Laura Lambert wrote:

John Wong wrote: The purpose of this experiment is to determined the limiting operating temperature for Beta-SiC.  To do so, samples will be heated in sequence to observe any volatile Si coated on the window.  The coating is observed above 1400C for the conventional SiC (mixuture of alpha and beta) and this coating leads to HV shorting problem.  Thursday, May 19, 2016, 14:26 Beta-SiC (size ~1um) slurry was prepared and casted on a graphite foil.  Discs are cut into D-shape Average thickness (including graphite foil) = 0.349mm Graphite foil = 0.13mm Actual SiC thickness = 0.219mm (close to normal SiC thickness) Samples are loaded into a target boat. Total discs = 120 Total mass = 14.3507g Thursday, May 19, 2016, 14:32 Omega slope set to = 1.04 Heat-treatment #1: 1400C  Thursday, May 19, 2016, 17:04 TGHT ramping up to 250A at 0.5A/min    Friday, May 20, 2016, 08:53 IGP1 = 9.2e-6 Torr. Increasing ramping rate to 1.0A/min up to 250A  Friday, May 20, 2016, 09:17 IGP1 = 2.1e-5 Torr TGHT = 215A, 3.1V OMEGA = 1035C Stopping auto-ramp and tapping up manually...  Friday, May 20, 2016, 12:26 OMEGA slope changed to 1.04 OMEGA reached ~1430C and kept there for ~1hr. no change. no coating on window observed tapped up manually to OMEGA =1500C TGHT = 350A, 5.8V  Friday, May 20, 2016, 14:17 Not much change to window. Might be beginning of light dusting, hard to tell. Will be better observed after longer period of time at 1500C Will remain at 1500C over weekend.

 Tuesday, May 24, 2016, 11:15

Sample has been heated over the long weekend.  Temp dropped to 1400C.  TGHT at 350A/5.78V.  Vac at 1.5e-7 Torr.

It is hard to tell if there is any coating on the window.  Will increase temperature to 1800C

 Tuesday, May 24, 2016, 11:43

Temp at 1620C. TGHT at 440A/7.7V. 

At this temperature, the coating would have been seen for the conventional SiC target material.  But, no much of change on the window since the TGHT was tapped up from 1400C.

Continue to increase TGHT to reach 1800C

 Tuesday, May 24, 2016, 11:58

Temp at 1680C/TGHT 470A/8.4C - a very light film on the window was observed.  Not sure if this film was left from previous processes; it is just that the target container is getting very bright and hard to see.

 Tuesday, May 24, 2016, 12:15

TGHT at 510A/9.16V - Observed coating on window.  Omega got interfered, therefore temp is unknown.  But it was read at ~1720C before the window was getting coated and temp started to dropped.

Will leave at this stage for now...

 Tuesday, May 24, 2016, 16:57

Window is fully coated.  Based on the heating curve, at 500A, the temp should be at ~1900C (wrapped with a layer of heat shield).  Temperature reader dropped to1340C due to the coating interference. 

Cooling down TGHT at 2A/min. And will exam the materials tomorrow... 

Wednesday, August 03, 2016, 16:16

Tues July 26th had some problems with the transfer chamber

Transfer chamber was not going below -20in pressure, when usually it will drop all the way to -30in

To by pass and put the uranium target into the glove box, the transfer chamber was flushed 10x - when opened, no change in H2O and O2 in glove box; therefore, 'bypass' worked.

Pump removed and tested by vacuum group - showed no reading on gauge when being tested, how was it even pumping?

New pump installed July 27th.

New pump = bigger/ faster/ quieter 

 Dan made a set of new cooling lines for the Source Tray Heat Shield cooling yesterday. No joints on the lines. Use same VCR fitting 3/8 -> 1/4" as for the Heat Shield. The old lines had worn threads on the male VCR nut.

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...

Tuesday, December 20, 2016, 15:05

confirmed ~full tank of Ar for glove box --> ~1600psi 

 Friday, February 03, 2017, 14:17

The endcaps are stacked together with a punched out disc of graphite foil placed in between each endcap for separation so endcaps won't fuse together.

The end caps are further wrapped in a larger piece of graphite foil to hold together as a tube [same method used in elogID # 158 and 235]

There are also 4 coated springs, 2 on each side of the endcaps tube, with the endcaps tube residing in the middle of the boat.

The boat is wrapped with 3-layers of Ta heatshields.

Chamber is currently being pumped down.

Good vac at 3.0e-5, bad vac at 4.0e-5 Torr.

OMEGA slope = 0.98

 Monday, February 06, 2017, 09:29

Power outage this weekend and evap2 tripped off.

Re-pumping down now...

 Tuesday, February 07, 2017, 08:54

HS water valves opened, no leaks detected.

IGP1 = 1.9e-7 Torr

Tapped up manually to 35A

Vacuum stable.

IGP1 = 2.0e-7 Torr

Initiating auto-ramp at 0.2A/min with a final setpoint of 450A.

Final desired temperature = 1800C

 Wednesday, February 08, 2017, 09:52

IGP1 = 2.98e-7 Torr

TGHT = 325A, 3.5V

Vacuum stable.

Increasing ramping rate to 1.0A/min

 Wednesday, February 08, 2017, 11:46

IGP1 = 6.3e-7 Torr

TGHT = 433A, 4.89V

Increasing max setpoint to TGHT = 500A

OMEGA has still yet to show a temperature...should be reading points at this high in current

Will go down to the lab and follow up on OMEGA settings to confirm everything is set up ok before proceeding to a higher current...

 Wednesday, February 08, 2017, 16:03

IGP1 = 4e-7 Torr

TGHT = 500A, 5.75V

OMEGA still not reading

Initiating auto-cool at -2A/min

Will update elog with more details tomorrow

 Thursday, February 09, 2017, 10:52

Evap2 was cooled down and opened up this morning.

Turns out both legs on the target boat were touching the new heatshield and therefore had been loosing power.

Normally a boat at 500A would read ~1800C, in this scenario at 500A the boat read ~1000C.

A lot of power was being lost into the heatshield.

See photos attached of target boat sitting at 500A.

The heatshield is currently being ground down in those two spots to accommodate the target boat.

 Dave Morris did a remote restart of the IOC after the outage. Turbo pump started.

 Thursday, February 09, 2017, 11:47

A new heatshield with flexible water lines has been put into evap2 last Friday Feb3rd

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... 

Laura Lambert wrote:

Friday, February 03, 2017, 14:17 The endcaps are stacked together with a punched out disc of graphite foil placed in between each endcap for separation so endcaps won't fuse together. The end caps are further wrapped in a larger piece of graphite foil to hold together as a tube [same method used in elogID # 158 and 235] There are also 4 coated springs, 2 on each side of the endcaps tube, with the endcaps tube residing in the middle of the boat. The boat is wrapped with 3-layers of Ta heatshields. Chamber is currently being pumped down. Good vac at 3.0e-5, bad vac at 4.0e-5 Torr. OMEGA slope = 0.98  Monday, February 06, 2017, 09:29 Power outage this weekend and evap2 tripped off. Re-pumping down now...  Tuesday, February 07, 2017, 08:54 HS water valves opened, no leaks detected. IGP1 = 1.9e-7 Torr Tapped up manually to 35A Vacuum stable. IGP1 = 2.0e-7 Torr Initiating auto-ramp at 0.2A/min with a final setpoint of 450A. Final desired temperature = 1800C  Wednesday, February 08, 2017, 09:52 IGP1 = 2.98e-7 Torr TGHT = 325A, 3.5V Vacuum stable. Increasing ramping rate to 1.0A/min  Wednesday, February 08, 2017, 11:46 IGP1 = 6.3e-7 Torr TGHT = 433A, 4.89V Increasing max setpoint to TGHT = 500A OMEGA has still yet to show a temperature...should be reading points at this high in current Will go down to the lab and follow up on OMEGA settings to confirm everything is set up ok before proceeding to a higher current...  Wednesday, February 08, 2017, 16:03 IGP1 = 4e-7 Torr TGHT = 500A, 5.75V OMEGA still not reading Initiating auto-cool at -2A/min Will update elog with more details tomorrow  Thursday, February 09, 2017, 10:52 Evap2 was cooled down and opened up this morning. Turns out both legs on the target boat were touching the new heatshield and therefore had been loosing power. Normally a boat at 500A would read ~1800C, in this scenario at 500A the boat read ~1000C. A lot of power was being lost into the heatshield. See photos attached of target boat sitting at 500A. The heatshield is currently being ground down in those two spots to accommodate the target boat.

 Tuesday, February 14, 2017, 15:43

Heatshield was ground back and target boat now fits nicely into heatshield without contact.

Laura Lambert wrote:

Laura Lambert wrote:  Friday, February 03, 2017, 14:17 The endcaps are stacked together with a punched out disc of graphite foil placed in between each endcap for separation so endcaps won't fuse together. The end caps are further wrapped in a larger piece of graphite foil to hold together as a tube [same method used in elogID # 158 and 235] There are also 4 coated springs, 2 on each side of the endcaps tube, with the endcaps tube residing in the middle of the boat. The boat is wrapped with 3-layers of Ta heatshields. Chamber is currently being pumped down. Good vac at 3.0e-5, bad vac at 4.0e-5 Torr. OMEGA slope = 0.98  Monday, February 06, 2017, 09:29 Power outage this weekend and evap2 tripped off. Re-pumping down now...  Tuesday, February 07, 2017, 08:54 HS water valves opened, no leaks detected. IGP1 = 1.9e-7 Torr Tapped up manually to 35A Vacuum stable. IGP1 = 2.0e-7 Torr Initiating auto-ramp at 0.2A/min with a final setpoint of 450A. Final desired temperature = 1800C  Wednesday, February 08, 2017, 09:52 IGP1 = 2.98e-7 Torr TGHT = 325A, 3.5V Vacuum stable. Increasing ramping rate to 1.0A/min  Wednesday, February 08, 2017, 11:46 IGP1 = 6.3e-7 Torr TGHT = 433A, 4.89V Increasing max setpoint to TGHT = 500A OMEGA has still yet to show a temperature...should be reading points at this high in current Will go down to the lab and follow up on OMEGA settings to confirm everything is set up ok before proceeding to a higher current...  Wednesday, February 08, 2017, 16:03 IGP1 = 4e-7 Torr TGHT = 500A, 5.75V OMEGA still not reading Initiating auto-cool at -2A/min Will update elog with more details tomorrow  Thursday, February 09, 2017, 10:52 Evap2 was cooled down and opened up this morning. Turns out both legs on the target boat were touching the new heatshield and therefore had been loosing power. Normally a boat at 500A would read ~1800C, in this scenario at 500A the boat read ~1000C. A lot of power was being lost into the heatshield. See photos attached of target boat sitting at 500A. The heatshield is currently being ground down in those two spots to accommodate the target boat.    Tuesday, February 14, 2017, 15:43 Heatshield was ground back and target boat now fits nicely into heatshield without contact.

 Tuesday, February 14, 2017, 15:44

Boat with endcaps and springs reloaded today and pumped back down this afternoon.

HS water valves opened, no leaks detected.

Tapped up manually to 35A

Vacuum stable.

IGP1 = 3.5e-6 Torr

Initiating auto-ramp at 0.2A/min with a final setpoint of 400A.

Final desired temperature = 1800C

 Wednesday, February 15, 2017, 10:24

IGP1 = 7.2e-7 Torr

TGHT = 260A, 3.95V

OMEGA = 1158C

Vacuum stable.

Increasing ramping rate to 1.0A/min.

 Wednesday, February 15, 2017, 13:02

IGP1 = 2.0e-6 Torr

TGHT = 400A, 6.67V

OMEGA = 1530C

Increasing final setpoint to 450A

 Wednesday, February 15, 2017, 13:55

IGP1 = 2.5e-6 Torr

TGHT =450A, 7.7V

OMEGA = 1640C

Increasing final setpoint to 500A

 Wednesday, February 15, 2017, 15:13

IGP1 = 1.8e-6 Torr

TGHT = 500A, 8.59V

OMEGA = 1770C

MIKRON = 1740C

Tapping up manually to ~1800C...

 Thursday, February 16, 2017, 09:09

IGP1 = 5.28e-7 Torr

TGHT = 520A, 9.1V

OMEGA = 1821C

Target boat has remained at max setpoints for 17.5hrs.

Initiating auto-cool at 1A/min

 Thursday, February 16, 2017, 13:49

Increasing auto-cool to 2.0A/min

 Friday, February 17, 2017, 16:00

Vented in air and opened up today.

Endcaps looks good  see photos attached

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.

 Wednesday, April 05, 2017, 15:36

Coated container with TaC coating using spray technique this morning and let dry.

Wrapped with one long layer of Ta heat shield, wrapped around boat 3x

No ends to target boat

Installed in evap2 and pumping down now...

Laura Lambert wrote:

Wednesday, April 05, 2017, 15:36 Coated container with TaC coating using spray technique this morning and let dry. Wrapped with one long layer of Ta heat shield, wrapped around boat 3x No ends to target boat Installed in evap2 and pumping down now...

 Thursday, April 06, 2017, 08:56

Problems with IGP2

Won't turn on, has low voltage output.

See screenshot attached.

Laura Lambert wrote:

Laura Lambert wrote:  Wednesday, April 05, 2017, 15:36 Coated container with TaC coating using spray technique this morning and let dry. Wrapped with one long layer of Ta heat shield, wrapped around boat 3x No ends to target boat Installed in evap2 and pumping down now...    Thursday, April 06, 2017, 08:56 Problems with IGP2 Won't turn on, has low voltage output. See screenshot attached.

 Thursday, April 06, 2017, 11:12

Turns out it was just a bad connection.

See attached photos.

 Thursday, April 13, 2017, 12:01

Pellets made this morning and weighed.

Placed in a graphite boat which is placed inside a previously TaC coated boat.

Boat is wrapped with 3x Ta heat shields.

Loaded into evap2.

Chamber currently pumping down.

 Tuesday, April 18, 2017, 13:53

HS water valves were opened this morning, no leaks detected.

Tapped up manually to 100A, 1.28V

Vacuum stable.

IGP1 = 3.63e-6 Torr.

Initiating auto ramp at a rate of 1.0A/min to 150A

Final desired temperature of 1100C

 Tuesday, April 18, 2017, 14:57

TGHT = 150A, 2.08V

Still no temperature reading on OMEGA.

Vacuum stable, IGP1 = 1.16e-6 Torr.

Initiating auto ramp at the same rate of 1.0A/min up to 200A.

 Tuesday, April 18, 2017, 15:56

TGHT = 200A, 2.91V

OMEGA = 990C

IGP1 = 8.59e-7 Torr

Tapping up manually to 1100C...

 Wednesday, April 19, 2017, 08:34

TGHT = 235A, 3.47V

OMEGA = 1090C

IGP1 = 1.6e-7 Torr.

Has remained at ~1100C since 16:30 yesterday.

Intitiating auto-cool at 2.0A/min

 Thursday, April 20, 2017, 08:40

Vented in air and taken out yesterday.

Pellets look good.

No obvious colour change.