Tuesday, May 02, 2023, 14:03

Two np-TiO2 spun fibrous pellets and 1 batch of fibre mats were wrapped with graphite foils and loaded into a target boat.

Sample will be heated to 1875C, similar to the previous process, see e-log ID#605 (TGHT: 440A/7.6V).

TGHT will be autoramped to 350 A and monitor the conditions before ramping up further.

Good vacuum: 3e-5 Torr

Bad vacuum: 5e-5 Torr

Omega slope: 1.08

In the previous process (ID#605), Ta-foil was inserted at both ends of the tubes to hold the sample together. However, it was observed that the out-gassing of the material reacted with the Ta-foil, causing issues. Therefore, it's decided not to cover the ends with Ta-foil, and the sensor is now looking at the graphite foil. It had previously determined the slope for SiC material set for its emissivity, but need to note any errors that may have arisen due to the change in the sample setup.

See attachment#1 for sample setup - note that Omega sensor is slightly looking at the edge of the Ta-boat tube. 

Initiate autoramp: 1 A/min

Chamber has been pumped down below 5.6e-6 Torr.

 Tuesday, May 02, 2023, 15:31

Vacuum spike TGHT at 75A, auto-ramping down kicked in.

 Wednesday, May 03, 2023, 12:18Thursday, May 04, 2023, 15:16

TGHT has been holding at 350A/5.7V (1995W) for almost 2hrs, temp is reading at 1368C - 232C lower than the previous process (ID#605) with TGHT = 348/5.8V (2018W).

Pressure started to come down around 344A/5.5V, temp 1331C - see attachment #2.

Current status overall view - see attachment #3

Continue to ramp up t0 440A at 1A/min and monitor.

 Wednesday, May 03, 2023, 14:47

TGHT reached 440A/7.5V, temp reading at 1672C.  Pressure is coming down, currently at 1.8e-6 Torr.  Will keep at this setting overnight and will check the Omega/emmissivity to confirm the temperature.

 Thursday, May 04, 2023, 10:54

Eractic vacuum spikes started just over 3 hrs ago.  Temp at 1681 C; TGHT has been stable at 440A/7.6V. Pressure ranging between 5.0e-7 to 1.5 e-6 and gradually decreasing, see attachment #4. 

Will perform the omega/emmissivity measurement.

 Thursday, May 04, 2023, 15:16

Temperature was checked with the digital and analogue pyrometers. 

With the analogue pyrometer on the Ta-container (left end, top surface), measured temp = 1360 C, with e=0.22, correction + 200 C => 1560 C

With the Omega pyrometer (right end), 1-color mode with e= 0.22, temp = 1585 C. 

Setting Omega pyrometer to 2-color mode with e= 0.99 temp = 1516 C --  this is in agreement with the measurements for Ta.  Note that the pyrometer is looking at some part of the Ta container which is not covered by the sample wrapped with the graphite foil (see attachment #5). 

From e-log#596, temp was reported at 1520 C (slope at 0.99) with a Ta-foil at the end of the tube, but from e-log#605, temp was reported at 1864 C (slope at 0.99) - possibly an error occurred during that time.

In conclusion, the temp should be at 1530 C +/- 10C with TGHT = 440A/7.7V (3388W).

 Thursday, May 04, 2023, 15:43

Vacuum spikes continue every 30 min lasting for 10 min. 

Tapped down TGHT to 430A/7.5V, temp reading at 1500 C.  Will monitor if any improvement with the vacuum.

 Friday, May 05, 2023, 09:34

Vacuum spikes continue to happen; see attachment #6 for the striptool overview.

Lower TGHT to 420A/7.3V, temp = 1480 C.

 Friday, May 05, 2023, 10:10

Vacuum spikes continue every 20-30 min lasting for 10 min. 

Lower TGHT to 410A/7.1V, temp = 1450 C

 Friday, May 05, 2023, 11:25

Vacuum spikes continue,

Lower TGHT to 400A/6.93V, temp = 1433 C

 Friday, May 05, 2023, 12:20

Vacuum spikes - lower TGHT to 390A/6.7V, temp at 1407C

Friday, May 05, 2023, 13:19

Vacuum spikes - lower TGHT to 380A/6.5V, temp at 1388C

Friday, May 05, 2023, 13:47

Vacuum spikes - lower TGHT to 370A/6.3V, temp at1373 C

Friday, May 05, 2023, 14:16

Vacuum spikes - lower TGHT 360A/6.1V, temp at 1348 C

Friday, May 05, 2023, 15:11

Vacuum spikes - lower TGHT 350A/5.9V, temp at 1308 C

Friday, May 05, 2023, 16:34

Vacuum spikes - lower TGHT 340A/5.7V, temp at 1371 C

Friday, May 05, 2023, 16:56

Vacuum spikes continue; container possibly broken.

Slow ramp down TGHT at -0.5A/min to see when the vacuum spikes would stop.

 Monday, May 08, 2023, 09:54

TGHT was ramped down over the weekend.  Chamber was kept under vacuum and vacuum continued to spike; suspecting problem with the gauge?! see attachment &7 for an over view.

Will take out the samples for exam.

 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. 

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.

 Tuesday, January 19, 2016, 14:19

SiC nanofiber was prepared at UBC Material Engineering Sci.  

4 samples are loaded in a Ta target contained (sintered with TaC coating): 

Sample 1: 

size:  21.70 x 21.54 mm, mass: 0.0762g, thick: 0.224mm

Sample 2: 

size: 20.89mm x 23.95mm, mass: 0.0954g, thick: 0.232mm 

--> Sample 1 and 2 with graphite backing foil 

Sample 3: 

size: 22.55 x 25.56mm, mass: 0.0082g, thick: 0.110mm

Sample 4: 16.93 x 23.82mm, mass: 0.0048g, thick: 0.086mm

--> Sample 3 and 4 with no graphite backing foil. 

(see attachment) 

Test#1:  Heating temperature at 1600C for 24hrs. 

TGHT will be adjusted accordingly.  There are 2 Ta-heat shields wrapped around the container. 

Chamber is currently being pumped down.

 Tuesday, January 19, 2016, 16:19

Vacuum at 2.0e-6 Torr.

For 1600C, expected current is around 350A.

Stepping up TGHT gradually...

 Wednesday, January 20, 2016, 14:34

TGHT was ramped up to 390A/6.63V to reach 1600C.  Samples have been heated at that temp since 11pm last night.

Visual check on the fibers seem ok (see attachment).

Will continue to heat this for a total time of 24hours.

 Wednesday, January 20, 2016, 22:57

Samples have been heated at 1600C for 24hours. 

Initiated cooling at 1A/min.

 Wednesday, January 27, 2016, 12:34

First attempt - heating 1600C.  XRD result showed board "bumps" that could be SiO2? It is inconclusive. 

Second attempt - re-heating the same samples, namely

Sample 1 - only the fiber

Sample 2 - with graphite backing.  This sample is loaded with the fiber facing down to see how well it holds on the graphite foil.  (see attachment)

TGHT will be ramped up to reach 1800C

Chamber is currently being pumped down.

 Wednesday, January 27, 2016, 14:04

Water valves open; no leaks detected.

Ramping up TGHT to 400A at 2A/min

 Wednesday, January 27, 2016, 18:08

TGHT is at 481A to obtain 1800C.

Visual check on Sample 2 - fiber has fallen off graphite backing foil.

Will remain heated at this temperature for over night.

 Friday, February 12, 2016, 11:11

Heat treatment test#1 is complete.  XRD results are inconclusive.  Need to do EDX to determine Si/SiO2.  

(See my dropbox for more details)

Friday, February 26, 2016, 15:44

5 samples were prepared at UBC MTRL using Sol-gel tetraethyl orthosilicate (TEOS) coated on electrospun polyacrylonitrate (PAN). 

Each sample is sandwiched in between graphite foils. 

Sample labeling:

Direct, 0.2358g

Mix, 0.3486g

3X, 0.2273g

5x, 0.2079g

7x, 0.1735g

All samples are loaded in the target boat, stacking on each other.  The Container is wrapped with 2X- Ta shields.

Chamber is pumping down. 

Step#1 Carbonization temperature: 1600C

 Saturday, February 27, 2016, 10:07

Vac at 2.5e-7 torr.

Ramping up TGHT to 300A at 1A/min. monitoring temp.

Saturday, February 27, 2016, 17:38

TGHT at 400A, temp at 1600C. Vac 1.34e-6 Torr.

 Monday, February 29, 2016, 13:04

Samples have been heated at 1635C for almost 2 days. 

Pressure at 2.1e-7 Torr.

Initiated cooling at 2A/min.

 Thursday, March 24, 2016, 11:26

Samples were analyzed for Si using EDX.  Unfortunately, no Si was found.  The vapour pressure of SiO was too high for it to react with PAN to carbonize in a vacuum environment.  

Will look into a different technique.

Wednesday, May 11, 2016, 17:15

Nanofiber SiC (~50nm grain size)/PAN was prepared at UBC. 

SiC 0.50g, DMF 9.0g, PAN 1.0g, tiny bit of SDS.

The fiber mat was stabilized in air at 250C and then cut into discs, initial mass = 0.1072g

Discs were then bounded with PVA on 9 pieces of rounded graphite foil  (green mass gained to 0.6031g)

The stack of naofiber SiC/PAN was loaded on to Ta boated (coated) and wrapped with Ta heat shield. 

Chamber is currently being pumped down.

 Friday, May 13, 2016, 15:00

TGHT at 390A/6.966V.  Temp measured at 1615C. 

Will keep at that temperature for a few days.

 Monday, May 16, 2016, 15:44

Sample has been heated at ~1600C for 4 days.  TGHT at 400A/7.02V. 

Cooling down at 2A/min

 Tuesday, May 17, 2016, 11:18

Chamber vented.  Inspecting samples.

Monday, October 24, 2016, 17:43

Two samples were prepared and loaded into the target boat with 1 layer of heat-shied as shown in the attachment#1.

Ingredients used: np-SiC and very small about of 5% PVA to hold the powder together. 

Samples were dried in the oven at 110C before loaded in Evap#2. 

After dried:

Sample #1 (larger graphite boat, mass =0.3779) = 0.4259g (PVA mass unknown due to solution leaking out from the boat)

Sample #2 = 0.2306g (with 5% PVA of 0.4111g)

Test temperature at 1600C, expect TGHT to be around 400A. 

Monday, October 24, 2016, 17:50

Ramping up TGHT to 300A at 0.5A/min. Vac at 2.3e-6 Torr. 

 Tuesday, October 25, 2016, 12:59

TGHT reached to 300A and stabilized for 10 hours.  OMEGA temp reader at 1150C

Continue to ramp up TGHT

 Wednesday, October 26, 2016, 15:49

TGHT was ramped up to 450A/7.91V; the temp readers on MIKON and OMEGA were 1489 and 1535, respectively (see attachment).

The temperature was much lower than the previous two tests (see elog #296 and #335).  Not sure why... 

Will do composition analysis on the sample... 

Cooling down at 2A/min.

Tuesday, November 15, 2016, 16:48

Three samples were prepared  (see my logbook#1 page 3, preparing for carbonization).

One layer of Ta foil was used to wrap around the target boat. 

Chamber is currently being pumped down

 Wednesday, November 16, 2016, 11:04

Ramping up TGHT at 2A/min, set at 350A.

Desired temperature, ~1530C (similar heating condition as raw npSiC heat treatment, elog ID335)

 Thursday, November 17, 2016, 10:09

TGHT reached to 350A/5.80V, stayed for over 20 hours.  Temp measured at 1276 C (Mikon) and 1270 (Omega), vac at 6.07e-7 Torr. 

Stepping up TGHT to reach the desired temp.

John Wong wrote:

Tuesday, November 15, 2016, 16:48 Three samples were prepared  (see my logbook#1 page 3, preparing for carbonization). One layer of Ta foil was used to wrap around the target boat.  Chamber is currently being pumped down  Wednesday, November 16, 2016, 11:04 Ramping up TGHT at 2A/min, set at 350A. Desired temperature, ~1530C (similar heating condition as raw npSiC heat treatment, elog ID335)  Thursday, November 17, 2016, 10:09 TGHT reached to 350A/5.80V, stayed for over 20 hours.  Temp measured at 1276 C (Mikon) and 1270 (Omega), vac at 6.07e-7 Torr.  Stepping up TGHT to reach the desired temp.

 Thursday, November 17, 2016, 11:13

TGHT = 400A, 6.73V

IGP1 = 8.2e-7 Torr

OMEGA = 1385C

MIKRON = 1389C

Tapping up manually to 1500C or a max setpoint of 450A

Thursday, November 17, 2016, 11:56

TGHT = 450A, 7.85V

IGP1 = 1.7e-6 Torr

OMEGA = 1502C

MIKRON = 1510C

 Friday, November 18, 2016, 10:08

IGP1 = 5.3e-7 Torr

TGHT = 450A, 7.9V

OMEGA = 1510C

MIKRON = 1515C

Evap2 has remained at max setpoints for 23hrs.

Initiating auto-cool at 2.0A/min

Laura Lambert wrote:

John Wong wrote: Tuesday, November 15, 2016, 16:48 Three samples were prepared  (see my logbook#1 page 3, preparing for carbonization). One layer of Ta foil was used to wrap around the target boat.  Chamber is currently being pumped down  Wednesday, November 16, 2016, 11:04 Ramping up TGHT at 2A/min, set at 350A. Desired temperature, ~1530C (similar heating condition as raw npSiC heat treatment, elog ID335)  Thursday, November 17, 2016, 10:09 TGHT reached to 350A/5.80V, stayed for over 20 hours.  Temp measured at 1276 C (Mikon) and 1270 (Omega), vac at 6.07e-7 Torr.  Stepping up TGHT to reach the desired temp.    Thursday, November 17, 2016, 11:13 TGHT = 400A, 6.73V IGP1 = 8.2e-7 Torr OMEGA = 1385C MIKRON = 1389C Tapping up manually to 1500C or a max setpoint of 450A Thursday, November 17, 2016, 11:56 TGHT = 450A, 7.85V IGP1 = 1.7e-6 Torr OMEGA = 1502C MIKRON = 1510C  Friday, November 18, 2016, 10:08 IGP1 = 5.3e-7 Torr TGHT = 450A, 7.9V OMEGA = 1510C MIKRON = 1515C Evap2 has remained at max setpoints for 23hrs. Initiating auto-cool at 2.0A/min

 Friday, November 18, 2016, 17:27

The heat treatment of the fiber mats is done. 

Analyzing steps...

Thursday, February 09, 2017, 23:26

There are two types of samples being test for thermal stability:

1.  SiC-SiO2-Lys nanofiber mats

2.  SiC pellets

(see Lab Book for more info)

Desired temperature: ~1500C

One-Ta heat shield is used, est. TGHT 450A.

 Thursday, February 09, 2017, 23:38

TGHT currently at 322A/5.28V, OMEGA 1204C.

Vac 2.9e-6 Torr.

 Friday, February 10, 2017, 08:58

TGHT at 400A, temp at 1425C for 8 hours.

Decided to cool down for analysis.  Check for carboreduction for SiO2 at 1400C.  Then continue to ramp up to 1500C. 

Ramping down at 2A/min

 Friday, February 10, 2017, 10:47

Rapid out-gas (2.7e-6 to 3.8e-6 Torr) from TGHT 330A until current stopped at 400A (see attachment).  Could be the evolution of O2 from SiO2... 

Friday, March 10, 2017, 17:29

Three B3 pellets are loaded into the container for thermo test. 

(see lab book1 Pg 26, 28-30 for more detail about the materials)

Desired temp ~1500C; one long-sheet of Ta foil is used, est 400A. 

Auto ramping 0.5A/min to 300A first.  Check later...

 Saturday, March 11, 2017, 11:58

Increased TGHT from 300A to 350A last night at ramping rate of 0.5A/min.

Tapped up further from 350A to 400A, 6.92V (2.8kW), Temp measured at ~1550C. 

Pressure peaked at 1.5e-6 Torr and coming down when ramping TGHT from 350A to 400A. (see attachment1)

Will remain at the current.  Continue monitoring..

 Monday, March 13, 2017, 01:14

Temp was held at 1550C for about 1.5days. Vac stabilized at 3.08e-7 torr.  TGHT 400A/6.94V.

Initiated cooling at 1A/min. 

Next, Materials inspection.

 Monday, March 13, 2017, 11:24

Target has been at room temp for about 4 hours.  Venting chamber.

Friday, March 31, 2017, 12:21

Two compressed pellets loaded into the target boat and wrapped with Ta foil.  (see lab book p32 for details).

Chamber is pumping down.

Desired temp 1550C, TGHT expected to be around 400A.

 Friday, March 31, 2017, 16:31

Auto-ramp at 0.5A/min to reach 350A.

 Saturday, April 01, 2017, 12:30

TGHT reached to 350A/5.7V, temp around 1200C - notice voltage is much lower than previous process (ID 351), possible target/heat shield shorted therefore lower temp observed. (This should not cause any damage to the container.) 

Continue to ramp up to 400A.  Notice some evolution of gasses similar to the previous process (ID351) during ramping up of TGHT around 220A . (see attachment1)

 Saturday, April 01, 2017, 13:52

TGHT reached to 400A/6.7V; temp stabilized at 1400C. 

Tap up to 1550, TGHT 456A/8.08V (3.7KW, about 1KW higher than before).

Pressure coming down (see attachment 2)

Hold temp for several days.

 Saturday, April 01, 2017, 17:22

Temp went up by 10C. Lowered TGHT to 450A.

Thursday, April 20, 2017, 12:38

3 samples are loaded into the Ta boat and wrapped with heat shield (1 long piece, 3 rounds):  2x of B3-92Mpa pellets and 10% pure PAN pellet as control.  See lab book page 32 for more details.

The B3-92Mpa pellets were previously heated to 1550C (TGHT 400A/6.94V), see elog#351

Attempting to heat samples up to 1800C to determine the weight loss and shrinkage. 

Est. TGHT 480A.

OK to auto ramp to 400A at 1A/min.  Check for coating on the window. 

Chamber is currently being pumped down.

 Thursday, April 20, 2017, 14:28

Pressure 3.14e-6 Torr.  Auto ramp TGHT at 1A/min to reach 400A. 

 Friday, April 21, 2017, 10:56

TGHT at 400A/6.75V, temp at 1475C (75C/0.19V lower). 

Tapping up TGHT

 Friday, April 21, 2017, 12:32

TGHT ramped up to 530A/9.85V, temp at 1800C. 

 Friday, April 21, 2017, 15:38

TGHT dropped slightly, no coating on windows. 

Checked with Mikron, agreed with the dropped temp. 

Tapped up TGHt to 545A/10.1V to reach 1800C.  Will keep at that temp for several days.

 Wednesday, April 26, 2017, 17:06

Samples have been heated at 1800C (-25C) for 7 days now (see attachment for archiver). 

Cooling down TGHT at 1A/min.

Monday, July 10, 2017, 17:28

Two np-SiC fibrous pellets with different applied pressure:

1) 200MPa, 2)  335 MPa (see logbook pg 36 for more details). 

Desired heating temperature: 1550C (Previous setting: TGHT 400A/6.94V)

Two layers of Ta foils wrapped around the target boat.

Chamber is pumping down...

 Tuesday, July 11, 2017, 11:11

Pressured came down to 1.0e-6 Torr. 

Tapping up TGHT.

 Tuesday, July 11, 2017, 11:24

Tapped TGHT up to 45A - pressure stabilized at around 3.0e-5 Torr. 

Auto ramp 1.0A/min to reach 350A before tapping up further.

 Wednesday, July 12, 2017, 10:59

TGHT reached to 350A/5.5V, temp @ 1270C - much lower than expected; could be a short between the target container and the heat shield.  I actually had a had time adjusting the target legs to avoid shorting the cu-heat shield. 

Tapped TGHT further up to 375A/6.07V, Omega Temp at 1340C.  Holding current for about 50 mins, re-measured with pyrometer - temperature matches.

Wednesday, July 12, 2017, 14:49 

TGHT set at 450A/7.7A.  Temp at ~1550C.  See attachment for temp plot

Holding at temp for 5 days before cooling down on Monday July 17.

 Thursday, July 13, 2017, 17:52

TGHT tripped off due to bad IEVAP2:WFB1 water flow.  Not sure what was the cause.  Will leave the heater off for now and investigate this tomorrow.

 Friday, July 14, 2017, 11:48

Investigated the bad water flow situation.  It was due to a faulty water flow sensor.  The paddle wheel stopped turning until I gave it a tab.  We had a similar problem before with the water sensor, see elog ID 109.  It is probably the time to replace all the water sensors. 

Wednesday, September 27, 2017, 18:05

 3 samples from NS-npSiC pellets, pressured at 10T  (see lab book pg 53)

3 samples from B3 pellets, 600MPa (see lab book pg 50)

Desired temperature = 1550C, est current = 450A

 Thursday, September 28, 2017, 11:17

Vac at 8.8e-7 Torr.  

Ramping TGHT up to 450A at 0.2A/min

 Thursday, September 28, 2017, 17:54

Setup screen capture, see pg 53 for saved directory

 Friday, September 29, 2017, 23:54

TGHT reached to 450A/7.9V, temp at 1510C.

Tapping up TGHT to 465/8.2V to reach 1550C

Pressure coming down from 1.6e-6 Torr.

See attachment 1 for the 20-hour plot

 Sunday, October 01, 2017, 00:30

At around 20:00 on Sep 30, there was an increase of ~0.1 V which caused a rise in temp from 1550 to 1576C (see screen capture).  Pressure increased slightly.

Tapped down TGHT to 445A/8.05V; temp maintained at 1550C.

 Monday, October 02, 2017, 17:55

Cooling TGHT from 445A/8.07V, 1500oC to room temperature at 1A/min

 Tuesday, October 03, 2017, 11:09

Target has been cooled for over 10 hours. 

Venting chamber

Wednesday, October 04, 2017, 16:37

3 samples of npSiC/PAN cast-pellets, see lab book p. 57 for details.

Desired temperature 1550C, expected TGHT ~450A.

Chamber pumped down.

TGHT ramping at 0.2A/min

 Friday, October 06, 2017, 10:45

TGHt at 450A/7.7A, temp at 1510C.  (p.s voltage is lower than before, elog 389).

Tapped up to 466A/8.08v, temp reached to 1550C.  A slight increase in pressure when tapping up TGHT. (see attached screen capture)

Will maintain heating temperature for several days before cooling down

 Tuesday, October 10, 2017, 10:50

Samples was heated for several days at 1550C. 

Cooling down initiated at 2A/min.

 Tuesday, October 10, 2017, 18:07

Chamber is vented.

Process done

Monday, November 06, 2017, 18:21

Samples of Horn and Probe - npSiC. see pg 74.

6 samples in total, to be heated to 1550C, about 450A.  Set ramping rate at 0.2A/min.  

Chamber pumping down

 Tuesday, November 07, 2017, 15:01

TGHT reached to 450A/8.2V, temperature measured at 1460C.  See attachment 1.

Increased ramping to 480A, targeting 1550C.

 Tuesday, November 07, 2017, 22:26

Samples have been heating at 1550C with TGHT at 480A/8.78V for about 8 hours.

Vacuum stabilizes at 8.4e-7 Torr.

Initial cooling at 2A/min.

 Wednesday, November 08, 2017, 10:36

Venting chamber.

Tuesday, May 01, 2018, 18:06

21 fibrous discs of nanoSiC are loaded into a tube container (coated/Sintered with TaC). 

Thermal treatment temperature at 1600C, TGHT is ~338A/5.5V, according to elog #407.

 Wednesday, May 02, 2018, 08:27

20 mins ago... initiate auto ramping at 0.2A to reach TGHT 250A.  Instead of ramping incrementally, TGHT jumped straight to 250A; vacuum shot up to milli torr.

Turn off TGHT immediately to let vacuum stable down to 10-6 Torr. 

System problem??  Archive striptool for more details. 

Re-activate auto-ramping - OK!

Once TGHT reached 250A (18 hours later from now), will continue ramping up to reach 1600C

 Friday, May 04, 2018, 01:09

TGHT just reach 250A, temp at about 1190C.  Pressure remained high at 4.2e-5 Torr. 

Continue autoramping to reach TGHT 300A.

 Friday, May 04, 2018, 11:07

TGHT at 300A for about 1.5 hr.  Temp at 1315C.  Pressure at 5.7e-6 Torr.

Autoramp to 320A.

 Friday, May 04, 2018, 14:39

Tapping up to 330A; temp at 1560C with slope changed to 1.05 (for carbide material). Will keep at this current/temp.

 Sunday, May 06, 2018, 13:25

TGHT at 330A/5.2V; holding temp at 1550C.  No coating on windows.  Pressure at 1.6e-7 Torr.

Cooling down at 2A/min. 

 Monday, May 07, 2018, 10:49

Evap cooled.  Venting chamber. 

Inspection of the discs next...

mass loss = 6.79 - 3.62 = 3.1 g (46%) [in agreement, good]