Tuesday, August 18, 2020, 09:06

A short tantalum tube was coated with TaC and wrapped with 3 layers of Ta,

a Ta foil was attached to the end of the tube to be able to measure the temperature during heating

Desired temperature= 1900 C,

Omega Slope set = 0.990,

IGP1 = 3.75e-7 Torr

Autoramp set to TGHT at 0.2 A/min to reach 52 A

Tuesday, August 18, 2020, 13:47

IGP1=  6.8e-7 Torr

TGHT =0 .511 V, 51.3 A

IGP1 = 6.8e-7 Torr

Autoramp set to TGHT at 0.5 A/min to reach 100 A

IGP1 = 3.3e-7 Torr

Autoramp set to TGHT at 0.5 A/min to reach 430 A 

Wednesday, August 19, 2020, 06:57 

Autoramp stopped at 402 A

IGP1 = 1.12e-6 Torr

TGHT = 5.6 V, 403.65 A

Autoramp set to TGHT at 1 A/min to reach 500 A 

Wednesday, August 19, 2020, 08:59

IGp1 = 1.7e-6 Torr

 TGHT = 7.22 V, 500.34 A

After 30 min at 1900 °C, autoramp set to TGHT at -1 A/min to reach 450 A, the ramp will be stopped when the temperature reads 1850 °C

Autoramp stopped at 1845 °C

IGP1 = 1.17e-6 Torr

TGHT = 6.8 V, 472.95 A 

Thursday, August 19, 2020, 17:28

 A short tantalum tube was coated with TaC and wrapped with 3 layers of Ta,

a Ta foil was attached to the end of the tube to be able to measure the temperature during heating

Desired temperature= 1900 C,

Omega Slope set = 0.990,

Thursday, August 20, 2020, 17:29

IGP1 = 4.25 e-7 Torr

Autoramp set to 0.5A/min to 400 A 

 Thursday, August 20, 2020, 20:36

IGP1 = 6.78e-7 Torr

TGHT = 267.7 A, 3.28 V

Autoramp set to 0.4 A/min to 450 A

Friday, August 21, 2020, 10:28

 IGP1=7.23e-7 torr

TGHT = 6.3 v, 446.3 A

Omega = 1603 °C

Autoramp set to -5 A/min

Saturday, August 22, 2020, 11:41

A Ta short tube was coated with TaC and sintered, then it was loaded with a c-cartridge

Now is currently under vacuum and it will be heated to 2000 °C during 3 days

Saturday, August 22, 2020, 11:43

Good vacuum = 3e-2 Torr

Bad vacuum = 5e-2Torr

IGP1 = 3.08e-7 Torr 

Autoram set to 10A/30 s to 200 A

 Saturday, August 22, 2020, 11:59

Good vacuum = 3e-2 Torr

Bad vacuum = 5e-2Torr

TGHT = 2.36 V, 200.1 A

IGP1 =2.46e-6 Torr

Autoramp set to to 300 A at 5A/30s 

Saturday, August 22, 2020, 13:03

TGHT = 7.32 V, 495.3 A

IGP1 = 2.7e-6 Torr

Omega = 2016 °C

AP = 1970.1 °C

Autoramp set to 550 A at 5A/30s

 Saturday, August 22, 2020, 13:11

TGHT =7.6 V, 523.2 A

IGP1 = 3.2e-6 Torr

Omega = 2077 °C

Monday, August 24, 2020, 07:59

Voltage increased ~0.2 V while current remained the same indicating an increment in resistance, temperature increment increased accordingly

TGHT = 7.815 V, 520.87 A

Omega = 2126 °C

Monday, August 24, 2020, 08:04

The current was reduced 0.1 A to 519.9

Monday, August 24, 2020, 08:55 Omega =  2112 °C

Monday, August 24, 2020, 09:12

The temperature returned to Omega = 2130 °C

The current was reduced 0.1 A to 519.8

Monday, August 24, 2020, 09:56

TGHT = 7.7 V, 518.3 A

Omega = 2132 °C 

Monday, August 24, 2020, 09:59 

The current was reduced 0.2 A to 519.6 A

TGHT = 7.7 V, 517.3 A

Monday, August 24, 2020, 10:07  Omega = 2130°C

 Monday, August 24, 2020, 10:08

The current was reduced 0.4 A to 519.2 A

TGHT = 7.7 V, 513.5 A

Monday, August 24, 2020, 10:13  Omega = 2129°C

Monday, August 24, 2020, 10:21

Voltage dropped to 7.6 V and temperature reduced to 2105 °C

Monday, August 24, 2020, 10:30

Voltage increased to 7.8 V and temperature increased to 2128 °C

Monday, August 24, 2020, 10:33

The current was reduced 0.4 A to 518.6 A

TGHT = 7.7 V, 513.06 A

Monday, August 24, 2020, 10:38  Omega = 2130 ­°C

Monday, August 24, 2020, 10:41

 The current was reduced 0.4 A to 518.2 A

Monday, August 24, 2020, 11:13 

 The current was reduced 0.4 A to 517.8 A

Monday, August 24, 2020, 11:19  Omega = 2128 °C

Monday, August 24, 2020, 11:19 

 The current was reduced 0.4 A to 517.4 A

Monday, August 24, 2020, 11:22  Omega = 2126

Monday, August 24, 2020, 11:22

 The current was reduced 0.4 A to 517.0 A

Monday, August 24, 2020, 11:25  Omega = 2123 °C

Monday, August 24, 2020, 11:26

 The current was reduced 0.4 A to 516.6 A 

Monday, August 24, 2020, 11:30  Omega = 2109 °C

Monday, August 24, 2020, 11:30 

 The current was reduced 0.4 A to 516.2 A

Monday, August 24, 2020, 11:36  Omega = 2100 °C

Monday, August 24, 2020, 11:37

  The current was reduced 0.4 A to 516.0 A

TGTH = 7.5 V, 512.9 A

Omega = 2095 °C

Monday, August 24, 2020, 14:17

Voltage dropped and later on increased 

TGHT = 7.7 V, 517.5 A

Omega = 2120 °C 

Monday, August 24, 2020, 14:18

 The current was reduced 0.4 A to 515.6 A

TGHT = 7.6 V, 509.4 A

Monday, August 24, 2020, 14:20  Omega = 2125 °C

Monday, August 24, 2020, 14:20

The current was reduced 0.4 A to 515.2 A

Monday, August 24, 2020, 14:22  Omega = 2122 °C

Monday, August 24, 2020, 14:22

 The current was reduced 0.4 A to 514.8 A

Monday, August 24, 2020, 14:29  Omega = 2116 °C

Monday, August 24, 2020, 15:27

The voltage dropped as well as the temperature

TGHT = 7.5 V, 512.5 A 

Monday, August 24, 2020, 15:28 Omega = 2095 °C

Monday, August 24, 2020, 22:06

TGHT = 7.6 V, 515.9 A 

Omega = 2105 °C

Tuesday, August 25, 2020, 09:07

TGHT = 7.6 V, 519.13 A

Omega = 2102 °C 

Tuesday, August 25, 2020, 13:02

TGHT = 7.6 V, 518.0 A

Omega = 2116 °C

IGP1 = 3e-7 Torr

Tuesday, August 25, 2020, 13:04 

Starting ramp down to 0 A at 5 A/min 

 Wednesday, August 26, 2020, 10:26

A Ta short tube was loaded with a C-cartridge

Currently, the tube is under vacuum and it will be heated to 2000 °C during 3 days.

IGP1 = 3.2e-7 Torr

 Wednesday, August 26, 2020, 16:15

IGP1 = 2.5e-7 Torr

Good vacuum = 3e-2 Torr

Bad vacuum = 5e-2Torr

Autoram set to 200A at 10A/30 s

Wednesday, August 26, 2020, 17:05

TGHT = 3.9 V, 301.3 A

IGP1 = 5.4e-7 torr 

Omega = 1378 °C

AP (slope 0.9) = 1441.8 °C

Wednesday, August 26, 2020, 17:20 

Autoramp set to 550 A at 5A/30s

Wednesday, August 26, 2020, 23:43 

TGHT = 7.561 V, 504.9 A

Omega = 2124 °C

AP = 2010.5 °C

Thursday, August 27, 2020, 07:15

TGHT =  7.461 V, 510.2 A

Omega = 2103 °C

 Thursday, August 27, 2020, 13:41

TGHT = 7.5 V, 510.8 A

Omega = 2099 °C

Friday, August 28, 2020, 09:24

TGHT = 7.4 V, 513.9 A 

Omega = 2103 °C

Friday, August 28, 2020, 13:12

TGHT = 7.46 V, 505.6 A

IGP1 = 2.7e-7 Torr

Omega = 2103 °C

Saturday, August 29, 2020, 14:18

IGP1 = 2.5e-7 Torr

TGHT = 7.5 V, 510.8 A

Omega = 2109 °C 

Saturday, August 29, 2020, 17:44

IGP1 = 2.4e-7 Torr

TGHT = 7.5 V, 505.2 A

Omega = 2119 °C 

Saturday, August 29, 2020, 17:51 

Starting ramp down to 0 A at 5 A/min

 Sunday, August 30, 2020, 06:47

A short tantalum tube was coated with TaC and wrapped with 3 layers of Ta,

a Ta cap was inserted to the end of the tube to be able to measure the temperature during heating

Desired temperature= 1900 C,

Omega Slope set = 0.990

Sunday, August 30, 2020, 06:48

IGP1 = 3.9e-7 Torr

Autoramp set to 0.5A/min to 400 A 

Sunday, August 30, 2020, 18:27

IGP1 8.41e-7 Torr

TGHT = 4.2 V, 327.15 A

Omega  = 1367 °C 

Sunday, August 30, 2020, 18:49

IGP1 = 9.6e-7 Torr

TGHT = 4.4 V, 337.1 a

Omega = 1402 °C 

Sunday, August 30, 2020, 19:25

IGP1 = 9.5e-7 Torr

TGHT = 4.6 A, 347.5 A

Omega = 1472 °C 

Autoramp set to 450 A at 0.1A/30s

Sunday, August 30, 2020, 19:59

IGP1 = 8.5e-7 Torr

TGHT = 4.8 V, 360.5 A

Omega = 1510 °C

 Sunday, August 30, 2020, 22:07

IGP1 = 7.2e-7 Torr

TGHT = 5.3 V, 392.6 A

Omega = 1675 °C 

 Sunday, August 30, 2020, 22:16

IGP1 = 7.1e-7 Torr

TGHT = 5.5 V, 403.2 A

Omega = 1678 °C

Autoramp set to 450 at 0.1A/min

 Sunday, August 30, 2020, 22:26

IGP1 = 6.9e-7 Torr

TGHT = 5.5 V, 399.15 A

Omega = 1689 °C

Monday, August 31, 2020, 08:08

IGP1 = 4.4e-7 Torr

TGHT = 6.4 V, 453.4

Omega =  1852 °C

Monday, August 31, 2020, 08:12 

Autorap set to 0 A at -5 A/min

 Monday, August 31, 2020, 12:23

A short naked Ta tube (no heat shielding), previously coated with TaC was set under vacuum, 

and it will be kept at 2000 °C for 3 days to later identify the TaC's carbon penetration.

Currently pumping down.

 Tuesday, September 01, 2020, 12:25

IGP1 = 2.0-7 Torr

Good vacuum = 3e-2 Torr

Bad vacuum = 5e-2Torr

Autoram set to 200A at 10A/30 s

Tuesday, September 01, 2020, 12:36

IGP1 = 5.2e-7 Torr

Autoramp set to 300 A at 5 A/30 s 

Tuesday, September 01, 2020, 14:11

IGP1 = 3.4e-7 Torr 

TGHT = 330.2 A, 4.2 V

Omega = 1234 °C

Tuesday, September 01, 2020, 14:31

IGP1 = 1.76e-6 torr

TGHT = 6.94 V, 510 A

Oemga = 1564 C, 

AP = 1390.2 C

Autoramp set to 600 A at 5 A/30s 

Tuesday, September 01, 2020, 15:33

TGHT power supply = 600 A, 8.74 V

Omega = 1807 C

Autoramp set to 700 A at same rate

 Tuesday, September 01, 2020, 15:33

TGHT power supply = 11.94 V, 765 A

Omega = 2157 °C

Wednesday, September 02, 2020, 10:15 

IGP1 = 1.0e-6 Torr

TGHT = 12.0 V, 772 A

Omega = 2167 °C

Wednesday, September 02, 2020, 13:26

IGP1  = 9.1e-7 Torr

TGHT = 12 V, 769.5 A

Omega = 2166 °C 

Wednesday, September 02, 2020, 16:06

IGP1 = 8e-7 Torr

TGHT = 12 V, 773.3 A

Omega = 2167 °C 

Wednesday, September 02, 2020, 20:53

IGP1 =7.4e-7 Torr

TGHT = 11.8 V, 760.95 A

Omega = 2164 °C 

Thursday, September 03, 2020, 09:54

IGP1 = 5.5e-7 Torr

TGHT = 11.9 V, 774 A

Omega = 2162 °C 

Thursday, September 03, 2020, 11:06

IGP1 = 5.3e-7 Torr

TGHT  = 11.9 V, 758.7A

Omega = 2161 °C

Thursday, September 03, 2020, 14:39

IGP1 = 4.8e-7 Torr 

TGHT = 11.9 V, 771.8 A

Omega = 2164 °C

Friday, September 04, 2020, 09:34

IGP1 = 3.9e-7 Torr

TGHT = 11.9 V, 760.1 A

Omega = 2168 °C 

Friday, September 04, 2020, 13:39

 IGP1 = 3.5e-7 Torr

TGHT = 11.9 V, 758.6 A

Omega = 2170 °C

 Friday, September 04, 2020, 15:55

IGP1 = 3.5e-7 Torr

TGHT = 12 v, 760.6 a

Omega = 2171 °C

Saturday, September 05, 2020, 12:56

A Ta tube was wrapped with 3 tantalum foils,

a tantalum cap was inserted in both sides of the Ta tube, the caps weren't sealed.

The tube was set in the EVAP2 

IGP1 = 3.6e-7 Torr 

Saturday, September 05, 2020, 12:57

Autoram set to 10A/30 s to 200 A

 Saturday, September 05, 2020, 13:11

TGHT = 2.7 V, 198.9 A

IGP1 =3e-6 Torr

Autoramp set to to 300 A at 5A/30s 

 Saturday, September 05, 2020, 14:45

IGP1 = 5.1e-7 torr

TGHT = 4.5 V, 303 A

Oemga = 1259 C, 

AP = 1233.5 C

Autoramp set to 450A at 5 A/30s 

 Saturday, September 05, 2020, 15:05

TGHT = 7.3 V, 457.7 A

IGP1 = 2.8e-6 Torr

Omega = 1722 °C

AP = 1572.2 °C

Saturday, September 05, 2020, 15:16 

TGHT = 9.2 V, 552.5 A

IGP1 = 7.5e-6 Torr

Omega = 2016 °C 

AP= 1735.9 °C

Saturday, September 05, 2020, 21:33 

IGP1 = 1.1e-6 Torr

TGHT = 11.2 V, 651.9 A

Omega = 2300 °C

 Thursday, September 17, 2020, 16:10

An LP-SIS was wrapped with 3 Ta layers, and installed in the EVAP2

Desired temperature= 1900 C, Omega Slope = 0.990

Friday, September 18, 2020, 10:56

IGP1 = 4.4e-7 Torr 

Leak check performed, no leak observed

Friday, September 18, 2020, 11:16

Power supplies on.

Good vac at 3.00e -5 Torr

Bad vac at 5.00e-5 Torr

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

 Friday, September 18, 2020, 11:21

Autoramp paused because, TBHT is not ramping

Ramping manually current to 10 A in 0.5 A steps

Friday, September 18, 2020, 11:38

Restarted autoramp  (Autoramp at 0.5A/min to 400A on TGHT and 230A on TBHT)

Friday, September 18, 2020, 22:50

IGP1 = 2.04e-6 Torr 

TGHT = 5 V, 322.8 A

TBHT = 4 V, 233.1 A

Omega = 1459 °C

Autoramp changed to 0.2 A/min to 450 A

Saturday, September 19, 2020, 10:49

IGP1 = 8e-7 Torr

TGHT = 7.3 V, 449.1 A

TBHT = 4 V, 233.1 A

Omega = 1789 degC

 Saturday, September 19, 2020, 13:25

IGP1 = 6.5 e-7 Torr

TGHT  7.2 V, 447.975 A

TBHT = 4.08 V, 233.09 A

Omega = 1785 °C

Saturday, September 19, 2020, 13:26

Starting ramp down at Commence cooling at -2 A/min for TGHT and -1 A/min for TBHT 

Monday, September 21, 2020, 09:16

Turning off pumps 

Monday, September 21, 2020, 16:47

EVAP2 was vented with air and the tantalum oven was removed, the coating seems sintered. 

 Monday, September 21, 2020, 16:50

450 graphite foils coated with graphite slurry were loaded in a tantalum tube, the tantalum tube was wrapped with 3 Ta heat shields and installed in the EVAP, to measure the temperature, a pack of 4 Ta foils were inserted in each side of the tube.

System is currently pumping down. 

 Tuesday, September 22, 2020, 07:54

IGP1 = 2e-6 Torr

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

The autoramp is set to 50 A at 1 A each 10 s 

Tuesday, September 22, 2020, 08:18 

IGP1 = 3.7e-6 Torr

TGHT = .586 V, 50.06 A

Autoramp is set to 80 A same conditions.

 Tuesday, September 22, 2020, 08:26

IGP1 = 0.0006 Torr

TGHT = .97 V 80.3 A

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

Tuesday, September 22, 2020, 08:45

IGP1 = 0.003 Torr 

TGHT = 1.3 V, 100.5 A

Autoramp is set to 120 A at same conditions 

Tuesday, September 22, 2020, 09:36

IGP1 = 0.0001 torr

TGHT = 1.6 v, 122 A

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

Tuesday, September 22, 2020, 10:19

IGP1 = 5.4e-5 Torr

TGHT = 2.9 V, 200.5 A

Omega = 1123 °C

AP = 1164 °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, September 22, 2020, 11:24

TGHT = 447.8 A, 7.4 V

IGP1 =  3.7e-5 Torr

Omega = 1750 °C

AP = 1720.4 °C

Autoramp set to 520 A at same conditions

 Tuesday, September 22, 2020, 11:38

TGHT = 8.9 V, 525.8 A

IGP1 = 4.8e-5 Torr

Omega = 1914 °C

AP = 1835.6 °C

Autoramp set to 560 A at same conditions

Tuesday, September 22, 2020, 12:13

Omega 2038 °C 

Tuesday, September 22, 2020, 12:14

Current manually reduced to 555 A 

TGHT = 9.8 V, 560.8 A

IGP1 = 2.5e-5 Torr

Tuesday, September 22, 2020, 12:17 

Omega = 2030 °C

Tuesday, September 22, 2020, 12:19 

Current manually reduced to 550 A 

TGHT = 9.8 V, 547.8 A

IGP1 = 2.3e-5 Torr

Tuesday, September 22, 2020, 12:27 

Omega = 2027 °C

Tuesday, September 22, 2020, 12:27

Current manually reduced to 540 A 

TGHT = 9.6 V, 541.6 A

IGP1 = 2e-5 Torr

Tuesday, September 22, 2020, 12:34

Voltage suddenly increased!

TGHT = 10.3 V, 533.8 A

IGP1 = 2.9e-5 Torr

Omega = 2129 °C

Current reduced manually to 520 A to compensate the voltage increment 

Tuesday, September 22, 2020, 12:52

Another voltage increment 

TGHT = 9.9 V, 519.75 A

IGP1 = 1.9 e-5 Torr

Omega 2108 °C

Current reduced manually to 500 A to compensate the voltage increment 

Omega = 2070 °C

Tuesday, September 22, 2020, 13:05 

TGHT = 9.4 V, 492.4 A

Omega = 2063 °C

Tuesday, September 22, 2020, 13:08

Another voltage increment! this time it was an spike 

Tuesday, September 22, 2020, 16:13

After 5 hours

IGP1 = 6e-6 Torr

TGHT = 9.5 V, 488 A

Autoramp was set to 0 A at 2 A/min 

Omega = 2044 °C

AP = 2003.7 °C

Wednesday, September 23, 2020, 16:18

EVAP2 vented with air, 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 

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

 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

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

 Tuesday, April 13, 2021, 09:51

IGP1 = 2.5e-7 Torr

Tuesday, April 13, 2021, 10:17 

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 15A 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 0.5A until 44.5A, 4.61V (2120 °C), the wire was kept at that temperature for 6 hours.

After that time, the current was ramped to 0A at 0.5A/min.

Thursday, April 15, 2021, 18:24

Tantalum samples were loaded in a tantalum testing tube and installed in the EVAP2 to heat under vacuum for 3 days at 2000 degC (~500A, 4kW).

The temperature is measured with the Omega pyrometer (slope 0.98)

Some of the samples are in contact with graphite and enclosed with Ta caps, the other samples are not in contact with carbon.

The testing tube is wrapped with 3 Ta heat shields and is not TaC coated.

Thursday, April 15, 2021, 18:31

IGP1 = 4.5e-7 Torr

Good vacuum = 3e-2 Torr

Bad vacuum = 5e-2Torr

The TGHT will be ramped to 500A at 5A/min

Thursday, April 15, 2021, 20:00

Finished ramping

TGHT = 502 A, 8.22 V, Omega 2012 degC

Sunday, April 18, 2021, 20:38

After 3 days at ~2000 degC, TGHT was ramped at -2A/min to 0A

Aaron Schmidt wrote:

Wednesday, August 07, 2024, 15:36: Roughing. Had initially been roughed & TP started w/ Marla CS, however it timed out. Restarting. Wednesday, August 07, 2024, 15:37: TP on. Wednesday, August 07, 2024, 15:46: Tripped at 4 KRPM. Restarted. Up to 5 KRPM. Failed to start. Thursday, August 08, 2024, 10:00: TP started.  Thursday, August 08, 2024, 10:12: TP Tripped but nearly spun up. Reset & Restarted. TP Green / on.

Thursday, August 08, 2024, 10:43

A cartridge was filled with graphite foils and loaded in an uncoated tantalum tube. The tube was wrapped with four Ta-sheets. A Ta-foil was placed in the tube's right end for measuring the temperature.

Good vacuum 3e-5 Torr

Bad vacuum 5e-5 Torr

Initial IGP1 = 5.06E-7 Torr

Starting ramp at 1A/min to 200 A

Friday, August 09, 2024, 09:40 Pressure started to rise, but temperature is not within pyrometer range yet. Current 42 A, Voltage 0.5 V

Friday, August 09, 2024, 10:46 Pressure started to reduce (peak 1.4e-5 Torr). Temperature is not within pyrometer range yet Current 100 A, Voltage 1.3 V

Friday, August 09, 2024, 11:28 Temperature started to be detected, but not stable enough. Current 135 A, Voltage 1.9 V

Friday, August 09, 2024, 12:54 Temperature 1129 °C, current 196 A, voltage 3 V.

Friday, August 09, 2024, 12:56

Next ramp 0.5A/min while taking temperature readings periodically until 250A

Friday, August 09, 2024, 14:45

IGP1 = 1.0e-6 Torr

Next ramp 1A/min to 480 A aiming at 2000 °C

Friday, August 09, 2024, 17:13

IGP1 = 1.9e-6 Torr, Current 327A, Voltage 5.3V

Ramp changed to 2A/min to 480 A aiming at 2000 °C

Coolded down after 4 hours at ~2000°C

at -2A/min