carbon Mesh, WC - RF sputtered - Then WC coated and sintered.

Target boat is loaded with a piece of WC coated carbon mesh (1/4 size cut out with the laser cutter).  Chamber is pumping down, currently at 3.2e-6 Torr.

HS water valve open - no leaks are detected. 

TGHT will be ramped up to 500A at 1.0A/min. 

RGA is running.  

Material temp will be measured... 

Monday, May 05, 2014, 17:35

Test #1:

TGHT was ramped up to 680A/13.77V.  Vacuum was at 1.62e-6 Torr (and coming down).  Carbon mesh was heated up to 1900C.   See the link to the dropbox above for more results.

Monday, May 05, 2014, 17:39

Test #2:  Carbon mesh (pure) coated with WC - then sintered. 

Chamber has been pumped down to 3.5 e-6 Torr. 

Sample will be heated up to 500A at 1.0A/min.  (Then step up to 680A while monitoring the vacuum).

RGA is running. 

 Wednesday, May 07, 2014, 14:36

Observations:

TGHT was at 650A/12.96V for 6 hrs and temperature was measured at 1930C. 

At some point after that (~20:40hr on May 6), the voltage went up to 14.77V (current remained constant at 650A), the temp went up 2110C - for only about 45 minute before the voltage dropped

back down to 12.53V and the temperature ~1800C.  Is the boat creaking more??? There were a few crack lines on the boat after Test#1. 

Today, TGHT was raised up to 725A and after an hour at that current the temperature was measured at 1930A. 

Now, at Wednesday, May 07, 2014, 14:47 - Lowered the current back to 685A/13.78V - temperature measured at 1900C. 

One thing to note... the vacuum is showing a lot of spikes but remains at around 7.5e-7 Torr. 

The RGA/Current/Voltage/Temp can be found here: https://www.dropbox.com/sh/1yaa7ez3nydl67m/8v4ZRT2slq

Thursday, May 29, 2014, 16:56 

The process is done. Chamber was vented...

Laura Lambert wrote:

Friday, June 13, 2014, 14:53 Container is filled with 400 discs of Ta foils. No Ta foil heat shield. No caps inserted. Chamber pumped down this morning. HS cooling water valves opened, no leaks detected. IG @ 5.8e-6 Torr. TGHT max = 580A TBHT max = 230A Ramping rate 0.2A/min.  Monday, June 16, 2014, 11:46 TGHT and TBHT reached their respective 580A and 230A over the weekend. IGP1 currently at 3.2e-7 Torr. Internal temp [measured using mikron, right side of EVAP2, pointed at discs inside] = 1375C

 Monday, June 16, 2014, 17:21

Further stepping up TGHT to 650A.

Temperature measured on target discs = 1542C. Vac @ 3.28e-7 Torr.

Initiate cooling down process; 2A/min for TGHT; 1A/min for TBHT

Laura Lambert wrote:

Friday, June 20, 2014, 11:14 Total number of foils: 515 discs Total mass of materials [incl graphite foils]: 64.7224g Total length packed: 17.8cm Container is wrapped with 3x Ta-heat shields. Currently being pumped down.  Friday, June 20, 2014, 14:56 HS cooling water valves opened, no leaks detected. IGP1 = 6.2e-6 Torr TGHT max = 820A/ 17V TBHT max = 300A/ 5V Stepping up manually to 40A  Friday, June 20, 2014, 16:04 IGP1 = 8e-6 Torr Slowly stepped up to 35A manually. Vacuum has stabilized. Initiating auto-ramp at 0.1A/min

 Friday, June 20, 2014, 16:16

Changing the heating current... 

From the previous SiC targets, TGHT was ramped up to 800A and yellow crystals were found; the end caps and target legs were also found broken (see my iPad).  This might be too hot for the Ta-boat to handle the sintering process. 

For this process,

TGHT will ramp up to 600A and TBHT to 230A over the weekend. 

Then, the temperature will be measured.  The sintering temperature of SiC is ~1800 - 2000C. 

Laura Lambert wrote:

John Wong wrote: Laura Lambert wrote:  Friday, June 20, 2014, 11:14 Total number of foils: 515 discs Total mass of materials [incl graphite foils]: 64.7224g Total length packed: 17.8cm Container is wrapped with 3x Ta-heat shields. Currently being pumped down.  Friday, June 20, 2014, 14:56 HS cooling water valves opened, no leaks detected. IGP1 = 6.2e-6 Torr TGHT max = 820A/ 17V TBHT max = 300A/ 5V Stepping up manually to 40A  Friday, June 20, 2014, 16:04 IGP1 = 8e-6 Torr Slowly stepped up to 35A manually. Vacuum has stabilized. Initiating auto-ramp at 0.1A/min    Friday, June 20, 2014, 16:16 Changing the heating current...  From the previous SiC targets, TGHT was ramped up to 800A and yellow crystals were found; the end caps and target legs were also found broken (see my iPad).  This might be too hot for the Ta-boat to handle the sintering process.  For this process, TGHT will ramp up to 600A and TBHT to 230A over the weekend.  Then, the temperature will be measured.  The sintering temperature of SiC is ~1800 - 2000C.     Monday, June 23, 2014, 09:45 IGP1 = 5e-6 Torr TGHT and TBHT are at ~200A Increasing ramping rate to 0.2A/min  Monday, June 23, 2014, 11:19 IGP1 = 6.9e-6 Torr Increasing ramping rate to 2.0A/min Monday, June 23, 2014, 12:09 JW:  Pressure went up too fast... lower the TGHT ramping up rate to 1A/min.  Tuesday, June 24, 2014, 16:06 Increasing current with respect to temperature: See attached table

 Tuesday, June 24, 2014, 23:44

Target has been heated at 600A.  Local temperature measured on the right leg = 1814C. 

RGA/ striptool/temperature data can be found on this link: 

https://www.dropbox.com/sh/69memvh6fthodoz/AABZiSKAR9njhbqO4sBATVbla

Something interesting was observed about the out gassing of this target - the right window was coated when the temperature rose above 1500C (on the right end, could be hotter inside?) - see attachment.

I suspect this is Si vapour deposited on the window when the target heater got closed to the sintering temperature for SiC (1800 - 2000C).  

Once the chamber is vented, the coated window will be inspected and analyzed.  More details later...  

Initiate auto-cooling (slow cool down)  TGHT 1A/min; TBHT 0.5/min.  Chamber should be able for venting tomorrow afternoon.  

Wednesday, July 23, 2014, 15:07

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 0.2A/min.

Chamber is currently being pumped down

 Wednesday, July 23, 2014, 17:40

Vacuum came down to mid 10-6 Torr.

Stepped up TGHT and TBHT to 30A - IG1 @ 1.4e-5 Torr.

Initiated auto-ramping.

 Thursday, July 24, 2014, 17:19

TGHT and TBHT have reached to 100A, and vacuum is coming down to 1.4e-6 Torr.

Increase ramping rate, TGHT to 1A/min, TBHT 0.5A/min.

 Friday, July 25, 2014, 11:26

Target container temperature reaches ~1550C at 580A on TGHT and 230A TBHT, and it has been heated for ~10 hrs.

Auto-cooling initiated at 2A/min.

Laura Lambert wrote:

Monday, July 28, 2014, 14:41 Total number of foils: 445 discs Total mass of materials [incl graphite foils]: 49.027 g Total length packed: 11.2 cm Container has no Ta heat shields. Currently being pumped down.

 Tuesday, July 29, 2014, 11:19

Chamber was pumped down overnight to ~5.5e-7 torr.

HS water valve opened; no leaks were detected.

Stepped up TGHT/TBHT to 40A. IG went up 8e-6 Torr and stabilized. 

Initiated auto-ramping TGHT @ 580A, TBHt @ 230A at 0.2A/min

Laura Lambert wrote:

Tuesday, August 05, 2014, 12:02 The target container end caps were coated with TaC spray and let dry. The caps are inserted in the target boat vertically, wrapped in graphite foil with 3 x Ta-heat shield. [see attached photo] The chamber is currently being pumped down.

 Tuesday, August 05, 2014, 17:19

HS water valve opened; no leaks detected. 

Pressure @ 2.5e-6 Torr.

Ramping up TGHT to 580A @ 1A/min.

Wednesday, August 06, 2014, 15:59

Target consists of 400 Ta discs. 

Total packed length 4.5cm

Total mass 47.490g.

Re foil inserted.

Wednesday, August 06, 2014, 16:07

Chamber is currently being pumped down.

No Ta heat-shield wrapped (Want to check the temperature without it) 

One end-cap inserted on left (wrt ionizer into the page).

TGHT and TBHT will be ramped up to 820A/230A at 2A/min.

 Wednesday, August 06, 2014, 18:07

Vacuum at 2.3e-6 Torr.  HS water valve opened.  No leaks.

Initiated auto-ramping.

 Thursday, August 07, 2014, 11:39

Target has been heated for 11hrs at TGHT/TBHT = 820A/230A.

Temperature measured with pyrometer:

Target leg = 1600C + (250 correction for e=0.25) = 1850C

Inside target material = dark, temp can't be measured.

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