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. 

Friday, February 22, 2013, 15:49

The LP-SIS RFQ target container was previously coated with TaC and sintered up to ~1500C (TGHT @ 600A, TBHT @ 300A). 

The container is loaded with 325 discs of SiC, a total of 10.9cm in length. 

For this process,

TGHT will be ramped up to 600A and at the same time TBHT will go up to 300A.  No Ta-heat shield is used. 

The ramping rate is set to 0.2A/min.

The chamber is currently being pumped down. 

 Friday, March 01, 2013, 15:57

The target was further heated up to 650A TGHT and 300A TBHT for 4 hours yesterday; then it was cooled down.  

Some reactions on the target end (where the D-cap inserted) was observed.  

Yellow crystals on the D-cap was formed, just as we have seen before.  

Overall, the target looks good!  

See attachment#2 for the target production. 

More about the gasses analyst from the RGA later...  

 Monday, February 18, 2013, 16:28

The RFQ target container is coated with TaC and ready to be sintered.  No Ta-heat shields are used.  This container will be used for the SiC#28-LPSIS-RFQ. 

Two thermocouples are welded on the container:  One on the end cap and the other on the back block (see attachment#1)

The target will be heated to at least  TGHT at 580A and TBHT at 300A; the vacuum and gasses will be monitored.  

The chamber is currently being pumped down...  

 Friday, February 22, 2013, 14:24

The gasses were analyzed with the RGA:

TGHT @ 520A, TBHT @ 300A:  Mass 28 (CO) reached to max current of ~5pA before the current started to decrease, (see attachment #2).  This could be the indication of the material(s) in the target container was "sort of" fully reduced. 

TGHT was further ramped up  to 600A and heated for a few hours.  The temperature on the end was measured at 1252C and the center block was at 1580C.  (see attachment #3).

The container was successfully sintered with TaC. 

 Tuesday, January 22, 2013, 12:38

This is to test the newly developed RFQ target to be commissioned this year.  The purpose of this test is to see how well the RFQ components can sustain the high temperature.  One thermocouple is connected inside the target and the other is connect outside of the Cu heat-shield.  RGA will be running to analyze the gasses. 

TGHT will be auto-ramped up at the rate of 5A/20min to max current at 1000A.  

More info later... 

Wednesday, February 06, 2013, 16:11 

Heat testing Test#1 complete.  Data acquisition in progress....  The test was successful. 

Re-heating Test#2 is in progress.  This time, with a new re-design target container (less black block mass).  Two thermocouples are connected:  One on the back block and the other inside the RFQ components.  

The TGHT current will go up to at least 580A and the gasses will be monitored with the RGA. Ramping rate:  0.5A/min.  Set final current at 400A for now. 

TBHT will remain off at this point until we can know the temperature when TGHT is up to 580A.  

 Thursday, February 07, 2013, 11:39

TGHT reached to 400A/6.30V. 

Back block temperature measured at 18.307mV = 1003 C. 

RFQ component temperature measured at  = 143 C.

TGHT will be ramped up to 580A. 

Continue to monitor...

 Saturday, February 09, 2013, 09:40

TGHT at 580A, TBHT at 271A (setpoint).  Seeing CO2 gassing out.  Ramped down TBHT to zero A and continue to monitor.

Tuesday, February 12, 2013, 16:39  

TGHT heated up to 580A and remained at that current over the long weekend.  

The thermocouple on the back block was reading wrong because the wires away from the tip were fused to the container at high current.  (see attachment #1) 

TBHT was ramped up to 300A and then lower to 280A; mass 32 (CH3OH), and 44 (CO2) were detected.  This is unusual at 580A = 1200C. 

Both TBHT and TGHT were ramped down to zero and the outgassing of these molecules continue to detect on the RGA. (see attachment #2).  Suspect of these gasses from the Cu heat-shield or the thermocouple SiO insulator.

For complete process on screenshots, see my dropbox.

Next:  Coat this container with TaC and use for the SiC target.

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".

 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"

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. 

Tuesday, October 16, 2012, 14:12

Target is filled with 360 discs of TiC (with 1 mole of graphite) backed on C-grv foil.  

No Ta heat-shields wrapped around the container.

One regular end-cap is inserted and expanded.  The other end is inserted with a D-cap for out-gassing.

Re ionizer foil is inserted.

TGHT will be ramped up to 580A, TBHT to 230A; ramping rate at 0.2A/min.

Chamber is currently being pumped down...

 Tuesday, October 16, 2012, 16:11

HS water valve is opened.  No leaks is detected.

Vacuum is coming down steadily.  IGP1 currently at 1.7e-5 Torr.

 Wednesday, October 17, 2012, 11:41

The chamber was pumped down overnight.  IGP1 reads at 5.8e-7 Torr.

Both TGHT & TBHT were stepped up to 30A. P/S OK! 

Initiated auto-ramping...

Monday, October 22, 2012, 10:58

TGHT and TBHT have reached to 580A & 230A, respectively (see attachment#1).

IGP1 currently at 6.27e-6 Torr.  BP@20mTorr.

Currents will remain at max for another 3 hours. 

Local temperature measured at 1500C (container surface), 1300C (center block)

 Monday, October 22, 2012, 17:27

Auto cooling initiated.

 Tuesday, October 23, 2012, 17:54

TGHT & TBHT are at 0A.  P/S & pumps off. 

The chamber will be vented, and the target will be taken out for inspections.

Wednesday, October 10, 2012, 16:35

Target container is coated with TaC.  No Ta-heat shields are used.

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

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

Chamber is currently being pumped down

 Wednesday, October 10, 2012, 17:31

Chamber was pumped down to mid 10-6 Torr.  HS water valve was opened and no leak in vacuum was observed.

TGHT and TBHT were stepped up to 30A.  Everything seems fine...

Initiated auto-ramping:  Good vac = 2.0e-5 torr, Bad Vac = 3.0e-5 Torr. 

 Thursday, October 11, 2012, 10:35

TBHT has reached to 230A, 3.52V. 

TGHT has reached to 232A.  Vacuum is stabilizing at 8.0e-7 Torr, BP at 19 mTorr. 

Increased TGHT ramping rate to 2.0A/min. 

 Thursday, October 11, 2012, 14:55

TGHT reached to 580A/9.95V, local 575A/10.03V. 

TGHT at 230A/3.62V

Local target container temperature measured at ~1430C, central block at ~1220C

IGP1 currently at 1.68e-6 Torr. 

Heaters will be remained on for another 2 hours or so before auto-cooling is initiated.

 Thursday, October 11, 2012, 17:49

Target container has been heated for over 4 hrs.

IGP1 @ 1.10e-6 Torr, BP @ 18mTorr

Auto-cooling initiated, rate @ 2A/min.

 Friday, October 12, 2012, 10:02

TBHT/TGHT have reached to zero current. 

P/S off.

Venting chamber..

see attachment#1: striptool archiver

 Tuesday, October 16, 2012, 10:35

Container looks good.  It will be used for TiC#3

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.

 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:

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)

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.

 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.

Wednesday, August 22, 2012, 17:25

Note:  LP-FEBIAD target container ( W.O#37918-3) was coated with TaC and sintered on July 19 for UCx#5 target.  Then, a last minute request from the Sci Dev. to run the UCx#5 in LP-SIS. 

The target container was coated with TaC  (Using IR heat lamp to speed the drying time)

It's wrapped with 3 layers of Ta as the heat-shield, including the backblock.

TGHT will be ramped up to 580A at 0.5A/min.

TBHT will be ramped up to 230A at 0.5A/min.

Chamber is currently being pumped down.

 Wednesday, August 22, 2012, 18:27

Chamber was pumped down to 5.4e-6 Torr; the HS cooling water valve was opened and no leaks were detected.

Stepped up TGHT/TBHT to 20A.

Initiated auto-ramping...

 Friday, August 24, 2012, 00:21

TGHT/TBHT have reached to 580A/230A, respectively, and have remained at the currents for ~10hrs.

Current, IG1 is at 9.3e-7 torr.  The sintering process is done.

Initiating auto-cool down at 2A/min.

 Friday, August 24, 2012, 13:31

TGHT & TBHT power supplies are off.

The chamber is vented.

Nikita Bernier wrote:

Nikita Bernier wrote: Nikita Bernier wrote:  Friday, August 10, 2012, 19:54   Target boat with TaC coating, inside covered with a 0.002 inches thick Ta foil, wrapped with a 0.002 inches thick Ta foil, contains a Ta foil with TaO coating. See John's Ipad for their recipes. Evaporator #2 is now auto-ramping overnight at 0.2 A/min, up to 830 A, with the maximum voltage limited at 14 V, between 2.00e-05 (Good vacuum) and 3.00e-05 Torr (Bad vacuum).    Saturday, August 11, 2012, 19:15 Heating process was going smoothly up to 400 A. See Attachment 1. Around 420 A, vacuum went up again and the voltage increased more quickly. It seems like resistance is building up. After reaching 530 A, the current was tapped down to 420 A in an effort to save the Ta boat. See Attachment 2. The current will stay at 420 A for the weekend until John takes a look at this.    Monday, August 13, 2012, 13:46  TGHT was ramped down at 2 A/min and then tapped down to 0A. See Attachment 1.  The target boat will be cooled down for about an hour before turning off the chiller.

 Tuesday, August 14, 2012, 16:56

Summary:

The purpose of this experiment is to test the chemical and high temperature (1600C) resistance of a Ta foil (0.001" thick) coated with Ta2O5, so it can be used as the under-layer for the BeO sintering process.

The Ta2O5 (white powder, -325 mesh) was prepared in a non-aqueous solution and was sprayed on a piece of Ta foil. 

The coated foil was rolled up and inserted in a Ta-coated (previously sintered) target boat for heating.

The foil was heated up to 520A (~1200C) and evidently,Ta2O5 started to react with Ta foil, and the foil became brittle and cracked (see attachment#1).

In conclusion, Ta2O5 is not a good protection layer for Ta material - at least for our applications.

Tuesday, August 14, 2012, 15:44

This SiC target was prepared in May 2011 with the Evaporator#1.  The target will not used for online. 

Two endcaps were inserted with the new expansion tool.  The target will be heated up to the normal operating condition (TGHT =580A, TBHT = 230A). 

The chamber is currently being pumped down. 

 Tuesday, August 14, 2012, 16:21

Earlier, the Cu-heat shield was removed from the evaporator to replace the insulators, so all the seals were placed with new ones.  However,

there seems to be some leaks after the HS cooling water is turned on.  (see attachment#1).

The TP off, and the chamber is vented for investigation.

 Tuesday, August 14, 2012, 17:25

All the 3 seals for the Cu-heat shield were replaced.  The chamber has been pumped down and the HS water valve is open.  No leaks are detected.

Tuesday, August 14, 2012, 17:29

Initiated auto-ramping at 2A/min for both TGHT and TBHT.

Parameter constraints: good vac @ 2.0e-5 Torr, bad vac @ 3.0e-5 Torr.

Currently, IG1 @ 6.5e-6 Torr.

 Wednesday, August 15, 2012, 09:52

TGHT and TBHT have reached to 520A and 230A, respectively, and have stayed at the currents for about 10 hours. (see attachment #2) 

IG is currently at 7.7e-7 Torr.  

Initiating auto-cool down at 2A/min. 

 Thursday, August 16, 2012, 11:23

Chamber is vented.

Tuesday, August 14, 2012, 15:01

The Cu-heatshield insulators are broken due to prolong heating time during the target processes (see attachment#1). 

The insulators are replaced with the MM800 type (see attachment #2).

Nikita Bernier wrote:

Nikita Bernier wrote:  Friday, August 10, 2012, 19:54   Target boat with TaC coating, inside covered with a 0.002 inches thick Ta foil, wrapped with a 0.002 inches thick Ta foil, contains a Ta foil with TaO coating. See John's Ipad for their recipes. Evaporator #2 is now auto-ramping overnight at 0.2 A/min, up to 830 A, with the maximum voltage limited at 14 V, between 2.00e-05 (Good vacuum) and 3.00e-05 Torr (Bad vacuum).    Saturday, August 11, 2012, 19:15 Heating process was going smoothly up to 400 A. See Attachment 1. Around 420 A, vacuum went up again and the voltage increased more quickly. It seems like resistance is building up. After reaching 530 A, the current was tapped down to 420 A in an effort to save the Ta boat. See Attachment 2. The current will stay at 420 A for the weekend until John takes a look at this.

 Monday, August 13, 2012, 13:46

 TGHT was ramped down at 2 A/min and then tapped down to 0A. See Attachment 1.  The target boat will be cooled down for about an hour before turning off the chiller.

Nikita Bernier wrote:

Friday, August 10, 2012, 19:54   Target boat with TaC coating, inside covered with a 0.002 inches thick Ta foil, wrapped with a 0.002 inches thick Ta foil, contains a Ta foil with TaO coating. See John's Ipad for their recipes. Evaporator #2 is now auto-ramping overnight at 0.2 A/min, up to 830 A, with the maximum voltage limited at 14 V, between 2.00e-05 (Good vacuum) and 3.00e-05 Torr (Bad vacuum).

 Saturday, August 11, 2012, 19:15

Heating process was going smoothly up to 400 A. See Attachment 1.

Around 420 A, vacuum went up again and the voltage increased more quickly. It seems like resistance is building up. After reaching 530 A, the current was tapped down to 420 A in an effort to save the Ta boat. See Attachment 2.

The current will stay at 420 A for the weekend until John takes a look at this.