Nikita Bernier wrote:

Nikita Bernier wrote:  Monday, September 24, 2012, 15:01 The target boat with TaC coating is being used again. The inside of the boat is covered with a 0.002 inches thick Ta foil with TaC coating, wrapped with a 0.002 inches thick Ta foil. Chamber was pumped down to 6e-6 Torr before the Heat Shield cooling water valve was opened. A small vacuum bump was detected (See attachment #1). It is not clear if it was caused by a water leak or not. After consulting with Peter, I will wait for the vacuum to be below e-07 Torr before turning the target heater on.        Monday, September 24, 2012, 18:02 The vacuum was stable until 1e-06 Torr. The target heater was turned on and tapped up to 60 A (0.8 V).  Evaporator #2 is now auto-ramping overnight at 0.2 A/min, up to 800-850 A, with the maximum voltage limited at 14 V, between 2.00e-05 (Good vacuum) and 3.00e-05 Torr (Bad vacuum).     Tuesday, September 25, 2012, 15:11 Sintering process is going smoothly. See Attachment 1. The auto-ramping was increased to 1 A/min up to 800-850 A.     Tuesday, September 25, 2012, 16:11  And the voltage limit was increased to 18 V ! See Attachment 2.    Tuesday, September 25, 2012, 19:13 Around 806 A (readback), voltage increased more quickly than the current. It seems like resistance is building up. After reaching 836 A (readback), the current was tapped down to 800 A (readback)/ 816 A (setting) in an effort to save the Ta boat. See Attachment 3. The current will stay at 800 A for ~4 hours before ramping down.

 Wednesday, September 26, 2012, 14:31

The current was tapped down twice as resistance was building up. After 4 hours at ~800 A, the TGHT was ramped down at 2 A/min. See Attachment 1. The target boat was cooled down for 4 hours before the chiller was turned off.

Also I had trouble measuring the temperature. I was unable to get a clear picture with the pyrometer. Therefore the exact temperature remains unknown, but from previous experiments, 800 A was about 1400°C.

The TaC coated Ta foil is very brittle. There is a lot of crystallisation on the Ta boat. See attachment 2. It is unlikely that the boat would survive many more sintering. Therefore it will be used for BeO pellets tests. 

When John gets back, I suggest we use a new boat coated with TaC, without additional layers. (See message #15 when this target boat was sintered up to 900A (local 893A/16.88V), Measured temp @ 1500°C)

 Wednesday, September 26, 2012, 15:07

The samples were made of BeO powder with 30% PVB which was treated at 400 RPM for 26 minutes. A ratio of 10:1 of mineral oil was added before another high speed treatment for 10 minutes. The powder was then pressed into pellets.

Three pellets were loaded on the target boat coated with TaC, with an extra layer of TaC coated Ta foil. See Attachment 1. The target boat is wrapped with a Ta foil that is 0.002 inches thick.

Target chamber was pumped down. The cooling water was turned on and no leak were observed.

TGHT was stepped up to 55A before the auto ramping was initiated at 0.5 A/min.  The vacuum limit parameter was set for good vac at <3.0 e-5 Torr and bad vac at >4.0 e0-5 Torr.  

Nikita Bernier wrote:

Wednesday, September 26, 2012, 15:07   The samples were made of BeO powder with 30% PVB which was treated at 400 RPM for 26 minutes. A ratio of 10:1 of mineral oil was added before another high speed treatment for 10 minutes. The powder was then pressed into pellets. Three pellets were loaded on the target boat coated with TaC, with an extra layer of TaC coated Ta foil. See Attachment 1. The target boat is wrapped with a Ta foil that is 0.002 inches thick. Target chamber was pumped down. The cooling water was turned on and no leak were observed. TGHT was stepped up to 55A before the auto ramping was initiated at 0.5 A/min.  The vacuum limit parameter was set for good vac at <3.0 e-5 Torr and bad vac at >4.0 e0-5 Torr.

 Friday, September 28, 2012, 12:50

Sintering was coming up smoothly. As expected, resistance started building up quickly at higher temperatures (above 600°C). See Attachment 1. The target heater tripped off twice this morning. I was able to ramp up the current after the first trip until it tripped again. After the second time, the voltage went crazy and I had to ramp down the current. Attachment 2 shows the whole process.

Evap2 will be vented out shortly and the pellets will be examined.

Friday, September 28, 2012, 15:52  

 The boat comes in two parts. One pellet is missing. The two remaining pellets are black and grey. Also they shrank a lot. See Attachment 3.

So once again, a new batch of BeO pellets will have to be prepared and sintered in order to determine the dimensions of the final die. Therefore the best approach is still loading the pellets on a target boat coated/sintered with TaC and wrapped with a Ta foil.

 Tuesday, May 07, 2013, 16:48

5 BeO pellets were made.  Each weights about 1.3 g (including org mass). 

A piece of Re foil (0.002" thick) is used as the under layer to protect the reaction between Be(g) and the Ta-boat.  (see Pictures)

Another layer of Ta-foil is used as the heat-shield to wrap around the Ta-boat.

The chamber was pumped down. 

TGHT will be ramped up to 600 A (~1360°C) at 0.2 A/min. The vacuum limit parameter was set for good vacuum at < 3.0e-5 Torr and bad vacuum at > 4.0e0-5 Torr.

The pressure, voltage and current will be closely monitored. 

If the Ta-boat survives, the TGHT will continue to ramp up to max 800 A (~1580°C).

Nikita Bernier wrote:

Tuesday, May 07, 2013, 16:48   5 BeO pellets were made.  Each weights about 1.3 g (including org mass).  A piece of Re foil (0.002" thick) is used as the under layer to protect the reaction between Be(g) and the Ta-boat.  (see Attachments) Another layer of Ta-foil is used as the heat-shield to wrap around the Ta-boat. The chamber was pumped down.  TGHT will be ramped up to 600 A (~1360°C) at 0.2 A/min. The vacuum limit parameter was set for good vacuum at < 3.0e-5 Torr and bad vacuum at > 4.0e0-5 Torr. The pressure, voltage and current will be closely monitored.  If the Ta-boat survives, the TGHT will continue to ramp up to max 800 A (~1580°C).

 Monday, May 13, 2013, 12:48

TGHT has been at 600 A for about 13 hours with stable very low vacuum (10^-7). See Attachment #1.

Temperature measurement has been lost on Saturday. Last measurement was was above 1350°C, at around 480 A.

TGHT was ramped down at 1 A/min.

The chamber will be vented later today. The pellets and the thermocouples will be inspected.

Nikita Bernier wrote:

Nikita Bernier wrote:  Tuesday, May 07, 2013, 16:48   5 BeO pellets were made.  Each weights about 1.3 g (including org mass).  A piece of Re foil (0.002" thick) is used as the under layer to protect the reaction between Be(g) and the Ta-boat.  (see Attachments) Another layer of Ta-foil is used as the heat-shield to wrap around the Ta-boat. The chamber was pumped down.  TGHT will be ramped up to 600 A (~1360°C) at 0.2 A/min. The vacuum limit parameter was set for good vacuum at < 3.0e-5 Torr and bad vacuum at > 4.0e0-5 Torr. The pressure, voltage and current will be closely monitored.  If the Ta-boat survives, the TGHT will continue to ramp up to max 800 A (~1580°C).    Monday, May 13, 2013, 12:48   TGHT has been at 600 A for about 13 hours with stable very low vacuum (10^-7). See Attachment #1. Temperature measurement has been lost on Saturday. Last measurement was was above 1350°C, at around 480 A. TGHT was ramped down at 1 A/min. The chamber will be vented later today. The pellets and the thermocouples will be inspected.

 Monday, May 13, 2013, 17:21

The following table shows the characteristics of the pellets after sintering at 600 A for 13 hours.

Sample,   Mass (g),   Thickness (mm),   Density (g/cm3),    Diameter (mm)

1    0.8904 4.875 1.364 13.058

2    0.8991 4.744 1.396 13.148

3    0.8846 4.579 1.482 12.884

4    0.9142 4.981 1.254 13.650

5    0.9022 4.978 1.250 13.586

Avg 0.8981 4.831 1.345 13.265

Laura Lambert wrote:

Wednesday, June 14, 2017, 15:49 Pellets previously made by Marla and weighed. Pellets are placed inside a small graphite sample tube. Graphite sample tube loaded with pellets is loaded into a previously TaC coated boat. Boat is wrapped with 3x Ta heat shields. Loaded into evap2. Chamber currently pumping down.  Thursday, June 15, 2017, 11:24 HS water valves were opened this morning, no leaks detected. Tapped up manually to 50A, 0.44V Vacuum currently rising starting to settle. IGP1 = 1.51e-6 Torr. One vacuum stabilizes will initiate auto ramp at a rate of 1.0 A/min up to a final set point of 150 A. Final desired temperature of 1800C.

 Friday, June 16, 2017, 10:37

IGP1 = 7.91e-7 torr.

TGHT = 167 A, 2.3 V.

Tapped up manually to 350A yesterday, remained there overnight.

IGP1 = 4.55e-7 torr

TGHT=350 A, 5.6 V,

Changed slope to 0.98

Checked temperature readings with mikron to confirm slope

Mikron LS = 1260C, RS=1290C

OMEGA= 1295C

Initiating auto ramp at 1.0A/min to a final set point of 450A.

Final desired temperature of 1600C (no longer need to go to 1800C).

*note: graphite sample tube has graphite endcaps inserted

 Wednesday, July 19, 2017, 13:44

Discs previously casted by Marla and Pauline and weighed. 

Discs are placed inside a small graphite container.

Graphite container with discs loaded with 30 discs was loaded into Ta-boat previously coated with TaC.

Ta-boat is wrapped with 3 Ta heat shields.

Loaded in evaporator 2.

Chamber currently pumping down.

Thursday, July 20, 2017, 16:07

 HS water valves were opened in the morning, no leaks were detected.

Perform water test to confirm paddle wheels are working well.

Current was tapped manually to 40 A.

Read out on meter confirmed paddle wheels are registering 

Tap back down to 20 A, tripped off system on purpose by closing HS water valves.

TGHT tripped off as expected.

Water flow test was good, initiating ramp up of samples.

Taped manually to 40 A.

After the stabilization of the vacuum auto ramping was set up to 0.2 A/min.

Up to a final set up point of 250 A.

Final desired temperature ~1800 C.

 Friday, July 21, 2017, 10:20

Final set up from July 20 was reached.

Current reading: 244.6 A.

Voltage reading: 3.82 V.

Temperature reached: 1105 C.

Final set up was change to 1500 A.

The temperature reached at 6 pm was 1936 C so the current  was decreased  to 488 A.

The final temperature after 30 min was 1800 C.

The set up stayed the same for the weekend.

 Monday, July 24, 2017, 13:06

Temperature reading in the morning was 1856 C.

TGHT: 487.87 A, 9.07 V

TGHT power supply: 

IGP1: 3.75e-7 Torr

IGP2: 3.51e-7 Torr

Started to ramp down at 1 A/min rate.

Initiating auto cooling at 1.0A/min for TGHT.

 Tuesday, July 25, 2017, 09:27

LaC2/C discs were taken off of evap2.

LaC2/C discs were brought in to glove box.

 Monday, July 31, 2017,  

Pellets previously pressed by Marla and Pauline. 

Pellets are placed inside a small graphite container.

Graphite container loaded with 5 pellets was loaded into Ta-boat previously coated with TaC.

Ta-boat is wrapped with 3 Ta heat shields.

Loaded in evaporator 2.

 Tuesday, August 01, 2017,

Chamber pumping down.

 Wednesday, August 02, 2017, 16:03

HS water valves were opened, no leaks were detected.

Current was tapped manually to 40 A.

After the stabilization of the vacuum auto ramping was set up to 0.5 A/min.

Up to a final set up point of 300 A.

Final desired temperature ~1700 C.

 Friday, March 09, 2018, 11:03

LP-FEBIAD loaded into evap2 and pumped down.

Temperature measurements of the ionizer will be done by Fernando for ARIEL development.

Ta foil covering side holes on heat shield so no temp measurements can be done using OMEGA on side ports of evaporator as per request of Fernando

No Ta heat shields on container.

HS water valves opened, no leaks detected.

Tapped up to TGHT = 50 A, 0.54 V; TBHT = 50 A, 0.45 V

IGP1 = 1.8e-6 Torr

IGP2 = 1.4e-6 Torr

Initiating auto ramp for TGHT at 2.0A/min up to 310A and TBHT at 1.0A/min up to 210A

Monday, March 12, 2018, 10:16 

IGP1 = 8.8e-8 Torr

IGP2 = 6.6e-8 Torr

TGHT = 310A, 5.06V

TBHT = 210A, 2.98 V

TGHT and TBHT will be adjusted accordingly for temperature measurements

Tuesday, March 13, 2018, 16:00 

Temperature measurements done.

Initiated auto-cool.

TGHT cooling at 2.0A/min and TBHT at 1.0A/min.

Wednesday, March 14, 2018, 16:03

Removed from evap2.

 Monday, September 10, 2018, 15:09

Container is coated with TaC and wrapped with Ta heat-shield ( 3 layers)

Desired temp = 1900 C (expected TGHT ~445A/7.5V), TBHT will be set fixed at 230A (max).

Good vac at 3.00-5 Torr

Bad vac at 5.0e-5 Torr.

Chamber is currently being pumped down

 Tuesday, September 11, 2018, 09:27

Pressure at IGP1 8.61e-7 Torr. 

Auto ramping TGHT at 1A/min to reach 400A, and TBHT at 1A/min to reach 230A.

 Tuesday, September 11, 2018, 12:05

Pressure increased to 6.9e-e5 Torr and auto-ramp reduced the current:

TGHT from 94.6 A to 84.86 A

TBHT from 87.8 A to 78.87 A

(see figure EVAP2-_01)

EPICS automatically started ramping up TBHT and TGHT current when the pressure was between the good limit.

 Tuesday, September 11, 2018, 14:29

TBHT current reached ~230 A and EPICS stopped inputting current automatically. 

TBHT current reading on:

EPICS 232.8 A

Power supply: 235 A

 Tuesday, September 11, 2018, 16:53

TGHT reached 400 A, EPICS stopped auto-ramping automatically. (Fig. Heater-ramp and Plot_400A-230A)

Temperature read by OMEGA 1837 C (Fig. Tempeature-at-400A)

 Tuesday, September 11, 2018, 17:40

TGHT current was increased manually to 419 A (power supply current 422 A, EPICS plot 421.6 A) in steps of ~5A/2min

The temperature after ~30 min of being at 419 A is 1898 C.

The container will stay 5 hours at 1898 C 

Wednesday, September 12, 2018, 09:05 

EVAP2 remained at max setpoints for 5hrs

Auto-cool was set to 2.0A/min and 1.0A/min for the TGHT and TBHT respectively.

The automatic ramp decreased the TBHT current to 0A, but not so for TGHT, 

TGHT only reduced to 22 A, the TGHT was manually tapped to 0A

 Wednesday, September 12, 2018, 18:30

Process completed (fig. TaC-coating). 

Chamber was vented.

 Thursday, October 25, 2018, 10:36

Container is coated with TaC and wrapped with Ta heat-shield (3 layers)

Desired temp = 1900 C (expected TGHT ~445A/7.5V), TBHT will be set fixed at 230A (max).

Chamber is currently being pumped down

 Friday, October 26, 2018, 08:40

Pressure at IGP1 1.06e-6 Torr. 

Tapped up TGHT and TBHT manually to 40 A

Waited 1 hr for vacuum to stabilize.

IGP1 = 8.9e-6 Torr

Good vac at 3.00-5 Torr

Bad vac at 5.0e-5 Torr.

Initiating auto ramp for TGHT @ 1 A/min to a max setpoint of 350 A

Initiating auto ramp for TBHT @ 0.5 A/min to a max setpoint of 230 A

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

 Friday, October 26, 2018, 10:46

At 62 A, the vacuum overpassed the "Bad vacuum " limit and the current reduced to 54 A.

when the pressure returned to the "Good vac" limit the ramping started automatically.

Friday, October 26, 2018, 16:59

TGHT= 450 A, Temperature = 1878 C

Ramping rate increased to 1A/min for the TBHT.

Tapped manually to 454 A, Temperature 1880 C.

Saturday, October 27 2018, 10:00 

Ramping down to 0 A @ 2 A/min.

Monday, October 29, 2018, 12:39

 Venting EVAP2, TaC coat sintering completed.

 Wednesday, October 31, 2018, 19:35

Container is coated with TaC and wrapped with Ta heat-shield (3 layers)

Desired temp = 1900 C (expected TGHT ~445A/7.5V), TBHT will be set fixed at 230A (max).

Chamber is currently being pumped down

 Thursday, November 01, 2018, 10:31

Pressure at IGP1 9.44e-7 Torr. 

Tapped up TGHT and TBHT manually to 40 A

Thursday, November 01, 2018, 12:32

Waited ~1 hr for vacuum to stabilize.

IGP1 = 1.42e-6 Torr

Good vac at 3.00-5 Torr

Bad vac at 5.0e-5 Torr.

Initiating auto ramp for TGHT @ 1 A/min to a max setpoint of 350 A

Initiating auto ramp for TBHT @ 0.5 A/min to a max setpoint of 230 A

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

 Tapped manually to 445 A, Temperature 1896 C.

Friday, November 02, 2018, 07:35

TGHT 7.86 V 445.6 A

TBHT 3.22 V 233.3 A

IGP1 1e-6 Torr

Ramping down TGHT and TBHT to 0 A @ 2 A/min.  

Friday, November 02, 2018, 17:28

Monday, October 29, 2018, 12:39

Venting EVAP2, TaC coat sintering completed. 

 Friday, November 02, 2018, 17:33

A new LP-FEBIAD was coated and syntered (e-log 421 Evaporator_2) 

The container was loaded with an empty graphite insert.

Graphite insert mass = 24.1724 g

A current of 440 A TGHT and 230 A TBHT will be inputed to the container

EVAP2 currently pumping down

 Saturday, November 03, 2018, 08:04

IGP1 = 5.66e-7 Torr

Tapping manually to 40 A on TGHT and TBHT

Then auto/ramp wiill be set to 2 A/min on TGHT and 1 A/min on TBHT

Maximum temperature achieve 1802 C

 Tuesday, November 06, 2018, 14:49

Container has reduced and increased its temperature from ~1760 to 1802 C.

IGP1  3.44e-7 Torr

TGHT 441.7 A and 7.7 V

TBHT 233.2 A and 3.2 V

 Wednesday, November 07, 2018, 08:32

Temperature 1785 C

IGP1  2.90e-7 Torr

TGHT 441.38 A and 7.7 V

TBHT 233.2 A and 3.2 V

 Friday, November 09, 2018, 17:26

Temperature 1787 C

IGP1  2.12 -7 Torr

TGHT 442.03 A and 7.7 V

TBHT 233.06 A and 3.19 V

Tuesday, November 13, 2018, 14:13: Turbos, power supplies off. Prepare for venting. 

 Monday, November 19, 2018, 08:57

Tantalum tube was coated with TaC and wrapped with Ta heat-shield (3 layers)

Desired temp = 1900 C (expected TGHT ~445A/7.5V), TBHT will be set fixed at 230A (max).

Pressure at IGP1 2.61-7 Torr. 

Tapped up TGHT and TBHT manually to 40 A

Waited ~1 hr for vacuum to stabilize.

IGP1 = 4.27e-7 Torr

Good vac at 3.00e-5 Torr

Bad vac at 5.00e-5 Torr.

Initiating auto ramp for TGHT @ 1 A/min to a max setpoint of 350 A

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

Monday, November 19, 2018, 18:14

Temperature was 1755 C at 350 A

IGP1 = 9.28e-7 Torr

Tapped manually to 393 A (6.83 V)

IGP1 = 1.4e-6 Torr

Temperature 1904 C

The tube will stay at max current point overnight.

Tuesday, November 20, 2018, 08:17

 IGP1 = 9.28e-7 Torr

TGHT = 395 A, 6.98 V

Temperature 1903 C

Auto-ramp set to TGHT 0 A @ -2 A/min. 

 Thursday, November 22, 2018, 10:12

A previously sintered tantalum tube with 3 layers of shielding was loaded with a graphite insert.

The tube was loaded in evaporator 2 on Wednesday 21/11/2018 and pumped down

The graphite insert will be heated to 2000 C

current pressure IGP1 =  4.2e-7 Torr

TGHT manually tapped to 40 A

Autoramp set to 2 A/min on TGHT to 400 A aiming for 1800 C

 Thursday, November 22, 2018, 17:13

TGHT 401.25 A, 6.79 V

Temperature 1780 C

IGP1 7.89e-7 Torr

Tapping manually to reach 1800 C, final current 407.2 A, 6.96 V

  Friday, November 23, 2018, 17:13

 Tuesday, December 04, 2018, 07:53

TGHT 469.1 A, 8.814 V

Temperature 1983 C

IGP1 1.52e-7 Torr

Wednesday, December 05, 2018, 21:30

 TGHT 469.1 A, 8.75 V

Temperature 1983 C

IGP1 1.22e-7 Torr

Thursday, December 06, 2018, 12:25

 TGHT 468.9 A, 8.66 V

Temperature 1977 C

IGP1 1.42e-7 Torr

Friday, December 07, 2018, 17:59

  TGHT 468.9 A, 8.80 V

Temperature 1977 C

IGP1 1.42e-7 Torr

Wednesday, December 12, 2018, 12:18 

TGHT 469.2 A, 8.7 V

Temperature 1945 C

IGP1 1.10e-7 Torr

Thursday, December 13, 2018, 10:42

TGHT 469 A, 8.7 V

Temperature 1939 C

IGP1 1.04e-7 Torr

Ramping temperature down at -2 A/min

 Friday, December 14, 2018, 10:42

TGHT 0.0 A, 0.051 V

IGP1 4.36e-8 Torr

Thursday, December 20, 2018, 10:24

A tantalum tube was loaded in evaporator 2 on Wednesday 19/Dec/2018.

It is going to be heated to 2000 C during 3 weeks 

Pressure IGP1 =  4.88e-7 Torr

TGHT manually tapped to 40 A

Autoramp set to 2 A/min on TGHT to 400 A aiming for 1800 C

The system tripped due to a power outage.

the current went from 57 to 0 A.

The tube did not show damage signs.

 Tuesday, January 15, 2018, 17:30

Tantalum tube was coated with TaC and wrapped with Ta heat-shield (3 layers)

Desired temp = 1900 C (expected TGHT ~445A/7.5V), TBHT will be set fixed at 230A (max).

EVAP2 currently pumping down.

 Pressure at IGP1 4.71 -7 Torr. 

Tapped up TGHT manually to 40 A

Waited ~1 hr for vacuum to stabilize.

IGP1 = 9.96-7 Torr

Good vac at 3.00e-5 Torr

Bad vac at 5.00e-5 Torr.

Initiating auto ramp for TGHT @ 1 A/min to a max set point of 350 A

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

 Thursday, January 17, 2019, 15:31

The tube remained at ~1900 C for 6 hours.

IGP1=5.8e-7 Torr

TGHT = 427 A, 7.23 V

Min Temperature = 1890 C

Thursday, January 17, 2019, 15:33

 Auto-ramp set to TGHT 0 A @ -2 A/min. 

 Wednesday, January 23, 2019, 13:01

A previously coated tantalum tube with 3 layers of shielding (Details in e-log 426) was loaded with a graphite insert. 

The tube was loaded in evaporator 2 and pumped down

The graphite insert will be heated to 2000 C for 3 weeks

 Thursday, January 24, 2019, 10:04

Pressure = 3.66e-7 Torr

TGHT manually tapped to 45 A

Final pressure = 3.8e-7 Torr

Set autoramp to 350 A @ 2A/min

TGHT = 1643 C

Set autoramp to 400 A @ 2A/min

TGHT = 1790 C

Started to tapped manually at approx 5 A every 30 s

Final TGHT => 1896 C, 8.16 V, 480.46 A

The current will stay at 480 A until temperature stabilizes. 

The current was reduced to 476 A to stay at 1900 C

Friday, January 25, 2019, 17:16

Pressure = 3.22e-7 Torr

TGHT = 8.17 V, 477.65 A, 1882 C 

Monday, January 28, 2019, 09:09 

Pressure = 1.67e-7 Torr

TGHT = 8.07 V, 477.65 A, 1859 C 

The temperature readings are fluctuating between 1880 and 1859 C

Tuesday, January 29, 2019, 07:32

Pressure = 1.55e-7 Torr

TGHT = 8.17 V, 477.75 A, 1880 C 

Tuesday, January 29, 2019, 11:34

 Pressure = 1.55e-7 Torr

TGHT = 8.27 V, 477.56 A, 1897C 

Tuesday, January 29, 2019, 12:47 

 Pressure = 1.53e-7 Torr

TGHT = 8.19 V, 477.75 A, 1899C 

Tuesday, January 29, 2019, 13:38

 Pressure = 1.55e-7 Torr

TGHT = 8.25 V, 477.75 A, 1905C

Thursday, January 31, 2019, 16:12  

 Pressure = 1.40e-7 Torr

TGHT = 8.4 V, 476.81 A, 1918C

Thursday, January 31, 2019, 22:32

Pressure = 1.39e-7 Torr

TGHT = 8.37 V, 476.71 A, 1914C

The current will be ramped down @1 A/min

Friday, February 01, 2019, 09:58

 Last 22 A tapped to 0 manually

Tantalum tube was removed from the EVAP2

 Wednesday, March 13, 2019, 15:41

An uncoated tantalum tube was loaded with a graphite insert (with conical caps).

3 tantalum foils were wrapped around the tantalum tube and a Ta cap was added.

EVAP2 is currently pumping down

The tube will be hated for 5 days at 2000 C

Thursday, March 14, 2019, 10:07

IGP1 = 5.37e-7 Torr

The TGHT will be tapped manually to 50 A  

After aprox 1 hour IGP1 = 5.08e-7 Torr, TGHT=46.5 A, 0.224 V

Autoramp is set to 1A/min to 300 A

 Autoramp is set to 1A/min to 450 A

Autoramp was stopped at 425 A when 2000 C were achieved

 Sunday, March 17, 2019, 00:25

IGP1 = 2.03e-7 Torr

TGHT=424.2 A, 7.117 V, temp 1976 C

Sunday, March 17, 2019, 15:04 

IGP1 = 21.6e-7 Torr

TGHT=424.1 A, 7.085 V, temp 1967 C

cooling down -1 A/min