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  ID Date Author Target Material Target Oven W.O# Source Status Subject
  255   Thursday, January 30, 2020, 10:15 Marla CervantesUO2/CP2N-02 ProblemsP2N target material carbothermal reduction

Marla Cervantes wrote:

Wednesday, January 29 2020, 05:55  

A P2N container  with heat shields, and with a UO2/C loaded graphite container was installed in the EVAP1

Chamber is currently being evacuated.


Thursday, January 30, 2020, 08:56

Pressure limits:

Good vacuum 1e-1 Torr

Bad vacuum 5e-1 Torr

Initial pressure: 

IGP1=1.52e-6Torr

Current ramp set to 1A/min to 10 A, voltage is stable.

Current ramp increased to 1A/10s to 100 A. The pressure started raising around 80 A.

Current was kept 5min at at 100 A, voltage was stable


Thursday, January 30, 2020, 09:32 

Current ramp set to 1A/20s to 150 A (same pressure limits)

Pressure keep increasing during heating


Thursday, January 30, 2020, 09:53 

Current was kept at 150 min during 5 min, the voltage is stable, pressure started to stabilize:

IGP1 = 0.027 Torr

TGHT = 0.418 V

Ramp set to 1A/min to 200 A.


Thursday, January 30, 2020, 10:02

Pressure decreasing:

TGHT= 153 A 

 Thursday, January 30, 2020, 10:15

At 155 A while pressure decreasing, the power supply tripped off,

Controls has been notified, waiting for instructions.

 
  254   Thursday, January 30, 2020, 09:37 Marla CervantesUO2/CP2N-02 In progressP2N target material carbothermal reduction

Wednesday, January 29 2020, 05:55  

A P2N container  with heat shields, and with a UO2/C loaded graphite container was installed in the EVAP1

Chamber is currently being evacuated.


Thursday, January 30, 2020, 08:56

Pressure limits:

Good vacuum 1e-1 Torr

Bad vacuum 5e-1 Torr

Initial pressure: 

IGP1=1.52e-6Torr

Current ramp set to 1A/min to 10 A, voltage is stable.

Current ramp increased to 1A/10s to 100 A. The pressure started raising around 80 A.

Current was kept 5min at at 100 A, voltage was stable


Thursday, January 30, 2020, 09:32 

Current ramp set to 1A/20s to 150 A (same pressure limits)

Pressure keep increasing during heating


Thursday, January 30, 2020, 09:53 

Current was kept at 150 min during 5 min, the voltage is stable, pressure started to stabilize:

IGP1 = 0.027 Torr

TGHT = 0.418 V

Ramp set to 1A/min to 200 A.


Thursday, January 30, 2020, 10:02

Pressure decreasing:

TGHT= 153 A 

  253   Wednesday, January 29, 2020, 10:11 Marla CervantesEmptyP2N-02 DoneP2N test#2
The assembly consists of two tantalum foils, 0.001" thick, which are radially crimped to form a cylindrical surface. The outside support are two P2N  conditioning legs, and the inside supports are tantalum tapered rings. The solidworks geometry for this test is ITD0811 in PDM. 
 
 The P2N is attached to EVAP1 with copper legs and copper shims. A current ramp up to 600 A on the target wrapped with heat shields is attempted to benchmark the current/voltage increase in a bare target, so that we have reference values for future rampings with graphite and target material inside. 
The heat shields consist on two layers of Ta sheets on the body of the P2N secured with Ta-wire and two layers of Ta sheets on one side of the P2N.

Tuesday, January 28, 2020, 10:11

A P2N container  with heat shields, and without graphite container was installed in the EVAP1

Chamber is currently being evacuated.


Wednesday, January 29, 2020, 10:12

Pressure IGP1=1.87e-6 Torr

Final desired current TGHT = 600 A

Manually tapped to 40 A.

Voltage increased accordingly in an stable way.


Wednesday, January 29, 2020, 10:33 

Autoramp is set to 3/30s to 300 A 

The voltage and vacuum were stable so the autoramp was kept at 4/30s and the final current was set to 600 A

Accidentally went up to 600 A (1.98 V)!

When updating autoramp to 600 A, did not realize that procedure status was Active.

NOTE: If the procedure status is "active" the heater autoramp, does not "ramp" the current input in "final value", it will go in one step to that current.

The current was manually ramp down to 300 A

TGHT=299.52A, 0.89 V


Wednesday, January 29, 2020, 13:25

After approximately 2 hours conditions IGP1=1.6e-6Torr, TGHT =300 A, 1V.

The current ramp was started again: 4A/30s  to final value of 600 A


 Wednesday, January 29, 2020, 14:07

After 15 min, TGHT=599.424A, and 1.983 V (unstable) (see figure "P2N-test2_final voltage")

The current was ramp down to 0 A  at -5A/20s 


EVAP1 was vented with aair and the container was removed,

the copper shims and legs did not present signs of damage

the body's tantalum sheet had wrinkles inside,

the tantalum foils unfasten a bit, but were adjusted.

Attachment 1: P2N-test2_final_voltage.JPG
P2N-test2_final_voltage.JPG
Attachment 2: P2N-test2.JPG
P2N-test2.JPG
  252   Wednesday, January 22, 2020, 18:10 Marla CervantesEmptyP2N-02  DoneP2N test#1
The assembly consists of two tantalum foils, 0.001" thick, which are radially crimped to form a cylindrical surface. The outside support are two P2N  conditioning legs, and the inside supports are tantalum tapered rings. The solidworks geometry for this test is ITD0811 in PDM. 
 
A first current ramp up to 600 amperes on the bare naked target is attempted to benchmark the current/voltage increase in a bare target, so that we have reference values for future rampings with graphite and target material inside. 

Wednesday, January 22, 2020, 18:07

A P2N container  with no heat shields, and no graphite container was installed in the EVAP1

Chamber is currently being evacuated.


 Thursday, January 23, 2020, 09:45

Pressure IGP1=1.87e-6 Torr

Final desired current TGHT = 600 A

Manually tapped to 40 A

 The voltage looks ok, at 32 A the voltage's behavior change (see picture "voltage at 32 A") but is stable


Thursday, January 23, 2020, 13:20

Autoramp is set to 4/30s to 300 A 

The voltage and vacuum were stable so the autoramp was kept at 4/30s and the final current was set to 600 A

At 600 A the voltage was 2.4 V, the current and voltage remained stable for 1 hour (see figures 600A and 600A-zoomed)


Thursday, January 23, 2020, 15:57

The current was ramp down to 0 A  at -5A/20s 


Thursday, January 23, 2020, 16:36 

After 10 min at 0A, the current was ramp up to 600 A at 4A/30s.

At 600 A the voltage was 2.43 V (TGHT)

The container was left at 600 A overnight.


Friday, January 24, 2020, 10:51

The PN2 stayed at 600 A for 15 hrs

The voltage increased 0.1 V during the first 7hr at 600 A and then it stabilized at 2.5 V (see figure "second ramp voltage")


Friday, January 24, 2020, 10:57

The current was ramp down to 0A at -5A/20s  


 

Attachment 1: p2n_conditioning_-_Naked_target_installed.jpg
p2n_conditioning_-_Naked_target_installed.jpg
Attachment 2: voltage_at_32_A.JPG
voltage_at_32_A.JPG
Attachment 3: 600A.JPG
600A.JPG
Attachment 4: 600A-zoomed.JPG
600A-zoomed.JPG
Attachment 5: First_current_ramp_up.JPG
First_current_ramp_up.JPG
Attachment 6: Second_ramp_voltage.JPG
Second_ramp_voltage.JPG
  251   Wednesday, November 06, 2019, 11:48 Marla CervantesUC244062-3 LP-SISDoneUCx#30 Conditioning

 Tuesday, November 05, 2019, 16:43

A TaC coated target container  was loaded with a graphite cartridge with UCx

The target container has 3 heat shields

EVAP1 pumping down


Wednesday, November 06, 2019, 11:46 

IGP1 = 2.09e-6 Torr

Good vacuum 5e-5 Torr

Bad vacuum 8e-5 Torr

Autoramp set up to:

TGHT= 1 A/min to 465 A (same current used to reach 1865 C in evap2 when sintering TaC coating - e-log 464 evap2)

TBHT= 1 A/min 230 A


 Thursday, November 07, 2019, 10:15

After approximately 4 hours at maximum temperature the pressure was 5.85e-6 Torr and the autoramp was set to:

TGHT -1 A/min

TBHT -0.5 A/min

After 4 hours that the current stayed at 0 A, EVAP1 was vented with argon and the target was removed; before transferring the target to the preparatory glove box, the tantalum cap to collect deposits from the target was inspected, there was not deposits on it so it was determined that the conditioning was successful and the target was transferred to the preparatory glove box.

  250   Tuesday, November 05, 2019, 14:50 Aaron Schmidt   MaintenanceFallen Bolt.

 One of the TBHT bolts  fell out of reach and may be sitting on the isolation valve or TP.

Remove TP as per WP:  I2019-11-05-9

Tuesday, November 05, 2019, 14:48: Completed. Found 2 TBHT bolts, a broken insulator, one small vented screw, and a piece of rubber.

Turbo pump mesh clear. Magnetic grabbing tool left in Evap 1 to potentially pickup /  grab materials before they fall down the hole if needed. The tip of the tool is contaminated.

Tuesday, November 05, 2019, 15:03: Evap 1 pumped down. TP1 started, IV1 opened. Ok. 

 

 

  249   Thursday, October 31, 2019, 13:59 Marla CervantesUO2/C TARGET BOATProblemsUCx#30 Carbothermal Reduction

Marla Cervantes wrote:

Monday, October 28, 2019, 10:29

A loaded graphite cartridge was set in a tantalum boated and wrapped with 3 tantalum sheets

The set up was installed in the EVAP1 and pumped dwon during the weekend.

IGP1 = 1.10 e-6 Torr


Monday, October 28, 2019, 10:31

Good vacuum = 1e-1 Torr

Bad vaccum = 5e-1 Torr

The current ramp is 1 A each 10 s from 0 A to 100 A


Monday, October 28, 2019, 11:13 

After 18 min the pressure started dropped.


Monday, October 28, 2019, 11:22 

When the pressure reduced to 5e-4 Torr the current ramp was changed to 3.3 A each 10 s to 480 A, the vacuum limits stayed the same.


Monday, October 28, 2019, 11:45

The limit was set to 500 A with same ramp


Monday, October 28, 2019, 11:48 

The ramp was changed to 1A/10s to 550 A


 Monday, October 28, 2019, 11:55

At 520 A the pressure reach 1e-1 Torr and the autoramp stopped


Monday, October 28, 2019, 13:39

the current was increased manually at aprox. 1A/30 s 

The current dropped suddenly even though the pressure was under the limits and the ramping was in the limits.

Autoramp was set to 3 A/ 10 s from to to 500 A

Then it was changed to 1 A  /30s from 500 to 506 A

Finally it was changed to 1 A/ 10 s from 506 to 520 A

Manually tapped to 530 A


Monday, October 28, 2019, 15:40

At 13:45 the current reached 530 A. 

The final pressure was IGP1 = 3.3e-6 Torr 

After 18 hrs at maximum temperature the autoramp was set to -2 A/min to 0 A.

  248   Monday, October 28, 2019, 11:23 Marla CervantesUO2/C TARGET BOATIn progressUCx#30 Carbothermal Reduction

Monday, October 28, 2019, 10:29

A loaded graphite cartridge was set in a tantalum boated and wrapped with 3 tantalum sheets

The set up was installed in the EVAP1 and pumped dwon during the weekend.

IGP1 = 1.10 e-6 Torr


Monday, October 28, 2019, 10:31

Good vacuum = 1e-1 Torr

Bad vaccum = 5e-1 Torr

The current ramp is 1 A each 10 s from 0 A to 100 A


Monday, October 28, 2019, 11:13 

After 18 min the pressure started dropped.


Monday, October 28, 2019, 11:22 

When the pressure reduced to 5e-4 Torr the current ramp was changed to 3.3 A each 10 s to 480 A, the vacuum limits stayed the same.


Monday, October 28, 2019, 11:45

The limit was set to 500 A with same ramp


Monday, October 28, 2019, 11:48 

The ramp was changed to 1A/10s to 550 A


 Monday, October 28, 2019, 11:55

At 520 A the pressure reach 1e-1 Torr and the autoramp stopped


Monday, October 28, 2019, 13:39

the current was increased manually at aprox. 1A/30 s 

The current dropped suddenly even though the pressure was under the limits and the ramping was in the limits.

Autoramp was set to 3 A/ 10 s from to to 500 A

Then it was changed to 1 A  /30s from 500 to 506 A

Finally it was changed to 1 A/ 10 s from 506 to 520 A

Manually tapped to 530 A


Monday, October 28, 2019, 15:40

At 13:45 the current reached 530 A. 

Attachment 1: UCx30-CarbothramlReduction.JPG
UCx30-CarbothramlReduction.JPG
Attachment 2: UCx30-CurrentDrop.JPG
UCx30-CurrentDrop.JPG
  247   Tuesday, October 08, 2019, 09:53 Marla CervantesUC244062-6LP-SISDoneUCx29 Conditioning

Monday, October 07, 2019, 09:51 

A TaC coated target container  was loaded with a graphite cartridge with UCx

The target container has 3 heat shields


Tuesday, October 08, 2019, 09:51 

IGP1 = 1.9596e-6 Torr

Autoramp set up to:

TGHT= 1 A/min to 425 A (same current used to reach 1900C in evap2 when sintering TaC coating - e-log 241 evap2)

TBHT= 1 A/min 230 A

The limits are:

Good vacuum 5e-5 Torr

Bad vacuum 8e-5 Torr


Wednesday, October 09, 2019, 13:58

After 4 hours at maximum current, the current was ramped down at 1 A/min for both.


Wednesday, October 09, 2019, 14:00

EVAP1 was vented with Ar, and the target oven was removed to access the Ta cap.

The Ta cap difference in mass was 0.002 g

  246   Wednesday, October 02, 2019, 11:10 Marla CervantesUO2/C TARGET BOATDoneUCx#29 Carbothermal reduction

 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 

Attachment 1: CarbothermalReduction-UCx29.JPG
CarbothermalReduction-UCx29.JPG
  245   Wednesday, October 02, 2019, 11:07 Marla CervantesUC244062-4LP-SISDoneUCx28 Conditioning #5

Monday, September 30, 2019, 10:54 

After being exposed to air for 1.5 hours,

the target UCx28 that was previously conditioned , was set again in the EVAP1 for re-conditioning.

The UCx28 was wrapped with 3 new Ta-heat shields and placed in the EVAP1, 

EVAP1 is currently pumping down.


Tuesday, October 1, 2019, 08:33

The heating conditions are:

TGHT= 1 A/min to 430 A 

TBHT= 1 A/min 230 A

Initial vacuum IGP1 = 1.22193-6 Torr

 


Since the ends of the target container are crystallized and the voltage is starting to vary, the target was heated only for 3 hours instead of 4.

The cooling conditions are the same as the previous conditioning:

TGHT= -1 A/min 

TBHT= -0.5 A/min


Wednesday, October 02, 2019, 11:01 

EVAP1 was vented with Ar and the target was removed form EVAP1 and assembled,

the assembly was placed in the glove box.

The tantalum cap used to collect the outgassed material from the target container was not fully coated.

  244   Friday, September 27, 2019, 18:04 Marla CervantesUC244062-4LP-SISDoneUCx28 Conditioning #4

Friday, September 27, 2019, 18:03

The target UCx28 that was previously conditioned , was set again in the EVAP1 for re-conditioning,

the reason was to get rid of all the material that could evaporate from the target and has the potential of clogging the ionizer.

EVAP1 currently pumping down.


Saturday, September 28, 2019, 09:33 

The heating conditions are the same as the previous conditioning:

TGHT= 1 A/min to 438 A (same current used to reach 1900C in evap2 when sintering TaC coating - elog-455 evap2)

TBHT= 1 A/min 230 A

IGP1 = 1.419e-6 Torr

The ramping started at 9:36 am on Septemper 28th 


Sunday, September 29, 2019, 12:30

The cooling conditions are the same as the previous conditioning:

TGHT= -1 A/min 

TBHT= -0.5 A/min


Monday, September 30, 2019, 11:40 

After 23 hours being heated, the target was cooled down and EVAP1 was vented with Ar

The target was removed form EVAP1 and placed in the fumehood.

The tantalum cap used to collect the outgassed material from the target container was not fully coated.


The heat shields of the target container were removed and the target container was inspected,

the ends of the Ta container were crystallized, the area above the graphite cartridge does not have signs of crystallization. 

Attachment 1: IMG_1393.JPG
IMG_1393.JPG
  243   Wednesday, September 25, 2019, 14:00 Marla CervantesUC244062-4LP-SISDoneUCx28 Conditioning #3

Wednesday, September 25, 2019, 14:00 

The target UCx28 that was previously conditioned , was set again in the EVAP1 for re-conditioning,

the reason was to get rid of all the material that could evaporate from the target and has the potential of clogging the ionizer.

EVAP1 currently pumping down.


Thursday, September 26, 2019, 07:09 

The heating conditions are the same as the previous conditioning:

TGHT= 1 A/min to 438 A (same current used to reach 1900C in evap2 when sintering TaC coating - elog-455 evap2)

TBHT= 1 A/min 230 A

IGP1 = 1.51e-6 Torr


Friday, September 26, 2019, 12:56

The cooling conditions are the same as the previous conditioning:

TGHT= -1 A/min 

TBHT= -0.5 A/min


Friday, September 27, 2019, 17:59

EVAP1 was vented with Ar, the target was removed from the heating chamber to exchange the Ta cap for a new one.

The old Ta cap was not fully coated and it presented a different coloration with respect to the 2 previous caps used for conditioning.

  242   Tuesday, September 24, 2019, 06:53 Marla CervantesUC244062-4LP-SISDoneUCx28 Conditioning #2

 Tuesday, September 24, 2019, 06:52

The target UCx28 that was previously conditioned e-log 241, was set again in the EVAP1 for re-conditioning,

the reason was to get rid of all the material that could evaporate from the target and has the potential of clogging the ionizer.

The heating conditions are the same as the previous conditioning:

TGHT= 1 A/min to 438 A (same current used to reach 1900C in evap2 when sintering TaC coating - elog-455 evap2)

TBHT= 1 A/min 230 A

IGP1 = 2.91e-6 Torr


 Wednesday, September 24, 2019, 18:30

IGP1 = 5.77e-6 Torr

The cooling conditions are the same as the previous conditioning:

TGHT= -1 A/min 

TBHT= -0.5 A/min


 Wednesday, September 25, 2019, 13:56

EVAP1 was vented with Ar,

The target container was removed to look at the Ta cap

The Ta cap was coated.


Wednesday, September 25, 2019, 13:58 

A new Ta cap was set in the transfer tube hole and the target container was installed again.

  241   Wednesday, September 18, 2019, 09:57 Marla CervantesUC244062-4LP-SISDoneUCx28 Conditioning #1

Wednesday, September 18, 2019, 07:48

A TaC coated target container  was loaded with a graphite cartridge with UCx

The target container has 3 heat shields


IGP1 = 9.3e-6 Torr

Autoramp set up to:

TGHT= 0.2 A/min to 438 A (same current used to reach 1900C in evap2 when sintering TaC coating - elog-455 evap2)

TBHT= 0.1 A/min 230 A

The limits are:

Good vacuum 5e-5 Torr

Bad vacuum 8e-5 Torr


Wednesday, September 18, 2019, 09:55

The autoramp where changed to 1 A/min on both the TGHt and the TGHT.


 Wednesday, September 18, 2019, 21:06

After 4 hours at TGHT = 4.15 V, 437.76 A and TBHT = 2.77 V, 228.31 A (and pressure of 1.07e-5 Torr)

The autoramp was set to TGHT = - 1 A/min and TBHT = -0.5 Torr


Tuesday, September 29, 2019, 14:05

 The EVAP1 was vented with Ar and the target was removed, 

The target was directly assembled after removing it from EVAP1

Finally, the assembly was transferred to the glove box

  240   Tuesday, July 30, 2019, 10:27 Marla CervantesUO2/C TARGET BOATDoneUCx#28 Carbothermal reduction

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 current rate was changed to 2 A each 10 s to 200 A

The final pressure obtained was 0.002 Torr

The current rate was changed to 3.2 A each 10 s to 292 A

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

Attachment 1: UCx28.JPG
UCx28.JPG
  239   Monday, June 17, 2019, 08:58 Marla CervantesUO2/C TARGET BOATDoneUCx#27 Carbothermal reduction

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

 

 

 

  238   Friday, May 24, 2019, 15:25 Marla Cervantes 43943-1 DoneGraphite insert test - FOILS

 Friday, May 24, 2019, 15:04

A TaC coated tantalum tube, loaded with graphite foils was transferred to EVAP1

https://elog.triumf.ca/TIS/Evaporator_2/445

The tueb will be heated with the same power used in EVAP2,

the power of the EVAP2 and EVAP1 will be matched using the fit from Document-126503

The chamber is currently pumping down


 Monday, May 27, 2019, 08:58

The current will be tapped to 50 A to replicate the procedure of EVAP2 

then the current will be set to 1 A/min to 500 A and increased to match with EVAP2 power.


 

  237   Wednesday, April 10, 2019, 13:38 Marla Cervantes 43630-3  DoneGraphite insert test #6

 Wednesday, April 10, 2019, 13:30

Tantalum foil caps were added to a graphite insert (see picture caps)

 The insert was set in a tantalum tube previously coated and wrapped with 3 Ta sheets.

The system was installed in the EVAP1, and it will be heated for a week at 2000 C.

Currently pumping down.


 Thursday, April 11, 2019, 13:26

IGP1 = 9.9e-7 Torr

The current is tapped to 40 A

After 1hr the autoramp is set to 1 A/min to TGHT 500 A


The TGHT current remained at 500 A for week

until at April 18 at ~4:30 pm

a localized power outage tripped the EVAP1.


The EVAP1 was ventd with air and the tantalum tube was removed

The tantalum tube did not break.

Attachment 1: caps.jpg
caps.jpg
Attachment 2: Curren-voltage-plot.JPG
Curren-voltage-plot.JPG
  236   Friday, April 05, 2019, 10:08 Marla Cervantes 43630-3 DoneTaC coating/sintering for graphite insert test

 Friday, April 05, 2019, 10:04

A tantalum tube was coated with TaC and wrapped with Ta heat-shield (3 layers)

Desired temp = 1900 C (expected TGHT ~445A/7.5V), TBHT will be set fixed at 230A (max).

Yesterday the tube was set in the EVAP1 and pumped down.


Friday, April 05, 2019, 10:07 

IGP1= 1.61e-6 Torr

The current is manually tapped to 40 A.


Friday, April 05, 2019, 13:25

After ~2 hours 

IGP1 = 1.54e-6 Torr

TGHT = 0.61 V, 40.39 A

Autoramp is set to 1 A/min to 400 A

Good vac at 3.00-5 Torr

Bad vac at 5.0e-5 Torr.


Sunday, April 07, 2019, 9:00

The current was increased to 424 A


Monday, April 08, 2019, 16:36

EVAP1 vented with air, sintered tube was removed. 

Attachment 1: EVAP1-TaC_Coating.JPG
EVAP1-TaC_Coating.JPG
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