Tuesday, May 14, 2013, 17:04

Target oven is coated with TaC, and wrapped with 3-Ta heat shields.

TGHT and TBHT will be ramped up to 820A and 300A, respectively.

Ramping rate set to 1A/min.

Good Vac at 3.e-5 Torr, Bad Vac @ 4.0e-5 Torr.

Chamber is currently being pumped...

 Wednesday, May 15, 2013, 10:56

Chamber has pumped down to 4.5e-7 Torr. 

HS cooling water valves opened; no leaks were detected.

Stepping up TGHT/TBHT to 80A; monitoring vacuum.

 Wednesday, May 15, 2013, 11:26

Pressure is increasing.  TGHT setpoint @ 80A, readback @ 88.6A/0.603V, local @ 83A/0.80V.

 Wednesday, May 15, 2013, 12:08

TGHT/TBHT stepped up to 140A and tripped off at high limit vacuum.

Restarted p/s and set TBHT/TGHT at 100A

Initiated auto ramping...

 Friday, May 17, 2013, 11:39

TGHT and TBHT reached to 820A and 300A, respectively.  Target has been heating at the max currents for ~12hrs. 

Vacuum is coming down to 4.3e-7 Torr. 

The TaC coating sintering is completed.

Autocooling is initiated.  TGHT ramping rate @ 2A/min, and 1A/min for TBHT.

Wednesday, May 22, 2013, 10:43

Sintering complete.

Chamber will be vented

 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

 CTL block on T/C F/T Ch 1
Supply on Ch 3
HS Return on Ch 4

Tuesday, April 30, 2013, 11:20: Roughing

Tuesday, April 30, 2013, 11:45: Turbo started

Wednesday, May 01, 2013, 08:43: Cooling water opened. Vacuum stable at 5.1E-7 T (IGP1)

Wednesday, May 01, 2013, 08:48: Ramping TGHT and TBHT to 850A and 300A at 1A/60s

Thursday, May 02, 2013, 09:10: TGHT reached voltage limit (12V) at ~780A yesterday at ~10pm. Increased limit to 12.5V and continued auto ramping. CTL block temp ~80C

Thursday, May 02, 2013, 10:08: TGHT voltage limit changed to 13V. TGHT:RDCUR goes to ~810A with TGHT:RDVOL at 12.5V. CTL block temp ~80C

Thursday, May 02, 2013, 11:33: TGHT manually stepped to 850A RDCUR at 846A, RDVOL at 13.1V. CTL block temp ~84C

Thursday, May 02, 2013, 15:13: Ramping down TGHT and TBHT to 580A and 280A at 2A/min and 1A/min

Friday, May 03, 2013, 08:30:  TGHT and TBHT at 580A and 280A. CTL block temp ~60C 

Friday, May 03, 2013, 08:37: Ramping down TGHT and TBHT to 0 at 2/min and 1A/min

Friday, May 03, 2013, 11:04: T/C logger removed

Monday, May 06, 2013, 09:37: Turbo stopped.

Monday, May 06, 2013, 10:26: Venting

Target installed with 4 T/C

The target assembly is ITD0300 with the CTL Cu cooling block slightly modified.

Ch1 - CTL cooling block T/C feedtrough
Ch2 - Heat shield below left gripper arm - T/C feedthrough
Ch3 - Heat shield below left gripper arm - 9 pin connector
Ch4 - Target left side leg on tube - 9 pin connector

Friday, April 19, 2013, 15:23: Roughing

Friday, April 19, 2013, 15:41: Started turbo

Monday, April 22, 2013, 09:43: Opened water supply. Vacuum stable at 2.8E-7 T (IGP1)

Anders Mjos wrote:

Target installed with 4 T/C The target assembly is ITD0300 with the CTL Cu cooling block slightly modified. Ch1 - CTL cooling block T/C feedtrough Ch2 - Heat shield below left gripper arm - T/C feedthrough Ch3 - Heat shield below left gripper arm - 9 pin connector Ch4 - Target left side leg on tube - 9 pin connector Friday, April 19, 2013, 15:23: Roughing Friday, April 19, 2013, 15:41: Started turbo Monday, April 22, 2013, 09:43: Opened water supply. Vacuum stable at 2.8E-7 T (IGP1)

Monday, April 22, 2013, 18:48

Ramping TGHT/TBHT to 850A/300A at 1A/min.

Tuesd ay, April 23, 2013, 10:07

TBHT / TGHT: 820A / 300A

TGHT:RDCUR: 816.6A
TBHT:RDCRU: 303.5A

Local P/S displays
TGHT: 821A / 11.05V
TBHT: 307A / 4.37V

Tuesday, April 23, 2013, 10:45: Ramping down TBHT to 0A @ 5A/min

Tuesday, April 23, 2013, 12:49: Ramping down TGHT to 0A @ 5A/min

Tuesday, April 23, 2013, 15:52: Swithced off TGHT and TBHT P/S. TGHT P/S showed 30A read back value, while local value was 0A

 Wednesday, April 24, 2013, 09:53: Turbo stopped

Wednesday, April 24, 2013, 12:00: Target removed 

The ionizer tube was found to have deformed as seen in the attached photo.

 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.

Monday, April 08, 2013, 17:39

Target container is coated with TaC; the container will be used for the UCx#6 target. 

No Ta-heat shields are used.

For the sintering process:

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

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

Chamber has been pumped down.  HS cooling H2O valve opened; no leaks have detected.

Thursday, April 11, 2013, 14:35 

Target and tube heaters have reached to optimum.

Auto-cooling initiated...

 Friday, April 12, 2013, 11:17

P/S off.  Chamber vented. 

Done!

Thursday, March 12, 2013 

The CTL was removed and target heated to 580A / 300A

T1: Left target leg close to tube
T2: Heat Shield above CTL
T3: Heat Shield cooling water Supply
T4: Heat Shield cooling water Return

Thursday, March 13, 2013  

The target was cooled down 

Results attached as PDF and Excel

Wednesday, March 13, 2013 

Thermocouple channels (see attached PDF for photos)
T1 - Left target leg at tube
T2 - Between cooling fins close to tube, left side
T3 - Supply water HS
T4 - Return water HS

Friday, March 22, 2013

Test not conducted. Target removed.

Wednesday, March 06, 2013

The Cool Transfer Line (CTL) test target is installed for thermal tests. Drawing number is ITD0431 REV A.

Thermocouple channels are as follows:

T1: Cu block on CTL
T2: Heat Shield above CTL
T3: Heat Shield cooling water Supply
T4: Heat Shield cooling water Return

Cooling water is in Evap2 supplied to the cooling line that goes directly to the area on the Heat Shield above the CTL.

Test results attached.
 

Anders Mjos wrote:

Wednesday, March 06, 2013 The Cool Transfer Line (CTL) test target is installed for thermal tests. Drawing number is ITD0431 REV A. Thermocouple channels are as follows: T1: Cu block on CTL T2: Heat Shield above CTL T3: Heat Shield cooling water Supply T4: Heat Shield cooling water Return Cooling water is in Evap2 supplied to the cooling line that goes directly to the area on the Heat Shield above the CTL.

 Wednesday, March 06, 2013, 17:23

The target has been pumping down to 5.3 e-7 Torr.  On the RGA mass scan, mainly H2O (mass 18 + constituents) was detected at ~2.7pA (see attachment #1).

The target will be heated up: TGHT = 850A (rate @ 1A/min); TBHT = 300A (rate @ 1A/min).

 Thursday, March 07, 2013, 11:51

TGHT and TBHT reached to 850A (local, 845A\13.80V) and 300A, respectively.  The out gassing of CO (mass 28) reached to ~5pA at the max currents.  (see attachment #2) 

 TBHT will be ramped down to 0A to compare the temperatures.  

 Thursday, March 07, 2013, 15:55

TBHT at 0A.  See attachment#3 for the temperatures and RGA data before further ramping down the TGHT.

Monday, March 11, 2013

The CTL test target was installed again for a second thermal test. CTL block fastened to HS with 1 in lbs. A small piece of Ta-foil of 0.001" thickness was used between the CTL Cu-block and the Ta transfer line to reduce the heat transfer..

Thermocouples were re-attached to CTL and Heat Shield (see above for channels #s).

See attached graph (PDF) for details.

Anders Mjos wrote:

Anders Mjos wrote: Wednesday, March 06, 2013 The Cool Transfer Line (CTL) test target is installed for thermal tests. Drawing number is ITD0431 REV A. Thermocouple channels are as follows: T1: Cu block on CTL T2: Heat Shield above CTL T3: Heat Shield cooling water Supply T4: Heat Shield cooling water Return Cooling water is in Evap2 supplied to the cooling line that goes directly to the area on the Heat Shield above the CTL.   Monday, March 11, 2013 The CTL test target was installed again for a second thermal test. CTL block fastened to HS with 1 in lbs. A small piece of Ta-foil of 0.001" thickness was used between the CTL Cu-block and the Ta transfer line to reduce the heat transfer.. Thermocouples were re-attached to CTL and Heat Shield (see above for channels #s).

 Monday, March 11, 2013, 15:55

Chamber was pumped down to 2 e-7 Torr.  HS water valve opened and no leaks were detected.  

TGHT and TBHT are ramping up to 850A and 300A at 2A/min, respectively.  

RGA is running... 

Tuesday, March 12, 2013, 10:44  

TGHT/TBHT reached to max currents. 

See attachment #1 for temperature and RGA measurements. 

Cooling down in process... 5A/min. 

 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.

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. 

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"

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

 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.

 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.

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.

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, 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.