Thursday, August 22, 2013, 17:31

1st attempt:

UO2/C green was prepared on Aug 14, 2013 (wed).  The slurry was cast on a piece of glass coated with WD40.

The cast was let dry until Aug 26 (Mon) - couldn't peel off from the glass. 

2nd attempt:

So, scrapped off cast, mixed with 30ml H20 in the WC jar, re-milled for 3 hrs, and cast/let dry over night  - SAME SHIT! couldn't peel off!  Don't understand why?!

3rd attempt:

scrapped off, added the additional compositions:

1g PEG400,1g Glycerol, 10g 7% PVA, 2ml n-butanol, 2ml methonal, 20ml DI H2O.

Re-milled for 3 hours, cast and let dry!  Wahlaa... it works! (See attachment#1: pretty uranium pancake!)

However... During this process, some lost of uranium was resulted.  The slurry was more viscous than normal.  Some material was stuck to the WC jar wall and the balls.

Initial UO2 powder used = 50.14g (Inventory R-00835A UO2 + bottle = 795.56 before use)

Graphite powder used = 10g.

1st attempt dried UO2/C + organic  mass = 55.75g

2nd attempt = didn't measure

3rd attempt + additional org mass = 44.5g  (expecting to loss more uranium from the scraping/sticking to jar/balls)

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

The Ta-target boat was wrapped with 3-Ta layers of heat shield and installed in Evap1 on Aug 22, 2013.

Chamber is currently being pumped down. IG1 @ 2.4e-4 Torr.

Target will be ramped up to 520A at the rate of 0.1A/min

Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr

 Monday, August 26, 2013, 11:28

Chamber has been pumped down over the weekend.  IG currently @ 5.2e-6 Torr, BP @ 38mTorr.

Stepped up TGHT to 30A/0.151V. 

 Monday, August 26, 2013, 12:28

TGHT has been at 30A for almost 50 min.  Pressure has gone up but stabled at ~ 3.7e-5 Torr.

Initiated auto-ramping...

 Monday, September 09, 2013, 15:35

The carbonization process has come to an end. 

TGHT is at 520A for almost a day; IG currently at 1.3e-5 Torr (coming down), see attachment #2.

Auto cooling initiated at 2A/min.

The chamber will be vented with Ar.

John Wong wrote:

Thursday, August 22, 2013, 17:31 1st attempt: UO2/C green was prepared on Aug 14, 2013 (wed).  The slurry was cast on a piece of glass coated with WD40. The cast was let dry until Aug 26 (Mon) - couldn't peel off from the glass.  2nd attempt: So, scrapped off cast, mixed with 30ml H20 in the WC jar, re-milled for 3 hrs, and cast/let dry over night  - SAME SHIT! couldn't peel off!  Don't understand why?! 3rd attempt: scrapped off, added the additional compositions: 1g PEG400,1g Glycerol, 10g 7% PVA, 2ml n-butanol, 2ml methonal, 20ml DI H2O. Re-milled for 3 hours, cast and let dry!  Wahlaa... it works! (See attachment#1: pretty uranium pancake!) However... During this process, some lost of uranium was resulted.  The slurry was more viscous than normal.  Some material was stuck to the WC jar wall and the balls. Initial UO2 powder used = 50.14g (Inventory R-00835A UO2 + bottle = 795.56 before use) Graphite powder used = 10g. 1st attempt dried UO2/C + organic  mass = 55.75g 2nd attempt = didn't measure 3rd attempt + additional org mass = 44.5g  (expecting to loss more uranium from the scraping/sticking to jar/balls) The green was rolled up and wrapped in a piece of graphite sheet. The Ta-target boat was wrapped with 3-Ta layers of heat shield and installed in Evap1 on Aug 22, 2013. Chamber is currently being pumped down. IG1 @ 2.4e-4 Torr. Target will be ramped up to 520A at the rate of 0.1A/min Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr

 Friday, August 23, 2013, 15:08

The chamber wasn't pumping down well; there was a problem with the seal on the lid.

Rick M. replaced it. 

The chamber is currently being pumped down;  it seems OK!

John Wong wrote:

John Wong wrote: Thursday, August 22, 2013, 17:31 1st attempt: UO2/C green was prepared on Aug 14, 2013 (wed).  The slurry was cast on a piece of glass coated with WD40. The cast was let dry until Aug 26 (Mon) - couldn't peel off from the glass.  2nd attempt: So, scrapped off cast, mixed with 30ml H20 in the WC jar, re-milled for 3 hrs, and cast/let dry over night  - SAME SHIT! couldn't peel off!  Don't understand why?! 3rd attempt: scrapped off, added the additional compositions: 1g PEG400,1g Glycerol, 10g 7% PVA, 2ml n-butanol, 2ml methonal, 20ml DI H2O. Re-milled for 3 hours, cast and let dry!  Wahlaa... it works! (See attachment#1: pretty uranium pancake!) However... During this process, some lost of uranium was resulted.  The slurry was more viscous than normal.  Some material was stuck to the WC jar wall and the balls. Initial UO2 powder used = 50.14g (Inventory R-00835A UO2 + bottle = 795.56 before use) Graphite powder used = 10g. 1st attempt dried UO2/C + organic  mass = 55.75g 2nd attempt = didn't measure 3rd attempt + additional org mass = 44.5g  (expecting to loss more uranium from the scraping/sticking to jar/balls) The green was rolled up and wrapped in a piece of graphite sheet. The Ta-target boat was wrapped with 3-Ta layers of heat shield and installed in Evap1 on Aug 22, 2013. Chamber is currently being pumped down. IG1 @ 2.4e-4 Torr. Target will be ramped up to 520A at the rate of 0.1A/min Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr      Friday, August 23, 2013, 15:08 The chamber wasn't pumping down well; there was a problem with the seal on the lid. Rick M. replaced it.  The chamber is currently being pumped down;  it seems OK!

 Tuesday, September 10, 2013, 12:13

The TGHT reached zero on Monday and the chamber was left under vacuum overnight at 1.3e-6 Torr.

The chamber was accidentally vented in air until ~25mTorr for ~10min, then it was quickly pumped down again for ~10min before it was vented in Ar.

The chamber was vented in Ar and the UC2 flakes were transported into the Ar-glove box.

The process is complete 

Thursday, September 19, 2013, 15:35

UO2/C green was prepared on Aug 17, 2013. The slurry was cast on a piece of glass coated with WD40.

The cast was let dry until Aug 19, 2013.

Initial UO2 powder used = 49.97g (Inventory R-00835A UO2 + bottle = 745.42 before use)

Graphite powder used = 10.12g

Green cast dried UO2/C + organic mass = 59.62g

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

The Ta-target boat was wrapped with 3-Ta layers of heat shield and installed in Evap1 on Sept 19, 2013.

Chamber is currently being pumped down. IG1 @ 9.97e-12T.

Target will be ramped up to 520A at the rate of 0.1A/min

Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr

Laura Lambert wrote:

Thursday, September 19, 2013, 15:35 UO2/C green was prepared on Aug 17, 2013. The slurry was cast on a piece of glass coated with WD40. The cast was let dry until Aug 19, 2013. Initial UO2 powder used = 49.97g (Inventory R-00835A UO2 + bottle = 745.42 before use) Graphite powder used = 10.12g Green cast dried UO2/C + organic mass = 59.62g The green was rolled up and wrapped in a piece of graphite sheet. The Ta-target boat was wrapped with 3-Ta layers of heat shield and installed in Evap1 on Sept 19, 2013. Chamber is currently being pumped down. IG1 @ 9.97e-12T. Target will be ramped up to 520A at the rate of 0.1A/min Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr

 Friday, September 20, 2013, 13:48

Chamber has been pumped down overnight.  IG at 6.2e-6 Torr, BP @ 32mT.

Stepping up TGHT to 30A.

 Friday, September 20, 2013, 15:12

TGHT auto ramping initiated.  

 Monday, October 07, 2013, 14:09

TGHT has reached to 520A/5.5V.

Vac at 7.7e-6 Torr. 

The carbonization process is complete.

Auto-cooling is initiated at 2A/min, and the chamber will be vented in Ar after the target is cooled.

 Thursday, October 09, 2014, 13:36

*update* RENAME: batch #07 - 09192013 to UC2Flk_00 used for UCx#11

Tuesday, August 30, 2011, 09:29: Target Boat wrapped with 3 Ta heat shields. 6 D-End Caps and 6 End Caps coated with TaC. Pumping down - vac at 3.6e-5 torr.

Tuesday, August 30, 2011, 10:35: Stepped heater up to 100 A. Vacuum tripped heater. Stepped back up to 80 A then 70 A. Vac at 4.5e-5 torr.

Tuesday, August 30, 2011, 14:30: Manually increased heater to 580 A. Vac is 2.5e-5 torr. Local reading is 561 A for 570 A and 570 A for 580 A set points.

Tuesday, August 30, 2011, 15:57: Manually decreased heater in 12 min to 0 A from 460 A  vac starting at 6.3e-6 torr.

Anders Mjos wrote:

Tuesday, August 30, 2011, 09:29: Target Boat wrapped with 3 Ta heat shields. 6 D-End Caps and 6 End Caps coated with TaC. Pumping down - vac at 3.6e-5 torr. Tuesday, August 30, 2011, 10:35: Stepped heater up to 100 A. Vacuum tripped heater. Stepped back up to 80 A then 70 A. Vac at 4.5e-5 torr. Tuesday, August 30, 2011, 14:30: Manually increased heater to 580 A. Vac is 2.5e-5 torr. Local reading is 561 A for 570 A and 570 A for 580 A set points. Tuesday, August 30, 2011, 15:57: Manually decreased heater in 12 min to 0 A from 460 A  vac starting at 6.3e-6 torr.

 Vented evaporator. 

Monday, September 12, 2011, 13:07

Target boat is loaded with coated TaC end caps for sintering.  Target boat is wrapped with 3 Ta-heat shields. 

Max TGHT = 580A

Monday, September 12, 2011, 14:58 

Vac @ 3.72e-6 Torr.  Stepping up TGHT to 90A; pressure starting to increase.

 Monday, September 12, 2011, 15:33

Evaporator tripped twice when TGHT was at 90A and 85A.  Lowered TGHT to 75A.

Tuesday, September 13, 2011, 09:56 

TGHT was on auto-heating and reached to 580A yesterday evening.  The auto cooling began at mid-night after heated for a few hours. 

The chamber will be vented shortly.

See attachment#1: striptool.

Wednesday, June 01, 2022, 08:39

A loaded graphite cartridge was set in a tantalum boated and wrapped with 3 tantalum sheets (previous day)

IGP1 = 1.6 e-6 Torr

Good vacuum = 5e-2 Torr

Bad vacuum = 5e-1 Torr

Current ramp is 1A per 10s from 0A to 40A then continue to 80A at 1A/10s.  Then at 1A/min to 120 A and allow degas and then autoramp 1A/10s from 120A to (450-550A)

Wednesday, June 01, 2022, 09:51

IGP1= 3.0e-4 Torr

TGHT = 120A, 1.0V

Start autoramp at 1A/10s to 420A

Wednesday, June 01, 2022, 10:02

Increased ramp rate to 3A/10 s as per SOP to 440 A then will slow down the ramp to observe pressure behavior.

Wednesday, June 01, 2022, 10:19

At 430 A, autoramp set to 1A/10s to 500A as pressure was increasing. 

Will observe behavior of pressure curve then leave for 4 hours

Wednesday, June 01, 2022, 11:04

Pressure started dropping at 520A.  Stopped ramping and will leave for 4 hours.

Wednesday, June 01, 2022, 14:48

Autoramp to 400 A at 2A/30s and leave for 8 hour treatment

Wednesday, June 01, 2022, 23:00

IGP1= 2.1e-6 Torr

TGHT= 400A

Ramping down @-2A/min to 0A

Thursday, June 02, 2022, 10:09

IGP1= 6.7e-7 Torr

Ready to dismount

Tuesday, June 07, 2022, 07:05

A loaded graphite cartridge was set in a tantalum boated and wrapped with 3 tantalum sheets (previous day)

IGP1 = 1.2 e-6 Torr

Good vacuum = 5e-2 Torr

Bad vacuum = 5e-1 Torr

Current ramp is 1A per 10s from 0A to 80A at 1A/10s.  Then at 1A/min to 120 A and allow degas and then autoramp 1A/10s from 120A to (450-550A)

Tuesday, June 07, 2022, 08:28

IGP1=9.8e-5 Torr

TGHT = 120A, 0.85V

Start autoramp at 1A/10s to 420A

Tuesday, June 07, 2022, 08:45

Increased ramp rate to 3A/10 s as per SOP to 450 A then will slow down the ramp to observe pressure behavior.

Tuesday, June 07, 2022, 09:04

slowed autoramp to 2A/min to observe (1A/30s)

some erratic pressure oscillations observed then stabilized. 

Tuesday, June 07, 2022, 09:32

At TGHT = 495A pressure started dropping even while current ramping up.  Stopped ramp.  Will keep for 4 hours.

TGHT = 495.6A, 4.7V

Tuesday, June 07, 2022, 13:30

TGHT = 495.6 A, 4.7V

IGP1= 8.5 e-6 Torr

Start rampdown to 400A at 2A/30s and leave for 8 hour treatment

Thursday, October 25, 2012, 14:50

Previous sintering BeO tests, pellets 1 to 4 were done in Evaporator#2.

3 BeO pellets were made.  Each weights about 1.3g (including org mass). 

A piece of Re foil (0.002" thick) is used as the under layer to protect the reaction between Be(g) and the Ta-boat.  (see attachment#1)

Another layer of Ta-foil is used as the heat-shield to wrap around the Ta-boat.

The chamber is currently being pumped down. 

TGHT will be ramped up to 600A (~1360C) at 0.2A/min.

The pressure, voltage and current will be closely monitored. 

If the Ta-boat survives, the TGHT will continue to ramp up to max 800A (~1580C).

 Friday, October 26, 2012, 11:15

Chamber has been pumped down over night. 

IG1 @ 8.93e-6 Torr. 

Auto-ramping parameter:

Good Vac @ 2.0e-5 Torr, Bad Vac @ 3.0e-5 Torr.

rate @ 0.2A/min. 

 Tuesday, October 30, 2012, 10:57

TGHT has reached to 370A. The organic binder has burnt off. 

The pressure came down to  6.6e-6 Torr, but it is slowly going up to 8.6e-6 Torr (something is outgassing... Dissociation of BeO --> Be(g) + O(g) ?).  BP @ 39mTorr.  (see attachment#2).

 Wednesday, October 31, 2012, 12:07

TGHT has reached to 600A/6.338V for just over 6 hours.  IG is slowly coming down fro 1.2e-5 Torr.  BP @ 38mTorr. (see attachment #3)

 Wednesday, October 31, 2012, 16:49

Vacuum is coming down to 8.49e-6Torr.  TGHT has stayed at 600A/6.24V for over 11hrs.  (see attachment #4)

Auto-cooling initiated at 1A/min. 

The chamber will be vented tomorrow and the material will be inspected.

 Thursday, November 01, 2012, 10:57

TGHT has reached to 0A.  Vacuum holding at 1.9e-6Torr.

Turning off P/S and pumps prior to venting chamber.

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.

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 

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.

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.

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.

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.

Marla Cervantes wrote:

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.

 Thursday, August 13, 2020, 14:33

XRD analysis of the P2N material showed that the carbothermal reduction was not completed

The material was loaded again in its oven, new Ta caps where secured to the edges, the body remained the same

The oven was set in the EVAP1 using Ar to avoid oxidation of the P2N material

Currently pumping down.

 Saturday, August 15, 2020, 14:45 

Vacuum is having a strange behavior, pressure shows that is going from 8e-11 to 4e-6 Torr (fig. 200815-Vaccum_P2N)

Proceeded to turn off turbo pump

Tuesday, August 18, 2020, 10:38

The IGP1 head was replaced with the EVAP1's IGP1 head

The vacuum will be started again

Marla Cervantes wrote:

Marla Cervantes wrote: 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.  Thursday, August 13, 2020, 14:33 XRD analysis of the P2N material showed that the carbothermal reduction was not completed The material was loaded again in its oven, new Ta caps where secured to the edges, the body remained the same The oven was set in the EVAP1 using Ar to avoid oxidation of the P2N material Currently pumping down.  Saturday, August 15, 2020, 14:45  Vacuum is having a strange behavior, pressure shows that is going from 8e-11 to 4e-6 Torr (fig. 200815-Vaccum_P2N) Proceeded to turn off turbo pump Tuesday, August 18, 2020, 10:38 The IGP1 head was replaced with the EVAP1's IGP1 head The vacuum will be started again

 Tuesday, August 18, 2020, 20:44

The pressure reading are normal after swapping the IGP1's gauge head