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.

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. 

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.

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

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 

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.

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.

 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. 

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. 

Thursday, August 04, 2011, 17:44:  All the UCx material from target oven 38634-3 was recovered and repacked in this new oven.  Total mass recovered = 45.911g and packed in 10.7cm length.  Target is currently being pumped down. 

Thursday, August 04, 2011, 20:23:  Current vac 5.6e-6 Torr.  Stepping up TGHT to 104A, vac increasing slowly.  Being auto heating @ 2A/min to 200A. 

Thursday, August 04, 2011, 21:32 THGT @ 200A,( see attachment1: 200A.jpg)

Friday, August 05, 2011, 09:04:  TGHT reached to 520A, and was cool down last night by ISAC Ops.  (See attachment2: re-conditioning).  Target looks good! 

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.

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...

 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.  

Before began the carbonization process, two cameras were setup in the hotlab for monitoring the evaporator and the power supply.  On duty ISAC Ops also helps to monitor on a regular basis and to grab the striptools + cameras (twice/shift) and put this information in the ISAC Logbook with subject header:  "UCx_2011_B 'date time'", for easy search.  

P/S camera: http://isaccamera1, user/pw = admin

Evaporator camera: http://isac-cam01, user =admin, pw=yield 

Thu Jun 30 12:24:31 2011

UO2 used = 50.29g 

Green UO2/C = 71.96g, rolled up /w graphite sheet (15cm x 12cm), and put in the target boat, then wrapped with 3 Ta-heat shields.  The target is installed in the evaporator and is being pumped down.

Thu Jun 30 12:45:39 2011: Currently Vac @ 3.75e-5, CG2 @ 0.045T.

Friday, July 01, 2011, 13:28:  Vac @ 2.2-6 Torr.  TGHT set at 10A yesterday.   

Friday, July 01, 2011, 13:42:  TGHT stepped up to 36A (panel 33A), 0.134V.  No change in vacuum,  2.38e-6 Torr, CG @33mT. 

Friday, July 01, 2011, 13:51:  TGHT stepped up to 50A (panel 47A), 0.194V.  Vac @ 5.7e-6 Torr, CG2 @ 33mT.  

Friday, July 01, 2011, 14:09 :  Vac was rising slowly.  TGHT stepped up to 57A and the pressure started to increase faster.  TGHT was brought back down to 30A, and vac is coming down gradually.  (See attachment 1#2: Startup Vac/Current)

Friday, July 01, 2011, 14:16 :  Auto ramping began.  0.1/min, max currently @ 525A. (see attachement #3: Parameter)

Monday, July 04, 2011, 12:33:  TGTH @ 146.20A, Vac @ 4.74e-5 Torr.  (see attachment#4: 3-day trend).  Increase auto ramping rate to 0.5/min. 

Monday, July 04, 2011, 13:01:   TGHT @ 148A, Vac @ 5.20e-5 torr.  Auto rampiing paused until vacuum goes down to 5.0e-5 torr.  (see attachment#4)

Monday, July 04, 2011, 17:34:  TGHT @ 220A, VAC started to come down, indicating the burning off organics was done.  Increased heating rate to 1A/min. 

Friday, July 08, 2011, 21:30:  As per Peter Kunz, "I started the target cooldown sequence for IEVAP:TGHT1 at 20:35. The pressure came down to 4e-6 torr. The ramp down rate is 2A/min. Please check if the target heater current comes down to 0A. Then it can cool off over the weekend."

Monday, July 11, 2011, 12:17:  Evap glove box flashed with Ar gas, set pressure ~100psi.  Chamber also vented with Ar, set pressure  @ ~5psi.

Before began the carbonization process, two cameras were setup in the hotlab for monitoring the evaporator and the power supply.  On duty ISAC Ops also helps to monitor on a regular basis and to grab the striptools + cameras (twice/shift) and put this information in the ISAC Logbook with subject header:  "UCx_2011_A 'date time'", for easy search.  

Wed May 25 14:39:31 2011:  UO2/C cast was dried in the fumehood over the weekend.  The cast was pilled off from the coated WD40 glass plate, rolled up and put in a target heating boat (/w TaC coating & sintered).   The boat was wrapped with 3 Ta-heat shields, then installed in the evaporator which is currently being pumped down.

Thu May 26 11:40:06 2011:  Vac @ 1.75e-6 torr, BP @ 0.032T.  TGHT stepped up to 30A/0.092V (panel @ 27A), ; TGHT has been held for over 10 mins, no change in vacuum yet.

Thu May 26 11:46:48 2011: TGHT @ 40A/0.123V (panel @ 37A), Vac 2.3e-6 Torr, BP@0.032T. 

Thu May 26 15:13:19 2011:  TGHT has been at 40A/0.123V for sometime.  Currently, Vac @ 4.39e-5 Torr, BP@ 0.27T.  (See Attachement#1)

Thu May 26 17:28:36 2011:  Auto ramping has begun.  (see attachment#2).  TGHT @ 40.60A, (panel @ 38A), vac @ 3.84 e-5 Torr.  

Wed Jun 1 13:28:58 2011:  TGHT currently at 395A/3.16V, vac @ 4.47e-5 Torr.  Heating sequence changed for the increment from 4.5e-5 Torr to 5.0e-5 Torr. 

Fri Jun 3 09:54:28 2011 :  The organics burnoff and the carbonization process are complete (see Attachment#3 for the striptool).  The cooling process will begin at a rate of 2A/min.  

Tue Jun 14 21:24:41 2011 :  The evaporator was about to be vented by argon on Jun 10 (Fri), but it was found that the argon cylinder was almost empty; a new one was replaced (see Attachment #4: Evaporator_Ar_flow).  After the argon cylinder was replaced,  the evaporator was purged with the gas and the vent valve was connected to the cylinder for venting of the evaporator.  The target oven was removed and stored in the hermetic transfer vessel, then transferred to the glove box.  (See attachment #5: UC2, Note: typo. Should read Ar gas, NOT N2).  The flakes were stored in the jar labelled "Stock# 2011_A", with total weight of 35g. 

Wed May 18 13:12:24 2011:  Target is wrapped with 3 Ta-heat shields and is installed in the evaporator which is being pumped down.

Wed May 18 23:11:42 2011:  TGHT was raised to 40A and held for about 6 hours; Vac gradually came down to 2.1e-6 Torr.  TGHT increased to 90A and pressure is going up, currently vac @ 2.9 e-5 Torr.  Auto heating will begin soon at 0.5A/min --> 820A.  

Thu May 19 10:23:34 2011:  TGHT at 92A/0.32V, vac @ 4.47 e-5 torr.  (See Attachment#1: heating_past_12hrs)

Tue May 24 10:22:59 2011:  TGHT reached to max currrent 820A and held for over the long weekend.  The cooling process began at 15:00 yesterday.  Evaporator is vented.  P/S off.

Mon May 30 17:03:01 2011

The end caps of the target after the sintering process were found damage; the caps were vaporized just like the previous SiC target w.o#38481-8.  (See attachments#2: SiC000-003).  After some investigation, it looks like some reaction had occurred when the target heater was ramped up beyond 550A.  (See Attachment#3: SiC_striptool).

The yellow solid will be analyzed using EDX/SEM.  More details will be posted later....

Wednesday, September 14, 2011, 10:16 

SEM/EDX were done.  See attachment #9 for the EDX results. 

The formation of the yellow solid is the condensation of silicon.  As seen on the EDX results, the solid is mainly Si, C and some trace of Al (could be from the loading rod).  

The new D-end cap has be used to allow a better out-gassing.  

The evaporator ion gauge filament burnt out on May 11, 2011.  A target was in the evaporator at that time and was about to being the sintering process.  The gauge had two filaments, so vacuum group helped to switch to the second filament.  The evaporator was vented on May 17, 2011, and a new ion gauge with two filaments was installed.  The gauge was tested and it's working fine. 

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. 

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).

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).