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. 

 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. 

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.

Tuesday, June 21, 2022, 09:43

Total number of foils: 377 ( including 6 analysis discs on the right side of the container)

Total weight = 1454 g (includes heatshields, spring and T bar)

Total length packed 15.5 cm (excluding 6 analysis discs that will be removed)

container has 3 Ta heat shields and is coated

No endcaps inserted to facilitate out-gassing

Ta coated spring at  front (right) side

Initially to ramp TGHT and TBHT to 80A at 2 A/min

then to 120A and slow down ramp when pressure begins to increase

max approx 675A on TGHT and 230A on TBHT (Omega slope set = 0.990)

Then temperature = 1800C

TBHT will be set fixed at 230 A (max).  TBHT heated manually and automatically to max.

Good vac at 3.00 e -4 Torr

Bad vac at 5.00 e-2 Torr

 IGP1=3.6 e-07 Torr at start of initial ramp.

Tuesday, June 21, 2022, 13:54

IGP1= 7.1 e-05 and dropping.  Start ramp to 150A for both TGHT and TBHT @1A/min

Tuesday, June 21, 2022, 21:27

Increased ramp rate to 3A/min for TGHT to 675A

Tuesday, June 21, 2022, 22:38

Ramp up to 685 A on TGHT and leave for 4 hours. 

OMEGA = 1645 C but suspect reading not on Ta surface.

Wednesday, June 22, 2022, 02:28

IGP1=7.7e-6 Torr

OMEGA =1610C

TGHT = 685A, 10.5V

TBHT = 230A, 3V

initiate rampdown at -2A/min and -1Amin TGHT and TBHT

Tuesday, June 07, 2022, 07:19

Total number of foils: 403 ( including 5 analysis discs on the right side of the container)

Total weight = 1535.3 g (includes heatshields, spring and T bar)

Total length packed 16.4 cm (excluding 5 analysis discs that will be removed)

container has 3 Ta heat shields.

No endcaps inserted to facilitate out-gassing

Ta coated spring at  front (right) side

Initially to ramp TGHT and TBHT to 50A at 3 A/min

then continue to 80A and slow down ramp when pressure begins to increase

max approx 700A on TGHT and 230A on TBHT (Omega slope set = 0.990)

Then temperature = 1800C

TBHT will be set fixed at 230 A (max).  TBHT heated manually and automatically to max.

Good vac at 3.00 e -4 Torr

Bad vac at 5.00 e-2 Torr

 IGP1= 7.6 e-07 Torr at start of initial ramp.

 Tuesday, June 07, 2022, 11:14

Ramping to 150A on TGHT and TBHT at 1A/min

Ramped TGHT and TBHT to 230A at 2A/min

Tuesday, June 07, 2022, 13:12

Ramping TGHT to 600A at 4A/min

TBHT at 230A, 3.0V

Tuesday, June 07, 2022, 16:41

TGHT= 740 A, 12.1V

TBHT= 232A, 3.0 V

OMEGA reading 1616C but questionable.  Will leave for 4 hours at 740A top TGHT.

Wednesday, June 08, 2022, 22:15

Early Wednesday morning the left TGHT bolt was found damaged.  The target leg was coated with bolt material rendering the Target inoperable.   

The Heatshield assembly was swapped and surfaces cleaned.  A "dummy" FEBIAD was installed to test if the system can withstand high current. 

The system was pumped down and ramped to 740A on TGHT at 4A/min.  It was then left at that current for 4 to 5 hours.

Currently starting rampdown at -2A/min to 0A. 

Photos of the incident attached in *eLog 580*.  IGP1= 5.7e-06 Torr

TGHT= 742A, 11.4V

 Wednesday, May 18, 2022, 09:46

Total number of foils: 415 ( including 10 analysis discs on the right side of the container)

Total weight = 1580 g (includes heatshields and T bar)

Total length packed 17 cm (including 10 analysis discs that will be removed)

container has 3 Ta heat shields.

No endcaps inserted to facilitate out-gassing

Ta coated spring at  front (right) side

Initially to ramp TGHT and TBHT to 30A at 3 A/min

then continue to and slow down ramp when pressure begins to increase

max approx 700A on TGHT and 230A on TBHT (Omega slope set = 0.990)

Then temperature = 1800C

TBHT will be set fixed at 230 A (max).  TBHT heated manually and automatically to max.

Good vac at 3.00 e -4 Torr

Bad vac at 5.00 e-2 Torr

 IGP1= 7.1 e-07 Torr at start of initial ramp.  Note, first real operation with new noisy Turbo Pump.

Wednesday, May 18, 2022, 10:18

Pressure increase observed starting around 60A.  Ramped to 70 A and will leave until pressure stabilizes

After about 30 minutes pressure dropped so ramped up to 90 A @1A/min on both TGHT and TBHT

Wednesday, May 18, 2022, 11:37

pressure spike around 90A.  will leave until pressure stabilizes 

Wednesday, May 18, 2022, 12:54  

start autoramp to 100A at 1A/min.  IGP1= 1.4e-4 Torr

Wednesday, May 18, 2022, 13:15

autoramp to 150A @1A/min 

Wednesday, May 18, 2022, 13:41

 At 110A another spike in pressure.  System waiting for good vacuum

Wednesday, May 18, 2022, 15:24

ramped to 150A on both TGHT and TBHT.  Ramping to 200 A at @A/min for both TGHT and TBHT

currently IGP1=  2.0e-4 Torr

Wednesday, May 18, 2022, 15:33  

Pressure still trending down; therefore will start ramp at 4A/min to 400 amp on TGHT and 230A to TBHT

Wednesday, May 18, 2022, 16:22 

Increasing ramp to 4A/min on TGHT

Wednesday, May 18, 2022, 17:26 

switched to 6A/min in 1A/10s increments on TGHT

Wednesday, May 18, 2022, 17:43 

Set final current to 730 A as per regression attached.

Wednesday, May 18, 2022, 17:54

Final current on TGHT = 740A, 11.9 V

OMEGA = 1775 C

TBHT = 230A, 

Will leave for 4 hours

Wednesday, May 18, 2022, 19:56

Temperature dropped so increased current to 755A for the remaining of the time.

Friday, May 20, 2022, 08:58

Final notes:  The difference between initial and final mass was 6 g as expected.  Slight coating on window of evaporator may explain apparent temperature drop.  Next time will keep current at projected setting.  The material looks good with slight overheating on the outer discs of left side.

Thursday, November 24, 2022, 11:01

Target container contains one disc of e-spun TiO2/PAN fibrous disc, (Ref sample P-134).

Sample will be heated to 1875C, similar to the previous process, see e-log ID#599.

TGHT will be autoramped to 350 A and monitor the conditions before ramping up further.

Good vacuum: 3e-5 Torr

Bad vacuum: 5e-5 Torr

Omega slope: 0.99

Initiate autoramp: 1 A/min

Chamber has been pumped down below 5.0e-6 Torr.

 Friday, November 25, 2022, 08:38

TGHT reached to 348A/5.8V; temp is holding at 1600 C since 19:00 yesterday, see attachment#1.

Stepping up TGHT to 400A and continue to monitor.

 Friday, November 25, 2022, 09:45

TGHT reached to 400A/6.8V; temp holding at 1758C.  Pressure coming down from 6.6e-7 Torr.

Ramping up to 410A.

 Friday, November 25, 2022, 12:28

TGHT reached 410A/7.08V.  temp holding at 1790 C.  Pressure coming down from 6.9e-7 Torr. 

Ramping up to 430A.

 Friday, November 25, 2022, 13:01

TGHT reached 430A/7.4V. Temp holding at 1837 C.  Pressure coming down from 7.73e-7 Torr.

Ramping up to 440A.

 Friday, November 25, 2022, 13:50

TGHT reached to 440A/7.6V.  Temp holding at 1864C.  Tapping TGHT to 444A (readback 443A - 449 A)/7.7V. 

Desired Temp has reached, 1875 C.  Will continue to hold on this temp over the weekend.

 Sunday, November 27, 2022, 21:14

TGHT has been holding at 442A (lowered by 2 A on Fri to maintain 1875C).  Temp increased to 1887C.  Pressure at 2.5e-7 Torr. 

See attachment#2 for plots/temp. 

Initiated cooling at 1A/min.

 Tuesday, October 18, 2022, 13:52

38 pieces of samples made of TiO2/C/PVP loaded into a target boat wrapped with 2 layers of Ta-heat shield.

Samples will be heated to 1700, 1800, 1900, and 2000 C

Some of the pieces will be removed after each target temperature 

Target chamber has been pumping down and the current pressure reading is 6.62e-6 T

 Tuesday, October 18, 2022, 14:12

TGHT will be autoramped to 250 A

Good vacuum: 3e-5 Torr

Bad vacuum: 5e-5 Torr

Omega slope: 0.99

Initiate autoramp: 1 A/min

Hannah Toy wrote:

Tuesday, October 18, 2022, 13:52 38 pieces of samples made of TiO2/C/PVP loaded into a target boat wrapped with 2 layers of Ta-heat shield. Samples will be heated to 1700, 1800, 1900, and 2000 C Some of the pieces will be removed after each target temperature  Target chamber has been pumping down and the current pressure reading is 6.62e-6 T  Tuesday, October 18, 2022, 14:12 TGHT will be autoramped to 250 A Good vacuum: 3e-5 Torr Bad vacuum: 5e-5 Torr Omega slope: 0.99 Initiate autoramp: 1 A/min

 Wednesday, October 19, 2022, 09:42

TGHT has reached to 250A/3.95V, Temp at ~1100 C.  (The archiver is currently not working; already contacted Control to look into it.)

Pressure reached below 4.9 e-7 Torr. 

Auto-ramp to 300 A at 2A/min.  Continue to monitor.

 Wednesday, October 19, 2022, 10:24

TGHT reached to 300 A/4.89V.  Temp at 1206 C. 

Pressure went up slightly and came down after the TGHT setpoint was reached, see attachment#1.

Continue to auto-ramp to 350A at 2A/min.

 Wednesday, October 19, 2022, 11:35

TGHT reached to 350A/5.8V.  Temp at 1360C.

Pressure reached above 1e-6 Torr and came down after TGHT reached the setpoint. 

Continue to auto-ramp to 400 A at 2A/min

 Wednesday, October 19, 2022, 11:57

TGHT reached to 400 A/6.89V.  Temp at 1485C.

Pressure went up to 3.3e-6 Torr and came down after TGHT reached the setpoint,  see attachment#2.

A temp vs current plot has been generated (see shared folder \Hannah\) - est TGHT 480A to reach 1700 (T1).

Auto-ramp to 420 at 1A/min.  Continue to monitor closely...

 Wednesday, October 19, 2022, 13:01

TGHT reached 420A/7.23V, Temp at 1520 C.

Continue auto-ramping to 440A at 1A/min.

 Wednesday, October 19, 2022, 13:42

TGHT reached 440A/7.65V.  Temp at 1572 C

Continue auto-ramping to 460A at 1A/min.

Wednesday, October 19, 2022, 14:10

TGHT reached to 460A/8.10 V.  Temp at 1628 C.

Tapping up TGHT to reach 1700 C

 Wednesday, October 19, 2022, 15:33

TGHT was tapped up to 474A, Temp reached to 1700 C since 14:30.

Pressure is slowing coming down, currently at 1.4 e-6 Torr.

Will hold at this target current for a few hours.

 Wednesday, October 19, 2022, 16:58

Temp went up slightly to 1713 C as the pressure is coming down. 

Lower TGHT to 468A/8.45V to maintain the temp at 1700 C.

 Wednesday, October 19, 2022, 19:55

Temp went up again to 1716 C, but this time the pressure also went up, see attachment#3.  Not sure why the target got hotter... the voltage seems normal and consistent. 

Lower TGHT to 462A/8.44V to maintain at 1700 C. 

Continue monitoring...

 Wednesday, October 19, 2022, 22:56

Temp went up another 10 C, to 1710 C, TGHT is holding at 462 A/8.48V.  Notice the TGHT current readback is fluctuating between 458A - 463 A. 

Initiated cooling.. 2A/min

 Friday, October 21, 2022, 08:55

 All the samples were taken out from the Evap on Thursday Oct 20.  We decided to do so because there was not enough sample in each batch for XRD analysis.  All the sample will be analyzed as treated at 1700 C. 

See attachement #$ for the overall TGHT/Vac plot.

 Previous TP would only spin up to 4KRPM. New TP installed.

Monday, June 05, 2023, 14:50: Roughing. 

Monday, June 05, 2023, 15:10: Controller reset. TP on. 

Thursday, March 27, 2014, 17:38

TEST #1

WC slurry was prepared in non-aqueous environment (see lab book for procedures).  The solution was dripped on two Ta plates (3.1cm2) and let dry. 

Another Ta plate (3.1 cm2) was sprayed with TaC coating (for comparison).

All 3 coated Ta plates are put in a target boat and the boat is wrapped with 3 layers of Ta-heat shields.

HS water valves open; no leaks detected.

TGHT will be ramped up to 700A at 2.0A/min.

RGA is running and gases are being monitored.  See link:

https://www.dropbox.com/sh/625xl7zgepbybmu/GQJTlMo-5a

 Friday, March 28, 2014, 09:13

TGHT reached to 700A and samples were heated up over night. 

Cooling down Evap at 4A/min. 

 Tuesday, April 01, 2014, 17:37

Previous samples, namely WC#1, #2, TC#1 were fully sinterred.  See above link for photos.

TEST#2

Samples WC#3, #4, #5 are sprayed coated with WC solution.  Grains were pre-treated at 400RPM.

These 3 new samples are loaded in a boat, wrapped with 3 layers of Ta-heat shields.

Chamber is pumped down; no water leaks are detected.

TGHT will be ramped up to 700A at 2.0A/min

RGA is running.

Samples were analyzed with SEM/EDX.  The results are inconclusive because W and Ta peaks are very close together.  And WC coated layer may be even too thin to analyze. 

 Monday, April 14, 2014, 16:32

Test#3:  Coated WC on Endcap.  Total mass WC ~350mg.

Sintered at 500A/9.5V; measure temperature on actual sample surface ~1700C.  Sample heated >24hr.

Cooling down TGHT at 2A/min.  IG currently at 3.1e-7 Torr.

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

 Wednesday, May 06, 2015, 13:54

Two different samples of ZrC are wrapped in graphite sheet and loaded into the target boat.

Sample #1 = ZrC

Sample #2 = ZrC+C

Both samples are hand punched with a 18mm die.

The target boat is wrapped with 3x Ta heat shield.

Pumped down this morning.

HS water valves opened, no leaks detected.

IGP1 = 1.5e-6 Torr.

Tapping up manually to 35A...

 Waited ~50min for vacuum to stabilize.

IGP1 = 5.3e-6 Torr.

Initiating auto-ramp at 0.1A/min for the TGHT with a max setpoint of 275A/ 10V

Good vacuum = 3.00e-5 Torr. Bad vacuum = 4.00e-5 Torr.

Wednesday, May 06, 2015, 15:37  

Increasing ramping rate to 0.2A/min

 Thursday, May 07, 2015, 11:15

Stopping auto ramp.

TGHT = 273A.

Tapping up manually and recording data...

IGP1 = 6.6e-7 Torr.

 Thursday, May 07, 2015, 14:21

Increased max voltage to 14V

 Friday, May 08, 2015, 09:33

EVAP2 reached 2000C yesterday evening and remained at max setpoint overnight.

IGP1 = 3.8e-7 Torr

Initiated auto-cool this morning at 2.0A/min.

 Friday, May 08, 2015, 11:32

IGP1 = 2.1e-7 Torr

TGHT = 221A, 3.21V

OMEGA = 1100C

Increasing auto-cool to 5.0A/min.

 Friday, May 08, 2015, 15:53

Vented in air and opened up this afternoon.

See attachment for data results.

 Wednesday, May 13, 2015, 15:21

Three different samples of ZrC are loaded into a target boat.

Sample A: ZrC + NO graphite

Sample B: ZrC + graphite [1:0.5 molar ratio]

Sample C: ZrC + graphite [1:1 molar ratio]

Each sample consists of 20 discs, stacked together and wrapped in graphite sheet

The target boat is wrapped with 3 x Ta heat shield.

EVAP2 pumping down overnight...

 Thursday, May 14, 2015, 08:20

HS water valves opened up this a.m, no leaks detected.

IGP1 = 6.6e-7 Torr

Tapping up manually to 35A.

Good Vacuum = 3.00 e-5 Torr. Bad Vacuum = 4.00 e-5 Torr.

Thursday, May 14, 2015, 09:51

Tapped up manually to 30A.

After ~25min, vacuum gone up to IGP1 = 3.5e-5 Torr!

Backed off to 20A.

Waited ~10min. IGP1 = 1.75e-5 Torr.

Tapped back up to 25A.

Waited ~20min, IGP1 = 1.4e-5 Torr.

Tapped up to 30A.

Waited ~20min, IGP1 = 2.2e-5 Torr.

Tapped up to 35A

Waited ~50min, IGP1 = 2.5e-5 Torr.

Continuing manual tap-up...

 Thursday, May 14, 2015, 13:27

IGP1 = 9e-6 Torr

Tapped up to 40A.

Waited ~45min, IGP1 = 1e-5 Torr

Initiating auto-ramp at 0.1A/min for the TGHT with a max setpoint of 275A/ 8.0V

 Friday, May 15, 2015, 08:25

Max setpoints were changed to 400A/ 8.0V last night.

Reached 400A ~4.5hrs ago.

IGP1 = 4.9e-5 Torr

Initiating manual tap up and recording data.

 Friday, May 15, 2015, 15:50

Samples remained at ~2000C for ~4 hours [see attachment for data]

IGP1 = 7.8e-7 Torr.

Initiating auto-cool at 1.0A/min.

 Tuesday, May 19, 2015, 08:27

Vented in air and opened up this morning.

Purpose: Sinter one sample of each of TiC, VC, Cr3C2, ZrC, NbC, Mo2C, TaC, and WC on 5x10 mm tantalum foil to see if the samples are usable for SEM.

Samples were prepared using a solution of PEG (2.56 g), PVB (2.45 g), paraffin oil (1.12 g), MEK (15 mL), and EtOH (23 mL). Slurries made using 0.0013 mol of each carbide with ~230 uL of the solution. Applied via paintbrush onto 5x10 mm tantalum foil. 

The samples were placed directly on the target boat, no graphite layer between. We will check to see if the tantalum foil fuses to the boat or not.

Currently (May 29th), the chamber is still pumping down. John and I will continue the procedure tomorrow.

 Pressure down to 7.1e-7 Torr. Water valve to heat shield was opened; pressure remained stable. 

Current turned up to 40 A for now.  Will increase at 2 A/min up to 500 A over the weekend, then on Monday we will turn it up to 600 A and check the temperature. 

Auto-ramp started. Max current = 500 A, voltage = 11.05 V. Current is being increased at 2 A/min. In the first 20 minutes, the pressure went up to about 10E-6 T, but has slowly decreased since then. Everything looks ok. The system will be left until Monday morning (June 9th). 

Manually changed current from 500 to 615 A, monitoring the temperature. Temperature went from 1657 C up to 1838 C. Pressure increased up to 7.2e-7 T. Samples should be left for about 4 hours (615 A started just before 13:00), then the goal is to ramp current back to zero.

 Target boat is now being cooled at 1 A/min from the starting point (616 A) down to 0 A. 

Wednesday, August 24, 2016, 17:05

Target container was previously coated with TaC and sintered up to 1900C at 420A/7.01V

Container is loaded with beta-SiC 432 discs at 16cm in length. 

Container is wrapped with Ta-heat shield; no end-caps are used at this time.

Chamber is being pumped down.

 Thursday, August 25, 2016, 12:04

Chamber has been pumped down overnight.  Pressure at 5.9e-7 Torr.

HS water valve opened; no leaks were detected.

Sintering temperature 1800C. TGHT will be set accordingly to get the desired temperature.  TBHT max at 230A.

Thursday, August 25, 2016, 12:12

Tapped up TGHT/TBHT to 40A.  Vac at 7e-6 and slowly going up  but still below limit.

 Monday, August 29, 2016, 11:04

TGHT and TBHT reached to 250A (3.65V)//230A(3.02V), respectively, and kept stable over the weekend. 

Temp measured at 1372C with slope set at 1.04 (1230C at slope 0.98). 

No visible coating on windows. 

Setting up TGHT to reach 1800C; monitoring locally

 Monday, August 29, 2016, 14:35

Stepped up TGHT to 390A/6.54V; light coating was observed on the windows.  The temperature should be around 1800C which should be in line with the power (current) deposited in the container during the TaC coat sintering process (1900A at 420A); however, with the light coating the reading may be off.  

Mikron was used to measured inside of the tube (away from the discs); temperature was measured at ~1800C, (see attachment)  [adjusted slope at 1.00 to compensate the SiC disc and Ta]  

Omega was used to measured the temperature of the discs.  It is difficult to know what's the temperature inside the tube, so this measurement  is only taken as a guideline.  Slope changed from 1.04 to 1.15 to match Mikron's reading.  

After heated at  390A for 30 mins, the windows are now coated.  Temp reading is no longer reliable.  The temperature could be above 1800C.  Keeping a close monitor!!!

No blockage inside the tube was observed.  

Will remain heating at 390A/6.44V for overnight before proceeding with the re-conditioning. 

 Tuesday, August 30, 2016, 10:41

Target was heated at 390A  for over 10 hours and then cool down at 1A/min (see attachment#2).  Windows were fully coated and Omega couldn't register any reading. 

Chamber will be vented and target will be inspected before proceeding with the re-conditioning step.

Tuesday, August 30, 2016, 12:13  

Target was inspected; no visible damage was observed (see attachment)

Material coated on the windows and the cu heat shields;  all parts were wiped off with acetone. 

No visible material build up inside the container. 

Chamber is now being pumped down for re-conditiing.  

 Tuesday, August 30, 2016, 13:05

HS water valves open; no leaks detected.  

Vac at 3.6 e-6 Torr.  

Ready to set up TGHT/TBHT

 Tuesday, August 30, 2016, 16:41

TGHT/TBHT stepped up to 340A (5.40V) /230A (3.1V), respectively. 

Temperature was measured at 1835C at TGHT of 340A.  Omega, Mikron and analogue pyrometer were all reading ~1800C inside the tube (not on the SiC surface).  For that reason, I decided to stop the current at 340A, instead of 390A.  

TGHT voltage is running stable.  

No visible coating or blockage inside the tube was observed.  

Wednesday, August 31, 2016, 11:53

A thin layer of coating is observed on both the side windows (see attachment 5).  The temp reading is no longer reliable.

TGHT remains at 340A/5.45V.  P/S voltage is performing steadily.  

No clogging inside the tube is observed. 

Setting up another Omega reader to measure temperature from the front window since this window is clear and won't get coated (see attachment #6).

Temperature measurement from the front window is ~1140C; this corresponds to the measurement from the analogue pyrometer with the correction of e=~0.2 for tantalum at 1100C.

Note:  The temperature measurements should be taken as relative.  Since the reading from the side windows isn't reliable any longer, the centre window will give some information how stable the temperature is holding during the reconditioning process.  Continue to monitor.

 Wednesday, August 31, 2016, 16:24

About two hours ago, I increased TGHT to 350A and stayed there for a few mins (see attachment 7).  No change in temp was observed - that's mainly due to the coating on the windows.  As for the temp measurement from the center window, a more power current input would require to see the change as heat is slowly propagating through the layers of Ta heatshields.

Local inspection on the target: no clogging inside the tube. Voltage/Current is stable at 340A/5.45V.  Vac at 1.43e-7 Torr.

 Wednesday, August 31, 2016, 23:00

Strange observation:  Temperature readers on both omega have gone up. (see attachment 8).

I'm not sure if the temperature is reiiable.  I actually saw the increase in temperature ~1850C  last night around the same time; no change in TGHT current/voltage.  By the next morning, it went back down to 1400C with significant coating on the windows.

 Wednesday, August 31, 2016, 23:28

I had ISAC Op (Justin) to help me go into the Hotlab and take a look at the reading on Mikron.  Indeed, it is reading about 2000C which is close to the Omega reading.  He also looked into the tube through Mikron scope and found no clogging inside the tube.

To be safe, I am going to lower the TGHT heater down to reach ~1800C.

Wednesday, August 31, 2016, 23:41

Lower TGHT to 305A/4.81V; OMEGA reading at 1830C.  Vac at 1.27e-7 Torr.  Will remain at this current over night. 

 Thursday, September 01, 2016, 12:16

Checked on the target.  

Temperature readings, right windows (omega)= 1726C, centre = 1100C (omega), left (Mikron) = 1720C.  

No blockage inside the tube.  

TGHT stabilizes at 305A/4.79V.  Vac at 1.09e-7 Torr.  

 Thursday, September 01, 2016, 16:32

 About an hour ago, the temp dropped to 1660C with no change in TGHT current/voltage (see attachment 9).

Vac is a 1.06e-7 Torr. 

After consulting with Friedhelm, we decided to cool the target down and inspect it tomorrow.

Ramping TGHT/TBHT at 2A/min.

 Wednesday, September 07, 2016, 15:13

The target was removed from the Evap and inspected. 

Some spots on both ends and ionizer tube were crystalized.  (see attachment 10). 

No blockage inside the tube was observed. 

End caps were inserted.

The target was assembled and tested - All seems fine.