Nikita Bernier wrote:

Nikita Bernier wrote:  Monday, September 24, 2012, 15:01 The target boat with TaC coating is being used again. The inside of the boat is covered with a 0.002 inches thick Ta foil with TaC coating, wrapped with a 0.002 inches thick Ta foil. Chamber was pumped down to 6e-6 Torr before the Heat Shield cooling water valve was opened. A small vacuum bump was detected (See attachment #1). It is not clear if it was caused by a water leak or not. After consulting with Peter, I will wait for the vacuum to be below e-07 Torr before turning the target heater on.        Monday, September 24, 2012, 18:02 The vacuum was stable until 1e-06 Torr. The target heater was turned on and tapped up to 60 A (0.8 V).  Evaporator #2 is now auto-ramping overnight at 0.2 A/min, up to 800-850 A, with the maximum voltage limited at 14 V, between 2.00e-05 (Good vacuum) and 3.00e-05 Torr (Bad vacuum).     Tuesday, September 25, 2012, 15:11 Sintering process is going smoothly. See Attachment 1. The auto-ramping was increased to 1 A/min up to 800-850 A.     Tuesday, September 25, 2012, 16:11  And the voltage limit was increased to 18 V ! See Attachment 2.    Tuesday, September 25, 2012, 19:13 Around 806 A (readback), voltage increased more quickly than the current. It seems like resistance is building up. After reaching 836 A (readback), the current was tapped down to 800 A (readback)/ 816 A (setting) in an effort to save the Ta boat. See Attachment 3. The current will stay at 800 A for ~4 hours before ramping down.

 Wednesday, September 26, 2012, 14:31

The current was tapped down twice as resistance was building up. After 4 hours at ~800 A, the TGHT was ramped down at 2 A/min. See Attachment 1. The target boat was cooled down for 4 hours before the chiller was turned off.

Also I had trouble measuring the temperature. I was unable to get a clear picture with the pyrometer. Therefore the exact temperature remains unknown, but from previous experiments, 800 A was about 1400°C.

The TaC coated Ta foil is very brittle. There is a lot of crystallisation on the Ta boat. See attachment 2. It is unlikely that the boat would survive many more sintering. Therefore it will be used for BeO pellets tests. 

When John gets back, I suggest we use a new boat coated with TaC, without additional layers. (See message #15 when this target boat was sintered up to 900A (local 893A/16.88V), Measured temp @ 1500°C)

 Wednesday, September 26, 2012, 15:07

The samples were made of BeO powder with 30% PVB which was treated at 400 RPM for 26 minutes. A ratio of 10:1 of mineral oil was added before another high speed treatment for 10 minutes. The powder was then pressed into pellets.

Three pellets were loaded on the target boat coated with TaC, with an extra layer of TaC coated Ta foil. See Attachment 1. The target boat is wrapped with a Ta foil that is 0.002 inches thick.

Target chamber was pumped down. The cooling water was turned on and no leak were observed.

TGHT was stepped up to 55A before the auto ramping was initiated at 0.5 A/min.  The vacuum limit parameter was set for good vac at <3.0 e-5 Torr and bad vac at >4.0 e0-5 Torr.  

Nikita Bernier wrote:

Wednesday, September 26, 2012, 15:07   The samples were made of BeO powder with 30% PVB which was treated at 400 RPM for 26 minutes. A ratio of 10:1 of mineral oil was added before another high speed treatment for 10 minutes. The powder was then pressed into pellets. Three pellets were loaded on the target boat coated with TaC, with an extra layer of TaC coated Ta foil. See Attachment 1. The target boat is wrapped with a Ta foil that is 0.002 inches thick. Target chamber was pumped down. The cooling water was turned on and no leak were observed. TGHT was stepped up to 55A before the auto ramping was initiated at 0.5 A/min.  The vacuum limit parameter was set for good vac at <3.0 e-5 Torr and bad vac at >4.0 e0-5 Torr.

 Friday, September 28, 2012, 12:50

Sintering was coming up smoothly. As expected, resistance started building up quickly at higher temperatures (above 600°C). See Attachment 1. The target heater tripped off twice this morning. I was able to ramp up the current after the first trip until it tripped again. After the second time, the voltage went crazy and I had to ramp down the current. Attachment 2 shows the whole process.

Evap2 will be vented out shortly and the pellets will be examined.

Friday, September 28, 2012, 15:52  

 The boat comes in two parts. One pellet is missing. The two remaining pellets are black and grey. Also they shrank a lot. See Attachment 3.

So once again, a new batch of BeO pellets will have to be prepared and sintered in order to determine the dimensions of the final die. Therefore the best approach is still loading the pellets on a target boat coated/sintered with TaC and wrapped with a Ta foil.

Friday, January 11, 2013, 10:59

The insulator that holds the terminals was broken when a target container was installed.  The insulator had seen so much heat shine from the Cu heat-shield gaps, see attachment.  Tightening the bolts on the target container might further put more force on the insulator and eventually broke it.

To prevent this to happen again.  The Cu-heat shield gaps have covered with Ta-foil to prevent any shine from the target  container onto the insulator.  Also, a torque wrench will be used to tighten the bolts on the terminals.  At this point, we don't know the max torque the insulator can tolerate.  Some measurements were done on the target resistant (ohm) as a function of torque (in pounds).  The best torque to tighten the terminal bolts is 150 lbs. 

 Friday, January 11, 2013, 13:52

TEST#1

A new target boat is coated with TaC and will go through the sintering process at 580A (max).  Ramping rate 5A/20min.

For this test, two thermocouples are installed to measure the temperature of the container.  The QMS is also operating to analyze the gases. 

See attachment#1 for the thermocouple setup.  Note:  No Ta heat shield is used to wrap around the target container.  

See attachment#2 for an example of the QMS and temperature measurements.  

More details about the results later...  

Tuesday, January 22, 2013, 12:19  

The test was successfully complete. 

Short summary of the results: 

1.  A significant difference in the temperature dependence on the heater current could be found when ramping up/down (see attachment #3). 

2.  A difference of 200 C at the highest temperature was between the two thermocouples were measured. 

3.  The measured temperatures are lower than previous measurements with a pyrometer on an empty LP target container (see attachment#3).

4.  RGA spectra show most of the higher mass organic molecules are gone after initial heating at low temperature.  

5.  Above 560A, CO2 shows up again and decreases up to about 680A heating current. (see attachment #4).

6.  After running at high temperature for some time, only H2O & CO and their constituents are left.  (see attachment #5).

Data can be found on my dropbox, folder "RFQ-test\Test#1-ver1.0"

Next:  Re-heating the target

Tuesday, February 12, 2013, 17:10 

TEST#2: Re-heating the target again.  See if it fit the curves. Measuring concentrations of 14N, 16O, 18H2O, 28CO, 32 CH3OH, 40Ar, 44C02. 

Ramping rate 1A/min

Wednesday, March 06, 2013, 18:14 

Test#2 complete.  Data can be found on my dropbox, folder "RFQ-test\Test#2-ver1.0"

Wednesday, March 06, 2013, 18:14 

Test#3:  RFQ target container_version 2.0, thermal test.

Measuring back block temperature & analyze gases.  

Data can be found on my dropbox, folder "RFQ-test\Test#3-ver2.0"

John Wong wrote:

Friday, January 11, 2013, 10:59 The insulator that holds the terminals was broken when a target container was installed.  The insulator had seen so much heat shine from the Cu heat-shield gaps, see attachment.  Tightening the bolts on the target container might further put more force on the insulator and eventually broke it. To prevent this to happen again.  The Cu-heat shield gaps have covered with Ta-foil to prevent any shine from the target  container onto the insulator.  Also, a torque wrench will be used to tighten the bolts on the terminals.  At this point, we don't know the max torque the insulator can tolerate.  Some measurements were done on the target resistant (ohm) as a function of torque (in pounds).  The best torque to tighten the terminal bolts is 150 lbs.

The insulators were installed with torques as indicated in the attached PDF ITD0052. A torque test was performed on the broken insulator before installation. No damage was seen on torques of up to 60 in lbs for the 1/4-20 bolts, however for torques in excess of 50 in lbs the insulator material seems to "give".

 Monday, March 04, 2013, 17:39

This is the 2nd modified target container for RFQ LPSIS.  The container will be heated up to 650A TGHT and 150A on TBHT.  No Ta-heat shield is being used.  

Heating rate at 1A/min for both TGHT & TBHT.  Once the target is at the currents, TBHT will be further ramped up to 300A.  

Temperatures are being measured by two thermocouples (one on RFQ component and the other on the Cu heat-shield).  

Gases are being analyzed using the RGA. 

 A thermocouple feedthru was installed via 9 pin sub-D connector. It runs from the the conflat cross on the top of the evaporator to the upper 9 pin connector of the target mounting plate.

 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 Pictures)

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).

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.