Tuesday, May 26, 2015, 13:06

Endcaps were sprayed with TaC coating and let dry.

Each endcap is wrapped separately with a sheet of graphite foil and stacked in the target boat [see image]

The target boat is wrapped with 3-layers of Ta-heat shield.

The boat is installed in EVAP2, chamber is currently being pumped down.

 Wednesday, May 27, 2015, 08:50

HS water valves opened, no leaks detected.

Stepped up manually to 35A.

Initiated auto-ramp at 0.2A/min yesterday afternoon.

TGHT = 254A, 3.56V.

IGP1 = 5.9e-7 Torr.

Increasing ramping rate to 1.0A/min with a max setpoint of 400A.

Laura Lambert wrote:

Tuesday, May 26, 2015, 13:06 Endcaps were sprayed with TaC coating and let dry. Each endcap is wrapped separately with a sheet of graphite foil and stacked in the target boat [see image] The target boat is wrapped with 3-layers of Ta-heat shield. The boat is installed in EVAP2, chamber is currently being pumped down.  Wednesday, May 27, 2015, 08:50 HS water valves opened, no leaks detected. Stepped up manually to 35A. Initiated auto-ramp at 0.2A/min yesterday afternoon. TGHT = 254A, 3.56V. IGP1 = 5.9e-7 Torr. Increasing ramping rate to 1.0A/min with a max setpoint of 400A.

 Wednesday, May 27, 2015, 17:51

TGHT has been at 400A for almost 6 hours.  Temp at 1500C.

Cooling down to 0A at 1A/min.

Chamber will be vented to inspect the caps. 

May have to remove the graphite foil wrapped on the caps and re-sintered the caps to 1800C.

John Wong wrote:

Laura Lambert wrote:  Tuesday, May 26, 2015, 13:06 Endcaps were sprayed with TaC coating and let dry. Each endcap is wrapped separately with a sheet of graphite foil and stacked in the target boat [see image] The target boat is wrapped with 3-layers of Ta-heat shield. The boat is installed in EVAP2, chamber is currently being pumped down.  Wednesday, May 27, 2015, 08:50 HS water valves opened, no leaks detected. Stepped up manually to 35A. Initiated auto-ramp at 0.2A/min yesterday afternoon. TGHT = 254A, 3.56V. IGP1 = 5.9e-7 Torr. Increasing ramping rate to 1.0A/min with a max setpoint of 400A.    Wednesday, May 27, 2015, 17:51 TGHT has been at 400A for almost 6 hours.  Temp at 1500C. Cooling down to 0A at 1A/min. Chamber will be vented to inspect the caps.  May have to remove the graphite foil wrapped on the caps and re-sintered the caps to 1800C.

 Thursday, May 28, 2015, 08:13

Vented in air and opened up this morning.

Not fully sintered [see pictures]

 Thursday, May 28, 2015, 11:34

Endcaps were sintered [see elog#199]

A Ta foil is placed in the target boat with separate slots for each endcap [see image]

The target boat is wrapped with 3-layers of Ta-heat shield.

The boat is installed in EVAP2, chamber is currently being pumped down.

 Thursday, May 28, 2015, 14:01

HS water valves opened, no leaks detected.

IGP1 = 1.4e-6 Torr.

Initiating manual tap up.

 Thursday, May 28, 2015, 15:10

Manually tapped up TGHT  to 108A, 1.1V

Initiating auto-ramp at 2.0A/min with a max setpoint of 300A

 Thursday, May 28, 2015, 15:22

Hoping to speed up the process...

IGP1 = 1.0e-6 Torr.

Increasing ramping rate to 4.0A/min with a max setpoint of 500A

Final desired temperature = 1800C

Laura Lambert wrote:

Thursday, May 28, 2015, 11:34 Endcaps were sintered [see elog#199] A Ta foil is placed in the target boat with separate slots for each endcap [see image] The target boat is wrapped with 3-layers of Ta-heat shield. The boat is installed in EVAP2, chamber is currently being pumped down.  Thursday, May 28, 2015, 14:01 HS water valves opened, no leaks detected. IGP1 = 1.4e-6 Torr. Initiating manual tap up.  Thursday, May 28, 2015, 15:10 Manually tapped up TGHT  to 108A, 1.1V Initiating auto-ramp at 2.0A/min with a max setpoint of 300A  Thursday, May 28, 2015, 15:22 Hoping to speed up the process... IGP1 = 1.0e-6 Torr. Increasing ramping rate to 4.0A/min with a max setpoint of 500A Final desired temperature = 1800C

 Thursday, May 28, 2015, 17:42

TGHT at 500A. Temp at 1780C.

Increased TGHT to 580A (online operating current),  Temp 1945C, vac 2.9e-6 torr and coming down.  Will remain at that current for the sintering process.

Cooling it down later this evening.

Thursday, May 28, 2015, 21:27  

Temp stabilized at 1960C with TGHT at 580A for almost 4 hours.  Vacuum at 1.8e-7 Torr.

Cooling down initiated at 2A/min.

John Wong wrote:

Laura Lambert wrote:  Thursday, May 28, 2015, 11:34 Endcaps were sintered [see elog#199] A Ta foil is placed in the target boat with separate slots for each endcap [see image] The target boat is wrapped with 3-layers of Ta-heat shield. The boat is installed in EVAP2, chamber is currently being pumped down.  Thursday, May 28, 2015, 14:01 HS water valves opened, no leaks detected. IGP1 = 1.4e-6 Torr. Initiating manual tap up.  Thursday, May 28, 2015, 15:10 Manually tapped up TGHT  to 108A, 1.1V Initiating auto-ramp at 2.0A/min with a max setpoint of 300A  Thursday, May 28, 2015, 15:22 Hoping to speed up the process... IGP1 = 1.0e-6 Torr. Increasing ramping rate to 4.0A/min with a max setpoint of 500A Final desired temperature = 1800C    Thursday, May 28, 2015, 17:42 TGHT at 500A. Temp at 1780C. Increased TGHT to 580A (online operating current),  Temp 1945C, vac 2.9e-6 torr and coming down.  Will remain at that current for the sintering process. Cooling it down later this evening. Thursday, May 28, 2015, 21:27   Temp stabilized at 1960C with TGHT at 580A for almost 4 hours.  Vacuum at 1.8e-7 Torr. Cooling down initiated at 2A/min.

 Friday, May 29, 2015, 11:16

Vented in air and opened up this morning.

Endcaps look great!  

Sintering was spot on [see pictures]

 Monday, July 13, 2015, 11:53

A Ta foil is placed in the target boat with separate slots for each endcap [same as elog 200]

The target boat is wrapped with 3-layers of Ta-heat shield.

The boat is installed in EVAP2, chamber is currently being pumped down.

 Monday, July 13, 2015, 15:00

Opened HS water valves, no leaks detected.

IGP1 = 2.7e-6 Torr.

Tapping up manually.

 Monday, July 13, 2015, 15:41

Tapped up manually to 30A

TGHT = 30A, 0.05V

IGP1 = 7e-6 Torr.

Initiating auto-ramp at 0.2A/min up to 480A with a final desired temperature of 1800C

 Tuesday, July 14, 2015, 09:12

IGP1 = 7.8e-7 Torr

TGHT = 241A, 3.3V

OMEGA = 1010C

Increasing auto-ramp to 2.0A/min

 Tuesday, July 14, 2015, 11:12

Reached final setpoint of TGHT = 480A, 8.43V

OMEGA = 1667C

IGP1 = 3.3e-6 Torr.

Tapping up manually to reach final desired temperature of 1800C.

 Tuesday, July 14, 2015, 11:33

Reached TGHT = 500A, 8.8V by tapping up manually.

OMEGA = 1714V

IGP1= 3.5e-6 Torr.

Re-initiating auto-ramp at 2.0A/min with a final setpoint of 580A.

New final desired temperature min of 1900C

 Tuesday, July 14, 2015, 13:16

TGHT = 577A, 10.74V

OMEGA = 1938C

IGP1 = 3.2e-6 Torr

Endcaps have been at this temperature for just over an hour.

Spikes in vacuum started ~430A - this is due to the green TaC coating reacting with the Ta foil, the carbide is reacting directly with the Ta foil [see picture]

Stopping sintering early before endcaps break -> initiating auto-cool at 2.0A/min.

 Wednesday, July 15, 2015, 11:33

Vented in air and took out this morning.

Endcaps sintered on top side but not fully sintered on inner edge.

Inner edge is peeling off and unsintered green TaC.

The coating peeling off did not shrink, as seen with previous tests done, one would expect a shrinkage in the coating when heated.

The peeling is most likely due to the way to endcaps were placed  in the slots of the Ta foil.

This may have cause the foil to be hotter than the inside of the endcaps and subsequently the Ta foil and TaC coating on the inside reacted - with the Ta foil extracting the carbide from the coating.

This would cause the outer edges of the inside of the endcap to peel/curl inwards as it was heated [like a cast, as the cast dries the outer edges curl inwards].

See photos attached for clarification.

Endcaps will be re-coated and sintered again via a different procedure.

 Friday, July 31, 2015, 15:39

A Ta tube was coated with TaC.  The inner of the tube was filled with TaC solution and the excess was drained out to give a homogenous coating.  The outer layer of the tube was brushed with TaC. 

The tube is installed in a target boat and wrapped with 3 layers of heat shields.  

Chamber is currently pumped down and the target heater will be ramped up after the long weekend (Tue)

A new window port is installed (see photo).  TGHT will need to be ramped up slowly to make sure the new window can sustain the heat shine from the target - local check on the Evap is required to make sure it's safe to keep ramping up the heater.     

John Wong wrote:

Friday, July 31, 2015, 15:39 A Ta tube was coated with TaC.  The inner of the tube was filled with TaC solution and the excess was drained out to give a homogenous coating.  The outer layer of the tube was brushed with TaC.  The tube is installed in a target boat and wrapped with 3 layers of heat shields.   Chamber is currently pumped down and the target heater will be ramped up after the long weekend (Tue) A new window port is installed (see photo).  TGHT will need to be ramped up slowly to make sure the new window can sustain the heat shine from the target - local check on the Evap is required to make sure it's safe to keep ramping up the heater.

Tuesday, August 04, 2015, 11:26

HS water valves opened, no leaks detected.

IGP1 = 2.2e-7 Torr.

Tapped up manually to 30A.

IGP1 = 2.7e-7 Torr.

Initiating auto-ramp at 0.2A/min with a final value of 350A.

 Tuesday, August 04, 2015, 15:30

IGP1 = 2.8e-6 Torr.

TGHT = 79A.

Increasing ramping rate to 0.5A/min

 Wednesday, August 05, 2015, 15:25

EVAP2 reached 350A this morning, OMEGA = 1414C

Temperature measurements were taken using the FLUKE IR camera of the new window port to be used for the second OMEGA camera.

Measurements were taken of both the Cu seal on the inside of the window and in the centre of the window [the hottest point].

TGHT was ramped up at 2.0A/min from 1414C --> 1800C with auto ramp paused at each measurement reading taken.

See attachment for raw data.

TGHT remained at 500A/1800C for 4hrs and will be cooled down at a rate of 2.0A/min.

 Thursday, August 06, 2015, 15:32

Vented and opened today.

New window port passed inspection, max temperature reached = 32.4C

Coating on tube looks good, partial sintering. Internal sintered better than outside of tube.

See attached photos.

 Thursday, August 06, 2015, 15:36

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]

There are two separate tubes in the target boat:

1) endcaps coated with TaC coating - never been sintered

2) previously sintered [but not fully] endcaps with a second coating done on the one side of each endcap

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

Chamber is currently being pumped down.

 Friday, August 07, 2015, 08:45

HS water valves opened, no leaks detected.

IGP1 = 3.6e-7 Torr.

Tapped up manually to 30A.

 Friday, August 07, 2015, 11:23

IGP1 = 2.2e-6 Torr.

Vacuum stable.

Initiating auto-ramp at 0.2A/min with a final setpoint of 480A.

Will ramp up over the weekend, confirm temperature readings on monday and tap up to final desired temperature of 1800C manually.

 Friday, August 07, 2015, 13:04

Vacuum climbed quite fast.

IGP1 = 6.3e-6 Torr.

Stopped auto-ramp to allow vacuum to settle.

Waited ~1hr.

IGP1 = 4.3e-6 Torr.

Re-initiating auto-ramp.

 Monday, August 10, 2015, 09:22

TGHT reached 480A, 8.2V on the weekend.

OMEGA = 1708C

IGP1 = 3.8e-7 Torr.

Tapped up manually to 1803C, 520A, 9.0V

IGP1 = 5.9e-7 Torr.

 Monday, August 10, 2015, 14:50

EVAP2 remained at 1800C for 4.5hours.

Internal temperature taken at new window port read 1800C using the mikron.

Initiating auto-cool at 2.0A/min.

 Tuesday, August 11, 2015, 09:23

Vented in air and opened up this morning.

The following observations were noted:

1) single round sintered endcaps:

-Batch of green endcaps, single round of sintering look good. fully sintered.

-however when applying a scratch test, excess TaC scrapes off.

[see single round sintering photos]

-A few endcaps almost heated too long and started to appear brittle/ further crystallization on inside of endcap - the side that did not have a second coating applied.

-Outside of endcap looks good/ fully sintered - the side that had a second round of TaC coating

-further tests confirm this batch should still be okay to use

[see round2 batch photos]

 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)

 Tuesday, February 16, 2016, 14:19

coated with TaC yesterday and let dry overnight.

wrapped with one long Ta heat shield - wrapped around tube 3x, with Ta wire to offset Ta foil away from container

loaded into evap2 and currently pumping down.

 Wednesday, February 17, 2016, 10:51

HS water valves opened, no leaks detected.

Tapped up manually to 35A.

Waited ~20min, vacuum stable.

IGP1 = 5.9e-7 Torr.

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

Final desired temperature = 1900C

 Thursday, February 18, 2016, 09:16

IGP1 = 6.6e-7 Torr.

TGHT = 303A, 4.3V

OMEGA = 1311C

Increasing ramping rate to 1.0A/min.

Laura Lambert wrote:

Tuesday, February 16, 2016, 14:19 coated with TaC yesterday and let dry overnight. wrapped with one long Ta heat shield - wrapped around tube 3x, with Ta wire to offset Ta foil away from container loaded into evap2 and currently pumping down.  Wednesday, February 17, 2016, 10:51 HS water valves opened, no leaks detected. Tapped up manually to 35A. Waited ~20min, vacuum stable. IGP1 = 5.9e-7 Torr. Initiating auto-ramp at 0.2A/min to a final setpoint of 400A. Final desired temperature = 1900C  Thursday, February 18, 2016, 09:16 IGP1 = 6.6e-7 Torr. TGHT = 303A, 4.3V OMEGA = 1311C Increasing ramping rate to 1.0A/min.

 Thursday, February 18, 2016, 13:10

TGHT reached to 450A, temp at 1800C.  Stepped up TGHT 490A, temp measured at ~1900C. 

John Wong wrote:

Laura Lambert wrote:  Tuesday, February 16, 2016, 14:19 coated with TaC yesterday and let dry overnight. wrapped with one long Ta heat shield - wrapped around tube 3x, with Ta wire to offset Ta foil away from container loaded into evap2 and currently pumping down.  Wednesday, February 17, 2016, 10:51 HS water valves opened, no leaks detected. Tapped up manually to 35A. Waited ~20min, vacuum stable. IGP1 = 5.9e-7 Torr. Initiating auto-ramp at 0.2A/min to a final setpoint of 400A. Final desired temperature = 1900C  Thursday, February 18, 2016, 09:16 IGP1 = 6.6e-7 Torr. TGHT = 303A, 4.3V OMEGA = 1311C Increasing ramping rate to 1.0A/min.    Thursday, February 18, 2016, 13:10 TGHT reached to 450A, temp at 1800C.  Stepped up TGHT 490A, temp measured at ~1900C.

Thursday, February 18, 2016, 17:21

TGHT remained at max setpoint for 4hrs.

IGP1 = 6.6e-7 Torr.

OMEGA = 1913C

Initiating auto-cool for TGHT at 2.0A/min.

 Friday, February 19, 2016, 14:17

evap2 vented and opened up this morning.

container looks good.

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.

Thursday, March 24, 2016, 11:37  

SiC powder (<1um) [10%] was mixed with PAN solution [10%].  Solution was sonicated before e-spinning.  

Fiber mat was binded to graphite foil and heat treated to 250C in air for 1 hour.  

Samples were cut in pieces and rolled up and inserted in Ta target container (TaC coated).  Heat shield was added.

Heat Treatment #1:  

Temperature:  1600C (~350A)

Ramping up TGHT to 300A at 1A/min.  

 Tuesday, March 29, 2016, 11:11

TGHT was maintained at 410A for 1600C for 2 days (see attachment 1).  However at around 22:30 on March 28, there was a sudden increase in voltage.

Temperature raised up to 1750C.  Not sure there was a fault with the control system and it was caused by the Ta-heat shield. (see attachment #2).

 Target was cooled down around 2am on March 29. 

Samples will be removed from the chamber.

Wednesday, March 30, 2016, 11:30

Polycarbosilane fibers were prepared by UBC MTRL. 

Two samples with different fiber sizes were loaded in target boat and wrapped with heat shields.

Samples will be heated up to 1600C.

Chamber is currently being pumped down

 Thursday, March 31, 2016, 16:49

Ramping up TGHT to 300A at 1A/min

 Tuesday, April 05, 2016, 13:02

Samples was heated at 1600C for about 3 hours.  

Then it was cooled down at 2A/min. 

The process is complete. 

Thursday, April 07, 2016, 15:18

E-spun SiC/PAN fiber mats were produced at UBC.

12%PAN solution; 50% SiC to weight of PAN.

Materials used:

1.2g PAN, 8.8g DMF, 0.6g SiC, SDS ~0.1% to SiC

Fiber mats were heat treated at 250C in air.  Then cut into 18" discs and loaded into Ta target boat with heatshield wrapped. 

3 temperature treatments will carry out: 1200C, 1400C and 1600C

Chamber is being pumped down

 Friday, April 08, 2016, 10:02

TGHT at 285A, Temp at ~1200C.  Will remain at this temp for a few hours before cooling down. 

Some samples will be taken out for analysis. 

Next week, temperature treatment will continue at 1400C

 Friday, April 08, 2016, 14:26

Samples have been heated at 1200C for just over 4 hours.

Initiated auto-cooling at 2A/min

 Tuesday, April 12, 2016, 17:51

Heat treatment #2 - 1400C. 

Initial mass after 1200C = 0.0312g

 Monday, April 18, 2016, 12:55

Samples was heated at 1400C (TGHT maintained at ~370A) for 4 days (see attachment 1).

Chamber is vented; samples will be inspected.

 Tuesday, April 19, 2016, 17:49

Results

Sample mass after 1200C = 0.0312g

Sample mass after 1400C = 0.0294g

~5.78% mass  loss. 

Tuesday, April 19, 2016, 17:57

Heat Treatment#3: 1600C

sample mass before heating = 0.0238g (this sample is taken from the batch after it was heated at 1400C)

Chamber is being pumped.

 Thursday, April 21, 2016, 11:07

TGHT stepped up to 330A, temp measured at 1422C.

 Thursday, April 21, 2016, 12:05

TGHT at 415A/7.16V; temp at 1610C

 Thursday, April 21, 2016, 17:49

Temp dropped to 1590.  Increased TGHT to 425A; temp reads 1602A.

 Friday, April 22, 2016, 10:57

Voltage increased to 7.33V, TGHT stepped down to 418A, temp maintained at 1610A.

 Monday, April 25, 2016, 12:08

Sample was heat treated for almost 4 days.  Temperature dropped to 1578C, TGHT at 418/7.26V.  (see attachment #2)

Ramping down TGHT 2A/min.

 Monday, April 25, 2016, 16:00

Result:

Mass after 1600C = 0.0104g, 5.63% mass loss. 

Will do XRD/EDX

 Wednesday, May 04, 2016, 13:28

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

Larger niobium samples are placed in the slots, holding in place, to avoid warping; smaller niobium sample sitting inside the boat by itself.

Smaller sample closest to OMEGA IR reading [right side]

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

Loaded into evap2 yesterday.

Vacuum pump bearings gone - pump replaced this morning by vacuum group.

Pumping down now...

 Friday, May 06, 2016, 13:36

HS water valves opened, no leaks detected.

Tapped up manually to 35A.

IGP1 = 2.4e-7 Torr

Setting auto-ramp rate at 0.2A/min to 250A over the weekend.

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

 Monday, May 09, 2016, 09:38

OMEGA = 1128C

IGP1 = 1.3e-7 Torr

TGHT = 250A, 3.7V

Tapping up manually to 1400C...

 Monday, May 09, 2016, 14:05

Evap2 has reached ~1405C

TGHT = 341A, 5.34V

IGP1 = 1.9e-7 Torr

Will remain at max setpoints for min 4hrs then initiate cool down.

Laura Lambert wrote:

Wednesday, May 04, 2016, 13:28 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 Larger niobium samples are placed in the slots, holding in place, to avoid warping; smaller niobium sample sitting inside the boat by itself. Smaller sample closest to OMEGA IR reading [right side] Boat is wrapped with 1 large layer of Ta foil, wrapped around the boat 3x, careful to avoid touching samples. Loaded into evap2 yesterday. Vacuum pump bearings gone - pump replaced this morning by vacuum group. Pumping down now...  Friday, May 06, 2016, 13:36 HS water valves opened, no leaks detected. Tapped up manually to 35A. IGP1 = 2.4e-7 Torr Setting auto-ramp rate at 0.2A/min to 250A over the weekend. Will tap up manually monday to final desired temperature of 1400C.  Monday, May 09, 2016, 09:38 OMEGA = 1128C IGP1 = 1.3e-7 Torr TGHT = 250A, 3.7V Tapping up manually to 1400C...  Monday, May 09, 2016, 14:05 Evap2 has reached ~1405C TGHT = 341A, 5.34V IGP1 = 1.9e-7 Torr Will remain at max setpoints for min 4hrs then initiate cool down.

 Monday, May 09, 2016, 18:18

TGHT at 341A/5.34V for over 4 hours.  Vac stables at 1.78e-7 Torr.

Cooling down at 2A/min