Thu Apr 14 09:52:59 2011: Target is wrapped with 3-Ta heat shield and ready to go into the evaporator. 

Thu Apr 14 11:57:29 2011: The process is on hold until the problem with the screw and the washer of the evaporator is resolved.  See ID#15 for more details.

Fri Apr 15 11:22:27 2011:  The shorter fully threaded bolts and un-threaded washer are being used. 

Fri Apr 15 11:23:30 2011:  Target is in the evaporator and ready for the fin diffusion bonding.  The evaporator is currently being pumped down.

Fri Apr 15 15:57:40 2011: TGHT @ 20A, Vac @ 4.53e-6 Torr.  ISAC Ops will help to start the auto heating process at 18:00hr tonight  and  begin the auto cooling on April 16 @ 18:00 hr. 

 Mon Apr 18 10:53:39 2011:  Target was heated @ 820A over the weekend and pumped down on Saturday April 16 in the evening.  P/S is off and evaporator is vented.  (see Attachment#1 for the striptool)

Mon Apr 18 12:16:22 2011:  Target fin diffusion bonding is nicely done, and the evaporator shows no sign of any coating.  It looks like the problem from the bolts and washers is resolved.  

 Thu Apr 14 14:03:17 2011:  What did we see after the fin diffusion bonding of Ta fins for FEBIAD-HP (w.o#38481-7) ? :

1.  A problem occurred during the FEBIAD HP Ta fin diffusion bonding and was discovered after the evaporator chamber was opened.  The washer was "wielded" on to the left leg of the target (see attachment #1: washer on target leg). 

2. A look inside the evaporator chamber shows that more coating is found on the evaporator lid and the copper base plate (See attachment#2: Inside evap chamber). This coating was previously found when a HP FEBIAD target underwent for the fin diffusion bonding (See Message ID#4: Diffusion bonding of Ta Fins for FEBIAD-HP (w.o#38481-8)).  The evaporator chamber is cleaned with a wiper sheet and EtOH each time before a target is put in;  however the coating is not easily removed and there are always some residual remain. 

3.  The bolt and the washer are deformed.  The top part of the bolt is expended and can no longer fit into the threaded washer  (See attachment#3: Deformed bolt_washer). 

4.  The TIS group was called in to investigate the problem.  It was believed that the problem might have started from the bolts and the washers.  The un-threaded shank bolts and the threaded washers are made for remote handling purposes, so they do not fall apart everywhere in the hotcell.  However, if these bolts and the washers are used for the evaporator, which are bolted on and tighten against the gravity onto the conductors, this may create a gap if the threaded washer is tilted slightly.  (See attachment#4: Gap).  As a result, this causes an uneven pressure contact of the bolt/washer and the target leg.  

Solutions:

Use fully threaded bolts (same material as before - a mild steel) and remove the threads from the washers (See attachment#5: No Gap).

--> To be tested...

 Fri Apr 15 11:59:31 2011: 

The new bolts/washer were cleaned only with simple green and ultrasonic for 5 min.  The bolts and washer should not be cleaned for too long; some remaining grease actually helps prevent them from getting rusty.  The evaporator is wiped with EtOH and  the target is inside.  The bolts and washers are tighten and they are not showing at space like before (See attachment#6: new bolt_washer) .  The evaporator is being pumped down and the target heater will be raised to 820A; we will have to wait until the fin diffusion bonding is complete and the evaporator chamber is vented. 

 Mon Apr 18 12:30:35 2011: 

After a fin diffusion bonding of a HP FEBIAD target, there is no sign of coating in the evaporator.  The bolts/washer and the target look normal. 

--> The problem is solved.

Mon Apr 18 18:10:53 2011: 

FEBIAD-HP target (w.o 38295-8) is coated with TaC (previously prepared on Feb 15, 2011).  This target will be used for the SiC run in Oct, 2011.  The target is wrapped with 3 Ta-heat shields and is in the evaporator.  Pumping down of the evaporator is in process, currently vac @ 3.66e-5 Torr.   

Tue Apr 19 11:00:36 2011: Evaporator has been pumped down over night (~17hrs).  Vac is currently at 1.84e-6 Torr (See Attachment#1: pumping down curve).

Tue Apr 19 11:09:49 2011: TGHT @ 30A/0.086V, Vac @ 1.82e-6 Torr.

Tue Apr 19 11:13:05 2011: TGHT @ 60A/0.184V, Vac @ 1.75e-6 Torr.

Tue Apr 19 11:14:06 2011: Auto-heating will begin @ 0.5A/min until vacuum is stable then the auto ramping rate will increase. (See Attachment#2: parameter setup).

Tue Apr 19 14:27:08 2011:  TGHT is currently at 148A/0.65V, vac @ 1.92e-5 Torr.  The pressure spiked up to 7.7e-5 Torr (trip @ 8e-5 Torr) at ~124A.  The current was lowered down to 120A to allow the pressure to come down (See Attachment#3: Vac_curve).   Auto-heating rate has changed to 1A/min. 

Wed Apr 20 10:08:52 2011:  TGHT reached to 700A and stayed for about 5 hours.  ISAC Ops helped to start the auto cooling down process.  (See Attachment#3: Overall Process). 

Tue Apr 26 11:12:36 2011

Result:  The dried coating isn't looking the same like the rest of the target.  Typically, the finished coating looks gray.  But a layer (or line) of light brown coating can been seen from one end of the target to the other end. 

--> This target was heated up to 700A.  Will try to re-heat this again to 820A. 

Re-heating the Target

Tue Apr 26 12:44:30 2011:  Target is wrapped with 3 Ta-heat shield and is in the evaporator which is currently being pumped down. 

Tue Apr 26 17:39:40 2011:  TGHT was tapped up to 70A before began with auto-heating @ 2A/min to 820A max.  Currently TGHT at 204A/1.0V, Vac @ 3.97e-6 Torr.  ISAC Ops will help to start auto cooling at 04:00 on April 27.

Wed Apr 27 12:26:41 2011: Auto cooling completed.  P/S off and evaporator is vented, (See Attachment#5: Overall Process_2).  Target oven looks good; finished surface looks gray, as expected. 

Wed Apr 20 16:39:46 2011:  Target oven was coated with TaC early today.  The target was allowed to dry and then wrapped with 3 Ta heat-shields.  The target is in the evaporator and it is being pumped down.  Vac is currently at 9.48e-6 Torr. 

Wed Apr 20 17:51:12 2011 : TGHT @ 60A/0.225V, Vac @ 5.98e-6 Torr. 

Wed Apr 20 18:20:04 2011: Auto-heating begins @ 0.5A/min to max of 820A.

Thu Apr 21 10:12:34 2011: TGHT was auto ramping up slowly over night to 546A this morning.  The ramping rate has changed to 2A/min since the vacuuum is stable at ~3.9e-6 Torr.

 Tue Apr 26 11:10:03 2011:  TGHT reached to 820A max on April 21 and stayed at that current for a few hours.  ISAC Ops helped to ramped down the heater afterward.  (See attachment#1: Overall Process).

Result:  Good!  TaC is coated evenly on the target. 

Mon May 9 16:09:35 2011:  Target is wrapped with 3 Ta heatshields and the evaporator is begin pumped down.

Mon May 9 17:59:57 2011:  Vac is @ 1.33e-5 Torr.  TGHT was stepped up to 60A before starting the auto heating process (See Attachment#1: TGHT_ramping_up).   Note: Although the vacuum is at low e-5 torr, this should be fine to start the TGHT because it takes a while to heat up the high power target.

Tue May 10 11:10:44 2011:  TGHT reached to 820A and stayed for 4 hrs before ISAC Ops helped to begin the cooling process.  (See Attachment#2: Overall process).

Tue May 10 14:56:05 2011:  Target is wrapped with 3 heat-shields.  The evaporator is pumping down, vac @ 4.72e-6 Torr.  TGHT was raised to 60A/0.239V.  Auto heating will being now; THGT will be ramped up to 820A @ 2A/min. (See Attachment#1: Staring_process)

Wed May 11 10:16:03 2011: Auto cooling was started by ISAC Ops' help.  TGHT has ramped down to zero.  The p/s will be turned off and the evaporator will be vented soon. (See Attachment#2: Overall Process).

 Monday, July 18, 2011, 15:53:  Target oven was coated with TaC and let dry over the weekend.  The target is now installed in the evaporator and currently being pumped down.  No Ta-heat shields are required for LP target ovens. 

Wednesday, July 20, 2011, 11:42:  Evaporator had to be vented to remove the target because Ta-heat shields were actually required for UCx target at 2uA p+.  Target heater was never turned on.   After removing the target oven, it was rolled around Ta wire; this prevent the Ta foil to stick on the oven.  Then 3 Ta-heat shields were wrapped around it, plus 2 shields on the back block.  The evaporator has been pumped down over night, currently vac @ 1.30e-6 Torr. 

Wednesday, July 20, 2011, 12:35: TGHT stepped up to 110A, pressure began to increase exponentially.   Brought THGT down to 100A. Will being auto cooling soon.

Wednesday, July 20, 2011, 12:48:  Auto heating beings.  2A/min, max current @ 520A.

Wednesday, July 20, 2011, 17:49:  TGHT reached to 520A.  Increased heater to 570A according to last year UCx procedures.

Wednesday, July 20, 2011, 19:46:  TGHT held at 570A for about 2 hours.  Cooling down has begun.  Set rate at 0.5A/min for slow cool down.  

Thursday, July 21, 2011, 12:20 :  TGHT cooling rate increased to 2A/min at about 10:25 am.  At 10:55am, TGHT p/s tripped off, and the water valve was closed.  Not sure what was the reason.  Rest p/s and water valve, and turned back the p/s and continue to cool down from 74A.  (see attachment#1: striptool)

Thursday, July 21, 2011, 14:45 :  TGHT off, chamber about to be vented into atmosphere.  

Wednesday, August 03, 2011, 20:27 :  Target was wrapped with 3 new Ta-heat shields and 2 around the back block.  The tar from the previous UCx conditioning remained in the chamber was removed and cleaned.  Chamber is currently being pumped down, vac currently @ 8.3 e-6 Torr. 

Wednesday, August 03, 2011, 21:01:  Begin to step up TGHT, currently vac @ 7.5e-6 Torr.

Wednesday, August 03, 2011, 21:30 : TGHT stepped to 110A, vac raising exponentially. 

Wednesday, August 03, 2011, 21:34:  Brought down TGHT to 100A, and began auto heating.  Set rate @ 2A/min, max current to 520A. 

Thursday, August 04, 2011, 00:33:  THGT is ramping up nicely and the vacuum is coming down.  It should reach to 520at 01:30.  I asked ISAC Ops to cool down the target heater at 04:00.

Thursday, August 04, 2011, 10:26 :  TGHT has reached to 0A.  Chamber will be vented.  See attachment1 for striptool.

 Monday, August 29, 2011, 13:16: Target oven was coated with TaC and let dry over night.  The target oven is in the evaporator and currently being pumped down.  

Monday, August 29, 2011, 15:12: Currently vac @ 8.41e-6 torr. 

Monday, August 29, 2011, 15:32: Stepped current up to 77A, started to see increase in pressure. 

Monday, August 29, 2011, 15:39:  Stepped current up to 110A.  Vac @ 1.32e-5 Torr.

Monday, August 29, 2011, 15:53: Vac went up to 3.8e-5 Torr @ 110A after 8 mins.  Brought TGHT back down to 100A, and began auto heating @ 2.0A/min to max current of 520A.

Tuesday, August 30, 2011, 08:39:  TGHT reached to 520A and was cool down by ISAC Ops at around 00:30.  See attachment#1 for striptool.  Evaporator will be vented. 

Tuesday, August 30, 2011, 09:29: Target Boat wrapped with 3 Ta heat shields. 6 D-End Caps and 6 End Caps coated with TaC. Pumping down - vac at 3.6e-5 torr.

Tuesday, August 30, 2011, 10:35: Stepped heater up to 100 A. Vacuum tripped heater. Stepped back up to 80 A then 70 A. Vac at 4.5e-5 torr.

Tuesday, August 30, 2011, 14:30: Manually increased heater to 580 A. Vac is 2.5e-5 torr. Local reading is 561 A for 570 A and 570 A for 580 A set points.

Tuesday, August 30, 2011, 15:57: Manually decreased heater in 12 min to 0 A from 460 A  vac starting at 6.3e-6 torr.

Anders Mjos wrote:

Tuesday, August 30, 2011, 09:29: Target Boat wrapped with 3 Ta heat shields. 6 D-End Caps and 6 End Caps coated with TaC. Pumping down - vac at 3.6e-5 torr. Tuesday, August 30, 2011, 10:35: Stepped heater up to 100 A. Vacuum tripped heater. Stepped back up to 80 A then 70 A. Vac at 4.5e-5 torr. Tuesday, August 30, 2011, 14:30: Manually increased heater to 580 A. Vac is 2.5e-5 torr. Local reading is 561 A for 570 A and 570 A for 580 A set points. Tuesday, August 30, 2011, 15:57: Manually decreased heater in 12 min to 0 A from 460 A  vac starting at 6.3e-6 torr.

 Vented evaporator. 

John Wong wrote:

Monday, August 29, 2011, 13:16: Target oven was coated with TaC and let dry over night.  The target oven is in the evaporator and currently being pumped down.   Monday, August 29, 2011, 15:12: Currently vac @ 8.41e-6 torr.  Monday, August 29, 2011, 15:32: Stepped current up to 77A, started to see increase in pressure.  Monday, August 29, 2011, 15:39:  Stepped current up to 110A.  Vac @ 1.32e-5 Torr. Monday, August 29, 2011, 15:53: Vac went up to 3.8e-5 Torr @ 110A after 8 mins.  Brought TGHT back down to 100A, and began auto heating @ 2.0A/min to max current of 520A. Tuesday, August 30, 2011, 08:39:  TGHT reached to 520A and was cool down by ISAC Ops at around 00:30.  See attachment#1 for striptool.  Evaporator will be vented.

 Tuesday, September 06, 2011, 17:04:  Re-conditioning sintered-TaC-coated target oven filled with sintered D-endcap.  No heat-shields.  Evaporator is currently pumping down:  CG2 = 51mT, IG1 = 2.65e-5 Torr.

TGHT auto-heating started by ISAC Ops as per JW at 18:45 yesterday when vacuum level at 6.6 e-6 Torr.  Then auto-cooling began at 05:30 this morning. BP @ 50mT - time to change backing pump oil. (see attachement1: overall striptool)

Wednesday, September 07, 2011, 11:16: Vented evaporator.  BP oil will be changed by Edi. 

Wednesday, September 07, 2011, 11:18:  

IEVAP:CG2 @ 52mT before oil change. 

Edi D.V changed the oil for the backing pump.  WP#2011-09-07-2. CG2 currently @ 21mT.

2011-09-01:

• Glove box was leaking (air/argon) between base and box. Light was shining through.
• Removed old neoprene seal at base.
• Resealed glove box between base and box with DAP Butylflex. No light shining through after repair.
• Replaced rubber disks at 4 feed-throughs.
• Maico Dalla Valle replaced the inner ring on the glove ports. See dwg ITA2954 and ECO-2418.
• After the repair, the glove box has a significantly reduced leak, estimated to a few liters per minute at an air pressure of  0.5" H₂O.

Evaporator drawings can be found on ITA2900D

Work Permit: 2011-09-01-2 

Friday, September 09, 2011, 10:05

Target oven coated with TaC, and wrapped with 3-Ta heat shields.  Chamber is currently being pumped down. 

TGHT @ 140A, IG 9.2 e-6 Torr, BP 20mT. 

Started auto heating, rate @ 2A/min, to max current of 820A. 

Friday, September 09, 2011, 12:25

Evaporator tripped off at 163A. 

Stepped TGHT back to 160A.  Vacuum holding at 4.3e-5 Torr.

Monday, September 12, 2011, 09:55

Evaporator was cooled down over the weekend. 

Chamber will be vented shortly.

See attachment#1: striptool

Monday, September 12, 2011, 13:07

Target boat is loaded with coated TaC end caps for sintering.  Target boat is wrapped with 3 Ta-heat shields. 

Max TGHT = 580A

Monday, September 12, 2011, 14:58 

Vac @ 3.72e-6 Torr.  Stepping up TGHT to 90A; pressure starting to increase.

 Monday, September 12, 2011, 15:33

Evaporator tripped twice when TGHT was at 90A and 85A.  Lowered TGHT to 75A.

Tuesday, September 13, 2011, 09:56 

TGHT was on auto-heating and reached to 580A yesterday evening.  The auto cooling began at mid-night after heated for a few hours. 

The chamber will be vented shortly.

See attachment#1: striptool.

Wednesday, September 21, 2011, 13:23

Target oven was wrapped with 3-Ta heatshields including the back block. 

Target is in the chamber and currently being pumped down.

Wednesday, September 21, 2011, 15:52  

IG @ 5.9e-6 Torr.  

TGHT stepped up to 85A, and pressure slowly rising. 

Started auto heating:  0.5A/min.  TGHT to max 580A.  

Thursday, September 22, 2011, 10:19 

Target was heated up to 580A, and held for 3 hrs. 

Currently IG @ 6.15e-6 Torr.

Auto-cooling started...

Thursday, September 22, 2011, 20:20 

Target oven was removed from the evaporator, and it was successfully sintered with TaC. 

Friday, September 23, 2011, 13:39 :

See attachment1: Archiver_TGHt0-580A.

 Thursday, September 22, 2011, 20:21

Target oven was wrapped with 3 Ta-heat shields and has been pumping down.

IG currently @ 3.2e-6 Torr, BP @ 25mT. 

TGHT stepped up to 85A, 

Began auto-heating: TGHT to max 580A @ 0.5A/min. 

Monday, September 26, 2011, 10:23 

TGHT reached to 580A on last Friday and was held at that current for 3hrs then followed by the auto-cooling.

Chamber was vented.

Target oven looks great.

Thursday, April 05, 2012, 16:43

Target oven is coated with TaC.  The oven is wrapped with 3 Ta-heat shields.

The chamber is currently being pumped down.  Vac @ high 10e-5 Torr.  Heater will be turned on once the pressure is gone down to low 10e-6. 

TGHT will be heated up to 820A.

**** Sintering is postponed until the situation with the ventilation in the lab06 is cleared. ****

 Friday, May 04, 2012, 16:59

The short-term solution  for improving the ventilation system and for the safety in operating the evaporators has been implement.  The test results was reviewed and approved by the committee.  The labs (06 and 07) are now back in operational. 

Friday, May 04, 2012, 17:03

Pumping down evaporator, currently a 2.4e-5 Torr.

Turned on TGHT, and stepped up to 85A.  Pressure remained at low e-5 Torr. 

Initiated Auto-heating at 0.5A/min to Max current 820A.  Parameter set:  Increasing current if Vac <4.0e-8 Torr, Backing current if Vac >5.0e-8 Torr.

 Monday, May 07, 2012, 10:38

At 820A, the TaC coating only seemed to have partially sinterred.  Raised TGHT up to 900A and heated for >6hrs.  The vacuum continued to increase as the target heater was raised; that indicated the sintering reaction was ongoing.  (See attachment #1: Targetoven_TaCsintered_acrchive.jpg).

The auto-cool down was initiated last night.  TGHT is now at 0A.  The chamber will be vented.

Friday, October 04, 2013, 15:37

A LP target container is coated with TaC.  The container is wrapped with 3 layers to heat shield.  

This container will be used for the graphite tube test.  

Chamber is being pumped down.

 The HS cooling water valves are open and no leaks are detected. 

TGHT will be ramped up to 580A at 0.2A/min

TBHT will be ramped up to 230A at 0.2A/min.

The temperature will be monitored and measured.