EDS Detector Repair

[Probeman]

Justin Kraft posted this on the Microscopy List Server and I thought it worth posting here also:

I wanted to respond to this and let you know that Jim Nicolino, who used to run AAT, has retired. (If I'm wrong, I apologize)  There was another company- TNAS in Madison, WI that was repairing Si(Li) detectors.  I purchased that company, which was the company that purchased AAT.  (So AAT became TNAS became Aperture Scientific.) 

Unfortunately, unless the detector just needs a pumpdown and bakeout, there isn't much that can be done anymore to repair these.  Mostly, the issues arise with either the window, preamp, the crystal, or the FET (Which sits behind the crystal.)  There are currently no more crystals being manufactured.  I have a limited supply, and the quality of the used ones is dodgy at best.

When it comes to FETs, there are replacement FETs, however they are bare silicon, which will require proper installation in a mount, requiring a clean room, bonding equipment, etc.  It is not economically feasible for new FETs to be assembled for detector repair.

I do have a stock of preamps, however the supply is dwindling and I may or may not have a replacement available.

Finally, the window.  The window can be changed, as long as all other parts are functional.  The symptoms of a blown window are that when you vent the chamber of your microscope, the LN2 starts boiling off rapidly.

What I recommend to customers who contact me looking to repair their Si(Li) detector is to contact RaySpec in the UK to purchase a silicon drift detector.  There are some differences between the two, and you might need to slightly adjust your SOP, but ultimately it will be a much more efficient and cost-effective detector to install in the long-run.

I hope this helps.  If there is anything I can do to help further, please don't hesitate to reach out.

--Justin A. Kraft
Aperture Scientific, LLC