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.

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.  

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.

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.

Fri Apr 8 14:51:37 2011:  Target is wrapped with 3 Ta-heat shields.  The evaporator has been pumped down for over 4 hrs, currently vac @ 2.8e-6 Torr.  (See attachment #1, note: the drops in the IG1 reading were due to Controls group helping to fix the alarm handler notifications for the pagers.)

 Fri Apr 8 14:56:21 2011:  TGHT @ 20A/0.079V, panel reads 18V.   Vac @ 2.73e-6 Torr.

Fri Apr 8 14:57:42 2011: TGHT @ 40A/0.165V, panel reads 18A.  Vac @ 2.73e-6 Torr. 

Fri Apr 8 14:59:51 2011: Auto heating begins.  (See Attachment#2 for the parameter setup).  The target heater will read to 820A at 21:30.  ISAC Ops will help to cool down the target at around 05:00 on Saturday; instructions will be given.

Mon Apr 11 09:37:40 2011:  Target was cooling on last Saturday April 9 by the help from ISAC Ops.  (See Attachment#3 for the cooling down process).

Mon Apr 11 09:42:09 2011 :  Evaporator is vented.

Wed Apr 6 17:06:56 2011: Target oven is wrapped with 3 Ta-heat shields.  Pumping down evaporator in progress.

Thu Apr 7 09:32:36 2011: Evaporator has been pumped down for over 16 hrs, vac @ 1.74e-6 Torr (see attachment#1).   Target heater is turned on and about to ramp up.

 Thu Apr 7 09:37:11 2011: TGHT @ 20A/0.071V, panel reads 18A.

Thu Apr 7 09:38:16 2011: TGHT @ 40A/0.147V, panel reads 37A.

Thu Apr 7 09:40:53 2011:  Auto-heating begins.  (See attachment#2 for Parameter Setup)

Fri Apr 8 10:08:07 2011:  Auto-cooling process began last night at 8:30pm.  Instructions were given to the on shift ISAC-Ops to being the auto cooling.  The process was finished this morning at around 3am.  (See attachment#3 for the cooling down process).  The evaporator p/s is off and ready to be vented.

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. 

It's the NON-ACTIVE water that will go off.  The evaporator is on sity water, so it will be OK.

According to Jonathan Aoki, the electricians will be servicing another MCC which will result in loss of cooling water for about 8 hours starting at 16:00 March 30.  We shouldn't be running the evaporator or any condensers at that time.

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. 

John Wong wrote:

John Wong wrote: March 23, 2011 12:30: Pumping down evaporator 18:24: IEVAPIG1 is reading at 4.55e-6 Torr.  The p/s will be turned on tomorrow since there is no ISAC Ops on site.  March 24 11:57: Evaporator has pumped down over night.  Vacuum @ 2.01e-6 Torr.   14:42: TGHT @ 20A, Vac @ 1.65e-6 Torr. 14:52: TGHT @ 40A, Vac @ 1.66e-6 Torr. 14:52: Auto Heating begins: TGHT to max 820A.  Incrementing if vac < 4.5e-5 Torr, backing off if vac > 6.5e-5 Torr.  16:04: TGHT @ 181A, vac @ 7.59e-6 Torr. 18:03: TGHT @ 420A, vac @ 4.71e-6 Torr.   (See attachment 2 for TGHT/IG1 for the past 4 hours) March 25, 11:15:  TGHT has been at 820A for 14hr.  Vac @ 4.27e-6 Torr.  (See attachement 3 for TGHT/IG1 for these past hours) 11:17:  Auto cooling down is in progress... 17:21:  Auto cooling down ended at TGHT ~100A.  The TGHT was tabbed down manually from 100A to zero.  (See attachment #4 for the cooling down progress)  All the pumps are off.  The evaporator will be vented next week.

 Evaporator Vented.

John Wong wrote:

March 23, 2011 12:30: Pumping down evaporator 18:24: IEVAPIG1 is reading at 4.55e-6 Torr.  The p/s will be turned on tomorrow since there is no ISAC Ops on site.  March 24 11:57: Evaporator has pumped down over night.  Vacuum @ 2.01e-6 Torr.   14:42: TGHT @ 20A, Vac @ 1.65e-6 Torr. 14:52: TGHT @ 40A, Vac @ 1.66e-6 Torr. 14:52: Auto Heating begins: TGHT to max 820A.  Incrementing if vac < 4.5e-5 Torr, backing off if vac > 6.5e-5 Torr.  16:04: TGHT @ 181A, vac @ 7.59e-6 Torr. 18:03: TGHT @ 420A, vac @ 4.71e-6 Torr.   (See attachment 2 for TGHT/IG1 for the past 4 hours) March 25, 11:15:  TGHT has been at 820A for 14hr.  Vac @ 4.27e-6 Torr.  (See attachement 3 for TGHT/IG1 for these past hours) 11:17:  Auto cooling down is in progress... 17:21:  Auto cooling down ended at TGHT ~100A.  The TGHT was tabbed down manually from 100A to zero.  (See attachment #4 for the cooling down progress)

 All the pumps are off.  The evaporator will be vented next week. 

March 23, 2011

12:30: Target oven is wrapped with 3 Ta-heat shields.  Pumping down evaporator

18:24: IEVAPIG1 is reading at 4.55e-6 Torr.  The p/s will be turned on tomorrow since there is no ISAC Ops on site. 

March 24

11:57: Evaporator has pumped down over night.  Vacuum @ 2.01e-6 Torr.  

14:42: TGHT @ 20A, Vac @ 1.65e-6 Torr.

14:52: TGHT @ 40A, Vac @ 1.66e-6 Torr.

14:52: Auto Heating begins: TGHT to max 820A.  Incrementing if vac < 4.5e-5 Torr, backing off if vac > 6.5e-5 Torr.

 16:04: TGHT @ 181A, vac @ 7.59e-6 Torr.

18:03: TGHT @ 420A, vac @ 4.71e-6 Torr.   (See attachment 2 for TGHT/IG1 for the past 4 hours)

March 25,

11:15:  TGHT has been at 820A for 14hr.  Vac @ 4.27e-6 Torr.  (See attachement 3 for TGHT/IG1 for these past hours)

11:17:  Auto cooling down is in progress...

17:21:  Auto cooling down ended at TGHT ~100A.  The TGHT was tabbed down manually from 100A to zero.  (See attachment #4 for the cooling down progress)