Tuesday, November 22, 2016, 15:53

Target boat has a layer of niobium foil on the bottom of the boat.

A niobium foil has been made with slots to hold samples [similar to when sintering endcaps] *See attached photos

Niobium samples are placed in slots, holding in place, to avoid warping.

Smaller samples closest to MIKRON IR reading [left side]

Boat is wrapped with 1 large layer of Ta foil, wrapped around the boat 3x, careful to avoid touching samples.

Loaded into evap2 today.

Pumping down now...

 Wednesday, November 23, 2016, 11:45

HS water valves opened, no leaks detected.

Tapped up manually to 35A.

IGP1 = 6.4e-7 Torr

Setting auto-ramp rate at 0.2A/min to max setpoint of 250A.

Will tap up manually to final desired temperature of 1400C.

 Wednesday, November 23, 2016, 13:17

IGP1 = 5.9e-7

TGHT = 66A, 0.51V

Vacuum stable.

Increasing ramping rate to 1.0A/min

 Thursday, November 24, 2016, 08:46

IGP1 = 3.9e-7 Torr

TGHT = 250A, 3.41V      *NOTE: the current set reads 243.8A but the readout is 250A

OMEGA = 1013C

MIKRON has no reading yet

Tapping up manually to 1400C

 Thursday, November 24, 2016, 15:42

Samples have remained at ~1400C for 5hrs.

IGP1 = 5.8e-7 Torr

TGHT = 420A, 6.5V

OMEGA = 1410C

MIKRON = 1420C

Initiating auto-cool at 2.0A/min

 Friday, November 25, 2016, 11:39

Vented in air and opened up this morning.

Samples look good!

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...

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

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.

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.

Aurelia Laxdal wrote:

Aurelia Laxdal wrote: Laura Lambert wrote: Thursday, October 13, 2016, 18:04 Target loaded into evap2 No heat shields. Both endcaps inserted and expanded. Rh foil inserted [when inserting, the Ta rod used to expand the Rh foil inside the ionizer tube snapped off inside the container - this piece was able to be shaken out and is no longer inside] Chamber pumped down. HS water valves opened, no leaks detected   Tapped up manually to 35A   Vacuum stable, IGP1 = 5e-7 Torr   Initiating auto-ramp.   OMEGA slope = 0.98 TBHT will be ramped up to 230A at 1.0A/min. TGHT will be ramped up to 300A at 2.0A/min. Final desired temperature = 1900C Friday, October 14, 2016, 13:28 TGHT and TBHT had reached 300A/ 230A respectively. Power bump ~10min ago caused evap2 to trip off. Tapped back up manually to 35A. Re-initiating auto ramp now.   Friday October 14: the target was ramp up to 300A/230A after Laura started it. Then, I cooled down at 6pm before leaving TRIUMF. <br> Saturday October 15: restated the auto-ramp for Ta#50 in EVAP2. It's currently set to go to 300A/230A.  Sunday October 16: the target temperature measurements up to 620A/230A were performed today not on October 15 (yesterday, it was cooled down before reaching 300A/230A). Currently the target is cooling down, to be ready tomorrow morning for the Test Stand.

 Monday, October 17, 2016, 09:21

Vented in air and taken out this morning.

Target looks good!

Aurelia Laxdal wrote:

Laura Lambert wrote: Thursday, October 13, 2016, 18:04 Target loaded into evap2 No heat shields. Both endcaps inserted and expanded. Rh foil inserted [when inserting, the Ta rod used to expand the Rh foil inside the ionizer tube snapped off inside the container - this piece was able to be shaken out and is no longer inside] Chamber pumped down. HS water valves opened, no leaks detected   Tapped up manually to 35A   Vacuum stable, IGP1 = 5e-7 Torr   Initiating auto-ramp.   OMEGA slope = 0.98 TBHT will be ramped up to 230A at 1.0A/min. TGHT will be ramped up to 300A at 2.0A/min. Final desired temperature = 1900C Friday, October 14, 2016, 13:28 TGHT and TBHT had reached 300A/ 230A respectively. Power bump ~10min ago caused evap2 to trip off. Tapped back up manually to 35A. Re-initiating auto ramp now.   Friday October 14: the target was ramp up to 300A/230A after Laura started it. Then, I cooled down at 6pm before leaving TRIUMF. <br> Saturday October 15: restated the auto-ramp for Ta#50 in EVAP2. It's currently set to go to 300A/230A.

 Sunday October 16: the target temperature measurements up to 620A/230A were performed today not on October 15 (yesterday, it was cooled down before reaching 300A/230A). Currently the target is cooling down, to be ready tomorrow morning for the Test Stand. 

Laura Lambert wrote:

Thursday, October 13, 2016, 18:04 Target loaded into evap2 No heat shields. Both endcaps inserted and expanded. Rh foil inserted [when inserting, the Ta rod used to expand the Rh foil inside the ionizer tube snapped off inside the container - this piece was able to be shaken out and is no longer inside] Chamber pumped down. HS water valves opened, no leaks detected   Tapped up manually to 35A   Vacuum stable, IGP1 = 5e-7 Torr   Initiating auto-ramp.   OMEGA slope = 0.98 TBHT will be ramped up to 230A at 1.0A/min. TGHT will be ramped up to 300A at 2.0A/min. Final desired temperature = 1900C Friday, October 14, 2016, 13:28 TGHT and TBHT had reached 300A/ 230A respectively. Power bump ~10min ago caused evap2 to trip off. Tapped back up manually to 35A. Re-initiating auto ramp now.

Friday October 14: the target was ramp up to 300A/230A after Laura started it. Then, I cooled down at 6pm before leaving TRIUMF. <br>

Saturday October 15: restated the auto-ramp for Ta#50 in EVAP2. It's currently set to go to 300A/230A.

Thursday, October 13, 2016, 18:04

Target loaded into evap2

No heat shields.

Both endcaps inserted and expanded.

Rh foil inserted [when inserting, the Ta rod used to expand the Rh foil inside the ionizer tube snapped off inside the container - this piece was able to be shaken out and is no longer inside]

Chamber pumped down.

TBHT will be ramped up to 230A at 1.0A/min.

TGHT will be ramped up to 300A at 2.0A/min.

Final desired temperature = 1900C

Friday, October 14, 2016, 13:28

TGHT and TBHT had reached 300A/ 230A respectively.

Power bump ~10min ago caused evap2 to trip off.

Tapped back up manually to 35A.

Re-initiating auto ramp now.

John Wong wrote:

Laura Lambert wrote: Friday, October 07, 2016, 16:40 Target consists of 470 discs. Total packed length 3.4cm [exactly 7.8cm space on both sides] Total mass g [Incl foils + Ta wire on 6 packs] Note: Target consists of 350 single discs and 6x20 packs of Ta discs 3x Ta Heat shields. No endcaps inserted, no Rh foil inserted. Chamber currently pumping down. TBHT will be ramped up to 230A at 1.0A/min. TGHT will be ramped up to 300A at 2.0A/min. Final desired temperature = 1900C  Tuesday, October 11, 2016, 10:02   HS water valves opened, no leaks detected   Tapped up manually to 35A   Vacuum stable, IGP1 = 2e-7 Torr   Initiating auto-ramp.   OMEGA slope = 0.98  Wednesday, October 12, 2016, 16:15 Tapped up to 1900C? [see attached link for data concerning temperature readings] TGHT = 450A, 7.16V TBHT = 230A, 4.1V OMEGA = 1748C IGP1 = 6.1e-7 Torr    Wednesday, October 12, 2016, 21:14 Current status before cooling down: TGHT at 450A/7.32V; TBHT at 230A/4.10V; OMEGA at 1747C Vacuum at 4.05 e-7 Torr. Initiate auto-rampping at 2A/min for TGHT and 1A/min for TBHT

 Thursday, October 13, 2016, 17:32

vented in air and opened up this morning.

target looks good.

Laura Lambert wrote:

Friday, October 07, 2016, 16:40 Target consists of 470 discs. Total packed length 3.4cm [exactly 7.8cm space on both sides] Total mass g [Incl foils + Ta wire on 6 packs] Note: Target consists of 350 single discs and 6x20 packs of Ta discs 3x Ta Heat shields. No endcaps inserted, no Rh foil inserted. Chamber currently pumping down. TBHT will be ramped up to 230A at 1.0A/min. TGHT will be ramped up to 300A at 2.0A/min. Final desired temperature = 1900C  Tuesday, October 11, 2016, 10:02   HS water valves opened, no leaks detected   Tapped up manually to 35A   Vacuum stable, IGP1 = 2e-7 Torr   Initiating auto-ramp.   OMEGA slope = 0.98  Wednesday, October 12, 2016, 16:15 Tapped up to 1900C? [see attached link for data concerning temperature readings] TGHT = 450A, 7.16V TBHT = 230A, 4.1V OMEGA = 1748C IGP1 = 6.1e-7 Torr

 Wednesday, October 12, 2016, 21:14

Current status before cooling down:

TGHT at 450A/7.32V; TBHT at 230A/4.10V; OMEGA at 1747C

Vacuum at 4.05 e-7 Torr.

Initiate auto-rampping at 2A/min for TGHT and 1A/min for TBHT

Friday, October 07, 2016, 16:40

Target consists of 470 discs.

Total packed length 3.4cm [exactly 7.8cm space on both sides]

Total mass 47.6889g [Incl foils + Ta wire on 6 packs]

Note: Target consists of 350 single discs and 6x20 packs of Ta discs

3x Ta Heat shields.

No endcaps inserted, no Rh foil inserted.

Chamber currently pumping down.

TBHT will be ramped up to 230A at 1.0A/min.

TGHT will be ramped up to 300A at 2.0A/min.

Final desired temperature = 1900C

 Wednesday, October 12, 2016, 16:15

Tapped up to 1900C? [see attached link for data concerning temperature readings]

TGHT = 450A, 7.16V

TBHT = 230A, 4.1V

OMEGA = 1748C

IGP1 = 6.1e-7 Torr

 Wednesday, September 28, 2016, 17:08

Container coated with TaC using 'flushing technique' today, cleaned ionizer tube with acetone, no coating inside ionizer tube

Dried by blowing air into tube

Wrapped with 3 x Ta heat shields, incl center block - new method of each layer being one long single Ta foil covering entire container incl center block

Currently pumping down in evap2

 Thursday, September 29, 2016, 11:11

HS water valves opened

Tapped up to 35A

Waited ~45min, vacuum stable

IGP1 = 1.4e-6 Torr

Initiating auto ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively.

Max setpoints for TGHT = 350A and TBHT  = 230A

Once max setpoints achieved, will tap up manually to final desired temperature of 1900C

 Friday, September 30, 2016, 10:51

IGP1 = 7.8e-7 Torr

TGHT = 315A, 4.57V

TBHT = 174A, 2.8V

Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.

 Friday, September 30, 2016, 11:44

Changed OMEGA slope to 0.98

IGP1 = 1e-6 Torr

TGHT = 350A, 5.2V

TBHT = 201A, 3.4V

Increasing ramping rate of TBHT to 1.0A/min

OMEGA = 1625C / MIKRON = 1625C

 Friday, September 30, 2016, 15:45

IGP1 = 1.1e-6 Torr

TGHT = 430A, 6.79V

TBHT = 230A, 4.07V

OMEGA = 1903C

Will remain at max setpoints over weekend.

See attached link for raw data of manual tap up.

Also see attached photos of screenshots showing oval - not circular - tube of target container at two different temperatures...

 Monday, October 03, 2016, 13:28

IGP1 = 1.79e-7 Torr

TGHT = 430A, 6.87V

TBHT = 230A, 4.06V

OMEGA = 1892C

MIKRON = 1847C

Attached is a picture taken through the MIKRON, the slight oval shape appears to be a minor bend in the target container:

With the ionizer tube facing into the page, the bend appears to be in the center with both ends of the container bent slightly towards the page

This possible bend in the container gives the appearance of the oval shape through the camera while it is being heated, due to the angle of the camera

Remained at max setpoints over weekend.

Initiating auto-cool at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.

 Tuesday, October 04, 2016, 13:40

Vented in air and opened up this morning.

Container done, TaC coating looks good.

Waiting further inspection...

 Tuesday, October 04, 2016, 14:48

Container placed on jig and inspected.

Approved to go ahead for use online by Anders and Friedhelm.

John Wong wrote:

Laura Lambert wrote: John Wong wrote: Laura Lambert wrote:  Thursday, September 15, 2016, 16:23 Target container contains 487 discs of SiC  Target packed length = 16cm.  Mass of SiC(green)  = 58.8795g Container is wrapped with 1x heatshield around each side of cooling fins; no end caps are inserted yet - coated spring inserted both sides to hold discs in place. Sintering temp = 1800C Chamber is currently being pumped down.   Friday, September 16, 2016, 10:50 Tapped up manually to 50A Waited ~1hr , vacuum stable. IGP1 = 1.24e-5 Torr Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. TGHT max = 500A.  TBHT max at 230A.  Slope on OMEGA = 1.15  Monday, September 19, 2016, 10:53 OMEGA = 1230C TGHT = 360A, 4.75V TBHT = 204A, 2.68V IGP1 = 5.3e-6 Torr Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.  Monday, September 19, 2016, 11:57 OMEGA = ~1300C TBHT = 230A, 3.16V TGHT = 409A, 5.55V Lowering ramping rate to 0.2A/min while vaccum high IGP1 = 3.05e-5 Torr  Monday, September 19, 2016, 13:22 OMEGA = 1350C TGHT = 425A, 5.82V IGP1 = 1.97e-5 Torr Stepping ramping rate back up to 1.0A/min    Monday, September 19, 2016, 18:24 Measuring the temperature on the SiC is difficult due to the changing in emissivity as the temperature goes up.  So, I will use the MIKRON to measure the temperature on the Ta surface near the end of the tube and OMEGA for measuring the inside.   Using the analogue pyrometer, the temperature on the Ta surface at the end of the tube was measured at around ~1450C; this temperature match the temperature on the Mikron at slope 0.98 (as usual).  To match it with OMEGA, I changed the slope to 1.04 since this measurement is taking readings on the  inside of the tube and on the SiC material.    Note:  The measurements are NOT the absolute temperature.  These are relative temperature measurements  which give some guideline where the target current should be at for the sintering process.  Please plot the temp vs current as the TGHT is being ramped up.  At some point, the windows will get coated and the measurement is no longer reliable.   The plot will be used to give an estimation of the current for 1800C.        Tuesday, September 20, 2016, 15:18 there was a temperature fluctuation resulting in the MIKRON no longer matching the readout on the OMEGA this prompted another change in the slope on the OMEGA to 1.08 TGHT was then tapped up manually to 600A/ 1800C will remain at this max setpoint for a few days before ramping down see attachment for raw data  Wednesday, September 21, 2016, 11:34 temperatures dropped a small amount overnight. tapped up manually to 625A/ 1810C still no coating on window. see attachment for updated raw data    Thursday, September 22, 2016, 12:07 Temperature reader on OMEGA dropped slightly to 1785C overnight.  The temperature on the leg remained at 1800C (MIKRON).  No coating on windows.   Increased TGHT to 635A/10.12V (local 10.40V).  OMEGA reads 1800C, MIKRON ~1817C.   Continue to monitor… (see dropbox for captured photos)

 Monday, September 26, 2016, 13:24

Temperature decreased over weekend.

MIKRON dropped from ~1800C to ~1670C, OMEGA on right side remained ~1800C

Comparing screen shots of temperature readings and camera looking at target from left side, changes can be seen:

-darker area on top edge of target tube, above inside tube, grows larger when temperature drops - indicating 'cooler area' has grown

-initially darker area covers top above target materials on tube, when drops to ~1670C darker area extends down sides of target tube and reaches past target material area

See attached picture showing these details

Target has remained at this max setpoint for ~4-5 days

Windows remain un-coated.

Current and voltage readings remain un-changed.

Initiating auto-cool at 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.

 Wednesday, September 28, 2016, 17:05

Vented in air, target taken out today.

Target looks good!

A small amount of material was removed from the windows in evap2, very thin layer of coating.

Will update tomorrow with photos

Endcaps inserted.

Laura Lambert wrote:

John Wong wrote: Laura Lambert wrote:  Thursday, September 15, 2016, 16:23 Target container contains 487 discs of SiC  Target packed length = 16cm.  Mass of SiC(green)  = 58.8795g Container is wrapped with 1x heatshield around each side of cooling fins; no end caps are inserted yet - coated spring inserted both sides to hold discs in place. Sintering temp = 1800C Chamber is currently being pumped down.   Friday, September 16, 2016, 10:50 Tapped up manually to 50A Waited ~1hr , vacuum stable. IGP1 = 1.24e-5 Torr Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. TGHT max = 500A.  TBHT max at 230A.  Slope on OMEGA = 1.15  Monday, September 19, 2016, 10:53 OMEGA = 1230C TGHT = 360A, 4.75V TBHT = 204A, 2.68V IGP1 = 5.3e-6 Torr Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.  Monday, September 19, 2016, 11:57 OMEGA = ~1300C TBHT = 230A, 3.16V TGHT = 409A, 5.55V Lowering ramping rate to 0.2A/min while vaccum high IGP1 = 3.05e-5 Torr  Monday, September 19, 2016, 13:22 OMEGA = 1350C TGHT = 425A, 5.82V IGP1 = 1.97e-5 Torr Stepping ramping rate back up to 1.0A/min    Monday, September 19, 2016, 18:24 Measuring the temperature on the SiC is difficult due to the changing in emissivity as the temperature goes up.  So, I will use the MIKRON to measure the temperature on the Ta surface near the end of the tube and OMEGA for measuring the inside.   Using the analogue pyrometer, the temperature on the Ta surface at the end of the tube was measured at around ~1450C; this temperature match the temperature on the Mikron at slope 0.98 (as usual).  To match it with OMEGA, I changed the slope to 1.04 since this measurement is taking readings on the  inside of the tube and on the SiC material.    Note:  The measurements are NOT the absolute temperature.  These are relative temperature measurements  which give some guideline where the target current should be at for the sintering process.  Please plot the temp vs current as the TGHT is being ramped up.  At some point, the windows will get coated and the measurement is no longer reliable.   The plot will be used to give an estimation of the current for 1800C.        Tuesday, September 20, 2016, 15:18 there was a temperature fluctuation resulting in the MIKRON no longer matching the readout on the OMEGA this prompted another change in the slope on the OMEGA to 1.08 TGHT was then tapped up manually to 600A/ 1800C will remain at this max setpoint for a few days before ramping down see attachment for raw data  Wednesday, September 21, 2016, 11:34 temperatures dropped a small amount overnight. tapped up manually to 625A/ 1810C still no coating on window. see attachment for updated raw data

 Thursday, September 22, 2016, 12:07

Temperature reader on OMEGA dropped slightly to 1785C overnight.  The temperature on the leg remained at 1800C (MIKRON).  No coating on windows.  

Increased TGHT to 635A/10.12V (local 10.40V).  OMEGA reads 1800C, MIKRON ~1817C.  

Continue to monitor… (see dropbox for captured photos) 

John Wong wrote:

Laura Lambert wrote:  Thursday, September 15, 2016, 16:23 Target container contains 487 discs of SiC  Target packed length = 16cm.  Mass of SiC(green)  = 58.8795g Container is wrapped with 1x heatshield around each side of cooling fins; no end caps are inserted yet - coated spring inserted both sides to hold discs in place. Sintering temp = 1800C Chamber is currently being pumped down.   Friday, September 16, 2016, 10:50 Tapped up manually to 50A Waited ~1hr , vacuum stable. IGP1 = 1.24e-5 Torr Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. TGHT max = 500A.  TBHT max at 230A.  Slope on OMEGA = 1.15  Monday, September 19, 2016, 10:53 OMEGA = 1230C TGHT = 360A, 4.75V TBHT = 204A, 2.68V IGP1 = 5.3e-6 Torr Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.  Monday, September 19, 2016, 11:57 OMEGA = ~1300C TBHT = 230A, 3.16V TGHT = 409A, 5.55V Lowering ramping rate to 0.2A/min while vaccum high IGP1 = 3.05e-5 Torr  Monday, September 19, 2016, 13:22 OMEGA = 1350C TGHT = 425A, 5.82V IGP1 = 1.97e-5 Torr Stepping ramping rate back up to 1.0A/min    Monday, September 19, 2016, 18:24 Measuring the temperature on the SiC is difficult due to the changing in emissivity as the temperature goes up.  So, I will use the MIKRON to measure the temperature on the Ta surface near the end of the tube and OMEGA for measuring the inside.   Using the analogue pyrometer, the temperature on the Ta surface at the end of the tube was measured at around ~1450C; this temperature match the temperature on the Mikron at slope 0.98 (as usual).  To match it with OMEGA, I changed the slope to 1.04 since this measurement is taking readings on the  inside of the tube and on the SiC material.    Note:  The measurements are NOT the absolute temperature.  These are relative temperature measurements  which give some guideline where the target current should be at for the sintering process.  Please plot the temp vs current as the TGHT is being ramped up.  At some point, the windows will get coated and the measurement is no longer reliable.   The plot will be used to give an estimation of the current for 1800C.

 Tuesday, September 20, 2016, 15:18

there was a temperature fluctuation resulting in the MIKRON no longer matching the readout on the OMEGA

this prompted another change in the slope on the OMEGA to 1.08

TGHT was then tapped up manually to 600A/ 1800C

will remain at this max setpoint for a few days before ramping down

see attachment for raw data

 Wednesday, September 21, 2016, 11:34

temperatures dropped a small amount overnight.

tapped up manually to 625A/ 1810C

still no coating on window.

see attachment for updated raw data

Laura Lambert wrote:

Thursday, September 15, 2016, 16:23 Target container contains 487 discs of SiC  Target packed length = 16cm.  Mass of SiC(green)  = 58.8795g Container is wrapped with 1x heatshield around each side of cooling fins; no end caps are inserted yet - coated spring inserted both sides to hold discs in place. Sintering temp = 1800C Chamber is currently being pumped down.   Friday, September 16, 2016, 10:50 Tapped up manually to 50A Waited ~1hr , vacuum stable. IGP1 = 1.24e-5 Torr Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively. TGHT max = 500A.  TBHT max at 230A.  Slope on OMEGA = 1.15  Monday, September 19, 2016, 10:53 OMEGA = 1230C TGHT = 360A, 4.75V TBHT = 204A, 2.68V IGP1 = 5.3e-6 Torr Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.  Monday, September 19, 2016, 11:57 OMEGA = ~1300C TBHT = 230A, 3.16V TGHT = 409A, 5.55V Lowering ramping rate to 0.2A/min while vaccum high IGP1 = 3.05e-5 Torr  Monday, September 19, 2016, 13:22 OMEGA = 1350C TGHT = 425A, 5.82V IGP1 = 1.97e-5 Torr Stepping ramping rate back up to 1.0A/min

 Monday, September 19, 2016, 18:24

Measuring the temperature on the SiC is difficult due to the changing in emissivity as the temperature goes up.  So, I will use the MIKRON to measure the temperature on the Ta surface near the end of the tube and OMEGA for measuring the inside.  

Using the analogue pyrometer, the temperature on the Ta surface at the end of the tube was measured at around ~1450C; this temperature match the temperature on the Mikron at slope 0.98 (as usual).  To match it with OMEGA, I changed the slope to 1.04 since this measurement is taking readings on the  inside of the tube and on the SiC material.   

Note:  The measurements are NOT the absolute temperature.  These are relative temperature measurements  which give some guideline where the target current should be at for the sintering process.  Please plot the temp vs current as the TGHT is being ramped up.  At some point, the windows will get coated and the measurement is no longer reliable.   The plot will be used to give an estimation of the current for 1800C.  

 Thursday, September 15, 2016, 16:23

Target container contains 487 discs of SiC 

Target packed length = 16cm. 

Mass of SiC(green)  = 58.8795g

Container is wrapped with 1x heatshield around each side of cooling fins; no end caps are inserted yet - coated spring inserted both sides to hold discs in place.

Sintering temp = 1800C

Chamber is currently being pumped down. 

 Friday, September 16, 2016, 10:50

Tapped up manually to 50A

Waited ~1hr , vacuum stable.

IGP1 = 1.24e-5 Torr

Initiating auto-ramp at 0.2A/min and 0.1A/min for the TGHT and TBHT respectively.

TGHT max = 500A.  TBHT max at 230A. 

Slope on OMEGA = 1.15

 Monday, September 19, 2016, 10:53

OMEGA = 1230C

TGHT = 360A, 4.75V

TBHT = 204A, 2.68V

IGP1 = 5.3e-6 Torr

Increasing ramping rate to 1.0A/min and 0.5A/min for the TGHT and TBHT respectively.

 Monday, September 19, 2016, 11:57

OMEGA = ~1300C

TBHT = 230A, 3.16V

TGHT = 409A, 5.55V

Lowering ramping rate to 0.2A/min while vaccum high

IGP1 = 3.05e-5 Torr

 Monday, September 19, 2016, 13:22

OMEGA = 1350C

TGHT = 425A, 5.82V

IGP1 = 1.97e-5 Torr

Stepping ramping rate back up to 1.0A/min

John Wong wrote:

John Wong wrote:  Wednesday, September 07, 2016, 14:45 Container was previously coated with TaC solution and wrapped with 1-full length layer of Ta- heat shield around the fins.   Chamber is being pumped down.  Vac at 5.6e-7 Torr before HS water valves were open; no leaks were detected.  Sintering Temperature 1900C (Omega slope @ 0.98); expected TGHT ~765A/11.90V, TGHT max at 230A.  Thursday, September 08, 2016, 18:14 At about 1600C, it was observed that the coating inside the tube seems to chip off (see attachment 1). TGHT was ramped up to 745A/11.85V and TBHT to 230A/3.25V.  Temperature measured on OMEGA/Mikron = 1914C/1881C; both instruments slopes set at 0.98. Will remain at this TGHT current over night Vac at 3.0e-6 Torr and coming down. Friday, September 09, 2016, 11:01  Target has been heated at the stable temperature at 1914C (for OMEGA) and 1881C (for Mikron) with current at 745A/11.94V (see attachment 2) for almost 19 hours.  No fluctuation in p/s current or temperature was observed.  The ramping up process is captured and can be view from the link below: https://www.dropbox.com/sh/9lgtin54o17ds6j/AABn1-XjvK44mm74TjqTAmvta?dl=0 Pressure at 1.07e-6 Torr.  Cooling down TGHT at 2A/min and TBHT at 1A/min.  Continue to capture the cooling down process.   Friday, September 09, 2016, 15:17  While the target container was cooling down, the chip-like particle began obvious (see attachment 3).   Will inspect the container.. TGHT currently at 260A.    Monday, September 12, 2016, 16:54 The TaC coating chipped off from the surface and didn't get sintered with the container.  (See attachment1).  There are a few possible reasons why this happened: 1.  The coating was too think.  This may cause the TaC  layer to curl up while the heater was ramped up.  2.  The coated material got brittle.  The container was flushed with TaC (probably a few weeks ago?) before it went through the sintering process.  Prolong exposure to air/light usually degrade the polymers viscoelasticity. 3.  TaC solution has got bad.  The particles can agglomerate over time and this can cause uneven surface. 4.  Combination of all... ??? Anyway, the chipped off TaC layer was gently scraped off with a stainless steel rod.  Then using kimwipes, i was able to remove most of the chipped off coating; it was not easy - especially trying to remove it from the inner tube. Instead of "flushing" the tube with TaC, I decided to spray it with thin layer.  And using the air supply, I could quickly dry the coating and installed it back to the evaporator for 2nd Round sintering as we are approaching the deadline! .

 Monday, September 12, 2016, 17:24

Chamber was pumped down to low 10e-6 Torr before HS water valves were open - no leaks detected.

TGHT/TBHT auto ramped at 2A/min to 600A/230A.

Will continue to monitor..

 Wednesday, September 14, 2016, 17:04

TGHT was stepped up to 700A and temp 1851C (OMEGA), 1930C(Mikron).  (see attachment 1).  The container was heated over night before it was cool down at 2A/min. 

Target container seems to properly sintered with TaC (see attachment 2); it will be used for SiC#35. 

John Wong wrote:

Wednesday, September 07, 2016, 14:45 Container was previously coated with TaC solution and wrapped with 1-full length layer of Ta- heat shield around the fins.   Chamber is being pumped down.  Vac at 5.6e-7 Torr before HS water valves were open; no leaks were detected.  Sintering Temperature 1900C (Omega slope @ 0.98); expected TGHT ~765A/11.90V, TGHT max at 230A.  Thursday, September 08, 2016, 18:14 At about 1600C, it was observed that the coating inside the tube seems to chip off (see attachment 1). TGHT was ramped up to 745A/11.85V and TBHT to 230A/3.25V.  Temperature measured on OMEGA/Mikron = 1914C/1881C; both instruments slopes set at 0.98. Will remain at this TGHT current over night Vac at 3.0e-6 Torr and coming down. Friday, September 09, 2016, 11:01  Target has been heated at the stable temperature at 1914C (for OMEGA) and 1881C (for Mikron) with current at 745A/11.94V (see attachment 2) for almost 19 hours.  No fluctuation in p/s current or temperature was observed.  The ramping up process is captured and can be view from the link below: https://www.dropbox.com/sh/9lgtin54o17ds6j/AABn1-XjvK44mm74TjqTAmvta?dl=0 Pressure at 1.07e-6 Torr.  Cooling down TGHT at 2A/min and TBHT at 1A/min.  Continue to capture the cooling down process.   Friday, September 09, 2016, 15:17  While the target container was cooling down, the chip-like particle began obvious (see attachment 3).   Will inspect the container.. TGHT currently at 260A.

 Monday, September 12, 2016, 16:54

The TaC coating chipped off from the surface and didn't get sintered with the container.  (See attachment1). 

There are a few possible reasons why this happened:

1.  The coating was too think.  This may cause the TaC  layer to curl up while the heater was ramped up. 

2.  The coated material got brittle.  The container was flushed with TaC (probably a few weeks ago?) before it went through the sintering process.  Prolong exposure to air/light usually degrade the polymers viscoelasticity.

3.  TaC solution has got bad.  The particles can agglomerate over time and this can cause uneven surface.

4.  Combination of all... ???

Anyway, the chipped off TaC layer was gently scraped off with a stainless steel rod.  Then using kimwipes, i was able to remove most of the chipped off coating; it was not easy - especially trying to remove it from the inner tube.

Instead of "flushing" the tube with TaC, I decided to spray it with thin layer.  And using the air supply, I could quickly dry the coating and installed it back to the evaporator for 2nd Round sintering as we are approaching the deadline!

.