Monday, November 10, 2014, 13:51

target container was sprayed with TaC on friday and sintered over the weekend.
vented and removed from evap2 this morning, looks good.

this container will be used as a round2 for UCx #11 since the last container broke as it was being assembled.

hopefully all the materials can be recovered and re-used/re-loaded into the new container...

Laura Lambert wrote:

Thursday, October 23, 2014, 15:34 *See elog #142 for target description* one endcap still in place, one removed for OMEGA-IR2C beam to reach material [see pic] no heat shields currently being pumped down  Friday, October 24, 2014, 11:34 EVAP2 pumped down overnight. IGP1 = 7e-7 Torr HS water valves opened, no leaks detected. TGHT will be ramped up to 1400C TBHT will be ramped up to 230A  Friday, October 24, 2014, 14:32 TBHT reached 230A, TGHT reached 1400C Stepped TGHT up manually to 1600C; TGHT = 693A, 10.6V [see pic]  Friday, October 24, 2014, 15:58 TGHT = 760A, 12.07V [local read back] = setpoint. epics readback TGHT = 754.8A, 11.76V OMEGA = 1700C Friday, October 24, 2014, 16:26 OMEGA = 1800C epics readback TGHT = 828.7A, 13.15V Friday, October 24, 2014, 16:34 OMEGA = 1900C epics readback TGHT = 899A, 14.53V Friday, October 24, 2014, 16:46 OMEGA = 2000C epics readback TGHT = 967A, 15.8V MIKRON target spot on SiC = 1650C, e = 0.97

 Tuesday, November 04, 2014, 15:59

Target was heated up to 2000C and last for about 1.5 days before the right leg (ionizer points into the page) broke off. 

Interesting discovery...  The "yellowish" crystals are forming on the discs. 

Suspecting a phase transformation of 6H (hexagonal/- alpha SiC (hexagonal) polytype to 3C(cubic) - beta SiC

More study needs to be done... 

See elog # 168.

The leg of this target was repaired in the Machine shop. 

THIS TARGET WILL NOT BE USED ONLINE -  IT WILL BE USED FOR OFFLINE R&D PURPOSES.

Tuesday, November 04, 2014, 16:08

The purpose of this experiment is to improve the fabrication of SiC.  Previously, the SiC target was heated to 2000c and yellow crystals were observed.

In this experiment, 10g of SiC powder (7um size) was previously milled down (actual size to be determined under SEM).  The powder was mixed with 5% PVA and the slurry was pour onto a glass and let dry.  The semi-dry slurry was rolled up into balls. The SiC balls were let dry in over (115C) over night. Taken out 2.903g SiC + 5% PVA, it's rolled up with a small sheet of graphite foil.  Then the targer boat is filled with the sample and wrapped with 3-layers of Ta-heat shield.

The sample will be heated up to 2000C to see if the yellow crystals are reproducible.  It is suspected that there might be a phase transformation from 6H alpha-SiC to 3C beta-SiC. 

Chamber is currently being pumped down... 

Wednesday, November 05, 2014, 14:04

TGHT was ramped up over night, currently at 485A = 1800 C. 

Will do manual step up to get to 2000C. 

 Thursday, October 23, 2014, 15:34

*See elog #142 for target description*

one endcap still in place, one removed for OMEGA-IR2C beam to reach material [see pic]

no heat shields

currently being pumped down

 Friday, October 24, 2014, 11:34

EVAP2 pumped down overnight.

IGP1 = 7e-7 Torr

HS water valves opened, no leaks detected.

TGHT will be ramped up to 1400C

TBHT will be ramped up to 230A

 Friday, October 24, 2014, 14:32

TBHT reached 230A, TGHT reached 1400C

Stepped TGHT up manually to 1600C; TGHT = 693A, 10.6V [see pic]

 Friday, October 24, 2014, 15:58

TGHT = 760A, 12.07V [local read back] = setpoint.

epics readback TGHT = 754.8A, 11.76V

OMEGA = 1700C

Friday, October 24, 2014, 16:26

OMEGA = 1800C

epics readback TGHT = 828.7A, 13.15V

Friday, October 24, 2014, 16:34

OMEGA = 1900C

epics readback TGHT = 899A, 14.53V

Friday, October 24, 2014, 16:46

OMEGA = 2000C

epics readback TGHT = 967A, 15.8V

MIKRON target spot on SiC = 1650C, e = 0.97

Thursday, October 09, 2014, 17:36

Target boat consists of 5 Nb discs.  Each disc is wrapped with Nb foil, and to be heated to 1400C for 4 hours.

Chamber has been pumped down to 6.5e-7 Torr.  HS valves open - no leaks detected.

TGHT has ramped to 330A to maintain the 1400C temperature. 

At 21:30, the target will be cooled down.

Temperature can be monitored from this link:

https://www.dropbox.com/sh/kor6gnutnlimqxw/AAAee2yb-Hj3JEbBysrAW2oYa?dl=0

 Thursday, October 09, 2014, 22:48

Samples have been heated at 1420C for over 4 hours.  

Pressure at 6.6 e-7 Torr. 

Cooling process initiated, ramping down at 2A/min. 

 Friday, October 10, 2014, 13:50

Samples were successfully conditions; no signs of any damage.

Laura Lambert wrote:

John Wong wrote: Laura Lambert wrote:  Thursday, October 02, 2014, 11:51 Target container sprayed with TaC, currently drying in fume hood  Monday, October 06, 2014, 12:11 Target container & back block is wrapped with 3 layers of Ta-heat shield.  The chamber has been pumped down over the weekend.  Pressure currently at 2.23e-7 Torr.  HS water valves open; no leaks detected. TGHT will be ramped up to 580A at 0.2A/min TBHT will be ramped up to 230A at 0.2A/min.    Monday, October 06, 2014, 12:16 Stepped up both TGHT/TBHT to 35A.  Tuesday, October 07, 2014, 12:54 TBHT reached to 230A/3.7V and TGHT is still ramping up, currently at 303A/4.5V. Temp measured with Omega-IR2 = 1165C with e'=0.85 Pressure @ 5.2e-7 Torr.  Increase ramping rate to 2A/min.  Tuesday, October 07, 2014, 16:21 TGHT is now at 580A and TGHT at 230A. Temperature is measured with OMEGA-IR2, MIKRON, and analog pyrometer - All the measurements are agreed at 1700C (without the tantalum emissivity correction of 250C) The OMEGA-IR2 slope has changed to 0.97 for the correction - The real temperature reading from the display is showing 1935C. Now... attempting to low TBHT to see any temperature change.  Tuesday, October 07, 2014, 17:01 TGHT @ 580A. TBHT = 180C, Temp = 1925C TBHT = 130C, Temp = 1920C Not much of change in the temperature on the target tube... Tuesday, October 07, 2014, 17:07 Attempting to increase the temperature to 2000C TGHT = 600A, Temp = 1955C TGHT = 620A, Temp = 2000C Target will continue heating at this temperature overnight... Will continue to monitor.  Tuesday, October 07, 2014, 20:59 After almost 4 hours of heating at 620A on TGHT, the temperature has dropped to 1980C.   Pressure is coming down to 1.17e-6 Torr.   Increased TGHT to 630A to maintain temp @ 2000C    Wednesday, October 08, 2014, 11:46 Temperature readout from omega-IR2C = 2054C TGHT = 11.14V, 628.0A TBHT = 2.01V, 129.8A IGP1 = 8.2e-7Torr Initiating auto-cool for TGHT @ 2A/min, TBHT @ 1A/min  Thursday, October 09, 2014, 16:00 vented in air and opened up this morning target container looks good!

 Thursday, October 09, 2014, 16:36

Photos for the OMEGA-IR2C temp measurement can be found on this link (see also the subfolder for the heating process):

https://www.dropbox.com/sh/n5sxcepg7e847xw/AACMubuKW1idd49D1Nz_0diNa?dl=0

Thursday, October 09, 2014, 15:56

The target boat contains 5 samples of Nb discs.  Each disc is wrapped with Nb foil and labelled. 

Samples will be heated up to 1400C for 4 hours. 

chamber has been pumped down to 3.9e-6 Torr. HS valves open - no leaks detected.

Ramping up TGHT...

John Wong wrote:

Laura Lambert wrote:  Thursday, October 02, 2014, 11:51 Target container sprayed with TaC, currently drying in fume hood  Monday, October 06, 2014, 12:11 Target container & back block is wrapped with 3 layers of Ta-heat shield.  The chamber has been pumped down over the weekend.  Pressure currently at 2.23e-7 Torr.  HS water valves open; no leaks detected. TGHT will be ramped up to 580A at 0.2A/min TBHT will be ramped up to 230A at 0.2A/min.    Monday, October 06, 2014, 12:16 Stepped up both TGHT/TBHT to 35A.  Tuesday, October 07, 2014, 12:54 TBHT reached to 230A/3.7V and TGHT is still ramping up, currently at 303A/4.5V. Temp measured with Omega-IR2 = 1165C with e'=0.85 Pressure @ 5.2e-7 Torr.  Increase ramping rate to 2A/min.  Tuesday, October 07, 2014, 16:21 TGHT is now at 580A and TGHT at 230A. Temperature is measured with OMEGA-IR2, MIKRON, and analog pyrometer - All the measurements are agreed at 1700C (without the tantalum emissivity correction of 250C) The OMEGA-IR2 slope has changed to 0.97 for the correction - The real temperature reading from the display is showing 1935C. Now... attempting to low TBHT to see any temperature change.  Tuesday, October 07, 2014, 17:01 TGHT @ 580A. TBHT = 180C, Temp = 1925C TBHT = 130C, Temp = 1920C Not much of change in the temperature on the target tube... Tuesday, October 07, 2014, 17:07 Attempting to increase the temperature to 2000C TGHT = 600A, Temp = 1955C TGHT = 620A, Temp = 2000C Target will continue heating at this temperature overnight... Will continue to monitor.  Tuesday, October 07, 2014, 20:59 After almost 4 hours of heating at 620A on TGHT, the temperature has dropped to 1980C.   Pressure is coming down to 1.17e-6 Torr.   Increased TGHT to 630A to maintain temp @ 2000C

 Wednesday, October 08, 2014, 11:46

Temperature readout from omega-IR2C = 2054C

TGHT = 11.14V, 628.0A

TBHT = 2.01V, 129.8A

IGP1 = 8.2e-7Torr

Initiating auto-cool for TGHT @ 2A/min, TBHT @ 1A/min

 Thursday, October 09, 2014, 16:00

vented in air and opened up this morning

target container looks good!

Laura Lambert wrote:

Thursday, October 02, 2014, 11:51 Target container sprayed with TaC, currently drying in fume hood  Monday, October 06, 2014, 12:11 Target container & back block is wrapped with 3 layers of Ta-heat shield.  The chamber has been pumped down over the weekend.  Pressure currently at 2.23e-7 Torr.  HS water valves open; no leaks detected. TGHT will be ramped up to 580A at 0.2A/min TBHT will be ramped up to 230A at 0.2A/min.

 Monday, October 06, 2014, 12:16

Stepped up both TGHT/TBHT to 35A. 

Tuesday, October 07, 2014, 12:54

TBHT reached to 230A/3.7V and TGHT is still ramping up, currently at 303A/4.5V. Temp measured with Omega-IR2 = 1165C with e'=0.85

Pressure @ 5.2e-7 Torr. 

Increase ramping rate to 2A/min.

 Tuesday, October 07, 2014, 16:21

TGHT is now at 580A and TGHT at 230A.

Temperature is measured with OMEGA-IR2, MIKRON, and analog pyrometer - All the measurements are agreed at 1700C (without the tantalum emissivity correction of 250C)

The OMEGA-IR2 slope has changed to 0.97 for the correction - The real temperature reading from the display is showing 1935C.

Now... attempting to low TBHT to see any temperature change.

 Tuesday, October 07, 2014, 17:01

TGHT @ 580A.

TBHT = 180C, Temp = 1925C

TBHT = 130C, Temp = 1920C

Not much of change in the temperature on the target tube...

Tuesday, October 07, 2014, 17:07

Attempting to increase the temperature to 2000C

TGHT = 600A, Temp = 1955C

TGHT = 620A, Temp = 2000C

Target will continue heating at this temperature overnight... Will continue to monitor.

 Tuesday, October 07, 2014, 20:59

After almost 4 hours of heating at 620A on TGHT, the temperature has dropped to 1980C.  

Pressure is coming down to 1.17e-6 Torr.  

Increased TGHT to 630A to maintain temp @ 2000C

John Wong wrote:

Thursday, October 02, 2014, 11:22 It was found that after the last process, Evap#2 has broken insulators - the cylinder insulator that supports the target centre legs and the block insulator that supports the terminals.   Informed Anders/Rick.

 Friday, October 03, 2014

• Insulators replaced. Torque 55 in lbs on all fasteners.
• Cleaned TGHT terminals with scotch-brite and methanol.
•  New (clean) heat shield prepared WO-39230-2.
• Re-installed right side heat shield alignment pin (previously removed to allow line of sight to the target).

 Thursday, October 02, 2014, 11:51

Target container sprayed with TaC, currently drying in fume hood

 Monday, October 06, 2014, 12:11

Target container & back block is wrapped with 3 layers of Ta-heat shield.  The chamber has been pumped down over the weekend. 

Pressure currently at 2.23e-7 Torr. 

HS water valves open; no leaks detected.

TGHT will be ramped up to 580A at 0.2A/min

TBHT will be ramped up to 230A at 0.2A/min.

 Thursday, October 02, 2014, 11:22

It was found that after the last process, Evap#2 has broken insulators - the cylinder insulator that supports the target centre legs and the block insulator that supports the terminals.  

Informed Anders/Rick.

Thursday, September 25, 2014, 17:32

Target boat is filled with Ta-coated endcaps.  The caps are stacked together.  In between each cap, a piece of graphite foil is used for separation so the Ta caps would not fused. 

See link for photos:

https://www.dropbox.com/sh/rydtdho6ggh4l3l/AAAYmvqT0mVQ_pnz4iecS4ksa?dl=0

The boat is wrapped with 3-layers of heatshields.  The chamber is currently being pumped down.

TGHT will be ramped up to 580A and the temperature will be measured.

Monday, September 29, 2014, 11:12

TGHt was stepped up to 40A on last Friday and chamber continues to pump down over the weekend.

Vac @ 2.56e-6 Torr, mp @ 19mTorr.

Ramping up TGHT 580A at 1.0A/min.

 Monday, September 29, 2014, 11:50

TGHT tripped off at 53A.  Reduce ramping rate to 0.5A/min for now.

 Monday, September 29, 2014, 16:17

Vacuum is coming down to 9.5e-7 Torr.  Increased ramping rate to 1.0A/min.

 Tuesday, September 30, 2014, 11:59

TGHT reached to 580A/10.18V.  Target has been heated at that current for almost 12 hrs. Vac @ 4.9e-7 Torr.

Local temp measured with Mikron = (1500C + 250 C correction) = 1750C

Cooling down at 2A/min.

 Thursday, October 02, 2014, 11:13

The coating is fully sintered; no sign of any damage on the endcaps.  

Process is successful.  

Laura Lambert wrote:

Tuesday, September 23, 2014, 15:00 A new target boat [new design with no end caps] was sprayed with TaC coating and let dry. The target boat is wrapped with 3-layers of Ta-heat shield. The boat was installed in EVAP2, chamber is currently being pumped down.

 Tuesday, September 23, 2014, 18:31

Chamber was pumped down to 2.5e-6 Torr. 

HS water valve open; no leaks detected.

Stepping up TGHT to 40A - pressure is increasing...

 Tuesday, September 23, 2014, 19:05

Auto-ramping TGHT to 580A at 0.5A/min.  Temperature will be measured and TGHt will be adjusted accordingly.

 Wednesday, September 24, 2014, 11:57

Pressure is stable at 2.2-6 Torr as TGHT is ramping up.  Increase ramping rate to 2.0A/min.  Currently TGHT at 540A.

 Wednesday, September 24, 2014, 15:36

TGHT at 580A for 2 hrs.  Inner tube temp (left side wall, viewing from the window port) ~1800C (measured with Mikron = 1550C +250C em. correction); Vac @ 1.67e-6 Torr.

Temperature measurement distance from the window to Mikron = 45cm.

Increase TGHT to reach 2000C (Mikron @ 1750C)

 Wednesday, September 24, 2014, 18:14

TGHT has gone up to 725A/13.2V.  Temp measured at 1740C (+250C = ~2000C).  Pressure gone up to 5.5e-6 Torr and it's coming down slowly.

Will continue heating at this temperature for a few hours; then cool down afterward.

 Wednesday, September 24, 2014, 18:56

Temperature is pretty stable at 1740C on Mikron, and pressure is still coming down, currently at 2.9e-6 Torr.

Slow ramping down TGHT at 1.0A/min.  The chamber should be ready for venting tomorrow. 

Target boat will be inspected.

 Thursday, September 25, 2014, 17:25.

The boat was inspected and it turned out great!  The coating was fully sintered and there is no sign of damage on the boat. 

See the link for photos.

https://www.dropbox.com/sh/m7ycqhkj4avfull/AABHVTweTsP4ajeWZ6uoY010a?dl=0

 Tuesday, September 23, 2014, 15:00

A new target boat [new design with no end caps] was sprayed with TaC coating and let dry.

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

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

 Thursday, September 11, 2014, 13:14

The target container end caps were coated with TaC spray and let dry.

The caps are inserted in the target boat wrapped in graphite foil with 3 x Ta-heat shields.

The chamber is currently pumping down.

 Friday, September 12, 2014, 14:17

Chamber was pumped down overnight.

HS cooling water valves opened, no leaks detected.

IGP1 = 7.2e-7 Torr.

TGHT stepped up to 35A, TBHT at 0A.

Waited ~30min, current stabilized, vacuum started to drop, auto-ramp initiated at 0.2A/min.

Will ramp TGHT to 580A with a max 10V.

Good vacuum: 3.00e-5 Torr; Bad vacuum: 4.00e-5 Torr.

 Monday, September 15, 2014, 11:31

TGHT stopped at 500A due to not high enough voltage max.

Increased max voltage to 12V

 Monday, September 15, 2014, 14:17

IGP1 = 6.3e-7 Torr

Increasing ramping rate to 1.0A/min

 Tuesday, September 16, 2014, 09:04

TGHT reached 577A and finished auto-ramping, then proceeded to drop down to 560A overnight.

Increased max voltage to 13.05A and TGHT to 580A.

 Tuesday, September 16, 2014, 13:52

TGHT reached 580A and sat there for ~5hrs.

IGP1 = 6.1e-7 Torr.

Initiating auto-cool at 2.0A/min.

 Wednesday, September 17, 2014, 13:03

Vented in air.

Opened up....looked 'deceivingly' ok.

then i took a layer of Ta off....grrrr  

the 1st layer of Ta was holding the boat together. as soon as that layer was taken off the target boat broke.

see attached photos.

John Wong wrote:

Wednesday, August 06, 2014, 15:59 Target consists of 400 Ta discs.  Total packed length 4.5cm Total mass 47.490g. Re foil inserted. Wednesday, August 06, 2014, 16:07 Chamber is currently being pumped down. No Ta heat-shield wrapped (Want to check the temperature without it)  One end-cap inserted on left (wrt ionizer into the page). TGHT and TBHT will be ramped up to 820A/230A at 2A/min.  Wednesday, August 06, 2014, 18:07 Vacuum at 2.3e-6 Torr.  HS water valve opened.  No leaks. Initiated auto-ramping.  Thursday, August 07, 2014, 11:39 Target has been heated for 11hrs at TGHT/TBHT = 820A/230A. Temperature measured with pyrometer: Target leg = 1600C + (250 correction for e=0.25) = 1850C Inside target material = dark, temp can't be measured. Cooling down at 2A/min for TGHT and 1A/min TBHT.

 Friday, August 08, 2014, 15:14

Vented in air and opened up up this morning.

Endcaps inserted and expanded.

Rh foil and salts added.

John Wong wrote:

Laura Lambert wrote:  Tuesday, August 05, 2014, 12:02 The target container end caps were coated with TaC spray and let dry. The caps are inserted in the target boat vertically, wrapped in graphite foil with 3 x Ta-heat shield. [see attached photo] The chamber is currently being pumped down.    Tuesday, August 05, 2014, 17:19 HS water valve opened; no leaks detected.  Pressure @ 2.5e-6 Torr. Ramping up TGHT to 580A @ 1A/min.

 Thursday, August 07, 2014, 08:11

Yesterday the target boat was taken out.

The boat broke as it turns out it was used for a Niobium target and therefore wasn't coated with TaC.

The end caps were fully sintered.

Wednesday, August 06, 2014, 15:59

Target consists of 400 Ta discs. 

Total packed length 4.5cm

Total mass 47.490g.

Re foil inserted.

Wednesday, August 06, 2014, 16:07

Chamber is currently being pumped down.

No Ta heat-shield wrapped (Want to check the temperature without it) 

One end-cap inserted on left (wrt ionizer into the page).

TGHT and TBHT will be ramped up to 820A/230A at 2A/min.

 Wednesday, August 06, 2014, 18:07

Vacuum at 2.3e-6 Torr.  HS water valve opened.  No leaks.

Initiated auto-ramping.

 Thursday, August 07, 2014, 11:39

Target has been heated for 11hrs at TGHT/TBHT = 820A/230A.

Temperature measured with pyrometer:

Target leg = 1600C + (250 correction for e=0.25) = 1850C

Inside target material = dark, temp can't be measured.

Cooling down at 2A/min for TGHT and 1A/min TBHT.

Laura Lambert wrote:

Tuesday, August 05, 2014, 12:02 The target container end caps were coated with TaC spray and let dry. The caps are inserted in the target boat vertically, wrapped in graphite foil with 3 x Ta-heat shield. [see attached photo] The chamber is currently being pumped down.

 Tuesday, August 05, 2014, 17:19

HS water valve opened; no leaks detected. 

Pressure @ 2.5e-6 Torr.

Ramping up TGHT to 580A @ 1A/min.