With the help of Anthony Ip from vacuum group, the problem was diagnosed to be the roughing pump itself. The pump was replaced and pumping improved. The chamber can now be evacuated and turbo ready to start in less than 10 minutes.

The filter is not stocked by vacuum group and could not be replaced.

Last week parts of the roughing line was cleaned by Rick. The PVC roughing line has been replaced with a SST bellows. The SST bellows is KF25 and should be replaced by a KF40 bellows in the long run.

See attached photo.

The Heat Shield has been taken to the Machine Shop for repair.

Friday, November 08, 2013

 The Heat Shield cooling line has been repaired and the lid re-installed in the evaporator. Photo attached.

Friday, November 08, 2013, 10:58 : Roughing Started

Friday, November 08, 2013, 11:05: Turbo started 

Friday, November 08, 2013, 11:15: Turbo at speed Vacuum at (IGP1) 5.7E-5 T 

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.

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. 

 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.

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.

 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.

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 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...

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.

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.