Thursday, August 01, 2013, 16:16

The target container was previously coated with TaC and sintered in Evap 2.

The target is loaded with 210 discs of UCx (material from batch # 04 - 05032013)

Total length = 7.2cm

The container is wrapped with 3 layers of Ta-heat shield, including the back block.

A regular TaC coated / sintered endcap is inserted on left, wrt the ionizer tube pointing out of the page. The right end is open with no cap.

The chamber is pumping down.

Instructions for conditioning the UCx target:

1. TGHT will need to heat up to ~ 175A to burn off the organics.

    Parameter setup: 5.0e-5 good vac, 6.0e-5 bad vac. The auto-ramping rate is set to 0.1A/min.

2. Once the organics have burnt off, ramp down the TGHT to 0A at 2A/min.

3. Purge the glovebox with argon gas.

4. Vent the chamber with Ar gas. Close the valve when it is completely vented.

5. Remove the target. Be careful the left end (view from the top) is open with the D-cap.

6. Clean the chamber with TCE and remove all the gunge.

7. Install the target back

8. Pump down the chamber to at least low 10e-6 Torr before begin the final carbonization process.

9. Auto-ramp the TGHT current to 175A at 1A/min.

10. Once the TGHT reach to 175A. Auto-ramp TGHT to 520A at 0.1A/min.

11. At 520A, keep heating the target for at least 4-5 hours.

12. Auto ramp TGHT to 0A at 2A/min.

13. Purge the glovebox with argon for at least 5 min.

14. Vent the chamber with argon gas. Close the valve when it is completely vented.

15. Remove the target from the chamber and put in the "orange james bond box" and transport to the Ar-glove box.

Done!

Laura Lambert wrote:

Thursday, August 01, 2013, 16:16 The target container was previously coated with TaC and sintered in Evap 2. The target is loaded with 210 discs of UCx (material from batch # 04 - 05032013) Total length = 7.2cm The container is wrapped with 3 layers of Ta-heat shield, including the back block. A regular TaC coated / sintered endcap is inserted on left, wrt the ionizer tube pointing out of the page. The right end is open with no cap. The chamber is pumping down. Instructions for conditioning the UCx target: 1. TGHT will need to heat up to ~ 175A to burn off the organics.     Parameter setup: 5.0e-5 good vac, 6.0e-5 bad vac. The auto-ramping rate is set to 0.1A/min. 2. Once the organics have burnt off, ramp down the TGHT to 0A at 2A/min. 3. Purge the glovebox with argon gas. 4. Vent the chamber with Ar gas. Close the valve when it is completely vented. 5. Remove the target. Be careful the left end (view from the top) is open with the D-cap. 6. Clean the chamber with TCE and remove all the gunge. 7. Install the target back 8. Pump down the chamber to at least low 10e-6 Torr before begin the final carbonization process. 9. Auto-ramp the TGHT current to 175A at 1A/min. 10. Once the TGHT reach to 175A. Auto-ramp TGHT to 520A at 0.1A/min. 11. At 520A, keep heating the target for at least 4-5 hours. 12. Auto ramp TGHT to 0A at 2A/min. 13. Purge the glovebox with argon for at least 5 min. 14. Vent the chamber with argon gas. Close the valve when it is completely vented. 15. Remove the target from the chamber and put in the "orange james bond box" and transport to the Ar-glove box. Done!

 Monday, August 05, 2013, 07:51

Chamber has been pumped down over the weekend.  IG1 currently at 2.65e-6 Torr,

Stepped up TGHT to 20A. 

Monday, August 05, 2013, 08:01  

Vacuum seems stable.  

Initiated auto-ramping for TGHT to reach 175A at 1A/min. 

 Sunday, August 11, 2013, 21:23

TGHT has reached to 175A; target has heated at that current for ~28hours.  

Vacuum is currently at 2.9e-6 Torr, BP @ 31mTorr. 

Cooling target down to 0A at 2A/min. 

The chamber will be vented in Ar tomorrow for cleaning. 

 Monday, August 12, 2013, 17:37 (Interesting day....Close call )

Early this morning, the target was removed from the chamber.  As it was transferred to the "orange" seal-box, half the length of the UCx discs fell out from the opening end of the container. 

The discs and the target were transferred to the Ar-glove box.  Tried to fill back the discs but only a few could get in; most of the discs were cracked;

Used the recently prepared UC flakes from Batch#5-18062013 to fill up the target. 

Total length remained the same ~7.2 cm.

The chamber was cleaned;

The target is now installed back in the chamber, and it's currently being pumped down.

The right end remains open (wrt. the ionizier pointing out of the page). 

TGHT will be ramped up to 520A at the rate of 0.1A/min for the full conditioning.

Tuesday, August 13, 2013, 07:51  

Chamber has pumped down to 5.1e-6 Torr. 

Stepping up TGHT to 50A, monitoring pressure... 

Tuesday, August 13, 2013, 08:08  

Vac @ 8.6e-6 Torr and slowly going up. 

Increase TGHT to 80A. 

Tuesday, August 13, 2013, 08:38  

Pressure reached to 6.4e-5 Torr and came down. 

Initiated auto heating.  TGHT max to 520A at 0.1A/min. 

 Monday, August 19, 2013, 10:56

TGHT has reached to max current @ 520A, and heated over the weekend. (See attachment #1)

IG1 currently @ 4.5e-6 Torr, BP @ 33mTorr

Cooling down in progress, rate @ 2A/min.

 Thursday, August 22, 2013, 17:27

Target was removed from the chamber yesterday. 

It looks good and the assembly is underway....

This process is completed.

 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. 

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, 15:31

125 discs of TaC/C

Total discs mass = 125

Total length = 4.5mm

Total Mass = 30.41g

No Ta-heat shield. 

Left opening with D-TaC-sintered cap, and Right opening with regular TaC-sintered cap (orientation with the ionizer tube pointing out of the page).

Target is currently in the evaporator and being pumped down. 

Thursday, September 08, 2011, 09:13

Evaporator has been pumped down over night, IG1 currently at 1.74 e-6 Torr.   

Will begin TGHT, max @ 580A.

TGHT @ 50A, vac stable @ 1.7e-6 Torr.

Thursday, September 08, 2011, 10:18 

THGT @ 90A, pressure is increasing, currently at 4.7e-5 Torr and going up. 

 Thursday, September 08, 2011, 10:25

Auto-heating has begun. Set rate at 2A/min to max current 580A.

Incrementing if vac < 5.0 e-5 Torr, backing off if vac > 6.0 e-5 Torr. 

Friday, September 09, 2011, 07:58

TGHT auto cool down started @ 02:00, and at 0A.  IG currently @ 1.3e-6 Torr.  Venting chamber in progress.  Target will be removed from the evaporator afterward.

Target looks good :)  No signs of damage on the end cap or the target oven overall. 

See attachment 1 for the striptool. 

See attachment 2 and 3 for the target and endcaps after the sintering 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, July 27, 2011, 12:58: 

Target length = 11.2cm

Total UC2/C foils = 245 discs

Total U/cm2 = 15.27g

Target has been pumped down over night,  Vac currently @ 1.64e-6 Torr.  BP @ 38mT.

TGHT @ 76A/0.27V.  Vacuum went up slowly to 4.8e-5 Torr.  TGHT brought back down to 68A, vacuum is holding at 4.8e-5 Torr. 

Wednesday, July 27, 2011, 14:43: Vac @ 2.3e-5 Torr.  Start auto-heating.  0.5A/min, TGHT max = 525A.

Sunday, July 31, 2011, 10:43:  TGHT has reached to 525A.  The pressure came down when the heater was stable at that current (see attachment: striptool_july 31); this implies that more power is needed to finish the carbonization process.  Peter Kunz was informed, and we decided to increase the target heater to 580A.  I will continue to monitor this from home. 

-----------------------------------

On Aug 01, Peter and I agreed to increase the TGHT to 600A (see attachment: striptool_july31_600A) .  Based on the heating curve with 3 Ta-heat shield @ 600A, the would give ~ 2050C/3700W (300C/1600W more than UCx#2).  By looking at the striptool, the pressure came down soon after.  More power might be needed to finish the carbonization process; however as per Peter the graphite vapour pressure increases above 2000C, and we don't know what will happen above that temperature.  So, we will keep it at 600A until the pressure comes down to low 10e-6 Torr.  Then I will being the auto cooling.  Anyway, we are running at 580A online.  On the safe side, 600A may be enough for the conditioning.   

-----------------------------------

 Tuesday, August 02, 2011, 11:19:  TGHT has reached to zero current (see attachment: UCx#2_conditioning).  The evaporator will be vented with Ar.

 Friday, August 05, 2011, 10:49

Unfortunately, after the evaporator was vented with Ar, the target was found be be broken into 3 segments. More details later...

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, November 03, 2011, 08:59

Target was previously coated/sintered with TaC & wrapped with 3 Ta-heat shields, including the back-block. 

Target was loaded with 365 UC2 discs + 3 samples for analysis. 

One regular endcap and one D-cap on the other end where the 3 samples sit. 

Evaporator has been pumped down since last night.  Currently vac @ 2.0e-6 Torr.  

For this final conditioning, here are the instructions: 

1.  Slowly stepping up TGHT  to 100A to burn off the organic binder.  Vacuum is expected to rise to the limit and stay at the plateau for a few days.  

2.  Once the vacuum has come down, the target will be cooldown and the chamber will be vented with Ar.  The cup-holder may be filled with the organic binder and needed to be clean.

3.  Pump back down the evaporator; step up TGHT to 100A and wait for the reaction. 

4.  Initial TGHT auto ramping.  Set TGHT to 520A @ rate of 0.1A/min.  

5.  Allow TGHT to held at 520A for 4 hours, then cool down. 

6.  Remove target from the chamber and store in the air-tight box and transferred to the Ar-glove box. 

Thursday, November 03, 2011, 09:13 

TGHT reached to 55A, and vacuum slowly to rise. Vac @ 5.7e-6 Torr. 

Wil stay at 55A for now... 

 Thursday, November 03, 2011, 09:51

A spike in vacuum and triggered the alarm handler but didn't tripped the TGHT.

Brought TGHT back down to 50A.

Initiated Auto-heating.  Set TGHT to 100A @ 0.1A/min. 

Thursday, November 03, 2011, 18:25  

I just found out that the target heater did not reach to 100A.  The auto-heating was running to bring up TGHT to 100, but the readback stayed at 50A.  Peter K. was contacted.  We stopped the auto-heating program and instantly the target heating jumped to 100A.  Quickly, we brought down the heater to 50A.  (see attachment1 for the stiptool).  Not sure what was happening.  

I stepped up the TGHT manually to 61A, and the pressure is slowing increasing.  

Thursday, November 03, 2011, 19:26  

Something is wrong with the TGHT power supply.  I stepped it up from 55 to 63A, and found the readback stuck at 58 (local @ 56).  So, I tapped the TGHT down to 58A and then the readback followed the setpoint.

I tried again to bring it up to 63 and it stuck at 60A, and tapping down and up the slider triggered the readback to follow the setpoint.  This is a fault in the system. 

Peter was informed, and is taking over this for now.  We need to bring up the THGT up to 100A to burn off the organic binder.  I don't know what we should do from here.  I need a break! 

Friday, November 04, 2011, 15:46  

As per Jane,  there is a problem with the network issue that controls the target heater power supply.  The power supply current is not regulating proper.  (see attachment #2)

TGHT was ramped down from 85A to 0A for Control to work on the problem since this morning.  

See e-fault#5672, WP#2011-11-04-5. 

 Monday, November 07, 2011, 11:12

 Control has fixed the network issue.  

Stepped up to 10A, local read 8A.

 Initiated autoramping, setp TGHT to 20A at 1A/min.  TGHT did reach to 20A with no problem.  

Stepped up further to 30A, local at 28A.  

I conclude that the power supply is now regulating properly.  

Conditioning of UCx#3 continues... 

 Monday, November 07, 2011, 12:14

TGHT at 84.5A, locat @ 82A.  Vacuum hovering at 7.2e-5 Torr.  

Initiated auto-ramping: TGHT set to 100A, at 0.1A/min.  Incrementing current if vac < 5.0e-5 Torr and backing off if vac >6.0e-5 Torr. 

Monday, November 14, 2011, 11:03 

TGHT reached to 175A on Nov 11, 2011 to finish off the organics burnout process. 

Then TGHT was cool down @ 2A/min until TGHT reached to zero.

Evaporator was vented with Ar and the chamber was open.

The target was removed from the evaporator; the organic binder was condensed out from the D-endcap and some from the ionizer tube (See attachment 3 & 4).

One of the samples was retrieved for analysis, and the D-endcap was put back.

The target was installed back, and the chamber was pumped down. 

The sintering and thermal reduction processes continued with TGHT ramped up to 520A.  Heating rate @ 0.1/min. 

Target has been heated at 520A for ~5hrs, vac @ 5.35e-6 Torr. (see attachment 5). 

Wednesday, November 16, 2011, 13:42

 Target looks good.  It has been installed in the heatshield, and it's being stored in the Ar-golve box. 

Evaporator is now off.  

Evaporator was cleaned Nov 11 from after target was conditioned up to 175A. There was significant condensation of oily fluid on the left side where the target container was open (D-shaped end cap). There were also deposits in the hole for the ionizer, but the ionizer itself seemed to be clean.

 Tuesday, February 14, 2012, 20:58

Evaporator is setup for UO2/Nb sintering process.  

Target oven filled with 402 discs of UO2/Nb, 5.0cm in length with tot mass of 61.49g. 

The chamber has been pumped down for 7 hrs, vac is currently at 4.6e-6 Torr. 

Parament set as follow, see attachment 1. 

 TGHT ramped up to 57A.  Pressure is stabilizing at 3.8e-5 Torr.  

Auto heating initiated.  0.1A/min.  Max TGHT = 500A. 

Sunday, February 19, 2012, 11:41 

TGHT has stayed at 500A for >10hrs,  Vac levels at 2.9e-6 Torr.

Target cool down initiated @ 2A/min.

 Monday, February 20, 2012, 10:23

Target has been cooled down over the weekend.  Vac currently at 5.77e-7 Torr.  

See attachment#2: UO2_Nb_1_striptool.jpg 

Chamber  vented in atmosphere.   

Monday, February 20, 2012, 16:23 

Pumps/ power supplies off. 

March 28, 2011

12:28:  Target oven is wrapped with 3 Ta-heat shields.  Pumping down evaporator

March 29,

12:14  Evaporator has been pumped down over night.  Vac @ 1.74e-6 Torr. 

12:24  TGHT @ 20A, Vac @ 1.66e-6 Torr.

12:29  TGHT @ 40A, Vac @ 1.56e-6 Torr.

12:30  Auto heating begins,  Paramenter Setup:  TGHT: 2A/min -->  max 820A.  Incrementing if Vac < 4.5e-5 Torr; backing off if vac > 6.5e-5 Torr.

18:37  TGHT @ 772A/7.395V  (see attachment#1 for the striptool).  Auto heating will stop when the TGHT gets to 820A, and the current will stay there over night. 

March 30

11:31 TGHT has been at 820A/7.8V for the past 17 hours.  (See attachment#2 for the striptool details.)

11:34 Auto-cooling beings

19:40 Auto-cooling has finished. TGHT is at zero and p/s has turned off.  Cooling water has stopped running.  Evaporator will be vented tomorrow.

March 31, 2011

11:13:  Venting evaporator.  All pumps are off and TGHT p/s has turned off. 

Thu Mar 31 11:57:20 2011 After removing the target from the evaporator,  some white coating (could be Tantalum oxide?) was found on the copper plate of the evaporator.  The white coating was found to have more on the left end side of the target and some just below the transfer tube.  The white coating was wiped off but it showed black residual on the wipers.  The target over looks fine.  Marik was informed, and we think this white coating could be  the organic substance burnt off from the target or the Tantalum oxide from the re-used Ta heat shields. 

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. 

Wed May 11 16:20:21 2011:  The HP-FEBIAD (w.o#38481-8) was filled with SiC (8.5mm, 555 discs).  The target is wrapped with 3 Ta-heat shields and is in the evaporator, which is being pumped down. 

Thu May 12 10:52:48 2011:  The evaporator ion gauge, IEVAPIG1 filament burnt out.  The gauge comes in two filaments, so it is now running on the second one.  The chamber has been pumped down overnight, currently it's @ 2.29e-6 torr. 

Thu May 12 11:15:59 2011:  TGHT was stepped up to 80A, vac @ 2.47e-6 Torr.  Begin auto heating at 1A/min to 820A and will increase the rate to 2A/min if the vacuum is stable. 

Thu May 12 12:27:35 2011:   TGHT went up to 101A, and the vacuum started to reach close to the trip limit (8.7e-6 Torr).  TGHT was auto ramped down but the vacuum kept rising and tripped off the heater @ 94A.  TGHT was turned back on after 30mins, vac @ 8.7e-6 Torr.  TGHT was tapped up slowly to 95A.  The ramping rate has also decreased to 0.5A/min.  (See attachment#1: high_vacuum)

Thu May 12 12:58:51 2011:  Lowered TGHT to 90A.  Vac stayed at 7.8e-5 Torr.

Fri May 13 15:47:42 2011:  TGHT @ 128A, incrementing rate @ 1A/min, Vac @ 5.4e-5 Torr after 30 hrs. (See Attachment#2:  current_pressure_30hrs)

Fri May 13 16:22:54 2011:  THGT and vacuum over the past 12 hrs.  (See Attachment#3: current_pressure_past12hrs)

Mon May 16 11:03:54 2011:  THGT reached to 820A and held for over 12 hrs.   (See Attachment#4_Sintering process). 

Tue May 17 16:26:34 2011

Problem Occurred: 

• The end caps of the target got vaporized after the sintering process.  (See Attachment#5:  end_caps_vaporized)
• The caps were not coated with TaC and a D-shaped graphite foil were used. 
  

Solutions: 

• The caps were removed - No damage to the target oven.  (See Attachment#6/#7: left_end/ right_end )
• New caps  were used and coated with TaC.   Two circled-graphite foils were used on the both ends and then sealed with the TaC coated caps. (See Attachment 8: TaC_coated_endcaps)
• Re-heating the target to 820A.

Tue May 17 16:35:13 2011:  Target is wrapped with 3 Ta-heat shields.  The target is in the evaporator which is being pumped down.  

Tue May 17 19:34:55 2011:  TGHT stepped up to 80A, Vac holding at 5.2e-6 Torr.  Auto heating began after 25 mins later.  Rate set at 2A/min to max 820A. 

 Tue May 17 22:02:36 2011:  TGHT @ 382A, Vac @ 1.23 e-5 Torr.  Increased ramping rate @ 3A/min.  Cooling down process will begin at 04:00 of May18, 2011;  ISAC Ops will help to start the auto cooling process.

Wed May 18 11:39:47 2011:  The cooling down process ended; TGHT reached to zero.  The camber will be vented. 

Wed Apr 13 10:37:25 2011:  Target is wrapped with 3 Ta-heat shields.  Evaporator is currently being pumped down.

Wed Apr 13 15:28:02 2011:  Evaporator has been pumped down for over 5 hrs.  Vac @ 2.38e-6 Torr.  (See attachment1: Pumping process)

Wed Apr 13 15:29:21 2011: Set TGHT @ 20A/0.074V, Vac 2.98e-6 Torr.

Wed Apr 13 15:30:00 2011: Set TGHT @ 40A/0.158V, Vac @ 2.30e-6 Torr. 

Wed Apr 13 15:37:42 2011:  Auto heating begins.  TGHT will increase to 820A by 2A/min.  Cooling down will take after the current has stayed at 820A for at least 4 to 5 hrs.   ISAC Ops will help to start the cooling process on April 14 at 03:00.  (See attachment#2: Parameter Setup).

Thu Apr 14 09:49:31 2011:  TGHT reached to 820A and stayed there for about 5.5 hrs.  ISAC Ops helped to start the cooling process (see attachment3: Cooling process).  The target is ready to come out from the evaporator.   P/S is off and evaporator is vented.

Mon Apr 18 12:18:55 2011:  A problem with the bolt and washer occurred during the fin diffusion bonding.  (See attachment #1 and Message ID#15 for more details) .  This target needs to be repaired.

 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.

Tue Apr 5 10:36:53 2011:  Target oven is wrapped with 3 Ta-heat shields.  The evaporator is in the process of pumping down. 

Tue Apr 5 14:54:00 2011:  Evap has been pumped down for over 4 hours.  Vac is currently at 5.5e-6 Torr. (See Attachment#1)

Tue Apr 5 15:16:31 2011: TGHT is turned on.  Set  @ 20A/0.102V; panel reads 18A.  Vac @ 4.62e-6 Torr. 

Tue Apr 5 15:18:16 2011: TGHT set @ 40A/0.216V; panel reads 37A.  Vac @ 4.63e-6 Torr. 

Tue Apr 5 15:19:03 2011: Start Auto-heating.  Parameter setup:  TGHT rate @ 2A/min --> 820A max.  Incrementing if vac <4.5e-5 Torr, and backing off if vac >6.5e-5 Torr.

 Wed Apr 6 09:18:22 2011: TGHT was left at the auto- heating mode over night and  had been at 850A for about 12hrs; Vac @ 4.36e-6 Torr.  (see Attachment#2) 

Wed Apr 6 09:20:53 2011: Auto-cooling down has just started. 

Wed Apr 6 15:33:51 2011:  Auto-cooling completed.  (see Attachment #3 for the overall process)

Wed Apr 6 15:37:10 2011: TGHT p/s off, Venting evaporator. 

Tue Apr 12 10:29:38 2011:  Target wrapped with 3 Ta-heat shields.  Evaporator is currently being pumped down.

Tue Apr 12 15:03:55 2011:  Evaporator has been pumped down for over 4 hrs.  Set TGHT @ 20A/ 0.066V, Vac @ 2.46e-6 Torr. (See Attachment#1 pumping down process).

Tue Apr 12 15:05:11 2011: TGHT @ 40A/0.142V, VAc @ 2.46e-6 Torr. 

Tue Apr 12 15:14:16 2011  Auto heating process begins (See attachment #2 for the parameter setup).  TGHT will reach to 820A max at around 21:45 and the current will stay there for at least 4 hours.  Instructions have given to ISAC Ops to being the auto-cooling down process tomorrow at 03:00 

Wed Apr 13 10:00:13 2011:  TGHT reached to 820A max and stayed for about 5 hrs before the cooling process begun (see Attachment#2: Cooling down process). 

Wed Apr 13 10:04:19 2011: p/s is now off and evaporator is now vented. 

Mon Apr 11 10:21:56 2011: Target is wrapped with 3 Ta-heat shields.  Evaporator is pumping down. 

Mon Apr 11 14:34:32 2011:  Evaporator has been pumped down for over 4 hours.  Vac @ 2.83e-6 Torr.  (see attachment#1 for pumping down process).

Mon Apr 11 14:38:05 2011:  Auto heating beings.  (see attchement#2 for the parameter setup)

Mon Apr 11 17:06:51 2011:  Auto heating is in process,  TGHT @ 324A/2.031V.  The target heater should reach at the max 820A at around 21:30 and will remain at that current for at least 3 to 4 hours.  ISAC Ops will help start the auto-cooling tomorrow at 03:00.

 Tue Apr 12 09:43:46 2011:  Auto cooling down process ended. TGHT stayed at 820A for about 5.5 hrs.  (see attchment# for cooling down process).

Tue Apr 12 09:59:43 2011: Pumps and p/s off, evaporator vented.

Tuesday, September 13, 2011, 16:51

Target is wrapped with 3-Ta heat shields. 

Loaded with 555 SiC discs (total mass 64.24g)

18cm in length.

D-end cap on one end, and a regular end end on the other.

Chamber is currently being pump down

 Wednesday, September 14, 2011, 09:58

Evaporator has been pumped down over night, currently IG @ 1.71e-6 Torr. BP @ 23mT.

The target will be heated up to 550A and will wait to see any reaction happen before increasing TGHT (Max 820A).

TGHT stepped up to 90A, local @ 87A.  Pressure slowly rising, IG @ 2.7e-6 Torr. BP @ 23mT. 

Start auto-heating @ 0.5A/min to max TGHT @ 500A.  

 Friday, September 16, 2011, 00:27:

TGHT @ 250A and pressure has already started to come down, currently at 2.8e-5 Torr.  

Increased TGHT rate from 0.5A/min to 2A/min, and pressure started to rise.  Stopped auto-ramping after pressure increased to 4.4e-5 Torr.  (see attachment#1: TGHT_270A-300A.jpg).

Decreased TGHT rate back to 0.5A/min and changed pressure limit to 3.0e-5 Torr.  

Friday, September 16, 2011, 01:49 :

TGHT @ 347A, and pressure seems to come down slowly. 

Change TGHT auto heating to 550A and pressure limit at 2.5e-5 Torr.  Vac currently at 2.4e-5 Torr.  Ramping rate at 0.5A/min. 

Friday, September 16, 2011, 10:58  

TGHT reached 580A and no spike in the vacuum.  Ramping up TGHT to 590A, keeping pressure limit @ 1.35e-5 Torr,

Currently IG @ 1.33 e-5 Torr.  Current TGHT @ 585.5A, local @  579A.

(see attachment 3: TGHT_580A)

Friday, September 16, 2011, 11:35:

TGHT reached to 590A, not much of out-gassing.  Pressure increased from 1.30e-5 Torr to 1.40e-5 Torr.  

Continue ramping up TGHT, set to 700A, pressure limiting @ 1.5e-5 Torr.

Friday, September 16, 2011, 15:29:

TGHT reached to 700A, local @ 692A; pressure was stable at 1.38e-5 Torr throughout the whole time.  

Continues ramping up TGHT to 820A (max) at 0.5A/min; pressure limiting @ 1.5e-5 Torr. 

Friday, September 16, 2011, 22:05 

TGHT reached to 820A (local 810A) and held for ~3hrs.  IG @ 5.4e-6Torr and coming down, BP @ 20mT. 

See attachment#4:  TGHT_820A.

TGHT cooling down begins... 

 Monday, September 19, 2011, 10:08

TGHT was cooled down over the weekend. 

See attachment#4: archiver_TGHT_0-820A. 

Currently, IG @ 6.9e-7 Torr, BP @ 27mT.

Evaporator will be vented. 

Tuesday, September 20, 2011, 08:51 

Target turned out well.  

D-cap was removed and replaced with a regular TaC-coated sintered endcap with a graphite foil.  

See attachments for details.

Target is now ready for assembly and test for test-stand.