Marla Cervantes wrote:

Marla Cervantes wrote: Monday, October 22, 2018, 17:55  UO2/C green was prepared , September 24, 2018 Initial UO2 powder used = 50.11 g (Inventory R-01032A, UO2 + bottle = 374.03 g before use) Graphite powder used = 10.13 g Green cast dried UO2/C + organic mass = 62.45 g  The green was rolled up and wrapped in a piece of graphite sheet. The Ta-target boat was wrapped with 3-layers of heat shield [2 reused, 1 new] and installed in evap1. Currently pumping down.  Tuesday, October 23, 2018, 15:38 IGP1 = 2.44e-6 Torr, Tapped to 60 A at 10A/10s with 20 s waiting every 10 A, Waited 28 min to vacuum to stabilize, tapped to 80 A at 10A/10s with 20 s waiting every 10 A, max pressure 7x10-3 Torr, waited 50 min to vacuum to drop Tapped to 100 A at 10A/10s with 20 s waiting every 10 A, max pressure 4x10-2 Torr, tapped current to 80 A, The pressure was dropping, when it was at 2x10-2 Torr, the current tripped off. IGP1 = 1x10-4 Torr Tapped back to 60 A at 10A/10s with 20 s waiting every 10 A, waited 5 min to tap to 80 A at same rate waited 5 min to tap to 100 A at same rate waited 25 min to vacuum to drop from 2e-2 Torr to 8e-4Torr Tapped to 110 A at same rate waited 3 min  to tap to 120 A at same rate waited 1 min  to tap to 130 A at same rate waited 1 min  to tap to 140 A at same rate   waited 15 min to pressure to drop from 6e-2 Torr to 7e-4 Torr   Changing manual rate to 10A/10s with waiting periods of 1 min, current was increased from 140 A to 260 A with this rate.   Changing manual rate to 20A/10s with waiting periods of 30 s, current was increased from 260 A to 480 A with this rate.   Waiting 4 min for the pressure to increase.   Changing the rate to 5A/30s, tapped until 510 A,   Changing the waiting period to 1 min, kept tapping to 530 A,   The pressure was dropping, when it was at 2x10-2 Torr, the current tripped off   The vacuum limit is 5e-1 Torr, and the pressure was dropping, there was no reason for the current to trip.   The pumps seems to be fine in the hot lab.  Wednesday, October 24, 2018, 17:51 Rod from controls checked on the system, seems that the controls are not the cause of the trip Rod suggested that the power supply might be overheating,  thermocouples were installed on the surface of the power supply to register the temperature during the process Tapping the current up again at accelerated rate see spread sheet for details. Since pressure was not decreasing the current was increased to 595 A (rate 1A/min) [see figure CT-2] The power supply's maximum temperature was 32.7 C which is a difference of 9.7 degrees with respect to the initial temperature.  The target will remain at maximum temperature overnight.

 Thursday, October 25, 2018, 09:07

Carbothermal reduction completed

IGP1 =  1.22e-5 Torr

Maximum power supply's temperature 33.3 C

Ramping current down at 2 A/min.

Monday, October 29, 2018, 12:30

Transferring  UCx to glove box

Mass = 48.384 g

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.

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.

 Wednesday, March 27, 2019, 08:50

A graphite insert was set into a tantalum tube in the evaporator 2 for 3 days

The objective of the test was to determine the current and voltage required to reach 2000 C

Current 424.2 A, voltage 7.17 V, P = 3 kW 

details can be find here https://elog.triumf.ca/TIS/Evaporator_2/433

The test will continue for 2 weeks in the EVAP1.

 Good vacuum 5e-4 Torr

Bad vacuum 1.00e-4

Pressure IGP1 = 1.55e-6 Torr

The autoramp was set to 420 A, at 1 A/min,

Monday, April 01, 2019, 07:57

TGHT = 4.68 V, 424.32 A

IGP1 = 9.61e-7 Torr

Autoramop is set to -1 A/min to 0 A

Monday, April 01, 2019, 11:19 

IGP1=5.43e-7 Torr

At TGHT = 223 A and 2.1 V the autoramp was increased to -2 A/min

Monday, April 01, 2019, 11:20

Sudden and unexpected  pressure increment to 1.4e-5 Torr, might be a glitch.

Monday, April 01, 2019, 13:10

IGP1 = 4.34e-7Torr

The autoramp was stopped at TGHT = 17.28 A, 0.0625 V,

and it was lower down to 0 A manually

 Results: The tantalum tube deformed in the contact points with the graphite insert

 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. 

 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.

 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.

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

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

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

 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.

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.

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. 

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.

 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 

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

 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.

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  

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.

Marla Cervantes wrote:

Marla Cervantes wrote: Marla Cervantes wrote: 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.    Thursday, January 30, 2020, 11:51 Controls respond "It looks like the power supplies were tripped by either the pirani gauge (IEVAP:IGP1) or the Nuclear vent or by both. But, it did not look like that the interlock tree latched the bad condition when the power supplies tripped. I modified the PLC to properly latch the cause of the trip." and gave green light to restart the carbothermal reduction.  Thursday, January 30, 2020, 13:09 IGP1=5.9e-6Torr Ramp set to 1A/10s to 200 A Pressure rising too fast at 200 A, current reduced manually to 190 A Pressure start dropping and system tripped, notify to controls again, "The strip tool shows the vacuum level shoot down to 0 then shoot back up for a quick second but that is enough to tell the PLC that IGP is “bad”" Thursday, January 30, 2020, 15:58  Restarting process to try to trip the system on purpose  Initial pressure IGP1 = 2.7e-6Torr Ramp set to 1/A/10s to 200 A, 0.59 V Ramp set to 2A/10s to 300 A Max pressure during process IGP1 = 0.03 Torr Voltage increased and stabilized (see voltage rising). Ramp kept at 2A/10s to 400 A Thursday, January 30, 2020, 16:48  TGHT = 1.54 V, 399.744 A IGP1 = 0.00016 Torr and going down Ramp set to 2A/10s to 500 A Thursday, January 30, 2020, 17:02  TGHT= 1.9V, 499.2 A IGP1 = 0.00014 Torr Ramp set to 2A/10s to 600 A Ramp set to 0.5 A/min to 700 A, ramp stopped at 680 A Manually tapped to 697 A Pressure dropping indicated that carbothermal reduction is done. Unfortunately, the system did not trip.  Contact Gelo for the  next run, such that he can monitor the system and we can spot the problem.

 Friday, January 31, 2020, 15:35

The EVP1 was vent with Ar and the P2N target was transferred to the glove box.