Tuesday, February 25, 2014, 16:08

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

The caps are inserted in the target boat vertically with no heat shield and no graphite foil. [see attached photo]

The chamber is currently being pumped down overnight.

 Wednesday, February 26, 2014, 09:54

Chamber was pumped down overnight to 4.2e-7 Torr.

HS cooling water valves opened; no leaks detected.

TGHT was stepped up to 35A, voltage max set at 14V. TBHT currently at 0A.

Waited ~20min, current stabilized, vacuum started to drop, auto-ramp initiated at 0.2A/min and max setpoint to 700A.

Will ramp up to 700A rather than the usual 580A due to last round of endcaps not fully sintering at 580A with new target boat design.

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

 Thursday, February 27, 2014, 09:38

TGHT has been slowly ramping up overnight at a rate of 0.2A/min.

IGP1 = 2.8e-7 Torr; TGHT = 311A, 4.3V

Stepping ramping rate up to 2.0A/min.

 Friday, February 28, 2014, 08:53

TGHT reached max setpoint of 700A yesterday evening.

Internal temp measured with Mikron = 1700C

IGP1 = 3e-7 Torr 

Power = 12.95V

Initiating auto-cooling at 2.0A/min.

 Monday, March 03, 2014, 11:46

Vented and opened chamber this morning.

End caps not fully sintered! 

See attached photo comparison of fully sintered [grey], partially sintered from this round [light green] and pre-sinter [dark green].

Will not bother re-sintering, as partial sinter is enough.

There was no signal going from the coils to the PLC. After manipulating the connection points on the coil a signal could again be established. Frequency is ~ 40Hz.

 Friday, March 07, 2014, 11:41

The target container end-caps were sintered previously, but did not fully complete the sintering process [See elog entry # 119 EVAP2]

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

The chamber was pumped down overnight.

IGP1 = 2e-7 Torr

HS cooling water valves were opened; no leaks detected.

TGHT was stepped up to 35A, voltage max set at 9.05V. TBHT currently at 0A.

 Friday, March 07, 2014, 11:52

Waited ~20min, current stabilized, vacuum started to drop, auto-ramp initiated at 0.5A/min and max setpoint to 500A.

Will ramp to 500A due to last failed round of end caps breaking with 3-ta heat shields at 580A.

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

 Friday, March 07, 2014, 13:21

IGP1 = 8e-7 Torr.

TGHT = 72A

Vacuum stable; therefore, increasing ramping rate up to 1.0A/min

 Friday, March 07, 2014, 14:20

IGP1 = 9.8e-7 Torr

TGHT = 130A

Vacuum stable; therefore, increasing ramping rate up to 2.0A/min

Laura Lambert wrote:

Friday, March 07, 2014, 11:41 The target container end-caps were sintered previously, but did not fully complete the sintering process [See elog entry # 119 EVAP2] The caps are inserted in the target boat wrapped in graphite foils with 3 x Ta-heat shields. The chamber was pumped down overnight. IGP1 = 2e-7 Torr HS cooling water valves were opened; no leaks detected. TGHT was stepped up to 35A, voltage max set at 9.05V. TBHT currently at 0A.  Friday, March 07, 2014, 11:52 Waited ~20min, current stabilized, vacuum started to drop, auto-ramp initiated at 0.5A/min and max setpoint to 500A. Will ramp to 500A due to last failed round of end caps breaking with 3-ta heat shields at 580A. Good vacuum: 3.00e-5 Torr; Bad vacuum: 4.00e-5 Torr.  Friday, March 07, 2014, 13:21 IGP1 = 8e-7 Torr. TGHT = 72A Vacuum stable; therefore, increasing ramping rate up to 1.0A/min  Friday, March 07, 2014, 14:20 IGP1 = 9.8e-7 Torr TGHT = 130A Vacuum stable; therefore, increasing ramping rate up to 2.0A/min

Friday, March 07, 2014, 22:22  

Target current was at 500A before it tripped off on the chiller.   Tried to reset the chiller but to no avail.  Don't know what is going on yet. 

The TGHT/TBHT cooling water is still on, and this should OK while the HOT target boat is cooling down at the moment. 

Will leave it for now and further investigate on Monday

Monday, March 10, 2014, 11:44

Rick replaced the backing pump hose from 1.5" to 2.0" for better flow.  And the HEPA filter was checked - it looks OK.

Monday, March 10, 2014, 11:45

The chiller tripped off on March 7, 2014.

• Water is not flowing into the chiller; paddle wheel shows no signal.
• Tried turning on the chiller locally; a few seconds later, it tripped off. 
• Motor is not responding;
• EPICS is not responding;
• All other water flow signals to TGHT, TBHT, HS, are responding;

Continue investigating...

 Monday, March 10, 2014, 14:36

The water line to the chiller is disconnected, and is re-connected straight to the TGHT power supply.  The paddle wheel is responding - the cooling line in the power supply is not blocked.

It is confirmed the chiller is broken. 

Will discuss if we can use the Evaporator without a chiller but with the DI water connected directly to the TGHT power supply....

Friday, March 14, 2014, 14:50  

The chiller was replaced with a "new" one.  

Checked the chiller interlock - It's working.  

The evaporator is now operational. 

 Friday, March 21, 2014, 16:19

Note about Auto-ramping program.

Previously the auto-rampiong program takes the Chiller as part of the reference to the interlocks.  Because the New chiller is not connected to EPICS; all the references to the Chiller on the auto-ramping program has been removed in order for it to function. 

Thursday, March 27, 2014, 17:38

TEST #1

WC slurry was prepared in non-aqueous environment (see lab book for procedures).  The solution was dripped on two Ta plates (3.1cm2) and let dry. 

Another Ta plate (3.1 cm2) was sprayed with TaC coating (for comparison).

All 3 coated Ta plates are put in a target boat and the boat is wrapped with 3 layers of Ta-heat shields.

HS water valves open; no leaks detected.

TGHT will be ramped up to 700A at 2.0A/min.

RGA is running and gases are being monitored.  See link:

https://www.dropbox.com/sh/625xl7zgepbybmu/GQJTlMo-5a

 Friday, March 28, 2014, 09:13

TGHT reached to 700A and samples were heated up over night. 

Cooling down Evap at 4A/min. 

 Tuesday, April 01, 2014, 17:37

Previous samples, namely WC#1, #2, TC#1 were fully sinterred.  See above link for photos.

TEST#2

Samples WC#3, #4, #5 are sprayed coated with WC solution.  Grains were pre-treated at 400RPM.

These 3 new samples are loaded in a boat, wrapped with 3 layers of Ta-heat shields.

Chamber is pumped down; no water leaks are detected.

TGHT will be ramped up to 700A at 2.0A/min

RGA is running.

Samples were analyzed with SEM/EDX.  The results are inconclusive because W and Ta peaks are very close together.  And WC coated layer may be even too thin to analyze. 

 Monday, April 14, 2014, 16:32

Test#3:  Coated WC on Endcap.  Total mass WC ~350mg.

Sintered at 500A/9.5V; measure temperature on actual sample surface ~1700C.  Sample heated >24hr.

Cooling down TGHT at 2A/min.  IG currently at 3.1e-7 Torr.

 Thursday, April 24, 2014, 17:25

The purpose of this experiment is to see if the carbon mesh is suitable for coating and sintering with uranium carbide.  For this test, the mesh is coated with WC slurry (previously prepared).

 The carbon mesh disks are bought from ERG aerospace corporation; the specifications of the mesh can be found on the link:  http://www.ergaerospace.com/RVC-properties.htm

Photos, EDX, SEM, RGA, etc... and be found on this link:  https://www.dropbox.com/sh/6ic932wu8yl9ad2/7rHFTiSzLY

Thursday, April 24, 2014, 17:51 

TEST #1:  Carbon Mesh, WC - RF sputtered - Then WC coated and sintered.

Target boat is loaded with a piece of WC coated carbon mesh (1/4 size cut out with the laser cutter).  Chamber is pumping down, currently at 3.2e-6 Torr.

HS water valve open - no leaks are detected. 

TGHT will be ramped up to 500A at 1.0A/min. 

RGA is running.  

Material temp will be measured... 

Monday, May 05, 2014, 17:35

Test #1:

TGHT was ramped up to 680A/13.77V.  Vacuum was at 1.62e-6 Torr (and coming down).  Carbon mesh was heated up to 1900C.   See the link to the dropbox above for more results.

Monday, May 05, 2014, 17:39

Test #2:  Carbon mesh (pure) coated with WC - then sintered. 

Chamber has been pumped down to 3.5 e-6 Torr. 

Sample will be heated up to 500A at 1.0A/min.  (Then step up to 680A while monitoring the vacuum).

RGA is running. 

 Wednesday, May 07, 2014, 14:36

Observations:

TGHT was at 650A/12.96V for 6 hrs and temperature was measured at 1930C. 

At some point after that (~20:40hr on May 6), the voltage went up to 14.77V (current remained constant at 650A), the temp went up 2110C - for only about 45 minute before the voltage dropped

back down to 12.53V and the temperature ~1800C.  Is the boat creaking more??? There were a few crack lines on the boat after Test#1. 

Today, TGHT was raised up to 725A and after an hour at that current the temperature was measured at 1930A. 

Now, at Wednesday, May 07, 2014, 14:47 - Lowered the current back to 685A/13.78V - temperature measured at 1900C. 

One thing to note... the vacuum is showing a lot of spikes but remains at around 7.5e-7 Torr. 

The RGA/Current/Voltage/Temp can be found here: https://www.dropbox.com/sh/1yaa7ez3nydl67m/8v4ZRT2slq

Thursday, May 29, 2014, 16:56 

The process is done. Chamber was vented...

Purpose: Sinter one sample of each of TiC, VC, Cr3C2, ZrC, NbC, Mo2C, TaC, and WC on 5x10 mm tantalum foil to see if the samples are usable for SEM.

Samples were prepared using a solution of PEG (2.56 g), PVB (2.45 g), paraffin oil (1.12 g), MEK (15 mL), and EtOH (23 mL). Slurries made using 0.0013 mol of each carbide with ~230 uL of the solution. Applied via paintbrush onto 5x10 mm tantalum foil. 

The samples were placed directly on the target boat, no graphite layer between. We will check to see if the tantalum foil fuses to the boat or not.

Currently (May 29th), the chamber is still pumping down. John and I will continue the procedure tomorrow.

 Pressure down to 7.1e-7 Torr. Water valve to heat shield was opened; pressure remained stable. 

Current turned up to 40 A for now.  Will increase at 2 A/min up to 500 A over the weekend, then on Monday we will turn it up to 600 A and check the temperature. 

Auto-ramp started. Max current = 500 A, voltage = 11.05 V. Current is being increased at 2 A/min. In the first 20 minutes, the pressure went up to about 10E-6 T, but has slowly decreased since then. Everything looks ok. The system will be left until Monday morning (June 9th). 

Manually changed current from 500 to 615 A, monitoring the temperature. Temperature went from 1657 C up to 1838 C. Pressure increased up to 7.2e-7 T. Samples should be left for about 4 hours (615 A started just before 13:00), then the goal is to ramp current back to zero.

 Target boat is now being cooled at 1 A/min from the starting point (616 A) down to 0 A. 

 Monday, July 28, 2014, 14:41

Total number of foils: 445 discs

Total mass of materials [incl graphite foils]: 49.027 g

Total length packed: 11.2 cm

Container has no Ta heat shields.

Currently being pumped down.

Laura Lambert wrote:

Monday, July 28, 2014, 14:41 Total number of foils: 445 discs Total mass of materials [incl graphite foils]: 49.027 g Total length packed: 11.2 cm Container has no Ta heat shields. Currently being pumped down.

 Tuesday, July 29, 2014, 11:19

Chamber was pumped down overnight to ~5.5e-7 torr.

HS water valve opened; no leaks were detected.

Stepped up TGHT/TBHT to 40A. IG went up 8e-6 Torr and stabilized. 

Initiated auto-ramping TGHT @ 580A, TBHt @ 230A at 0.2A/min

The maximum current of 580A was reached at 9:15.

TGHT:RDCUR 578 A

TGHT:RDVOL 9.87 V

IGP1:RDVAC 3.8e-6

The temperature was measured with the Minolta 2-color pyrometer:

from the side - inside target container : ~1200 deg C

from the front trough hole in the heat shield : ~1800 deg C

Target was conditioned for 4 hours at 580A.

Initiating ramp-down sequence @ 2A/min

Peter Kunz wrote:

Target was conditioned for 4 hours at 580A. Initiating ramp-down sequence @ 2A/min

 Tuesday, August 05, 2014, 12:00

target vented in air and taken out this morning

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.

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.