2020-10-27 10:24 setup introduced yesterday. Pumping over night IGP1: 5.7e-7T. Water leak check ok. Performing heating elements check.

 2020-10-27 10:43 Heating elements check show low cooling. Ramping up target 1A/15s to 200A.

 2020-10-27 11:54 all ok 200A, thermocouples show room temperature on cartridge and heat shield. Ramping up target 2A/10s to 300A.

 2020-10-27 11:54 all ok 300A, thermocouples show 28/25degC. Ramping up target 2A/10s to 400A.

 2020-10-27 11:54 all ok 400A, thermocouples show 36.5/29degC. Ramping up target 2A/10s to 500A.

 2020-10-27 11:54 all ok 500A, thermocouples show 48.9/33degC. Ramping up target 2A/15s to 550A.

 2020-10-27 12:43 all ok 550A, thermocouples show 55/34degC. Ramping up target 2A/15s to 600A.

 2020-10-27 12:43 all ok 600A, thermocouples show 61.5/35.2degC. Ramping up target 2A/15s to 625A.

 2020-10-27 13:14 all ok 625A, thermocouples show 64.6/34.2degC. Ramping up target 2A/15s to 650A.

2020-11-02 6:32: roughing on

2020-11-02 7:21: Turbo on for a while, IGP1:1.8e-5T . water leak check ok.

2020-11-02 7:47: IGP1:1e-5T . Ramping up target heater to 200A, 1A/10s.

2020-11-02 7:47: TGHT at 275A, pyrometer at 1300degC. Leaving it hot for 24h.

 2020-11-04 9:06: After 37h treatment, ramping down to 0A.2A/10s.

2020-11-04 9:46: target ramped down. Venting.

2020-11-04 17:30: Big amounts of outgassing non detected in GP1 coated some inner walls in evap2. The walls got cleaned with acetone. All as before now.

 2020-11-04 17:31: target installed with boat containing graphite container for outgassing. Roughing pump on.

 2020-11-04 17:49 turbo on, leaving it pumping over night.

 2020-11-05 11:32 leak check ok. Ramping up target to 200A 2A/10s.

 2020-11-05 11:53 IGP1:1.1e-6T . Ramping up target to 300A 1A/10s.

 2020-11-05 11:53 IGP1:1.2e-6T . Pyrometer:1320degC. Ramping up target to 400A 1A/10s.

 2020-11-05 11:53 IGP1:1.8e-6T . Pyrometer:1650degC. Ramping up target to 500A 1A/10s.

 2020-11-05 12:57 IGP1:3.4e-6T . Pyrometer:1910degC. Ramping up target to 525A 1A/10s.

 2020-11-05 13:02 IGP1:3.6e-6T . Pyrometer:1990degC. Leaving it hot for 1h.

 2020-11-05 14:00 IGP1:2e-6T stable . Pyrometer:1990degC. cooling down 2A/10s.

 2020-11-05 15:44 empty and naked boat in for heating up system and clean up. Turbo on.

 2020-11-06 16:58 IGP1:4e-7T leak check ok. Ramping up target to 500A. 1A/10s.

 2020-11-09 12:43 The target was left at 1500degC during the weekend. 

 2020-11-17 14:11 turbo pump off. Slow venting.

 2020-11-18 09:18 Evap2 vented. Target removed.

Tuesday, November 24, 2020, 09:23

A batch of 60 discs of 18 mm diameter were loaded in a tantalum tube. The tantalum tube was wrapped with 3 layers of Ta foil for heat shielding and mounted in the EVAP2. EVAP2 pumped down overnight and Aaron made a leak test this morning (elog 524). 

The target material will be heated to 1990 degC. To measure the temperature, the tube has a Ta foil close to the graphite foils and it is held in place with a tantalum spring. Another Ta spring holds the graphite foils in the opposite side of the tube. The temperature will be measured with the Omega pyrometer (slope 0.99)

IGP1 = 6e-7 Torr. Note: The pressure has an usual behavior (see 2020-11-24-IGP1  and 2020-11-24IGP1-zoom out). After ~9 hrs, the pressure became stable (see 2020-11-24IGP1 -stable)

Tuesday, November 24, 2020, 13:00

IGP1 = 6.7e-7 Torr

Good vacuum of 3e-2 Torr and Bad vacuum 5e-2 Torr

The autoramp is set to 80 A at 1 A each 10 s 

 Tuesday, November 24, 2020, 13:43

IGP1 = 2.7e-5 Torr

TGHT = 1.13 V 80.5 A

Autoramp is set to to 100 A at 1 A each 20 s

Tuesday, November 24, 2020, 13:57 

IGP1 = 2.5e-5 Torr and going down

TGHT = 100.2 A, 1.47 V

Autoramp is set to to 120 A at 1 A each 20 s

Tuesday, November 24, 2020, 14:06 

IGP1 = 2.09e-5 Torr

TGHT = 1.6 v, 122 A

Autoramp is set to 200 A at 2 A each 10 s

Tuesday, November 24, 2020, 14:18 IGP1 = 5.4e-5 Torr

IGP1 = 1.5e-5 Torr

TGHT = 2.9 V, 200.5 A

Omega = 1123 °C

Autoramp is set to 450 A, conditions:

2 A each 10 s with a good vacuum of 3e-2 Torr and a bad vacuum 5e-2 Torr 

Tuesday, November 24, 2020, 14:45

The autoramp was stopped at 424 A 

TGHT = 421.65 A, 8.353 V

IGP1= 2.5e-5 Torr and going down

Omega 2020 degC

The TGHT current was reduced to 420 A (8.27 V) and the temperature reduced to 2007 degC

Tuesday, November 24, 2020, 21:03

IGP1 = 2.09e-6 Torr

TGHT = 7.899 V, 421.312 A

Temperature = 1870 degC

Autoramp is set to 0 A at 1 A/min 

Monday, February 01, 2021, 13:52  

Ta boat loaded with 20 Disc on either end capped with Ta springs to prevent overexpansion.   discs wrapped Graphite foil and boat wrapped in Ta heat-shields (3 layers).

Sample A on left side and sample B on right side.

Desired temperature= 1800C (expected TGHT 410 A).

good vacuum = 3.00 e-05 Torr

bad vacuum = 5.00 e-05 Torr

Evap2 left to pump down over night.

 Tuesday, February 02, 2021, 10:01

Pressure stable at IGP1= 7.8e-7 Torr

TGHT autoramp  set to 50 A @ 1/min

Tuesday, February 02, 2021, 13:45

IGP1=3.5e-6 Torr

TGHT =49.9 A, 0.56 V

Ramp at 1A/min to 100A

Wednesday, February 03, 2021, 08:25

IGP1= 5.5 e-07 Torr

TGHT = 100 A, , 1.2 V

Yesterday the camera failed to operate.  Cloud service discontinued.  The TS camera is offline but it is a different provider.  Will start ramping to 400A .

Ramp rate 2A/min

Wednesday, February 03, 2021, 15:55

ramped up to 520 A and 9.1V TGHT

Temperature average 1644 C but suspect actual temperature higher.

Held for 5 hours and started ramp down at -2A/min

Thursday, February 04, 2021, 9:35

IGP1= 2.99e-7 Torr

Begin pumpdown procedure and remove container

Note:  SiC evaporation on most discs.  The temperature was too high.  Need to repeat.

Monday, February 08, 2021, 17:00: Installed brackets w/ Ta wire and a small piece of Re to test voltage drop.

Rough down, TP on. Waterlines open.

Tuesday, February 09, 2021, 06:44: Vacuum @ 8.63e-07T.

Tuesday, February 09, 2021, 06:45: Shut TP & roughing pump ff. Valves are close. Ready for power outage.

Tuesday, February 09, 2021, 11:30: BP1 & TP1 back on.

Tuesday, February 09, 2021, 11:37: PS on. Vacuum @ 9.7e-06T & continuing down.

micron slope 0.98

Tuesday, February 09, 2021, 16:01 Pressure 7.26e-7 Torr

aiming at a temperature of 2000 degC on the wire; wire is not in the visual range of pycnometer; simulations of the system indicate that wire will be at 2000 degC at 60 W, hence current will be increased slowly.

Rate: 0.1 A/60 s to 10 A

Tuesday, February 09, 2021, 16:47 Tendence showed that at 5 A the power will be ~10 W, final ramping step was updated accordingly.

Tuesday, February 09, 2021, 16:49 Pressure dropping a bit: Current reading 7e-7 Torr

Tuesday, February 09, 2021, 17:09Pressure going down, curent will be ramped down at 0.2 A/min

Pressure: 6.958e-7 Torr, TGHT: 5 A, 2.748 V, omega is reading 1625 degC somewhere somehow, wire will stay at this conditions for 10 min to see  if there is a pressure or voltage change.

Tuesday, February 09, 2021, 17:16 voltage and temperature are slowly increasing  2.789 V, and 1688 degC respectively.

Tuesday, February 09, 2021, 17:32 Voltage signal is noisy but it seems like the voltage is not increasing anymore, preassure has remained constant, wire is glowing, 1100 degC with manual pyrometer.

Tuesday, February 09, 2021, 17:44 TGHT: 2.81 V, 4.95 A, IGP1 6.63e-7 Torr. current will be increased manually at 0.2 A steps. At first step voltage is stable.

Tuesday, February 09, 2021, 18:13 TGHT: 6.6A, 3.981V (~26W), Omega 1741 degC and manual pyrometer ~1300 degC

Tuesday, February 09, 2021, 18:28 TGHT: 8A, 5.121V (~40W), omega 1816 degc, 1390 degC with manual pyrometer, step changed to 0.4A.

Tuesday, February 09, 2021, 18:34 TGHT: 8.8A, 5.88V (50W), omega 2008 degC, 1500 manual pyrometer

Tuesday, February 09, 2021, 18:56  TGHT: 9.6A, 6.64V, manual pyrometer 1800 degC, omega 2042 degC, wire is shinny enough for micron 2092 degC.

Tuesday, February 09, 2021, 19:01TGHT: 10A, 7V, ~1800 degC manual pyrometer, omega 2123 degC, micron 2152 degC

Tuesday, February 09, 2021, 19:15 TGHT: 10.5A, 7.47V, 2150 degC Omega, 2165 degC, ~1800 degC manual

Tuesday, February 09, 2021, 19:23 TGHT: 11A, 7.93 V, 2188 omega, 2210 deC micron

 Tuesday, February 09, 2021, 19:29 TGHT: 11.5A, 8.37V, 2188 omega, 2210 deC micron

Tuesday, February 09, 2021, 19:33 TGHT: 12A, 9V, 2325 degC, 1900 degC manual, the wire changed shape and the preassure increase a bit , micron was readjusted to read, micron 2454 degC. Wire might be touching tube, only one more amper will be imputed.

Tuesday, February 09, 2021, 19:55 TGHT 13A, 9.865 V, 2404 degC omega , 2558 degC micron, manual pyrometer still reads 1800 degC, pressure increased with the power increment, bbut it seems like the wire touching the tube so no more current will be imputed.

Tuesday, February 09, 2021, 20:08 started ramping at -0.2A/min

Wednesday, February 10th , 20211, 10:00 System unloaded from EVAP2, wire has straightened, it has not sintered to the copper brackets, system is clean there is no evidence of coating.

Thursday, February 10, 2021, 12:00

Objective: Heat a Re wire to evaporate it and deposit a layer of Re on the inner surface of a Ta tube.

A Re wire of 1mm diameter was clamped with Cu brackets in EVAP2, the wire is partially enclosed in a Ta tube. EVAP2 pumping down 

The wire needs to be heated to 2500 degC since this is its sublimation temperature at 8e-7 Torr

There is not a reliable system to measure the temperature of the wire but the readings of the micron, manual, and omega pyrometers will be register.

According to COMSOL simulations a power and taking in consideration the EVAP2's power loss, a power of 520 W (5A, 10V) is required.

Thursday, February 11, 2021, 15:39

Pressure 3.78e-7 Torr, current rate set to 10 A @ 0.5 A/min

Thursday, February 11, 2021, 16:32

Pressure: 4.01e-7 Torr, TGHT = 10A, 1.719 V. The voltage has stabilized, the wire is glowing but not enough for reading with micron nor omega, manual reads 970 degC. Also, the wire formed an arc (crest).

Thursday, February 11, 2021, 16:44

 Pressure 3.8e-7 Torr, TGHT  = 10 A, 1.723 V ramp set to 20A @ 0.2 A/min

Thursday, February 11, 2021, 17:26  

Pressure increasing 4.7e-7 torr, TGHT = 20 A, 4.016 V, the wire does not seem to be changing, 

Thursday, February 11, 2021, 18:02

Ramp set to 30A @0.4A/min

Pressure  7.2e-7 Torr, TGHT = 30A, 6.561V, manual pyrometer reads 1720degC

Ramp set to 40A @0.4A/min

Thursday, February 11, 2021, 18:35

 Pressure 2.1e-6Torr and increasing, TGHT = 40A, 9.1V, manual pyrometer reads ~1880 degC

Ramp set to 50A @ 0.4 A/min

Saturday, February 13, 2021, 08:10

Ta boat loaded with 80 discs enclosed in graphite foil in pockets of 20.  Sample A at both ends and sample B in the middle spaced out. Boat wrapped in Ta heat-shields (3 layers).

(A B B A)

Desired temperature= 1800C (expected TGHT approx 410 A).

good vacuum = 3.00 e-05 Torr

bad vacuum = 5.00 e-05 Torr

Evap2 left to pump down over previous night.

IGP1= 5.4e-7 Torr and stable

Initiating TGHT ramp up at 1 A/ min to 30 A

Saturday, February 13, 2021, 12:19

IGP1= 6.9e-06 Torr

Ramp to 50 A 1A/min

Saturday, February 13, 2021, 14:35

IGP1 = 6.4e-6 Torr

Pressure trending down. 

Saturday, February 13, 2021, 14:56

IGP1= 4.9 e-6 Torr

Initiate Ramp up @ 1 A/min to 400 A

Changed ramp up to 0.5 A/min at around 11:30 pm

Sunday, February 14, 2021, 11:43

The current will be ramped up to 420 A according to the trendline approximation (see attachement 1)

Sunday, February 14, 2021, 12:26

IGP1 = 8.9 e-06 Torr and trending down

TGHT = 420 A, 7.5 V

OMEGA = 1730 C

Will ramp up to 428 A manually 

Sunday, February 14, 2021, 12:30

Reached 428 A on TGHT.  

OMEGA = 1760 C

Will bump to 430 A and hold for 4 hours

OMEGA= 1765 C

Sunday, February 14, 2021, 18:00

OMEGA = 1789 C

IGP1= 7.5 e -7 Torr

TGHT = 430.5 A , 7.8 V

Start ramping down at -1A/min to zero A

 Tuesday, February 23, 2021, 08:49

Yesterday a heat shield was washed and when dry it was installed in the EVAP2,

A 1mm thick rhenium wire was held within two copper brackets to pass through a Cu tube with the intention of coating its inside face

Tuesday, February 23, 2021, 08:58  IGP1 = 7.7e-7 Torr

Pressure 5.88e-7 Torr, current rate set to 10 A @ 0.5 A/min

Pressure 6.1e-7 Torr, current rate set to 20 A @ 0.5 A/min

Pressure 8.51e-7 Torr current rate set to 30 A @ 0.5 A/min, temperature corrected 1800 degC (measured with filament pyrometer)

After 10 min the current and voltage are stable and the pressure is going down

Tuesday, February 23, 2021, 16:25

It seems like the wire is touching the tube so the system will be cool down.

Pressure 6.8e-7 Torr current rate set to 0A at -0.1 A/min

 Tuesday, February 23, 2021, 17:38

Pressure 6e-7 Torr, TGHT = 23.3 A, 4.854 V, Temp 1788 deg C Omega, 1540 degC filament

current rate set to 0A at 0.2A/min 

Wednesday, February 24, 2021, 09:37

Venting EVAP2 

Wednesday, February 24, 2021, 16:47

The wire and Cu tube were  fix such that the wire's deformation does not lead it to touch the tube, then the assembly was attached again and the EVAP2 was pumped down.

IGP1 = 9.3e-7 Torr, current rate is set to 5 A at 0.5 A/min

Wednesday, February 24, 2021, 17:04

IGP1 = 9e-7 Torr TGHT = 5.175A, 0,749 V

current rate is set to 10 A at 0.5 A/min

Wednesday, February 24, 2021, 17:23

IGP1 = 8.8e-7 Torr, TGHT = 10A, 1.78V

current rate is set to 20 A at 0.5 A/min

Since the wire seemed to be touching the tube, the system was vented.

The tube was shifted and the heat shield installed again, the system was pumped over nigth.

Thursday, February 25, 2021, 09:15

A water leak was performed and no leak was observed

IGP1= 4.95e-7 Torr

Thursday, February 25, 2021, 09:32  The current is increased at 0.5 A/min to 5 A

Thursday, February 25, 2021, 10:00

The current was tapped manually at 0.5 A to 6 A the wire is now glowing dimmly

Current rate set to 10A at .5 A/min

Current rate set to 20 A at 0.5A/min

Current rate set to 30 A at 0.5A/min

Thursday, February 25, 2021, 11:17  IGP1= 5.7e-7 Torr, TGHT=30.5A, 6.718V, filament=1740 degC

voltage and current stable, pressure going down.

Thursday, February 25, 2021, 11:21

Current rate set to 40 A at 0.4 A/min

Thursday, February 25, 2021, 11:53 IGP1 = 5.9e-7 Torr, TGHT = 9.267V, 39.15A, filament = 2060 degC

voltage and current stable, pressure going down.

Current rate set to 50 A @ 0.2A/min

During ramping the voltage reduced a bit and I decided to stop the ramp and reduce the current, the voltage stayed constant but the current started increasing slowly without me inputting it so I decided to ramp down the current at 0.2A/min.

When the current reached 0A the power supplies and the pumps were turned off, after an ~1h when the turbo pump had already stopped, the EVAP2 was vented and open.

The wire sintered to the copper tube confirming that the wire was in contact with the tube during heating.

The Cu tube present a grey metallic coloration indicating a Re coating.

The set up together with the copper heat shield were removed from the

 Tests were performed with external power supply. No target boat or container.

Small power on heating small heating elements on parasitic target attached on isac heatshield with water cooling on. 

Tuesday, March 02, 2021, 11:26 

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

Initial weight including heat-shields = 433.8 g

Desired temperature = 1900 C (expected TGHT ~430 A), TBHT will be set fixed at 230A (max).

Evap 2 will be pumped down over night.

Good vacuum = 3.00 e-5 Torr

Bad vacuum = 5.00 e-5 Torr

Wednesday, March 03, 2021, 13:28

IGP1 = 4.0 e-7 Torr

Start ramping @ 1A/min to 20A on both TGHT and TBHT

Wednesday, March 03, 2021, 15:03

Start ramping @1/min to 60A on Both TGHT and TBHT

Wednesday, March 03, 2021, 22:42

TGHT = 60A, TBHT = 60A

IGP1= 4.2 e-7 stable

Start ramping to 400A @ .5A/min for TGHT and @0.5A/min for TBHT to 230A

Thursday, March 04, 2021, 11:56

TGHT = 400 A, TBHT =230A

IGP1= 1.9e-6 Torr

OMEGA = 1695 C

Continue ramp up @0.5A/min to 430A on TGHT

Thursday, March 04, 2021, 14:02

IGP1 = 1.87e-6 Torr

TGHT = 434 A , 7.2 V

OMEGA = 1787 C

Will tap up manually 450A @ on TGHT and leave at that current for ~4 hours

Thursday, March 04, 2021, 19:35

After ~ 5 hours at 1829 C max OMEGA reading

OMEGA = 815 C 

Start ramp down at 1A/min on TGHT and 0.8A/min for TBHT

IGP1= 1.2e-6 Torr

 Friday, March 05, 2021, 10:47

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

Initial weight including heat-shields = 431.0 g

Desired temperature = 1900 C (expected TGHT ~430 A), TBHT will be set fixed at 230A (max).

Evap 2 will be pumped down over night.

Good vacuum = 3.00 e-5 Torr

Bad vacuum = 5.00 e-5 Torr

 Saturday, March 06, 2021, 10:29

IGP1= 2.7 e-07 Torr and stable

AutoRamp at 1A/min to 40 A on TGHT and TBHT

Saturday, March 06, 2021, 22:36

IGP1= 2.2e-07 Torr

TGHT = 40.3 A, .46V

TBHT = 38.48 A, .48 V  (set to 40 A)

Start Autoramp at 0.5A/min to 400 A on TGHT and 230A on TBHT

Sunday, March 07, 2021, 07:48

IGP1=8.5e-7 Torr

TGHT = 287 A, 4.6V

TBHT = 232 A, 4.0 V

OMEGA = 1493C

 Increase ramp speed on TGHT to 2A/min to 400A

Sunday, March 07, 2021, 08:36 

 IGP1=1.7 e-06 Torr

TGHT = 373.7 A, 6.3V

TBHT = 232.9 A, 4.1 V

OMEGA = 1752 C

Sunday, March 07, 2021, 08:53

 IGP1= 1.7e-06 Torr

TGHT = 400 A, 6.8 V

TBHT = 232.8 A, 4.1 V

OMEGA= 1842

Ramp TGHT @ 2A/min to 420 A as per attached current approximation

Sunday, March 07, 2021, 09:25

OMEGA=1915 C

TGHT = 420A, 7.2V

TBHT= 232.8 A, 4.1V

IGP1= 1.6 e-06 Torr

Tap down manually to approx 1900 C

TGHT = 412.9 A, 7.0 V and OMEGA=1900 C

Will leave for about 4 hours at this temperature

Sunday, March 07, 2021, 13:05

IGP1= 1.1 e-06 Torr

TGHT = 415 A, 7.2 V

TBHT = 232.8 A, 4.1 V

OMEGA = 1880C

Start cool down at -2A/min on TGHT and -1A/min TBHT

Tuesday, March 09, 2021, 11:54 

 Container coated with TaC and wrapped with 3 Ta heat shields.

Desired temperature= 1900 C, Omega Slope set = 0.990, Auto TGHT at 0.2A/min to reach 400A, TGHT will be increased  accordingly to reach desired Temp.

TBHT will be set fixed at 230 A max).

Good vac at 3.00e -5 Torr

Bad vac at 5.00e-5 Torr

Chamber pump down

Wednesday, March 10, 2021, 08:32

IGP1 = 2.6 e -07 Torr

Start autoramp @ 1A/min to 40 A on both TGHT and TBHT

***Autoramp aborted due to work on EF12 affecting EVAP2***

Will have to resume Thursday or Friday

Saturday, March 13, 2021, 7:54

  IGP1= 3.8e-07 Torr

Initiate heating @ 0.5A/min TBHT and TGHT to 60 A

Saturday, March 13, 2021, 23:01

IGP1 = 2.7e-07Torr

TGHT = 60.5A, 0.7V

TBHT= 60.0A, 0.7V

Initiate ramp @ 1 a/min to 400 A on TGHT and 230A on TBHT

Sunday, March 14, 2021, 08:45

IGP1= 8.2e-07 Torr

TGHT = 400A, 5.6V

TBHT = 232.9A, 3.0V 

OMEGA = 1142 C

Continue ramping to 460 A on TGHT at 1a/min

 Sunday, March 14, 2021, 10:11

IGP1 = 1.0 e-06 Torr

TGHT= 460.4 A, 6.5 V

TBHT = 232.9 A, 3.0 V

OMEGA = 1239 C

Will ramp up to 500 A at 1a/min on TGHT

Sunday, March 14, 2021, 10:53

 IGP1 = 1.3 e-06 Torr

TGHT= 495 A, 7.2 V

TBHT = 232.9 A, 3.0 V

OMEGA = 1316 C

Will ramp up to 600 A at 1a/min on TGHT

Sunday, March 14, 2021, 12:45

IGP1 = 3.0 e-06 Torr

TGHT= 604 A, 9.1 V

TBHT = 232.9 A, 3.1 V

OMEGA = 1610 C

Will ramp up to 660 A at 1a/min on TGHT 

Sunday, March 14, 2021, 17:01

IGP1= 2.4e-06 Torr

TGHT =  664 A, 10V

TBHT = 232.9 A, 3.1V

OMEGA = 1733 C

tapping TGHT to 740 A

OMEGA = 1883 C

 Sunday, March 14, 2021, 21:45

IGP1= 3.1e-06 Torr

TGHT =  744A, 11.5V

TBHT = 232.9 A, 3.2V

OMEGA = 1875 C

Start cooling TGHT @-3A/min and TBHT @-1A/min

 Tuesday, March 16, 2021, 08:28 

Each endcap is separated with a disc of graphite foil and rolled into packs of 5 within a foil envelope in a target boat.

There are also 4 coated springs, one in between endcaps and three on the ends

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

Chamber pumping down

OMEGA slope = 0.99

Will ramp TGHT up to 40 A then autoramp to 400A at 1A/min.

Final desired temperature on OMEGA (tap)= 1800C

Tuesday, March 16, 2021, 11:22

 IGP1= 3.5e-06 Torr

TGHT = 40A, 0.4V

Will ramp up at 1A/min to 400 A

Wednesday, March 17, 2021, 08:06

IGP1=  2.98 e-07 Torr

TGHT = 400 A, 4.3V

OMEGA shows no temperature reading.  Will ramp up to 450A at 1A/min

Wednesday, March 17, 2021, 08:58

OMEGA still shows no reading

IGP1= 4.2e-07 Torr

ramping to 470A @ 1A/min 

Wednesday, March 17, 2021, 09:21

OMEGA no reading

IGP1 = 4.4 e-07 Torr

TGHT = 470 A, 5V

ramp up to 490 A at 1A/min

Wednesday, March 17, 2021, 11:05 

TGHT at 490 A, 5.2 V since 10 am.  Will start cooling at 2 pm.  

Wednesday, March 17, 2021, 13:47

TGHT = 493A, 5.3V

IGP1= 3.2e-07 Torr and stable

Start ramp down at -2A/min

Thursday, March 18, 2021, 11:20 

The boat was dismounted but the materials had not sintered properly.  The boat looked very twisted.  Everything was transferred to a new boat with uncoated Ta caps at either end.  

It was left overnight to establish vacuum.

Friday, March 19, 2021, 08:23

IGP1= 2.2 e-07 Torr

initiate heating at 1A/min on TGHT to 60 A

Friday, March 19, 2021, 10:04

IGP1= 3.6 e-07 Torr

TGHT = 60 A, .73 V

Ramp up to 450 A @ 2A/min

Friday, March 19, 2021, 14:26

OMEGA 1895 at 455A, 8.4 V

manually ramp down to 1800C

OMEGA 1800C at 416A, 7.6V

will leave like that for 3 hours more

Friday, March 19, 2021, 17:12

OMEGA 1795 C

 TGHT = 415A, 7.6V

IGP1= 6.8e-07 Torr

Start ramp down at -2A/min

Monday, March 22, 2021, 23:07 

Marla removed from Evap 2.  Sintering vwas very good.  The container with Ta caps is better for sintering these pieces.

Objective: Coating the inner surface of a short tantalum boat with rhenium.

Result:

• The wire snnaped around 376 W (53 A, and 7.09 V) and 2170 °C (measured with filament pyrometer)
• The tube does not have indications of coating

Thursday, March 25, 2021, 11:23

Yesterday a heat shield was installed in the EVAP2.

The desired temperature of the Re wire is 2500 degC

A water leak was performed (elog 539 describes it), no leak was detected.

Tuesday, March 23, 2021, 11:01

Pressure 3.8e-7 Torr, current rate set to 6 A @ 0.5 A/min

The wire started glowing at TGHT =  4W, 7A, 0.56V

When reaching 7A the current was increased 0.5 A manually 

When reaching 16 A,  the current was increased 1 A manually until reaching 54 A when the wire snapped

Objective: Coating the inner surface of a short tantalum tube with rhenium.

Result:

• The wire snnaped around 376 W (53 A, and 7.09 V) and 2170 °C (measured with filament pyrometer)
• The tube is coated

Thursday, March 25, 2021, 11:23

Yesterday a heat shield was installed in the EVAP2.

The desired temperature of the Re wire is 2500 degC

A water leak was performed (elog 539 describes it), no leak was detected.

Tuesday, March 23, 2021, 11:01

Pressure 3.8e-7 Torr, current rate set to 6 A @ 0.5 A/min

The wire started glowing at TGHT =  4W, 7A, 0.56V

When reaching 7A the current was increased 0.5 A manually 

When reaching 16 A,  the current was increased 1 A manually until reaching 54 A when the wire snapped

Friday, March 26, 2021, 13:55

Yesterday a heat shield was installed in the EVAP2.

A 1mm thick rhenium wire was held within two copper brackets to pass through a Cu tube with the intention of coating its inside face.

The desired temperature of the Re wire is 2500 degC

A water leak was performed and no leak was detected

Objective: Coating the inner surface of a tantalum tube to make a destructive test and use a reference for the tantalum boats coatings

Results: 

Sunday, March 27, 2021, 11:23

No water leak

IGP1 = 3.7e-7 torr

Sunday, March 27, 2021, 16:10

The wire was heated in the same manner as the last three runs

From 0A to 7A the autoramp was set to 0.5A/min

At 8A the wire started the glow dimmly 

Above 8A, the wire was heated manually at 0.5A until 16A where the step was changed to 1A, 

the temperature was measured with the filament pyrometer every 2 A starting at 10A

At 42 A the step was changed to 0.6A until 42.6A, 4.38V (2020 °C), the wire was kept at that temperature for 90 min

After that time, the current was ramped down at 0.5A/min until ~20A when the current rampping was changed too 1A/min

Objective: Coating the inner surface of a tantalum tube to make a destructive test and use a reference for the tantalum boats coatings

Results: The tube was coated

Sunday, March 28, 2021, 11:23

No water leak

IGP1 = 2.3e-7 torr

Sunday, March 28, 2021, 16:10

The wire was heated in the same manner as the last three runs

From 0A to 7A the autoramp was set to 0.5A/min

At 8A the wire started the glow dimmly 

Above 8A, the wire was heated manually at 0.5A until 16A where the step was changed to 1A, 

the temperature was measured with the filament pyrometer every 2 A starting at 10A

At 42 A the step was changed to 0.6A until 42.6A, 4.38V (2020 °C), the wire was kept at that temperature for 90 min

After that time, the current was ramped down at 0.5A/min until ~20A when the current rampping was changed too 1A/min