Thursday, July 25, 2024, 15:18

Target container consists of two np-Ta fibres disk samples. Both disks are made from heat stabilized np-Ta fibres (150 C for 17 hours) and were pressed at 8 tons / 300 MPa.

Sample 1 was made from np-Ta fibres spun using Dope solution #1. Sample 1 disk has an average thickness of 0.727 mm and a diameter of 17.113 mm. Mass of the green sample 1 disk is 0.1957 g. 

Sample 2 was made from np-Ta fibres spun using Dope solution #6. Sample 2 disk has an average thickness of 0.688 mm and a diameter of 17.123 mm. Mass of the heat stabilized fibres used to make the green sample 2 disk is 0.1860 g. Mass loss from pressing the heat stabilized fibres was virtually zero. Therefore, although the mass of the green sample 2 disk was not measured, it can be extrapolated to be 0.1860 g. 

Target container was wrapped with Ta foil. Each sample disk was wrapped in graphite foil and placed inside the target container horizontally near the center. 

Omega slope was initially set to 0.980. After reviewing previous logbook on np-Ti (e-log ID#633), changed the Omega slope to 0.990. 

Chamber is currently being pumped down. The current reading (as of 15:40) is 4.70e-05 Torr. 

Two heating schedules will be tested. Heating schedule 1 entails heating both sample disks at ~1000 C until the pressure reaches below 1.00e-06 Torr. Once heating schedule 1 is completed, sample 1 will be removed. Heating schedule 2 entails heating sample 2 to ~1800 C until the pressure reaches below 1.00e-06 Torr. TGHT is estimated to be approximately 440A/7.6V to reach 1875 C (348A/5.8V to hold temperature at 1600 C). Refer to e-log ID#605. 

Angelina Chen wrote:

Thursday, July 25, 2024, 15:18 Target container consists of two np-Ta fibres disk samples. Both disks are made from heat stabilized np-Ta fibres (150 C for 17 hours) and were pressed at 8 tons / 300 MPa. Sample 1 was made from np-Ta fibres spun using Dope solution #1. The sample 1 disk has an average thickness of 0.727 mm and a diameter of 17.113 mm. The mass of the green sample 1 disk is 0.1957 g.  Sample 2 was made from np-Ta fibres spun using Dope solution #6. The sample 2 disk has an average thickness of 0.688 mm and a diameter of 17.123 mm. The mass of the heat stabilized fibres used to make the green sample 2 disk is 0.1860 g. The mass loss from pressing the heat stabilized fibres was virtually zero. Therefore, while the mass of the green sample 2 disk was not measured, it can be extrapolated to be 0.1860 g.  The target container was wrapped with Ta foil. Each sample disk was wrapped in graphite foil and placed inside the target container horizontally near the center.  The Omega slope was initially set to 0.980. After reviewing previous logbook on np-Ti The chamber is currently being pumped down. The current reading (as of 15:40) is 4.70e-05 Torr.  Two heating schedules will be tested. Heating schedule 1 entails heating both sample disks at ~1000 C until the pressure reaches below 1.00e-06 Torr. Once heating schedule 1 is completed, sample 1 will be removed. Heating schedule 2 entails heating sample 2 to ~1800 C until the pressure reaches below 1.00e-06 Torr. TGHT is estimated to be approximately 440A/7.6V to reach 1875 C (348A/5.8V to hold temperature at 1600 C). Refer to e-log ID#605.

 Friday, July 26, 2024, 09:52

Chamber has been pumped down overnight, pressure currently at 1e-6 Torr.

Initiate auto ramping 1A/min to reach 200 A. 

Good vac = 3 e-5 Torr

Bad vac = 5 e-5 Torr. 

Continue to monitor.

 Friday, July 26, 2024, 17:06

Gas evolution has seen observed to be completed as TGHT slowly ramping up.  Temp is currently reading at 1015 C, TGHT 164A/2.43V.  Pressure holding at 2.4e-6 Torr but slowly coming down, see attachment 1.  Will keep this setting and cool it down on Sunday.

 Sunday, July 28, 2024, 11:27

Temperature has been holding sturdy at ~1000C for over 36 hours, TGHT at 164A/2.59V (a slight increase in the voltage).  Pressure is currentlyat 4.5e-7 Torr (see attachment #2 for the archiver).

Ramping down TGHT at 1A/min. 

Will remove both samples on Monday to measure the mass loss.  Sample 1 will be analyzed.  Sample 2 will be loaded back to the Evap 2 for further heating to reach about 1800 C.

 Monday, July 29, 2024, 14:29

Both samples were removed from the chamber and measured for weight loss, and Sample 2 was put back for further heating; Thanks Darwin for helping up with this. 

Chamber is currently pump down, pressure at 6.0e-5 Torr. Will ramp up TGHT once the pressure has come down to 10e-6 Torr. 

 Monday, July 29, 2024, 16:52

Pressure at 6.5e-6 Torr.  Ramping up TGHT at 2A/min to reach 164A (previous setting at ~1000C).

 Tuesday, July 30, 2024, 09:02

Temperature has been holding at about 1000C. THGT at 160A(readback,, 164A setpoint)/2.56V.  Pressure 7e-7 Torr.

Stepping up 1A/min in 20A increment to reach 1800C. 

Continue to monitor.

 Tuesday, July 30, 2024, 10:07

Plotting out THGT (readback) vs Temp:

181 A/2.91V, 1070C

206A/3.34V, 1153C

225A/3.7V, 1213C

245A/4.1V, 1277C

Wednesday, July 31, 2024, 11:26

TGHT tripped off due to HS water flow NOT oK,  Attempted to clear it but did not work, see attachment #3. 

Will stop the process for now and investigate the problem. 

 Wednesday, July 31, 2024, 12:10

Darwin helped to check the surrounding of the lab for water leaks; everything was good and the chamber remained under vacuum. 

All the water paddle wheels were moving.  A slight touch of the HS paddle wheel somehow cleared the interlock. Maybe the connection was loose. 

We checked all the paddle wheels by shutting and opening the water valves.  All the interlocks responded correctly. 

Continue with the heating process...

Ramping up TGHT at 2A/min to reach 300A.

 Wednesday, July 31, 2024, 15:27

TGHT vs temp:

294A/5.1V 1477C

343A/6.0A, 1633C

402A/7.2V, 1818C

Will keep TGHT at 410A (setpoint) for night.(see attachment#4)

 Tuesday, August 06, 2024, 10:00

Venting Evap 2; the process is done.

The sample will be analyzed. 

Wednesday, August 07, 2024, 15:36: Roughing. Had initially been roughed & TP started w/ Marla CS, however it timed out. Restarting.

Wednesday, August 07, 2024, 15:37: TP on.

Wednesday, August 07, 2024, 15:46: Tripped at 4 KRPM. Restarted. Up to 5 KRPM.

Failed to start.

Thursday, August 08, 2024, 10:00: TP started. 

Thursday, August 08, 2024, 10:12: TP Tripped but nearly spun up. Reset & Restarted. TP Green / on.

Monday, August 19, 2024, 13:06

Target container consists of 2 samples, and both samples were heat stabilized at 150 C for 24 hours then pre-oxidized at 360 C for 4 hours:

1.  PVP (7% wt/v) spun fibres 0.0569 g

2.  np-Ta (Dope 7) spun fibres: 0.1730 g

Samples are wrapped in graphite foil and loaded into a target boat which is wrapped with Ta foil.

Omega slope set at 0.99.

Similar heat treatment as the 1st attempt, see e-log #667 (1800 C = 402A/7.2V).

Good vac = 3 e-5 Torr

Bad vac = 5 e-5 Torr.

Chamber is currently pumping down.

 Monday, August 19, 2024, 16:52

Chamber pressure @ 4.6e-6 Torr.

Initiate auto-ramping at 1A/min to reach 400A.

Continue to monitor the pressure and TGHT.

Tuesday, August 20, 2024, 09:48

TGHT reached 400 A/6.87V about 10 hr ago.  But the temperature has been holding at 1665 C. 

The voltage is much lower this time compared to the previous heat treatment.  See attachment #1 for the overall process.

Ramping up to 450A.  Continue monitoring..

Tuesday, August 20, 2024, 15:43

TGHT at 450A (readback 441A)/7.892V, temperature holding at 1803C

Pressure coming down from 1.62e-6 Torr. 

Continue to hold on the temperature for a few more hours before cooling it down

 Wednesday, August 21, 2024, 09:40

Temperature was holding for about 18 hours before ramping down TGHT was initiated at 2A/min.

The samples can be taken out after 2 pm.

Monday, September 09, 2024, 19:06

The coated container was wrapped in 4 Ta foil heatshields.

Vacuum IGP1 initial =2.6 e-06 Torr

Target temperature on OMEGA= 1800-1900 C

OMEGA slope:= 0.990

Target time at max temperature = 4 hours

Final Current TBHT= 230 A

Final TGHT current= ~400A (adjustable)

Heating autoramp starged at 1A/min on  TGHT   and TBHT until outgassin peak passed

Then at 1A/min  to =400 A TGHT and 230A TBHT

Good vacuum = 5.0 e-04 Torr

Bad vacuum = 5.0E-02 Torr

Monday, September 09, 2024, 19:08

Peak passed around 70A will continue ramp up at 1A/min to 400A on TGHT and 230A TBHT

Tuesday, September 10, 2024, 13:13

Was ramped down at -2 A/min TGHT and -1 A/min TBHT

A boat lined up with graphite and wrapped in 3 Ta heatshileds

Vacuum IGP1 initial =6.1 e-06 Torr

Target temperature on OMEGA= 1800-1900 C

OMEGA slope:= 0.990

Target time at max temperature = 4 hours

Final TGHT current= ~400A (adjustable)

Heating autoramp started semi-manually on  TGHT  to 65A and then at continue to 100A

After peak heat at 1A/min  to =400 A TGHT

Good vacuum = 5.0 e-04 Torr

Bad vacuum = 5.0E-02 Torr

Tuesday, September 10, 2024, 22:22

1810C OMEGA at 439A TGHT readback

Wednesday, October 02, 2024, 19:21

Ta endcup at front end of container

End-caps on the graphite cartridge have holes for outgassing. 

initial heating @ 2A/min to 85 A then 2A/min to 120A TGHT.  Allow pressure to drop and then ramp to 400 A at 2A/min, leave 4 hours and start ramp down.

OMEGA slope = 0.99

Vacuum limits up to 400A: 5.0e-04 Torr -- 1.0e-02 Torr

Max current~400A (1900 C)

Wednesday, October 02, 2024, 19:25

Starting IGP1 = 6.65e-06 Torr

Thursday, October 03, 2024, 05:09

Starting rampdown.  Pressure stable at 4.5 e-06 Torr

Top temperature 1850 C on OMEGA

ramping down at -2A/min

Saturday, November 23, 2024, 11:08

 No milling ZrC material sintering inside graphite cartridge

baseline standard discs included for comparison. 

4 Ta foils wrapped around  container

one spring at the back end to retain the graphite cartridge

One Ta cap with perforations at the front for T readings

initial heating at 2A/min to 50A, followed by heating at 1A/min to 90 A

Initial IGP1= 1.0e-6 Torr

OMEGA slope =0.990

Good and bad vacuum =5.0e-5 Torr and 5e-4 torr

Saturday, November 23, 2024, 11:20

autoramp start at 2A/min to 50A on tght

Saturday, November 23, 2024, 20:11

allowed pressure to drop to 3.3e-6 Torr after degassing. 

Started ramp to 90A at 1A/min

Saturday, November 23, 2024, 23:46

started ramping at 1.5A/120s or 0.75A/min to 400A

Sunday, November 24, 2024, 07:55

Reached 1900 C at 410 A setpoint and 402 A on RD

Pressure did not increase after bumping up to 410 setpoint so will keep at this current until 11 am (four hours near 1900 C in total)

Sunday, November 24, 2024, 10:58

Final IGP1 at start of rampdown = 2.9e-6 Torr

Ramping down at -2A/min

Tuesday, March 11, 2025, 15:44

The coated container was wrapped in 3 Ta foil heatshields.

16 caps and 4 springs

Target temperature on OMEGA= 1750-1800C

OMEGA slope:= 0.990

Target time at max temperature = 4 hours

Final Current TBHT= N/A

Final TGHT current= ~400A (adjustable)

Wednesday, March 12, 2025, 07:07

Heating autoramp started at 1A/min on  TGHT 90A

Then at 4A/min  to 400 A.

Good vacuum = 5.0 e-04 Torr

Bad vacuum = 5.0E-02 Torr

 IGP1 initial =4.8e-07 Torr

Wednesday, March 12, 2025, 09:52

starting ramp at 2A/min to 400A 

Wednesday, March 12, 2025, 10:21

increasing ramp to 4A/min (2A/30s)

Wednesday, March 12, 2025, 11:57

TGHT=441A, 7.2V

Will keep for 4 hours

1750C

Wednesday, March 12, 2025, 15:57

starting rampdown at -2A/min

Friday, April 11, 2025, 06:18

 initial IPG1=2.3 e=06 Torr

Ta container tube, wrapped in 4 Ta foil heat-shields, and loaded with _________ D shaped discs in a 12mm graphite cartridge with usable 11mm

conditioning tube WO = 41882-4

End-caps on the graphite cartridge have holes for outgassing.  One spring each end in the Ta container

initial heating @ 2A/min to 85 A then 2A/min to 120A TGHT

OMEGA slope = 0.99

Vacuum limits up to 400A: 5.0e-04 Torr -- 1.0e-02 Torr

Friday, April 11, 2025, 14:45

reached 1800 C on OMEGA at 398A readback

Will take to ~410 A and leave for 4 hours

Friday, April 11, 2025, 18:55

at 415A OMEGA was 1879 C

was left for 4 hours at this setting

starting rampdown at -2A/min

Wednesday, April 23, 2025, 06:46

initial IPG1=1.3 e06 Torr

Ta container tube, wrapped in 4 Ta foil heat-shields, and loaded with _________ D shaped discs in a 12mm graphite cartridge with usable 11mm

conditioning tube WO = 41882-4

End-caps on the graphite cartridge have holes for outgassing.  One spring each end in the Ta container

cartridge #26   TiC250307

initial heating @ 2A/min to 85 A then 2A/min to 120A TGHT

OMEGA slope = 0.99

Vacuum limits up to 400A: 5.0e-04 Torr -- 1.0e-02 Torr

Wednesday, April 23, 2025, 09:57

IGP1=3.2e-05 Torr

autoramping to 120A