Wednesday, October 02, 2019, 11:09

A graphite cartridge loaded with UO2/C foils, wrapped with three Ta heat shields was placed in the EVAP1.

The EVAP1 is currently pumping down.

 Thursday, October 03, 2019, 09:40

Pressure limits:

Good vacuum 1e-1 Torr

Bad vacuum 5e-1 Torr

Initial vacuum IGP1 = 9.54e-7 Torr

Current tapped manually to 80 A at 1A/s in 5 A blocks with a waiting period of 25 s between each increment. 

Thursday, October 03, 2019, 10:36

The pressure started decreasing after 45 min and the auto ramp was set to 1 A each 30 s to 86 A 

The autoramp was set to 2 A each 10 s to 180 A

The autoramp was set to 3.2 A each 10 s to 300 A

The autoramp was re start at 3.2 A each 10 s to 400 A 

The autoramp was set to 1 A each 10 s to 430 A 

The autoramp was set to 2 A each 10 s to 450 A 

The autoramp was set to 2 A each 10 s to 480 A 

Autoramp at 2 A per min to 500 A

Manually tapped to 545 A.

After 48 hrs at maximum temperature, the target was cooled done at -2 A/min 

Friday, June 26, 2019, 17:10

A 13 mm die was used to cut out discs from strips

The target consists of 264 discs of 10 cm in length - all single discs, no packs.

231 x UO₂/C discs = 25.76 g

10 UO₂ discs for measurements = 1.49 g

Graphite insert without caps= 17.44 g

The loaded insert is placed on target boat.

Boat previously coated with TaC and sintered.

Ta-target boat is wrapped with 3-layers (3 used) of heat shield and installed in evap1.

Chamber is pumping down. 

Tuesday, July 30, 2019, 09:45

Pressure limits:

Good vacuum 1e-1 Torr

Bad vacuum 5e-1 Torr

Initial vacuum IGP1 = 5.94e-7 Torr

Current tapped manually to 85 A at 1A/s in 5 A blocks with a waiting period of 25 s between each increment. 

Tuesday, July 30, 2019, 10:53

After 30 min, the pressure started stabilizing around 0.0013 g

The current rate was changed to 1 A/2min to 88 A

The current rate was changed to 1 A/min to 90 A

The current rate was changed to 1 A/30s to 100 A

The final pressure obtained was 0.0011 Torr

The current rate was changed to 2 A each 10 s to 170 A

The final pressure obtained was 0.04 Torr

The current rate was changed to 1 A each 10 s to 180 A

The final pressure obtained was 0.008 Torr

The final pressure was 0.001 Torr

The current was tapped manually to 400 A in intervals of 10 A at 1 A/s each 10 s

The autoramp was set to 1 A each 10 s to 450 A

Then the current was increased manually at 1 a each 20 s until 475 A

The current was increased in this manner until 480 A to make sure the pressure was not rising 

Tuesday, July 30, 2019, 12:00

After the pressure stabilized and started reducing the current was reduced to 480 A

After 3 hours at 475 A the autoramp was set to -2A/min

Friday, June 14, 2019, 17:10

A 14 mm die was used to cut out discs from strips

The target consists of 236 discs of 10 cm in length - all single discs, no packs.

231 x UO₂/C discs = 25.76 g

12 UO₂ discs for measurements = 1.49 g

Graphite insert without caps= 11.59 g

The loaded insert is placed on target boat.

Boat previously coated with TaC and sintered.

Ta-target boat is wrapped with 3-layers (2 new one used) of heat shield and installed in evap1.

Chamber is pumping down.

Monday, June 17, 2019, 08:56 

Pressure limits:

Good vacuum 1e-1 Torr

Bad vacuum 5e-1 Torr

IGP1 = 6.600777e-7 Torr

Current tapped manually to 80 A at 1A/s in 10 A blocks with a waiting period of 20 s between each increment.

Initial IGP1 = 5.31 e-6 Torr

Monday, June 17, 2019, 10:03

After 42 minutes the pressure started dropping and the current rate was changed to 1A/s with for 20 second intervals followed by 20 second wait while monitoring pressure.

Monday, June 17, 2019, 14:41

Current was tapped to 100A but the pressure increased too rapidly; therefore, the current was tapped down to 75A.

After pressure stabilized, the current was tapped up to 100 A @1A/s in 20A segments and 20 second pauses.

Continued tapping up at the above rate until 160A, at which point the pressure shot up and tripped the system.

The pressure stabilized within 18 minutes.

The wait interval on the heater ramps control was changed to 1s

The current increment was set to 0.2A with a final value of 200A

At 170A the autoramp was stopped and the current manually tapped down to 160A to prevent rapid pressure buildup.

5 minutes later the pressure had stabilized and autramp was restarted.

At 160A we changed the waiting interval to 10s and the current increment to 2A.

At 200A we stopped autoramp and manually tapped at 1A/s in 20A segments with 10s pauses. 

At 360A, we changed the current increment to 1A while keeping the wait interval at 10s.

At 440A the autoramp was stopped to change the current increment to 0.5A while the waiting interval was kept at 10s.

The autoramp final current was set to 500A.

At 495A the autoramp was stopped because the pressure was dropping significantly.

The Target was left for 3 hours at 495A.

Pre-cooling conditions:

TGHT = 494A, 4.8V

IGP1 = 6.7e-6 Torr

Cooling rate = -2A/min

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, July 07, 2021, 14:39

Target Provisional ID = 200929 was installed in the EVAP1 and pumped down (Tuesday July 7, 2021).

Target is going to be thermally reduced for 8 hours and then conditioned for an additional 8 hours

IGP1 = 2.0 e-6 Torr

Good vacuum = 1e-1 Torr

Bad vacuum = 5e-1 Torr

Power desired 1.6kW.

10 extra discs included for analysis

Wednesday, July 07, 2021, 14:49 

Ramping up TGHT at 6A/min [wait interval = 10 s at increments of 1A]

Wednesday, July 07, 2021, 15:58

IGP1= 5.7 e-5 Torr and trending down.  Will start ramp up to 450A at  18A/min [wait interval 10s at 3A increments]

Wednesday, July 07, 2021, 16:20 

IGP1= 2.2e-3 Torr

Will continue ramping TGHT to 500A and watch pressure

Wednesday, July 07, 2021, 16:26

Continue ramping to 550 at 3A/10s

 Wednesday, July 07, 2021, 16:29

holding at 550A, 5.1V for 8 hours 

Wednesday, July 07, 2021, 23:41 

TGHT = 550A, 5.7 V

begin ramp down at -2A/min to 450A and leave for 8 hours

Thursday, July 08, 2021, 08:20

 IGP1= 2.7 e-06 Torr

TGHT = 450A, 4.5V

Will start ramp down at -2A/min to 0A 

 Monday, September 03, 2018, 10:17

Graphite insert fully loaded with UCx was loaded into previously TaC coated target container.

No end caps on Ta target container.

Weight of graphite tube + UCx discs = 27.118 g

Currently pumping down in evap1.

Tuesday, September 04, 2018, 10:17 

IGP1 = 4.02e-6 Torr

Tapped up TBHT and TGHT manually to 100 A @1 A/s with pauses of 20 s.

Wait for 40 min to pressure to stabilize.

Max pressure 1.38e-4 Torr.

Final pressure 5.93e-5 Torr.

Tuesday, September 04, 2018, 11:46 

Good vacuum 5e-1 Torr

Bad vacuum 8e-1 Torr

Initiating auto ramp for TGHT @ 10 A/min to a max setpoint of 520 A

Initiating auto ramp for TBHT @ 5 A/min to a max setpoint of 245 A

 After achieving 520 A with auto ramp, manually tapped to 599 A.

Manually tapped back to 550 A.

Marla Cervantes wrote:

Monday, September 03, 2018, 10:17 Graphite insert fully loaded with UCx was loaded into previously TaC coated target container. No end caps on Ta target container. Weight of graphite tube + UCx discs = 27.118 g Currently pumping down in evap1. Tuesday, September 04, 2018, 10:17  IGP1 = 4.02e-6 Torr Tapped up TBHT and TGHT manually to 100 A @1 A/s with pauses of 20 s. Wait for 40 min to pressure to stabilize. Max pressure 1.38e-4 Torr. Final pressure 5.93e-5 Torr. Tuesday, September 04, 2018, 11:46  Good vacuum 5e-1 Torr Bad vacuum 8e-1 Torr Initiating auto ramp for TGHT @ 10 A/min to a max setpoint of 520 A Initiating auto ramp for TBHT @ 5 A/min to a max setpoint of 245 A  Tuesday, September 04, 2018, 12:54  After achieving 520 A with auto ramp, manually tapped to 599 A. Manually tapped back to 550 A.

 Friday, September 21, 2018, 10:21

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

Marla Cervantes wrote:

Monday, September 03, 2018, 10:17 Graphite insert fully loaded with UCx was loaded into previously TaC coated target container. No end caps on Ta target container. Weight of graphite tube + UCx discs = 27.118 g Currently pumping down in evap1. Tuesday, September 04, 2018, 10:17  IGP1 = 4.02e-6 Torr Tapped up TBHT and TGHT manually to 100 A @1 A/s with pauses of 20 s. Wait for 40 min to pressure to stabilize. Max pressure 1.38e-4 Torr. Final pressure 5.93e-5 Torr. Tuesday, September 04, 2018, 11:46  Good vacuum 5e-1 Torr Bad vacuum 8e-1 Torr Initiating auto ramp for TGHT @ 10 A/min to a max setpoint of 520 A Initiating auto ramp for TBHT @ 5 A/min to a max setpoint of 245 A  Tuesday, September 04, 2018, 12:54  After achieving 520 A with auto ramp, manually tapped to 599 A. Manually tapped back to 550 A.

 Saturday, September 29, 2018, 20:52

Target is taken out from the chamber and transferred to the Ar glove box.

 Thursday, May 10, 2018, 16:00 

Graphite insert fully loaded with UCx was loaded into previously TaC coated target container.

No end caps on Ta target container.

Weight of graphite tube + UCx discs = 27 g

Currently pumping down in evap1.

Friday, May 11, 2018, 11:41 

IGP1 = 1.13e-6 Torr

Good vac at 3.0e-4, bad vac at 6.0e-4 Torr.

Tapped up manually to 100A.

Pressure increased to ~2e-5 Torr

Vacuum stabilized after 40 min

IGP1 = 1e-5 Torr

Initiating auto ramp for TGHT @ 20 A/min to a max setpoint of 520 A

Initiating auto ramp for TBHT @ 10 A/min to a max setpoint of 245 A

Preassure increased o 1e-4 Torr and the auto ramp was aborted

After 8 min IGP1 = 3e-5 Torr

Initiating auto ramp for TGHT @ 10 A/min to a max setpoint of 520 A

Initiating auto ramp for TBHT @ 5 A/min to a max setpoint of 245 A

The vacuum is more stable.

TBHT reached 230 A at 13:00

TGHT reached 520 A at 13:24

Final pressure 1.15e-4 Torr

Target will stay at max current point for a week.

 Friday, May 18, 2018, 18:31

Evap1 was vented in Ar and UCx target was transferred to the glove box

 Tuesday, October 30, 2018, 10:12

A new LP-SIS was coated and syntered (e-log 420 Evaporator_2) 

The container was loaded with a graphite insert loaded with UCx

Graphite insert + UCx mass = 26.927 g

A current of 440 A TGHT and 230 A TBHT will be inputed to the contianer

IGP1 = 8.72e-7 Torr

 The current was tapped manually to 440 A TGHT and 230 A TBHT (see fig. Heatinf test)

Maximum pressure during heating = 1.7e-3 Torr.

Target will stay at maximum current for 1 week.

Marla Cervantes wrote:

Tuesday, October 30, 2018, 10:12 A new LP-SIS was coated and syntered (e-log 420 Evaporator_2)  The container was loaded with a graphite insert loaded with UCx Graphite insert + UCx mass = 26.927 g A current of 440 A TGHT and 230 A TBHT will be inputed to the contianer IGP1 = 8.72e-7 Torr  The current was tapped manually to 440 A TGHT and 230 A TBHT (see fig. Heating test) Maximum pressure during heating = 1.7e-3 Torr. Target will stay at maximum current for 1 week.

 Wednesday, October 31, 2018, 10:09

The current tripped off,  around 5:00 am, the pressure was below 1e-5 Torr (see fig. current-trip_off).

On a previous test, we measured the maximum temperature of the power supply = 33.3 C (e-log 227).

Power supply overheating doesn't seem to be the problem.

EPICS windows are half withe and not answering correctly.

Also, TBHT says that IGP1 < 500 mTorr, and its interlock needs reset (see figure EPICS).

Marla Cervantes wrote:

Marla Cervantes wrote:  Tuesday, October 30, 2018, 10:12 A new LP-SIS was coated and syntered (e-log 420 Evaporator_2)  The container was loaded with a graphite insert loaded with UCx Graphite insert + UCx mass = 26.927 g A current of 440 A TGHT and 230 A TBHT will be inputed to the contianer IGP1 = 8.72e-7 Torr  The current was tapped manually to 440 A TGHT and 230 A TBHT (see fig. Heating test) Maximum pressure during heating = 1.7e-3 Torr. Target will stay at maximum current for 1 week.  Wednesday, October 31, 2018, 10:09 The current tripped off,  around 5:00 am, the pressure was below 1e-5 Torr (see fig. current-trip_off). On a previous test, we measured the maximum temperature of the power supply = 33.3 C (e-log 227). Power supply overheating doesn't seem to be the problem. EPICS windows are half withe and not answering correctly. Also, TBHT says that IGP1 < 500 mTorr, and its interlock needs reset (see figure EPICS).

 Wednesday, October 31, 2018, 15:20

The problem was reported to controls, it will be also reported to power supply group.

In the meantime, the target will be ramp-up again with the auto ramp at:

TGHT = 20 A/min to 440 A

TBHT = 10 A/min to 230 A 

The pressure before heating is 4.07e-7 Torr

Wednesday, October 31, 2018, 19:24

The maximum pressure during heating was 6.57e-6 Torr.

Current pressure 3.00e-6Torr

Wednesday, November 07, 2018, 18:37

IGP1 = 9.7e-7 Torr

 TGHT = -2 A/min to 0A

TBHT = -1 A/min to 0A 

 Thursday, November 08, 2018, 16:16

EVAP1 was vented with Ar, and target was transferred to glove box.

The mass of the loaded graphite insert changed to 26.854 g

That is a difference of 0.075 g

The tantalum container "cathode" crystalized (see fig)

The rest of the tantalum container did not change.

 Thursday, November 22, 2018, 17:25

D-shaped discs were cut from cast #26

A 13mm punch was used to punch out discs from pre-cut strips

The target consists of 236 discs of 10 cm in length - all single discs, no packs.

236 x UO₂/C discs = 22.66 g

Graphite insert with caps = 11.74 g

The loaded inser is placed on target boat.

Boat previously coated with TaC and sintered.

Ta-target boat is wrapped with 3-layers (2 new one used) of heat shield and installed in evap1.

Chamber is pumping down.

 Friday, November 23, 2018, 08:53

Vacuum limits:

Good vacuum 1e-1 Torr

Bad vacuum 5e-1 Torr

IGP1 = 4.12 e-6 Torr

Current tapped manually to 100 A at 1A/s in 10 A blocks with a waiting period of 20 s between each increment.

Initial IGP1 = 5.31 e-6 Torr

Max  IGP1 = 0.066 Torr

Waited 20 min for pressure to rise and drop.

The current tripped off, when the 0.013 torr  (Fig. Nov23-CurrentTrip1).

Increasing the current to 100 A again.

IGP1 = 7.00e-5 Torr

Rate was increased to 25 A each 20 s until 200 A

The pressure increased and IV1 opened, current was dropped to 100 A

Pressure after 5 min 4e-4 Torr

Rate was increased again to 25 A each 20 s until 200 A

The current was reduced to 110 A because the pressure was rising to fast

Rate was increased again to 25 A each 20 s until 300 A

The automatic ramp was set to 20 A/ min from 0 to 300 A

The automatic ramp was changed to 10A/2min to 450 A

IGP1 = 2.15e-5 Torr

After 1.5 hour, the automatic ramp was set to 20 A/ min from 450 to 500 A

After 4hrs, the automatic ramp was set to -2 A/ min from 500 to 0 A

Marla Cervantes wrote:

Thursday, November 22, 2018, 17:25 D-shaped discs were cut from cast #26 A 13mm punch was used to punch out discs from pre-cut strips The target consists of 236 discs of 10 cm in length - all single discs, no packs. 236 x UO2/C discs = 22.66 g Graphite insert with caps = 11.74 g The loaded inser is placed on target boat. Boat previously coated with TaC and sintered. Ta-target boat is wrapped with 3-layers (2 new one used) of heat shield and installed in evap1. Chamber is pumping down.  Friday, November 23, 2018, 08:53 Vacuum limits: Good vacuum 1e-1 Torr Bad vacuum 5e-1 Torr IGP1 = 4.12 e-6 Torr Current tapped manually to 100 A at 1A/s in 10 A blocks with a waiting period of 20 s between each increment.   Initial IGP1 = 5.31 e-6 Torr Max  IGP1 = 0.066 Torr Waited 20 min for pressure to rise and drop. The current tripped off, when the 0.013 torr. Increasing the current to 100 A again. IGP1 = 7.00e-5 Torr Rate was increased to 25 A each 20 s until 200 A The pressure increased and IV1 opened, current was dropped to 100 A Pressure after 5 min 4e-4 Torr Rate was increased again to 25 A each 20 s until 200 A The current was reduced to 110 A because the pressure was rising to fast Rate was increased again to 25 A each 20 s until 300 A Pressure was ok and current tripeed off The automatic ramp was set to 20 A/ min from 0 to 300 A The automatic ramp was changed to 10A/2min to 450 A IGP1 = 2.15e-5 Torr After 1.5 hour, the automatic ramp was set to 20 A/ min from 450 to 500 A After 4hrs, the automatic ramp was set to -2 A/ min from 500 to 0 A

 Monday, November 26, 2018, 17:00

 The UCx was transferred to the glove box and loaded in  tantalum container  42218-3.

 Friday, August 17, 2018, 11:17

Four discs of UCx produced with the 1-step casting method were placed in a glass jar.

The mass of the discs was 0.400 g.

The glass jar with the discs were placed in the heating chamber of the IEVAP.

Currently IEVAP is pumping down until vacuum is in the order of  ~10^-6 Torr.

Friday, August 17, 2018, 16:28 

Final vacuum: 9.5x10^-6 Torr

IEVAP's heating chamber will be vented with air and the materials will be taken out.

 Friday, August 17, 2018, 17:27

Material was transferred to the glove box

Wednesday, June 06, 2012, 16:55

The UO2/C green was prepared on June 04, 2012. 

UO2 powder used = 50.26g

C-grv used = 10.14g. 

Dry UO2/C green mass = 61.71g.

The green was rolled and wrapped in a piece of graphite sheet.

The target boat was wrapped with 3 Ta-heat shield and installed in the Evap#1. 

The chamber is currently being pumped down.

 Tuesday, June 12, 2012, 11:42

Currently, IEVAPIG1= 1.83e-6 Torr, IEVAP:CG2= 48 mTorr.

Backing line pressure is slightly high.  Will get Edi to look into this.

 Tuesday, June 12, 2012, 14:38

The backing pump oil was changed (ISAC WP#2012-06-12-1).  IEVAP:CG2 is currently reading 27mTorr and IEVAPIG1 at 1.66e-6 Torr.

 Tuesday, June 12, 2012, 16:06

TGHT was tabbed up to 50A and stayed for 1.5 hrs.  Not much change in the pressure, currently at 1.8e-6 Torr, BP @ 25mTorr.  

Keep stepping up TGHT current...

 Tuesday, June 12, 2012, 16:37

TGHT at 65A.  Pressure is starting to rise.

 Tuesday, June 12, 2012, 16:46

Pressure at  6.8e-6 Torr and going up slowly. 

Initiated TGHT auto-ramping:

Max current = 525A,  rate @ 0.1A/min (see attachment #1)

 Wednesday, June 13, 2012, 13:22

TGHT has almost reached to 80A.  Pressure is limiting at 4.5e-6 Torr. (see attachment#2)

Thursday, June 14, 2012, 17:11

TGHT has reached to 95.40A, local @ 92A & 0.48V.  Pressure is still limiting at 4e-6 Torr.  (see attachment #3)

The TGHT current can not go up above 232A because it's voltage limiting at 1.953V (see attachment#4).  The carbon thermal-reduction process stops and the vacuum is going down to low 10e-6 Torr. 

The voltage can not be increased on EPICS; it has to be adjusted locally.  

Auto-ramping aborted.  

The TGHT current setpoint was lowered down to 228A.

Sunday, June 17, 2012, 12:03  

Asked ISAC Ops (Ed Parton) to help me increase the voltage locally.  The voltage nob was turned 1/4 clockwise, and the current was tapped up from 228 to 231A, and it was responding.  The voltage nob was further turned to 3/4 clockwise. 

Initiated auto-ramping. 

Currently, TGHT setpoint at 234.90A, local 231A/1.95V.  

Vacuum is responding and it's slowly going up (currently at 2.8e-6 Torr) - The carbon thermal reduction process continues... 

Monday, June 18, 2012, 00:20  

TGHT is going up slowly, currently at  285A.  The pressure is limiting as the carbonization process is under way (see attachment 5).

 Monday, June 25, 2012, 16:00

The EPICS control was down on Sunday night. So the auto-ramping was aborted.  

Control group fixed the problem, and the network is back online.

The auto-ramping has been re-initiated. 

TGHT is currently at 314.70A, local at 311/3.04V.  IG at 4.21e-5 Torr, BP at 15mTorr.

 Saturday, June 30, 2012, 23:08

The carbonization process has finished.

TGHT has reached to 520A and maintained at that current for about 5hrs. (see attachment #6).

Initiated auto-cool down.

Tuesday, July 03, 2012, 13:05 

TGHT is now at 0A.  The carbonization process is done.  

It took over 20 days for this process (see attachment #7), due to some control issues & power supply problem. Also the vacuum limit was set to 4.0e-5 Torrr; that might increase the pumping time.  

Next time, try setting the pressure limit to 5.0e-5 Torr.  

The chamber will be vented with Ar, and the UC2 flakes will be transferred to the Ar-glove box.  

John Wong wrote:

Wednesday, June 06, 2012, 16:55 The UO2/C green was prepared on June 04, 2012.  UO2 powder used = 50.26g C-grv used = 10.14g.  Dry UO2/C green mass = 61.71g. The green was rolled and wrapped in a piece of graphite sheet. The target boat was wrapped with 3 Ta-heat shield and installed in the Evap#1.  The chamber is currently being pumped down.

 Monday, June 11, 2012, 10:31

Last week during the pump down of the chamber (vacuum got down to low 10e-5 Torr), the cooling was open in preparation of turning on the target heater.  A vacuum excursion was triggered (pressure went up to 300mTorr), and the system was tripped off.  It was suspected that there was some leaks. 

A leak test was performed - all the water connecters & joints are fine.  The seal for the chamber lid was found leaky (5e-8 atm cc/sec).  The seal was replaced and the vacuum was improved but no perfect.

The chamber has been pumped down over the weekend, pressure currently at 2.3e-6 Torr. 

Coincidentally, the TGHT power supply is broken.  The initial action was to turn on the power supply at 0A when the chamber vacuum had gone down to 10-6 Torr.  But the power supply did not regular and shot up to 1000A and caused a vacuum excursion.  Ray Dube will replaced it. 

John Wong wrote:

John Wong wrote: Wednesday, June 06, 2012, 16:55 The UO2/C green was prepared on June 04, 2012.  UO2 powder used = 50.26g C-grv used = 10.14g.  Dry UO2/C green mass = 61.71g. The green was rolled and wrapped in a piece of graphite sheet. The target boat was wrapped with 3 Ta-heat shield and installed in the Evap#1.  The chamber is currently being pumped down.    Monday, June 11, 2012, 10:31 Last week during the pump down of the chamber (vacuum got down to low 10e-5 Torr), the cooling was open in preparation of turning on the target heater.  A vacuum excursion was triggered (pressure went up to 300mTorr), and the system was tripped off.  It was suspected that there was some leaks.  A leak test was performed - all the water connecters & joints are fine.  The seal for the chamber lid was found leaky (5e-8 atm cc/sec).  The seal was replaced and the vacuum was improved but no perfect. The chamber has been pumped down over the weekend, pressure currently at 2.3e-6 Torr.  Coincidentally, the TGHT power supply is broken.  The initial action was to turn on the power supply at 0A when the chamber vacuum had gone down to 10-6 Torr.  But the power supply did not regular and shot up to 1000A and caused a vacuum excursion.  Ray Dube will replaced it.

 Tuesday, June 12, 2012, 11:37

Ray Dube repaired the TGHT power supply.  It is now operational.

John Wong wrote:

Wednesday, June 06, 2012, 16:55 The UO2/C green was prepared on June 04, 2012.  UO2 powder used = 50.26g C-grv used = 10.14g.  Dry UO2/C green mass = 61.71g. The green was rolled and wrapped in a piece of graphite sheet. The target boat was wrapped with 3 Ta-heat shield and installed in the Evap#1.  The chamber is currently being pumped down.  Tuesday, June 12, 2012, 11:42 Currently, IEVAPIG1= 1.83e-6 Torr, IEVAP:CG2= 48 mTorr. Backing line pressure is slightly high.  Will get Edi to look into this.  Tuesday, June 12, 2012, 14:38 The backing pump oil was changed (ISAC WP#2012-06-12-1).  IEVAP:CG2 is currently reading 27mTorr and IEVAPIG1 at 1.66e-6 Torr.  Tuesday, June 12, 2012, 16:06 TGHT was tabbed up to 50A and stayed for 1.5 hrs.  Not much change in the pressure, currently at 1.8e-6 Torr, BP @ 25mTorr.   Keep stepping up TGHT current...  Tuesday, June 12, 2012, 16:37 TGHT at 65A.  Pressure is starting to rise.  Tuesday, June 12, 2012, 16:46 Pressure at  6.8e-6 Torr and going up slowly.  Initiated TGHT auto-ramping: Max current = 525A,  rate @ 0.1A/min (see attachment #1)  Wednesday, June 13, 2012, 13:22 TGHT has almost reached to 80A.  Pressure is limiting at 4.5e-6 Torr. (see attachment#2) Thursday, June 14, 2012, 17:11 TGHT has reached to 95.40A, local @ 92A & 0.48V.  Pressure is still limiting at 4e-6 Torr.  (see attachment #3) The TGHT current can not go up above 232A because it's voltage limiting at 1.953V (see attachment#4).  The carbon thermal-reduction process stops and the vacuum is going down to low 10e-6 Torr.  The voltage can not be increased on EPICS; it has to be adjusted locally.   Auto-ramping aborted.   The TGHT current setpoint was lowered down to 228A. Sunday, June 17, 2012, 12:03   Asked ISAC Ops (Ed Parton) to help me increase the voltage locally.  The voltage nob was turned 1/4 clockwise, and the current was tapped up from 228 to 231A, and it was responding.  The voltage nob was further turned to 3/4 clockwise.  Initiated auto-ramping.  Currently, TGHT setpoint at 234.90A, local 231A/1.95V.   Vacuum is responding and it's slowly going up (currently at 2.8e-6 Torr) - The carbon thermal reduction process continues...  Monday, June 18, 2012, 00:20   TGHT is going up slowly, currently at  285A.  The pressure is limiting as the carbonization process is under way (see attachment 5).

Sunday, June 24, 2012, 22:51  

The Evaporator IOC has lost communication (see attachment #6).  The TGHT auto ramping was not responding to the vacuum limit and kept ramping up, so the program had to be aborted.  

On the live camera,  it showed that TGHT stopped at 311A/3.02V and the pressure was at 5.05e-5 Torr.  

An email has sent to Controls and hopefully things get resolved on Monday. 

John Wong wrote:

John Wong wrote: Wednesday, June 06, 2012, 16:55 The UO2/C green was prepared on June 04, 2012.  UO2 powder used = 50.26g C-grv used = 10.14g.  Dry UO2/C green mass = 61.71g. The green was rolled and wrapped in a piece of graphite sheet. The target boat was wrapped with 3 Ta-heat shield and installed in the Evap#1.  The chamber is currently being pumped down.  Tuesday, June 12, 2012, 11:42 Currently, IEVAPIG1= 1.83e-6 Torr, IEVAP:CG2= 48 mTorr. Backing line pressure is slightly high.  Will get Edi to look into this.  Tuesday, June 12, 2012, 14:38 The backing pump oil was changed (ISAC WP#2012-06-12-1).  IEVAP:CG2 is currently reading 27mTorr and IEVAPIG1 at 1.66e-6 Torr.  Tuesday, June 12, 2012, 16:06 TGHT was tabbed up to 50A and stayed for 1.5 hrs.  Not much change in the pressure, currently at 1.8e-6 Torr, BP @ 25mTorr.   Keep stepping up TGHT current...  Tuesday, June 12, 2012, 16:37 TGHT at 65A.  Pressure is starting to rise.  Tuesday, June 12, 2012, 16:46 Pressure at  6.8e-6 Torr and going up slowly.  Initiated TGHT auto-ramping: Max current = 525A,  rate @ 0.1A/min (see attachment #1)  Wednesday, June 13, 2012, 13:22 TGHT has almost reached to 80A.  Pressure is limiting at 4.5e-6 Torr. (see attachment#2) Thursday, June 14, 2012, 17:11 TGHT has reached to 95.40A, local @ 92A & 0.48V.  Pressure is still limiting at 4e-6 Torr.  (see attachment #3) The TGHT current can not go up above 232A because it's voltage limiting at 1.953V (see attachment#4).  The carbon thermal-reduction process stops and the vacuum is going down to low 10e-6 Torr.  The voltage can not be increased on EPICS; it has to be adjusted locally.   Auto-ramping aborted.   The TGHT current setpoint was lowered down to 228A. Sunday, June 17, 2012, 12:03   Asked ISAC Ops (Ed Parton) to help me increase the voltage locally.  The voltage nob was turned 1/4 clockwise, and the current was tapped up from 228 to 231A, and it was responding.  The voltage nob was further turned to 3/4 clockwise.  Initiated auto-ramping.  Currently, TGHT setpoint at 234.90A, local 231A/1.95V.   Vacuum is responding and it's slowly going up (currently at 2.8e-6 Torr) - The carbon thermal reduction process continues...  Monday, June 18, 2012, 00:20   TGHT is going up slowly, currently at  285A.  The pressure is limiting as the carbonization process is under way (see attachment 5).   Sunday, June 24, 2012, 22:51     The Evaporator IOC has lost communication (see attachment #6).  The TGHT auto ramping was not responding to the vacuum limit and kept ramping up, so the program had to be aborted.   On the live camera,  it showed that TGHT stopped at 311A/3.02V and the pressure was at 5.05e-5 Torr.   An email has sent to Controls and hopefully things get resolved on Monday.

 Monday, June 25, 2012, 15:57

The Control Support group investigated the problem and found out that the fiber converters on both ends failed.  They have been replaced with brand new switches with fiber connections.

 The Evap EPICS is back online.