Nikita Bernier wrote:

Tuesday, May 07, 2013, 16:48   5 BeO pellets were made.  Each weights about 1.3 g (including org mass).  A piece of Re foil (0.002" thick) is used as the under layer to protect the reaction between Be(g) and the Ta-boat.  (see Attachments) Another layer of Ta-foil is used as the heat-shield to wrap around the Ta-boat. The chamber was pumped down.  TGHT will be ramped up to 600 A (~1360°C) at 0.2 A/min. The vacuum limit parameter was set for good vacuum at < 3.0e-5 Torr and bad vacuum at > 4.0e0-5 Torr. The pressure, voltage and current will be closely monitored.  If the Ta-boat survives, the TGHT will continue to ramp up to max 800 A (~1580°C).

 Monday, May 13, 2013, 12:48

TGHT has been at 600 A for about 13 hours with stable very low vacuum (10^-7). See Attachment #1.

Temperature measurement has been lost on Saturday. Last measurement was was above 1350°C, at around 480 A.

TGHT was ramped down at 1 A/min.

The chamber will be vented later today. The pellets and the thermocouples will be inspected.

Nikita Bernier wrote:

Nikita Bernier wrote:  Tuesday, May 07, 2013, 16:48   5 BeO pellets were made.  Each weights about 1.3 g (including org mass).  A piece of Re foil (0.002" thick) is used as the under layer to protect the reaction between Be(g) and the Ta-boat.  (see Attachments) Another layer of Ta-foil is used as the heat-shield to wrap around the Ta-boat. The chamber was pumped down.  TGHT will be ramped up to 600 A (~1360°C) at 0.2 A/min. The vacuum limit parameter was set for good vacuum at < 3.0e-5 Torr and bad vacuum at > 4.0e0-5 Torr. The pressure, voltage and current will be closely monitored.  If the Ta-boat survives, the TGHT will continue to ramp up to max 800 A (~1580°C).    Monday, May 13, 2013, 12:48   TGHT has been at 600 A for about 13 hours with stable very low vacuum (10^-7). See Attachment #1. Temperature measurement has been lost on Saturday. Last measurement was was above 1350°C, at around 480 A. TGHT was ramped down at 1 A/min. The chamber will be vented later today. The pellets and the thermocouples will be inspected.

 Monday, May 13, 2013, 17:21

The following table shows the characteristics of the pellets after sintering at 600 A for 13 hours.

Sample,   Mass (g),   Thickness (mm),   Density (g/cm3),    Diameter (mm)

1    0.8904 4.875 1.364 13.058

2    0.8991 4.744 1.396 13.148

3    0.8846 4.579 1.482 12.884

4    0.9142 4.981 1.254 13.650

5    0.9022 4.978 1.250 13.586

Avg 0.8981 4.831 1.345 13.265

Tuesday, May 28, 2013, 17:36

The target containers endcaps were coated with TaC solution and let dry. 

Each cap is wrapped with a small piece of graphite foil and inserted in the target boat.

The chamber is currently being pumped down. 

The HS cooling water valve will be opened tomorrow; any leak will be inspected.

When the vacuum is good,  TGHT will be ramped up to 580A. 

 Wednesday, May 29, 2013, 17:06

HS water valve was opened early this morning; no leaks were detected.

TGHT has stepped up to 50A.  IG is currently at 2.0e-6Torr. 

Initiated auto-ramping at 1.0A/min.

 Thursday, May 30, 2013, 11:12

TGHT reached to 580.  The end caps have been heated at that current for more than 7 hrs.

IG is coming down, currently at 8e-7 Torr.

Auto-cooling initiated, ramping down at 2A/min .

Tuesday, August 27, 2013, 16:48

Target boat is filled with TaC coated endcaps (brown) and some partial sinterred ones (gray) from before.  (see attachment#1).

The container is wrapped with Ta heat-shield.

Chamber has been pumped down; IG currently @ 7.3e-7 Torr. 

Heat-shield cooling water valves are open; no leaks are detected.

Initiated TGHT auto-ramping at 0.5A/min, set TGHT max at 580A.

 Wednesday, August 28, 2013, 16:09

TGHT has reached to 580A and been heated for over 4 hours.

IG is coming down, currently at 1.9 e-6 Torr.

Initiated auto-cooling.  2A/min. 

John Wong wrote:

Tuesday, August 27, 2013, 16:48 Target boat is filled with TaC coated endcaps (brown) and some partial sinterred ones (gray) from before.  (see attachment#1). The container is wrapped with Ta heat-shield. Chamber has been pumped down; IG currently @ 7.3e-7 Torr.  Heat-shield cooling water valves are open; no leaks are detected. Initiated TGHT auto-ramping at 0.5A/min, set TGHT max at 580A.  Wednesday, August 28, 2013, 16:09 TGHT has reached to 580A and been heated for over 4 hours. IG is coming down, currently at 1.9 e-6 Torr. Initiated auto-cooling.  2A/min.

 Thursday, August 29, 2013, 11:50

TGHT at 0 A

IG at 3.5e-7 Torr

Turning off EVAP2 and venting chamber

Process complete

Tuesday, September 17, 2013, 11:14

Target boat contains 5 Nb discs.  3 discs are wraps with 0.001" thin of Nb foil (99.8% pure), and 2 are wraps with 0.001" Ta foil (see attachment#1)

Chamber has been pumped down over night.  Pressure is currently at 9.8e-7 Torr. 

Heating instructions:

Samples will be heated up to 800C.  TGHT will be ramped up accordingly. (Two thermocouples are wielded on the target container.)

Once at the desired temperature; the samples will be heat for 4 hours before cooling down.

 Tuesday, September 17, 2013, 14:37

Target temperature has reached to 800C at around 13:00 (see attachment#2)

TGHT @ 230A/3.07V (local 233A/3.25V). 

IG @ 1.06e-6 Torr. 

The heater will be ramped down at ~17:00 at 2A/min.

 Tuesday, September 17, 2013, 17:36

Target temp: T1 = 805C, T2=797.6C

IG @ 9.4e-7 Torr.

Cooling down initiated. 

 Wednesday, September 18, 2013, 11:34

TGHT at 0A.  Temp at 22C. 

IG @ 5.8e-7 Torr.

Venting chamber.

John Wong wrote:

Tuesday, September 17, 2013, 11:14 Target boat contains 5 Nb discs.  3 discs are wraps with 0.001" thin of Nb foil (99.8% pure), and 2 are wraps with 0.001" Ta foil (see attachment#1) Chamber has been pumped down over night.  Pressure is currently at 9.8e-7 Torr.  Heating instructions: Samples will be heated up to 800C.  TGHT will be ramped up accordingly. (Two thermocouples are wielded on the target container.) Once at the desired temperature; the samples will be heat for 4 hours before cooling down.  Tuesday, September 17, 2013, 14:37 Target temperature has reached to 800C at around 13:00 (see attachment#2) TGHT @ 230A/3.07V (local 233A/3.25V).  IG @ 1.06e-6 Torr.  The heater will be ramped down at ~17:00 at 2A/min.  Tuesday, September 17, 2013, 17:36 Target temp: T1 = 805C, T2=797.6C IG @ 9.4e-7 Torr. Cooling down initiated.   Wednesday, September 18, 2013, 11:34 TGHT at 0A.  Temp at 22C.  IG @ 5.8e-7 Torr. Venting chamber.

 Thursday, September 19, 2013, 11:41

Target boat contains batch#2 Nb samples (see attachment #1)

Chamber has been pumped down over night.  

IG @ 5.5e-07 Torr. 

CG1B @ 0.033 T

CG1A @ 0.127 T

There is a leak in the backing line.  BV1 was bypassed in order to turn on the turbo pump. (Will investigate the leaks after the processes are done)  

*See attached picture to view samples

Laura Lambert wrote:

John Wong wrote: Tuesday, September 17, 2013, 11:14 Target boat contains 5 Nb discs.  3 discs are wraps with 0.001" thin of Nb foil (99.8% pure), and 2 are wraps with 0.001" Ta foil (see attachment#1) Chamber has been pumped down over night.  Pressure is currently at 9.8e-7 Torr.  Heating instructions: Samples will be heated up to 800C.  TGHT will be ramped up accordingly. (Two thermocouples are wielded on the target container.) Once at the desired temperature; the samples will be heat for 4 hours before cooling down.  Tuesday, September 17, 2013, 14:37 Target temperature has reached to 800C at around 13:00 (see attachment#2) TGHT @ 230A/3.07V (local 233A/3.25V).  IG @ 1.06e-6 Torr.  The heater will be ramped down at ~17:00 at 2A/min.  Tuesday, September 17, 2013, 17:36 Target temp: T1 = 805C, T2=797.6C IG @ 9.4e-7 Torr. Cooling down initiated.   Wednesday, September 18, 2013, 11:34 TGHT at 0A.  Temp at 22C.  IG @ 5.8e-7 Torr. Venting chamber.    Thursday, September 19, 2013, 11:41 Target boat contains batch#2 Nb samples (see attachment #1) Chamber has been pumped down over night.   IG @ 5.5e-07 Torr.  CG1B @ 0.033 T CG1A @ 0.127 T There is a leak in the backing line.  BV1 was bypassed in order to turn on the turbo pump. (Will investigate the leaks after the processes are done)   *See attached picture to view samples

Thursday, September 19, 2013, 17:01  

TGHT reached to 800A.  Temp at 795.9C for 4 hours.  Vac at 5.8e-7 Torr.

Cooling down initiated.  ramping rate at 2A/min. 

John Wong wrote:

Tuesday, September 17, 2013, 11:14 Target boat contains 5 Nb discs.  3 discs are wraps with 0.001" thin of Nb foil (99.8% pure), and 2 are wraps with 0.001" Ta foil (see attachment#1) Chamber has been pumped down over night.  Pressure is currently at 9.8e-7 Torr.  Heating instructions: Samples will be heated up to 800C.  TGHT will be ramped up accordingly. (Two thermocouples are wielded on the target container.) Once at the desired temperature; the samples will be heat for 4 hours before cooling down.  Tuesday, September 17, 2013, 14:37 Target temperature has reached to 800C at around 13:00 (see attachment#2) TGHT @ 230A/3.07V (local 233A/3.25V).  IG @ 1.06e-6 Torr.  The heater will be ramped down at ~17:00 at 2A/min.  Tuesday, September 17, 2013, 17:36 Target temp: T1 = 805C, T2=797.6C IG @ 9.4e-7 Torr. Cooling down initiated.   Wednesday, September 18, 2013, 11:34 TGHT at 0A.  Temp at 22C.  IG @ 5.8e-7 Torr. Venting chamber.

 Friday, September 20, 2013, 14:56

Target contains batch#3 sample wrapped with Nb foil. 

Chamber has been pumped down to 1.03e-6 Torr. 

Samples will be heated up to 1200C for 4 hours.  

 Friday, September 20, 2013, 16:54

TGHT at 450A, temp stabilizes at 1238C.

Will cool down at 20:30 tonight.

Friday, September 20, 2013, 20:40  

Samples has been heated for 4 hours at 1235C.  

Cooling down initiated. 

 Monday, September 23, 2013, 14:40

Chamber was vented.

Batch#3 process completed.

John Wong wrote:

John Wong wrote: Tuesday, September 17, 2013, 11:14 Target boat contains 5 Nb discs.  3 discs are wraps with 0.001" thin of Nb foil (99.8% pure), and 2 are wraps with 0.001" Ta foil (see attachment#1) Chamber has been pumped down over night.  Pressure is currently at 9.8e-7 Torr.  Heating instructions: Samples will be heated up to 800C.  TGHT will be ramped up accordingly. (Two thermocouples are wielded on the target container.) Once at the desired temperature; the samples will be heat for 4 hours before cooling down.  Tuesday, September 17, 2013, 14:37 Target temperature has reached to 800C at around 13:00 (see attachment#2) TGHT @ 230A/3.07V (local 233A/3.25V).  IG @ 1.06e-6 Torr.  The heater will be ramped down at ~17:00 at 2A/min.  Tuesday, September 17, 2013, 17:36 Target temp: T1 = 805C, T2=797.6C IG @ 9.4e-7 Torr. Cooling down initiated.   Wednesday, September 18, 2013, 11:34 TGHT at 0A.  Temp at 22C.  IG @ 5.8e-7 Torr. Venting chamber.    Friday, September 20, 2013, 14:56 Target contains batch#3 sample wrapped with Nb foil.  Chamber has been pumped down to 1.03e-6 Torr.  Samples will be heated up to 1200C for 4 hours.    Friday, September 20, 2013, 16:54 TGHT at 450A, temp stabilizes at 1238C. Will cool down at 20:30 tonight. Friday, September 20, 2013, 20:40   Samples has been heated for 4 hours at 1235C.   Cooling down initiated.   Monday, September 23, 2013, 14:40 Chamber was vented. Batch#3 process completed.

 Monday, September 23, 2013, 16:14

Batch#4.  Target container contains 2 Nb stables (a bullet type and a disc).  

Samples are wrapped with "dimpled" Nb foil to prevent diffusion bonding. 

Chamber has been pumped down to 8.3e-7 Torr, CG1B @ 30mT, CG1A @ 118mT. 

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

Monday, September 23, 2013, 17:46

TGHT at 620A. Temp at 1400C. Current pressure @ 2.5e-6 Torr. 

Tuesday, September 24, 2013, 16:45

Sample#4 was heated up to 1400C and after about 3hrs, the target container started to break.

See the link below for more details:

https://www.dropbox.com/s/9mhpkz66u6yqldm/Nb_1400C.mp4

 Tuesday, October 29, 2013, 15:50: Pumping down

Wednesday, October 30, 2013, 09:32: Turbo started

Wednesday, October 30, 2013, 14:50: The Cu-bars were heated to 600A and 300A for TGHT and TBHT respectively.

Wednesday, October 30, 2013, 15:17: PS off. Turbo off.

Results can be found on DocuShare and in the attached plot.

The source of the poor vacuum in the backing line seems to be related to a dirty filter. We will try to find a replacement filter next week.

The problem seem to have started September 17th, when backing preassure CG1A went from 40 mTorr to 130 mTorr. CG1B remained around 30 mTorr.

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.

The purpose of this experiment is to improve the TaC coating mixed with other metals as additives.  The coating solution will be sprayed on Ta metal (0.015" thick, same thickness as the target container).

The samples will be sintered at ~ 1800C.  Once the process is completed, a graphite tube will be inserted into the tube, and then re-heated it up to 1800C. 

This test will show how good the protective layer to prevent the graphite to react with the Ta metal.

Wednesday, November 06, 2013, 17:11

Step #1

Two samples: 

1.  A short tube (same diameter as the usual container)

2.  A cross section of the tube.

Both samples are coated with the TaC matrix spray: 

0.05 moles TaC

0.005 moles of Mo2C, VC, Cr3C2, NbC 

A Rh foil is used as a protective under layer.

see links for pictures:  https://www.dropbox.com/sh/866zsp44nnjeg2z/LqCThu-G_0

The target boat is wrapped with 3 layers of heat shields. 

Samples will be heated up to 600A ~1800C

Chamber is currently being pumped down.

 Friday, November 08, 2013, 17:13

Chamber was pumped down to ~2e-6 Torr.  HS water valve is opened and no leaks were detected. 

TGHT will be ramped up to 580A at 1A/min. 

Monday, November 11, 2013, 08:10  

TGHT has reached to 580A; samples has been heated at that current for over the weekend. 

IGP2 currently at 3.5e-7 Torr.

Auto cooling initiated, ramping rate at -2.0A/min.

 Step 2:

The coated tube is sintered with TaC-matrix.

The graphite tube is inserted in the tube and will be heated back up; see link for details:

https://www.dropbox.com/sh/ji0rhlj0v1tfj1w/cRv1I3VJXE

Chamber is currently pumped down to 1.8e-6 Torr.

TGHT will first be ramped up to 450A (1A/min) to see how the reaction behaves, then a caution ramp up to 600A will take place. 

 Friday, November 15, 2013, 11:04

TGHT reached to 450A.  Cooling down to 0A.  Chamber will be vented for inspection.

 Monday, November 18, 2013, 17:22

Continue Step#2:

The sample looks ok after heating at 450A.

Re-heating it to 500A. 

Chamber has been pumped down to 4.0e-6 Torr. 

Initiated auto-ramping...

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 

 Monday, January 20, 2014, 16:32

A new target boat was sprayed with TaC coating and let dry this morning.

The target boat is NOT wrapped with Ta-heat shield.

The boat was installed in Evap#2, chamber is currently being pumped down overnight.

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. 

 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.