Monday, September 12, 2016, 17:30

A bunch of end caps (12?) and a long Ta-wire in spring sharp  were coated with TaC coating and wrapped in a small sheet of graphite foil. 

Container is then wrapped with a sheet of Ta heat shield.

These caps and wires will be sintered in Evap 1, so they may be prompted to contamination from the uranium processes. 

I have no choice but to use Evap1 to do this work since we are falling behind with the schedule.  

In the future, please have all the materials (targets, end caps, binder, etc) well prepared. 

I do not know what is the required current to sinter the caps since there is no temp measurement.  So, the best is to go with how the container was sintered, 580A. 

Monday, September 12, 2016, 17:36

Chamber has been pumped down to mid 10-6 Torr. 

Auto ramp to 580A at 2A/min.

Tuesday, August 23, 2016, 17:33

Target boat coated with TaC (sprayed) and wrapped with Ta-heat shield. 

chamber is currently being pumped down. Vac currently at 3.3e-5Torr. 

TGHT to be ramped up to 580A.

Initiate autoramping at 0.1A/min

 Wednesday, August 24, 2016, 10:34

TGHT at 111A/1.07V.  Vac at 7.5e-6 Torr and coming down.

Increase ramping rate to 2A/min.

 Thursday, August 25, 2016, 12:01

TGHT has been stabilized at 580A/6.89V for over 24 hours.  Vac at 7.5e-6 Torr.

Initiated cooling at 2A/min.

 Monday, September 12, 2016, 17:30

Container was properly sintered.

Monday, July 11, 2016, 15:54

Target container was previously coated with TaC spray and sintered.

Container is wrapped with 3 layers of Ta-heat shield, including the center block - new wrapping method-see elog112 evap2

The target consists of 216 discs of UCx with 7.6cm in length [4 packs of 5 + 196 single discs].

A regular TaC coated endcap is inserted left, wrt the ionizer tube pointing down.

The right side is open with a TaC coated spring to help hold materials in.

The chamber is currently pumping down.

TGHT will be ramped up to 410A at 0.1A/min [same current used to reach 1900C in evap2 when sintering TaC coating - elog308 evap2]

Parameter setup: 5.0e-5 good vac, 6.0e-5 bad vac.

 Tuesday, July 12, 2016, 08:50

IG1 = 5.3e-6 Torr

Tapped up manually to 35A

Vacuum stable.

IG1 = 5.25e-6 Torr.

Initiating auto-ramp.

 Friday, July 15, 2016, 16:59

With evap2 not working, water was turned off to check valves...this tripped off evap1 since this also turned off the water to evap1.

TGHT was ~115A when evap1 tripped off.

Vacuum stable = 2.9e-6 Torr.

Tapped back up manually to 115A, 1.08V

Vacuum stable = 2.8e-6 Torr.

Restarting auto ramp at 0.1A/min.

 Friday, July 22, 2016, 16:25

Target has remained at max setpoints for 4.5days.

TGHT = 410A, 3.99V

IG1 = 2.5e-6 Torr

Voltage has wavered a small amount, between 3,91V-4.02V; this can be seen in the photo attached of the screenshot of the striptool.

Conditioning process is now complete.

Initiating auto-cool at 1.0A/min

 Tuesday, July 26, 2016, 16:48

Vented in Ar and currently transfering into glove box

will update elog tomorrow...

 Wednesday, July 27, 2016, 14:56

had a few problems with the transfer chamber in the glove box, but managed to get the target into the glove box okay last night.

was exposed to oxygen for minimal amount of time - transfer chamber wasnt flushing properly/ leak in james bond box

 Wednesday, May 18, 2016, 15:05

Target container was previously coated with TaC spray and sintered.

Container is wrapped with 3 layers of Ta-heat shield, including the center block - new wrapping method-see elog112 evap2

The target consists of 200 discs of UCx with 7.4cm in length [4 packs of 5 + 180 single discs].

A regular TaC coated endcap is inserted left, wrt the ionizer tube pointing down.

The right side is open with a TaC coated spring to help hold materials in.

The chamber is currently pumping down.

TGHT will be ramped up to 460A at 0.1A/min [same current used to reach 1900C in evap2 when sintering TaC coating - elog291 evap2]

Parameter setup: 5.0e-5 good vac, 6.0e-5 bad vac.

 Thursday, May 19, 2016, 09:25

IG1 = 3.4e-6 Torr

Tapped up manually to 35A

Vacuum stable.

IG1 = 3.5e-6 Torr.

Initiating auto-ramp.

 Wednesday, May 25, 2016, 13:05

Target has been heated at 460A, 4.5V for 5 hrs.

Vacuum at 6.4e-6 Torr. 

Initiated cool down at 1A/min. 

 Friday, May 27, 2016, 11:14

UCx done.

Vented in Ar and put in glove box yesterday.

Looked inside before inserting 2nd endcap - clean view all the way through the materials to the endcap/ not much visible shifting.

Ta coated spring helped hold materials in place.

Slightly darker markings on legs of container on side that was open in evap1.

2nd endcap put in.

Ready for assembly.

 Monday, May 16, 2016, 15:51

full clean of inside evap1 this afternoon.

 Tuesday, April 19, 2016, 09:47

Temperature measurements have been taken in evap2 on target containers. 

Previously all UCx targets have been conditioned in evap1 at 520A. The respective target containers TaC coating was sintered in evap2 at a different current.

All future UCx targets will now be conditioned in evap1 at the same current required to reach 1900C in evap2 when sintering the TaC coating on the container to be used for the respective target.

ie. If a container is being sintered in evap2 at 450A [1900C], this same container is used for UCx - then that specific UCx target will be conditioned in evap1 at 450A.

Confirm full carbonization has been achieved by following with the vacuum on the strip tool and make sure the final vacuum comes down at the end of the whole process.

Tuesday, April 05, 2016, 10:58

UO2/C green was prepared March 31, 2016.

The cast peeled off the glass nicely April 1, 2016 and finished drying over the weekend. [see attached picture]

Some materials were stuck on the WC jar wall and balls, consistent with every time.

Initial UO2 powder used = 50.47g (Inventory R-00835A, UO2 + bottle = 168.33g before use)

Graphite powder used = 10.05g

Green cast dried UO2/C + organic mass = 59.50g 

The green was rolled up and wrapped in a piece of graphite sheet.

The Ta-target boat was wrapped with 3-layers of heat shield and installed in evap1 yesterday.

Chamber has been pumped down overnight, currently at IG1 = 3.7e-6 Torr.

Manually stepping up to 35A...

Target boat will be ramped up to 520A at the rate of 0.1A/min.

Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr.

Tuesday, April 05, 2016, 15:04

Waited ~4hrs, vacuum stable.

IG1 = 8.5e-6 Torr.

Initiating auto-ramp.

 Friday, April 15, 2016, 13:50

IG1 = 3.2e-6 Torr

TGHT = 520A, 5.15V

TGHT remained at max setpoints for ~10hrs

Carbonization process is complete.

Initiating auto-cool at 2.0A/min.

 Monday, April 18, 2016, 11:08

vented in argon and removed from evap1.

stored in glove box.

will measure flakes produced tomorrow...

 Tuesday, April 19, 2016, 15:32

UC2 flakes produced = 45.99g

 Tuesday, March 08, 2016, 10:01

UO2/C green was prepared March 2, 2016.

This was the first time using the new rack built for holding multiple casts [see photo attached]

The cast peeled off the glass nicely March 3, 2014 and finished drying over the weekend. [see attached picture]

Some materials were stuck on the WC jar wall and balls, consistent with every time.

Initial UO2 powder used = 50.03g (Inventory R-00835A, UO2 + bottle = 218.54g before use)

Graphite powder used = 10.14g

Green cast dried UO2/C + organic mass = 60.08g 

The green was rolled up and wrapped in a piece of graphite sheet.

The Ta-target boat is wrapped with 3-layers of heat shield and installed in Evap1.

Chamber has been pumped down overnight, currently at IG1 = 4.5e-6 Torr.

Manually stepping up to 35A...

Target boat will be ramped up to 520A at the rate of 0.1A/min.

Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr.

Tuesday, March 08, 2016, 16:01

Waited ~3hrs, vacuum stable.

IG1 = 1.4e-5 Torr.

Initiating auto-ramp.

 Monday, March 21, 2016, 08:33

IG1 = 1.9e-6 Torr

TGHT = 520A, 5.13V

TGHT remained at max setpoints for ~63.5hrs [over the weekend].

Carbonization process is complete.

Initiating auto-cool at 2.0A/min.

 Thursday, March 24, 2016, 10:19

vented in argon and removed from evap1.

stored in glove box.

total flakes produced: 46.26g

John Wong wrote:

Laura Lambert wrote:  Thursday, February 18, 2016, 15:34 Target container was previously coated with TaC spray and sintered. Container is wrapped with 3 layers of Ta-heat shield, including the center block - same method as for sintering TaC coating [new wrapping method-see elog112 eva2]. The target consists of 244 discs of UCx with 7.8cm in length. A regular TaC coated endcap is inserted left, wrt the ionizer tube pointing down, so the right is open The chamber is currently pumping down. TGHT will be ramped up to 520A at 0.1A/min Parameter setup: 5.0e-5 good vac, 6.0e-5 bad vac.  Friday, February 19, 2016, 08:28 IG1 = 4.7e-6 Torr Tapped up manually to 35A. Waited ~1hr, vacuum stable IG1 = 3.8e-6 Torr. Initiating auto-ramp.    Friday, February 26, 2016, 10:26 Target has been heated at 520A for 10 hrs. Vacuum at 5.3e-6 Torr.  Initiated cool down at 1A/min.  Remember to vent with Ar.

 Monday, February 29, 2016, 16:15

Vented in Ar.

Target removed from evap1 this morning.

Currently sitting in glovebox.

Weird red discharge on the end of the right side, inside the container [wrt ionizer tube into page] - same side with no endcap during carbonization.

Materials look good, both endcaps inserted.

Rh foil still needs to be implanted.

 Wednesday, March 02, 2016, 10:13

The discoloration appears to be a simple change in the morphology of the TaC coating, future tests would need to be done to confirm this estimation.

This should not effect the container/ target.

See photo attached.

Laura Lambert wrote:

Thursday, February 18, 2016, 15:34 Target container was previously coated with TaC spray and sintered. Container is wrapped with 3 layers of Ta-heat shield, including the center block - same method as for sintering TaC coating [new wrapping method-see elog112 eva2]. The target consists of 244 discs of UCx with 7.8cm in length. A regular TaC coated endcap is inserted left, wrt the ionizer tube pointing down, so the right is open The chamber is currently pumping down. TGHT will be ramped up to 520A at 0.1A/min Parameter setup: 5.0e-5 good vac, 6.0e-5 bad vac.  Friday, February 19, 2016, 08:28 IG1 = 4.7e-6 Torr Tapped up manually to 35A. Waited ~1hr, vacuum stable IG1 = 3.8e-6 Torr. Initiating auto-ramp.

 Friday, February 26, 2016, 10:26

Target has been heated at 520A for 10 hrs.

Vacuum at 5.3e-6 Torr. 

Initiated cool down at 1A/min. 

Remember to vent with Ar. 

 Thursday, February 18, 2016, 15:34

Target container was previously coated with TaC spray and sintered.

Container is wrapped with 3 layers of Ta-heat shield, including the center block - same method as for sintering TaC coating [new wrapping method-see elog112 eva2].

The target consists of 244 discs of UCx with 7.8cm in length.

A regular TaC coated endcap is inserted left, wrt the ionizer tube pointing down, so the right is open

The chamber is currently pumping down.

TGHT will be ramped up to 520A at 0.1A/min

Parameter setup: 5.0e-5 good vac, 6.0e-5 bad vac.

 Friday, February 19, 2016, 08:28

IG1 = 4.7e-6 Torr

Tapped up manually to 35A.

Waited ~1hr, vacuum stable

IG1 = 3.8e-6 Torr.

Initiating auto-ramp.

 Thursday, December 10, 2015, 08:54

Filled graphite tube with 34 UO2/C discs cast onto graphite.

34 discs = 4.10g

graphite tube = 4.64g

IG1 = 2.8e-6 Torr.

Stepped up manually to 35A.

Waited ~1hr15, vacuum stable.

IG1 = 5.8e-6 Torr.

Initiating auto-ramp.

Target boat will be ramped up to 520A at the rate of 0.1A/min.

Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr.

 Monday, December 14, 2015, 08:58

IG1 = 3.9e-6 Torr.

TGHT = 520A, 5.7

UO2/C reached 520A yesterday and has remained at max setpoint for ~12hrs.

Carbonization process is complete.

Initiating auto-cool at 2.0A/min.

 Friday, December 18, 2015, 15:37

Vented in argon and removed from evap1

Graphite tube appears golden in colour [ see photo attached]

Materials spilled out of graphite tube, could be partially due to movement of target boat between evaporator and glove box and removal of heat shields.

Black graphite tube in weigh boat behind target is the graphite tube from the first round in evap1, shows a comparison in colour difference between the two rounds.

The difference between round 1 and round2:

-round1 contained 5 single discs packed together and a single 1cm/2cm square on the other end

-round2 contained 34 discs packed together consuming the whole graphite tube

All other parameters ie. max setpoints, were the same.

 Wednesday, December 02, 2015, 14:08

UO2/C was cast onto a graphite sheet in the fume hood and let dry.

Initial UO2 powder used = 25.11g (Inventory R-00835A, UO2 + bottle = 243.44g before use)

Graphite powder used = 5.16g

A 13mm punch was used to punch out discs from an 11mm wide strip.

5 discs were packed into one end of the graphite tube and a single 1cmx2cm strip was placed in the other end.

graphite tube = 4.57g

5 x UO2/C discs = 0.62g

2cm x 1cm strip = 0.21g

the graphite tube is placed inside a target boat.

The Ta-target boat is wrapped with 3-layers of heat shield and installed in Evap1.

Pumping down overnight.

Thursday, December 03, 2015, 09:23 

IG1 = 5.7e-6 Torr.

Stepped up manually to 60A.

Waited ~1hr45, vacuum stable.

IG1 = 6.3e-6 Torr.

Initiating auto-ramp.

Target boat will be ramped up to 520A at the rate of 0.1A/min.

Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr.

 Monday, December 07, 2015, 10:45

UO2/C reached 520A yesterday and has remained at max setpoint for 15hrs.

IG1 = 5.2e-6 Torr.

TGHT = 520A, 5.35V

Carbonization process is complete.

Initiating auto-cool at 2.0A/min.

 Wednesday, December 09, 2015, 10:09

Vented in argon and took the materials out yesterday.

Currently sitting in glove box.

All five discs and strip had fallen out of graphite tube and were sitting directly on the target boat.

^not sure if due to removal of heat shields [moving target boat around shook materials out of tube] or if this happened during carbonization process.

materials stuck to graphite foil fairly well, able to handle foils with tweezers and inspect without materials flaking off.

lightly scraped top of discs with spatula - no materials flaked off.

minor cracks are visible on discs.

graphite tube shows no visible changes.

John Wong wrote:

Thursday, October 15, 2015, 15:52 Target container previously sintered with TaC in Evap#2 - Target current at 440A, temp measured at 1900C.  A few tests on the temp measured were done (see Evap#2 elog #251 & 252).  Note:  This is the new design container with a small back block. Container is loaded with 245 discs of UC2; measured disc length 7.5 cm A regular TaC coated endcap is inserted left, wrt the ionizer tube pointing down, so the right is open - discs are held on with Ta wire spring. 3 layers of Ta-heat shield is used.  Target heater will be ramped up to 440A (according to the achieved temperature from Evap#2).  Ramping rate at 0.1A/min. Monitor closely on the vacuum around 400A to see if the carbonization process is complete.  Chamber is currently being pumped down.   Friday, October 16, 2015, 10:33 Chamber has pumped down to 2e-6 Torr.  Stepping up TGHT to 70A/0.23V.   Friday, October 16, 2015, 14:55 TGHT stepped up to 70A, pressure went to max 5.7e-5 Torr and it's coming down. Initated autoramping.  (good vac at 5e-5 Torr, bad at 6.0e-5 Torr)  Thursday, October 22, 2015, 12:26 TGHT has reached 440A/4.403V and stablized for about 5 hours.  Pressure started coming down at around 370A which indicated the ending of the carbonization process.  Currently vacuum is at 5.6e-6 torr.  Initiated cooling down process at 2A/min.

 Monday, October 26, 2015, 16:18

Target vented in argon, taken out and currently in glove box.

Target looks good, last one of the year! 

Endcaps inserted and need to be expanded, Rh foil still needs to be added.

Thursday, October 15, 2015, 15:52

Target container previously sintered with TaC in Evap#2 - Target current at 440A, temp measured at 1900C.  A few tests on the temp measured were done (see Evap#2 elog #251 & 252). 
Note:  This is the new design container with a small back block.

Container is loaded with 245 discs of UC2; measured disc length 7.5 cm

A regular TaC coated endcap is inserted left, wrt the ionizer tube pointing down, so the right is open - discs are held on with Ta wire spring.

3 layers of Ta-heat shield is used. 

Target heater will be ramped up to 440A (according to the achieved temperature from Evap#2). 

Ramping rate at 0.1A/min.

Monitor closely on the vacuum around 400A to see if the carbonization process is complete. 

Chamber is currently being pumped down. 

 Friday, October 16, 2015, 10:33

Chamber has pumped down to 2e-6 Torr. 

Stepping up TGHT to 70A/0.23V. 

 Friday, October 16, 2015, 14:55

TGHT stepped up to 70A, pressure went to max 5.7e-5 Torr and it's coming down.

Initated autoramping.  (good vac at 5e-5 Torr, bad at 6.0e-5 Torr)

 Thursday, October 22, 2015, 12:26

TGHT has reached 440A/4.403V and stablized for about 5 hours. 

Pressure started coming down at around 370A which indicated the ending of the carbonization process. 

Currently vacuum is at 5.6e-6 torr. 

Initiated cooling down process at 2A/min.

 Monday, September 14, 2015, 15:28

Green cast dried UO2/C + organic mass = 61.31g

The green was rolled up and wrapped in a piece of graphite sheet.

The Ta-target boat is wrapped with 3-layers of heat shield and installed in Evap1.

 Wednesday, September 16, 2015, 17:55

The work in the B2 level is done; the nuclear ventilation for the evaporators is now operational. 

Tried to turn on the backing pump, but failed. 

Submitted an fault #8428 to vacuum group

 Thursday, September 17, 2015, 12:23

Vacuum group responded to the e-fault, and a new pump is installed.

Chamber is currently being pumped down.

 Friday, September 18, 2015, 14:12

Chamber pressure is at 3.0e-6 Torr.

TGHT stepped up to 30A.

Target boat will be ramped up to 520A at the rate of 0.1A/min

Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr.

 Friday, September 18, 2015, 16:05

Pressure stabilized at 3.6e-5 Torr. 

Initiate autoramping

 Monday, September 21, 2015, 11:38

TGHT was found tripped off at 50A on Saturday at about 6am; the backing pump gauge went up to 150mTorr at the same time (see attachment)

Note that a refurbished backing pump was installed before starting this process.  It could be a leak somewhere; will let vacuum group to inspect this. 

 Monday, September 21, 2015, 15:34

Vacuum group took a look at the pump.  It was the bleeding valve that was not properly close while the pump was installed.  So after some period of running, the valve got loosen from the pump's vibration and caused the leak. 

The pump is now back to operational. 

Chamber is being pumped again.  Once the vacuum is good, TGHT will be stepped up to 50A and autoramping will be initiated once it's ready.

 Monday, September 21, 2015, 17:51

TGHT at 50A, IG at 3.6e-6 Torr.

Initiated autoramping.

 Wednesday, September 30, 2015, 10:11

TGHT has reached to 520A/5.36V.  The carbonization process is complete, vacuum at 3.29e-6 Torr, BP at 12mTorr. (see attachment#2)

Initiated auto-cooling at 2A/min.

Saturday, August 29, 2015, 16:10: Roughing

Saturday, August 29, 2015, 16:10: Starting turbo

Saturday, August 29, 2015, 16:12: Turbo running. IG1 at 2.4E-4 T

 Wednesday, August 19, 2015, 11:02

UO2/C green was prepared Aug 11, 2015. The slurry was cast on a piece of glass coated with WD40 on Aug 12, 2015.

The cast peeled off the glass nicely Aug 14, 2014 and finished drying over the weekend. [see attached picture]

Some materials were stuck on the WC jar wall and balls, consistent with every time.

Initial UO2 powder used = 50.34g (Inventory R-00835A, UO2 + bottle = 343.60g before use)

Graphite powder used = 10.14g

Green cast dried UO2/C + organic mass = 61.42g

The green was rolled up and wrapped in a piece of graphite sheet.

The Ta-target boat is wrapped with 3-layers of heat shield and installed in Evap1.

Chamber has been pumped down overnight, currently at IG1 = 2.5e-6 Torr.

Manually stepping up to 35A.

Target boat will be ramped up to 520A at the rate of 0.1A/min.

Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr.

 Wednesday, August 19, 2015, 14:05

Waited ~2.5hrs, vacuum stable.

IG1 = 1.2e-5 Torr.

Initiating auto-ramp.

 Monday, August 31, 2015, 09:38

EVAP 1 tripped off saturday 29th, due to a power outage with TGHT = ~450A at time of trip-off.

EVAP1 lost vacuum for ~4.5hrs [see archived photo]

Visual check performed of EVAP1 - OK.

IGP1 = 6.4e-7 Torr.

Re-initiating carbonization process.

 Monday, August 31, 2015, 10:05

Tapped up manually to 30A.

Vacuum stable.

Initiating auto-ramp at 2.0A/min to a final setpoint of 200A.

 Monday, August 31, 2015, 11:33

Increased max setpoint to 250A at 2.0A/min.

According to the archive, step 1 of the carbonization process was complete and vacuum dropped at ~TGHT = 250A

Vacuum still stable IGP1 = 2.7e-6 Torr.

Once 250A achieved, changed auto ramp to 0.2A/min with a final setpoint of 300A over lunch.

Will tap up manually after lunch.

 Monday, August 31, 2015, 13:07

IGP1 = 1.66e-6 Torr.

TGHT = 262A, 2.3V

Turning off auto-ramp, taking over manually...

 Monday, August 31, 2015, 16:15

Tapped up manually to TGHT = 355A, 3.5V

IGP1 = 5.8e-6 Torr.

Re-initiating auto-ramp at 0.1A/min with a final setpoint of 520A

 Wednesday, September 02, 2015, 09:04

IG1 = 7.5e-6 Torr

TGHT = 520A, 5.53V

TGHT remained at max setpoints ~12.5hours.

Carbonization process is complete.

Initiating auto-cool at 2.0A/min.

 Thursday, September 03, 2015, 11:55

UCx vented in Ar, removed from evap1 and currently in glove box this morning.

Will measure quantity obtained this afternoon.

 Thursday, September 03, 2015, 13:27

Attached are a few notable striptool screenshots from the entire carbonization process.

UCxflk_08 = 46.926g

John Wong wrote:

Thursday, July 30, 2015, 17:10 The mixture of UO2/C was prepared on July 13, 2015.  See screen shot for more info.  The material is loaded into a target boat and wrapped with 3 layers of Ta-heat shield.   Chamber is currently being pumped down Target boat will be ramped up to 520A at the rate of 0.1A/min Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr.  Friday, July 31, 2015, 14:33 Chamber has been pumped down overnight, currently at 3.3e-6 Torr. Manually stepping up to 35A. Set auto ramping TGHT to 200A at 0.1A/min for over the long weekend.  This current should be safe to just burn off the organic binder but not to start the carbonization process.  Wednesday, August 05, 2015, 11:05    TGHT reached 200A about 5 hours ago.  Organic burn out is complete.   Begin carbonization:  Increase TGHT to 520A at 0.1A/min rate.

 Tuesday, August 11, 2015, 08:38

IGP1 = 6.8e-6 Torr

TGHT = 520A, 5.5V

TGHT sat at max setpoint for ~15hours

Initiating auto-cool at 2.0A/min.

 Wednesday, August 12, 2015, 16:02

Vented in Argon and opened up this afternoon.

Transferred into glove box.

 Thursday, July 30, 2015, 17:10

The mixture of UO2/C was prepared on July 13, 2015.  See screen shot for more info. 

The material is loaded into a target boat and wrapped with 3 layers of Ta-heat shield. 

 Chamber is currently being pumped down

Target boat will be ramped up to 520A at the rate of 0.1A/min

Vacuum limit stop at 5.0e-5 Torr, backing off at 6.0e-5 Torr.

 Friday, July 31, 2015, 14:33

Chamber has been pumped down overnight, currently at 3.3e-6 Torr.

Manually stepping up to 35A.

Set auto ramping TGHT to 200A at 0.1A/min for over the long weekend.  This current should be safe to just burn off the organic binder but not to start the carbonization process.