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Entry  Tuesday, May 15, 2012, 17:03, John Wong, , , , Problems, TBHT cooling line leaky TBHT_cooling_line_leaky.pdf

 Tuesday, May 15, 2012, 17:00

It was found that there were water droplets from the TBHT cooling line.  The joint is leaky.  (see attachment 1) 

A message has sent to Rick M. 


 

Entry  Tuesday, May 15, 2012, 17:06, John Wong, , , , Problems resolved, TBHT power supply faulty tubeheater_control.png

 Tuesday, May 15, 2012, 17:03

The tube heater power supply current readback and setpoint are not matching.  Ray Dube checked the power supply and confirmed that it is faulty.  He will replace a functional p/s tomorrow. 


 Friday, May 18, 2012, 13:24

The original p/s was replaced with a new one and there was still a discrepancy between the readback and the setpoint.  After checking with the drawings for the ITE/ITW tube heaters, it was confirmed that the connections for the Evap#2 tube heater control were wrong.  (see attachment 1).  The connections were corrected and the power supply is now operational. 


 

    Reply  Wednesday, May 16, 2012, 14:04, John Wong, , , , Problems resolved, TBHT cooling line leaky 

John Wong wrote:

 Tuesday, May 15, 2012, 17:00

It was found that there were water droplets from the TBHT cooling line.  The joint is leaky.  (see attachment 1) 

A message has sent to Rick M. 


 

 Wednesday, May 16, 2012, 14:01

The connector was re-tighten.  The water valve was opened, and no water leaks were found.


 

    Reply  Tuesday, May 22, 2012, 16:45, Nikita Bernier, BeO, Target boat #2, , Done, Sintering BeO pellets #3 

Nikita Bernier wrote:

Thursday, April 05, 2012, 16:31

Target boat contains 6 BeO pellets :

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

1   1.2842,    5.406,        1.4647
2   1.2619,    5.150,        1.5108
3   1.2886,    5.316,        1.4946
4   1.2858,    5.310,        1.4931

5   1.3382,    5.520,        1.4948
6   1.3916,    5.650,        1.5187

 

Samples are made of BeO powder with 30% PVB which was treated at 400 RPM for 26 minutes. A ratio of 1:0.1 of mineral oil was added before another high speed treatment for 10 minutes. The powder was then pressed into pellets.

Pellets are loaded on a target boat coated/sintered with TaC. The target boat is wrapped with a Ta foil that is 0.002 inches thick.

**** Sintering is postponed until the situation with the ventilation in the lab06 is cleared. ****

 

 Tuesday, May 22, 2012, 16:44

Target chamber is currently being pumped down. Leak check will be done tomorrow by turning on the cooling water for the heat shield.

    Reply  Wednesday, May 23, 2012, 17:45, John Wong, BeO, Target boat #2, , Done, Sintering BeO pellets #3 past_5_hrs.JPGpast_21_hrs.pngpower_lost_2012-05-27_12_0630hr.pngTGHT_600A.pngTGHT@600A_past_12hr.JPG

Nikita Bernier wrote:

Nikita Bernier wrote:

Thursday, April 05, 2012, 16:31

Target boat contains 6 BeO pellets :

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

1   1.2842,    5.406,        1.4647
2   1.2619,    5.150,        1.5108
3   1.2886,    5.316,        1.4946
4   1.2858,    5.310,        1.4931

5   1.3382,    5.520,        1.4948
6   1.3916,    5.650,        1.5187

 

Samples are made of BeO powder with 30% PVB which was treated at 400 RPM for 26 minutes. A ratio of 1:0.1 of mineral oil was added before another high speed treatment for 10 minutes. The powder was then pressed into pellets.

Pellets are loaded on a target boat coated/sintered with TaC. The target boat is wrapped with a Ta foil that is 0.002 inches thick.

**** Sintering is postponed until the situation with the ventilation in the lab06 is cleared. ****

 

 Tuesday, May 22, 2012, 16:44

Target chamber is currently being pumped down. Leak check will be done tomorrow by turning on the cooling water for the heat shield.

 Wednesday, May 23, 2012, 17:38

TGHT was stepped up to about 55A before the auto ramping was initiated.  The vacuum limit parameter was set for good vac at <4.0 e-5 Torr and bad vac at >5.0 e0-5 Torr. 

The pressure is coming close to the trip limit (8.5 e-5 Torr) (see attachment 1: strip tool over the past 5 hours).  Changed the vacuum limit parameter:  good vac =3.0e-5 Torr, bad vac= 4.0e-5 Torr. 


 Saturday, May 26, 2012, 10:44

TGHT is auto ramping up smoothly as the pressure is regulating between 1e-5 to 4 e-5 torr.  (See attachment 2, past 21 hr)


Sunday, May 27, 2012, 12:25  

There could be a power bump  early this morning at 06:30hr, and tripped off the TGHT power supply (see attachment #3).  The computer in the cold lab was found to be off expectedly, so the alarm handler running on that computer was also shut off (*Need a UPS on this computer!)  

Called the ISAC Ops, and  nothing about any power bump around that time was noticed.  

Turned on TGHT p/s and set TGHT at 318A, local at 315A/4.58V.  TGHT has been running for about 10 mins.  Currently vac at 4.2e-7 Torr.  


Sunday, May 27, 2012, 12:35

Initiating TGHT auto ramping... 


 Monday, May 28, 2012, 00:20

TGHT has reached to 600A and will remain at that current for the rest of the night.  The target oven temperature will be measured tomorrow.

See attachment#4 for the striptool over the past 10hr.


 Monday, May 28, 2012, 10:56

TGHT stayed at 600A for about 12 hours.  Pressure gradually came down to 7.6e-7 Torr. (See attachment #5). 

At TGHT=600A, The target boat temperature was measured at 1400C (with the pyrometer), and the Ta-heat shield (1-layer) was at 1050C. [Note: These temperature measurements are very closed to the measurements with an empty LP target (with not heat shield), TGHT @ 600A = 1360C].


Monday, May 28, 2012, 11:04

Due to the water leak from the Evap2 chiller, the system has to be shut off for inspection. 

TGHT was tapped down to 0A.  The target was cooled down for about 20min before the chiller was turned off.

Will continue with the process after the problem is solved...


 

Entry  Monday, May 28, 2012, 11:15, John Wong, , , , Problems, Chiller is leaking water  Chiller_leaky.jpg

Monday, May 28, 2012, 11:08

It was discovered this morning that the Evaporator #2 chiller was leaking water from the bottom (see attachment 1).  A puddle of water was formed and eventually found its way down to the Hotcell. 

The evaporator was running over the weekend for the BeO pellets process.  The TGHT is now off and the chiller will be inspected... 


 

    Reply  Tuesday, May 29, 2012, 15:43, Nikita Bernier, BeO, Target boat #2, , Failed, Sintering BeO pellets #3 

John Wong wrote:

Nikita Bernier wrote:

Nikita Bernier wrote:

Thursday, April 05, 2012, 16:31

Target boat contains 6 BeO pellets :

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

1   1.2842,    5.406,        1.4647
2   1.2619,    5.150,        1.5108
3   1.2886,    5.316,        1.4946
4   1.2858,    5.310,        1.4931

5   1.3382,    5.520,        1.4948
6   1.3916,    5.650,        1.5187

 

Samples are made of BeO powder with 30% PVB which was treated at 400 RPM for 26 minutes. A ratio of 1:0.1 of mineral oil was added before another high speed treatment for 10 minutes. The powder was then pressed into pellets.

Pellets are loaded on a target boat coated/sintered with TaC. The target boat is wrapped with a Ta foil that is 0.002 inches thick.

**** Sintering is postponed until the situation with the ventilation in the lab06 is cleared. ****

 

 Tuesday, May 22, 2012, 16:44

Target chamber is currently being pumped down. Leak check will be done tomorrow by turning on the cooling water for the heat shield.

 Wednesday, May 23, 2012, 17:38

TGHT was stepped up to about 55A before the auto ramping was initiated.  The vacuum limit parameter was set for good vac at <4.0 e-5 Torr and bad vac at >5.0 e0-5 Torr. 

The pressure is coming close to the trip limit (8.5 e-5 Torr) (see attachment 1: strip tool over the past 5 hours).  Changed the vacuum limit parameter:  good vac =3.0e-5 Torr, bad vac= 4.0e-5 Torr. 


 Saturday, May 26, 2012, 10:44

TGHT is auto ramping up smoothly as the pressure is regulating between 1e-5 to 4 e-5 torr.  (See attachment 2, past 21 hr)


Sunday, May 27, 2012, 12:25  

There could be a power bump  early this morning at 06:30hr, and tripped off the TGHT power supply (see attachment #3).  The computer in the cold lab was found to be off expectedly, so the alarm handler running on that computer was also shut off (*Need a UPS on this computer!)  

Called the ISAC Ops, and  nothing about any power bump around that time was noticed.  

Turned on TGHT p/s and set TGHT at 318A, local at 315A/4.58V.  TGHT has been running for about 10 mins.  Currently vac at 4.2e-7 Torr.  


Sunday, May 27, 2012, 12:35

Initiating TGHT auto ramping... 


 Monday, May 28, 2012, 00:20

TGHT has reached to 600A and will remain at that current for the rest of the night.  The target oven temperature will be measured tomorrow.

See attachment#4 for the striptool over the past 10hr.


 Monday, May 28, 2012, 10:56

TGHT stayed at 600A for about 12 hours.  Pressure gradually came down to 7.6e-7 Torr. (See attachment #5). 

At TGHT=600A, The target boat temperature was measured at 1400C (with the pyrometer), and the Ta-heat shield (1-layer) was at 1050C. [Note: These temperature measurements are very closed to the measurements with an empty LP target (with not heat shield), TGHT @ 600A = 1360C].


Monday, May 28, 2012, 11:04

Due to the water leak from the Evap2 chiller, the system has to be shut off for inspection. 

TGHT was tapped down to 0A.  The target was cooled down for about 20min before the chiller was turned off.

Will continue with the process after the problem is solved...


 

 Tuesday, May 29, 2012, 15:30

Evap2 was vented out and the pellets were taken out of the boat and examined.

The six pellets are cracked and have a greyish colour. The cracking is probably caused by the instant cooling and reheating when the system tripped on Sunday morning.

The light grey colour and white spots suggest that the sintering process was not completed and so the shrinkage cannot be determined.

A new batch of BeO pellets will have to be prepared and sintered in order to determine the dimensions of the final die.

 

Entry  Wednesday, June 20, 2012, 17:29, Nikita Bernier, NiO, Ta target boat, , Done, NiO development NiO_density_measurements.xlsxCasts_thickness.GIF

Wednesday, June 20, 2012, 17:23

New Target boat, with no coating, wrapped with a 0.002 inches thick Ta foil, contains 3 NiO pellets :

Sample,   # Disks,    Mass (g),    Thickness (mm)

1    12,  1.9396,  1.938

2    13,  0.9592,  0.847

3    25,  2.6675,  3.06

See John's Ipad for their recipes.

Evaporator #2 is now auto-ramping overnight at 0.5 A/min, up to 580 A, with the maximum voltage limited at 14 V, between 3.00e-05 (Good vacuum) and 4.00e-05 Torr (Bad vacuum).


Thursday, June 21, 2012, 18:14  

See attachment #1, 2 for the density measurements and the graph for the disc thickness  -JW 


 

    Reply  Wednesday, June 20, 2012, 22:33, John Wong, NiO, Ta target boat, , Done, NiO development Photo_2012-06-21_8_27_40_AM.png

Nikita Bernier wrote:

Wednesday, June 20, 2012, 17:23

New Target boat, with no coating, wrapped with a 0.002 inches thick Ta foil, contains NiO D-shape discs :

Sample,   # Disks,    Mass (g),    Thickness (mm)

1    12,  1.9396,  1.938

2    13,  0.9592,  0.847

3    25,  2.6675,  3.06

See John's Ipad for their recipes.

Evaporator #2 is now auto-ramping overnight at 0.5 A/min, up to 580 A, with the maximum voltage limited at 14 V, between 3.00e-05 (Good vacuum) and 4.00e-05 Torr (Bad vacuum).


 

Wednesday, June 20, 2012, 22:28

TGHT tripped off at 78A due to high out-gassing pressure.  The current was tapped down to 75A before it was turned back on. 

Changed ramping rate from 0.5A/min to 0.2A/min.  

Initiate auto-ramping... 


 Thursday, June 21, 2012, 08:35

Vacuum has come down to 7e-7 as TGHT is being ramped up at 0.2A/min. (see attachment#1).

Increase TGHT rate to 2A/min.

The temperature should be measured when the heater gets up to around 500A.


 

    Reply  Thursday, June 21, 2012, 18:13, John Wong, NiO, Ta target boat, , Failed, NiO development - Container broke!  NiO_targets_temp.pdfTGHT_0-580A.GIFTGHT_200-580A.GIFTGHT_vs_VOL.GIFNiO_container_broke.png

John Wong wrote:

Nikita Bernier wrote:

Wednesday, June 20, 2012, 17:23

New Target boat, with no coating, wrapped with a 0.002 inches thick Ta foil, contains NiO D-shape discs :

Sample,   # Disks,    Mass (g),    Thickness (mm)

1    12,  1.9396,  1.938

2    13,  0.9592,  0.847

3    25,  2.6675,  3.06

See John's Ipad for their recipes.

Evaporator #2 is now auto-ramping overnight at 0.5 A/min, up to 580 A, with the maximum voltage limited at 14 V, between 3.00e-05 (Good vacuum) and 4.00e-05 Torr (Bad vacuum).


 

Wednesday, June 20, 2012, 22:28

TGHT tripped off at 78A due to high out-gassing pressure.  The current was tapped down to 75A before it was turned back on. 

Changed ramping rate from 0.5A/min to 0.2A/min.  

Initiate auto-ramping... 


 Thursday, June 21, 2012, 08:35

Vacuum has come down to 7e-7 as TGHT is being ramped up at 0.2A/min. (see attachment#1).

Increase TGHT rate to 2A/min.

The temperature should be measured when the heater gets up to around 500A.


 

 Thursday, June 21, 2012, 17:37

The NiO discs were heated up to 1500C at 560A.  The target heater was lowered in steps and the temperature was measured.  At 320A, the target container was ~1110C.  (see attachment #1) 

There was a sign of resistant on the target container as the p/s voltage started to go up at a higher rate.  (see attachment#2, 3, 4 for the archived striptool).

Unfortunately, the target container was broken; it was most likely reacted with the Ni.  (see attachment#5)

So.... the possible solution?!  TRY coating the container with Ta2O5.  Will discuss more in the Friday Jun 22 meeting. 


 

Entry  Thursday, July 12, 2012, 17:55, John Wong, NiO, targetboat (TaC coated), , Maintenance, NiO development- test#2 NiO_spray.PNGTGHT0-250A.png

Thursday, July 12, 2012, 17:29

NiO was sprayed on Ni foil.

Average/discs: mass= 0.075g, thickness=0.076mm, density = 7.023g/cm3.

4 set of samples were loaded onto the targetboat (coated/sintered with TaC).  A piece of Ta foil was used as the under layer (see attachment #1).

A 0.002" thick Ta foil was wrapped around the container as the heat-shield.

The chamber was pumped down to 5.0e-6 Torr before the cooling water valve was opened; no leaks was detected.

For this process, the target heater will only go up to 250A (~1100C), with auto-ramping rate at 0.5A/min.

The heater has been stepped up to 50A, local 32A/ 0.23V.  The vacuum reached to max 1.6e-5 Torr, and it's coming down.


Thursday, July 12, 2012, 17:51

Auto-ramping initiated...


 Friday, July 13, 2012, 09:42

TGHT reached to 250A and stayed for 6 hrs (see attachment #2).  At that current, the target wasn't glowing so the temperature could not be measured. 

Initiated auto-cooling at 2A/min. 


Friday, July 13, 2012, 11:00  

TGHT reached to 65A.  Stopped the auto-cooling process and manually tapped down the p/s to 0A.  

Vacuum is stable at 5.7e-7 Torr.  

In the next 30 min or so, the chamber will be vented and the NiO target material will be taken out for inspection. 


 

Entry  Tuesday, July 17, 2012, 16:00, John Wong, , targetboat (TaC coated), , Done, Sintering TaC coated regular- & D-endcaps 

Tuesday, July 17, 2012, 15:45

Target boat is filled with TaC coated regular- and D-endcaps. 

The boat is wrapped with a Ta heat-shield. 

Chamber is being pumped down, currently at 5e-6 Torr.


Tuesday, July 17, 2012, 15:58

Heat-shield cooling water valve opened; no leaks detected.

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


 Wednesday, July 18, 2012, 10:44

Yesterday evening, the target heater tripped off a few times due to high vacuum excursion.  The TGHT ramping rate was low to 0.2A/min.  The current was ramped up sturdily to 500A this morning.  


Wednesday, July 18, 2012, 10:46

Increased ramping rate to 2A/min.  Vacuum currently at 2.2e-6 Torr.


 Wednesday, July 18, 2012, 16:18

TGHt has reached to 580A and stayed for about 5 hrs. 

Cooling down in process...  2A/min for TGHT --> 0A.


 Thursday, July 19, 2012, 10:31

TGHT reached to 0A. 

Evaporator is off. 

Venting chamber... 


 

Entry  Monday, July 30, 2012, 15:42, John Wong, , , , Problems, Chiller maybe leaky chiller.jpg

Monday, July 30, 2012, 15:38

The evaporator was used for the processing the NiO target for 8 days and it was discovered today that there was a puddle of water underneath the chiller. 

The cover of the chiller was removed and some water around the plumbing was found (see attachment #1). 

Will continue to keep running the chiller to see if there is more water leaking out...


 

Entry  Friday, August 10, 2012, 19:57, Nikita Bernier, , , , Done, Sintering Ta foil with TaO coating 

 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).

 

    Reply  Saturday, August 11, 2012, 19:21, Nikita Bernier, , , , Done, Sintering Ta foil with TaO coating TaO1.pngTaO2.png

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.

 

    Reply  Monday, August 13, 2012, 13:50, Nikita Bernier, , , , Done, Sintering Ta foil with TaO coating TaO3.png

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.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Entry  Tuesday, August 14, 2012, 15:11, John Wong, , , , Maintenance, Replacing Cu-heatshield insulators insulators.PNGMM800_insulator.PNG

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).


 

    Reply  Tuesday, August 14, 2012, 17:11, John Wong, , , , Failed, Sintering Ta2O5 coating on Ta foil failed Ta2O5_coating.PNG

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.


 

 

Entry  Monday, September 24, 2012, 15:12, Nikita Bernier, TaC, , , Done, Sintering Ta foil with TaC coating striptool1.PNG

 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.

 

 

 

    Reply  Monday, September 24, 2012, 18:09, Nikita Bernier, TaC, , , Done, Sintering Ta foil with TaC coating striptool2.PNGstriptool4.PNGstriptool5.PNG

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.

 

 

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