Tuesday, May 15, 2012, 13:45

It was discovered that one of the insulators that supported the target module broke apart (see Attachment#1).  This might be caused by the heat from the target legs that reflected back from the base to the insulators.  The burnt marks are the evidence.  

A stainless metal sheet is used as the heat shield  (see Attachment #2). 

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. 

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).

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".

With the help of Anthony Ip from vacuum group, the problem was diagnosed to be the roughing pump itself. The pump was replaced and pumping improved. The chamber can now be evacuated and turbo ready to start in less than 10 minutes.

The filter is not stocked by vacuum group and could not be replaced.

Last week parts of the roughing line was cleaned by Rick. The PVC roughing line has been replaced with a SST bellows. The SST bellows is KF25 and should be replaced by a KF40 bellows in the long run.

Monday, March 10, 2014, 11:44

Rick replaced the backing pump hose from 1.5" to 2.0" for better flow.  And the HEPA filter was checked - it looks OK.

 Thursday, October 02, 2014, 11:22

It was found that after the last process, Evap#2 has broken insulators - the cylinder insulator that supports the target centre legs and the block insulator that supports the terminals.  

Informed Anders/Rick.

John Wong wrote:

Thursday, October 02, 2014, 11:22 It was found that after the last process, Evap#2 has broken insulators - the cylinder insulator that supports the target centre legs and the block insulator that supports the terminals.   Informed Anders/Rick.

 Friday, October 03, 2014

• Insulators replaced. Torque 55 in lbs on all fasteners.
• Cleaned TGHT terminals with scotch-brite and methanol.
•  New (clean) heat shield prepared WO-39230-2.
• Re-installed right side heat shield alignment pin (previously removed to allow line of sight to the target).

 Wednesday, November 26, 2014, 13:47

OMEGA-IR laser had a dark patch on it [see picture]

Cleaned window, still dark patch

When tested by itself, through air, not through window, patch still visible - cleaned lens of OMEGA-IR, still no change.

Conclusion: assuming laser used to be able to focus the OMEGA-IR to a specific area - so visual only, but the measurements itself will not be affected.

Wednesday, November 26, 2014, 13:53 

Backing pump trips off every time roughing valve turned on through epics.

Requested further investigation...

Friday, November 28, 2014, 12:09

Backing Pump has been replaced, waiting on a reply from OMEGA re: dark patch on laser

Pancake monitor was also acting funny. Background was reading 100cpm and jumping up to as high as 400cpm by simply moving the probe piece.

The wire connecting the probe to the monitor was replaced and works fine now.

 Tuesday, December 09, 2014, 15:55

Finally got a reply from the OMEGA people:

"That [ dark patch] would happen because of sharp bends in the fiber, or simply defective fiber cable.

As manufacturer we allow 2% of broken fibers, out of 870 in the bundle.

As far as measurements is concerned, if IR2 is used in dual colour mode, 

the field of view can be obstructed as much as 50%, 

without changing the readings accuracy. This laser issure should not affect readings."

-Quote from Brian Newport from OMEGA

 Thursday, December 11, 2014, 10:17

water supply and return valves closed for lab closure over the holidays.

all taps leading into evap2 have been closed.

evap2 was fully flushed leaving no water left inside the system.

 Wednesday, January 14, 2015, 13:46: Roughing

Wednesday, January 14, 2015, 14:57: Starting turbo

Monday, January 19, 2015, 13

Water opened up to one circuit at at time. No response on the vacuum could be seen.

IGP1 at 1.7E-7 T

IGP2 at 3E-8 T

Tuesday, January 20, 2015, 13:11: Stopped turbo and roughing pump.

Wednesday, January 21, 2015, 15:46: Venting

Rick and Anders found CG1A to be reading too high a value. A borrowed gauge from the vacuum group confirmed this. A new gauge will be installed

Thursday, January 22, 2015, 14:06: Roughing

Thursday, January 22, 2015, 14:18: Venting

The reading is consistent between CG1A and CG1B, which simplifies pump down.

 Thursday, July 30, 2015, 17:02

EVAP1 cooling system is now on the NALCW.  The city water has been removed from the system.  

Tested all the cooling system interlocks by shutting off each individual valve, and the main supply valve to the lab -  All Passed!  

Friday, July 31, 2015, 15:09

The left side port was installed on the evaporator #2.  Leak check was performed and no leak was detected. 

 Monday, August 24, 2015, 12:54

The turbo pump was found to be faulty.  The pump couldn't get on full speed and eventually timed out.  Vacuum group inspected the pump and it is time for a service.  

A new pump has been installed.  Leak  check was performed and no leaks were detected.  

Pump is now fully operational. 

Back in business…. 

 Thursday, January 14, 2016, 11:47

Backing pump was making very loud high pitched noises during last couple processes in the evaporator.

Replaced with a new one this morning.

Wednesday, August 03, 2016, 16:16

Tues July 26th had some problems with the transfer chamber

Transfer chamber was not going below -20in pressure, when usually it will drop all the way to -30in

To by pass and put the uranium target into the glove box, the transfer chamber was flushed 10x - when opened, no change in H2O and O2 in glove box; therefore, 'bypass' worked.

Pump removed and tested by vacuum group - showed no reading on gauge when being tested, how was it even pumping?

New pump installed July 27th.

New pump = bigger/ faster/ quieter 

 Dan made a set of new cooling lines for the Source Tray Heat Shield cooling yesterday. No joints on the lines. Use same VCR fitting 3/8 -> 1/4" as for the Heat Shield. The old lines had worn threads on the male VCR nut.

Tuesday, December 20, 2016, 15:05

confirmed ~full tank of Ar for glove box --> ~1600psi 

 Thursday, February 09, 2017, 11:47

A new heatshield with flexible water lines has been put into evap2 last Friday Feb3rd