[Sneap] HVEE Tandetron safety curcuit

[Scott McMaster]

Hello;

I'm hoping someone out there may have run into this problem or something
similar.......

We have a 1.25MV Tandetron that is intermittently tripping a computer
monitoring circuit called the "safety circuit".  When it trips it dumps
the vacuum gauge power supplies, the source filament and zeros all the
computer inputs to the source.  Timing on the trips is seemingly random
but it is frequent enough that we can't run.

To this point our experimentation and searching of manuals has been unable
to find the inputs the circuit is monitoring, making it pretty difficult
to trouble shoot.  It doesn't seem to be associated with any of the usual
"safety" suspects (customer interlocks, source deck HV interlocks,
cooling water etc.).

I'm at the point where our only choice is to start taking Canodes apart to
see what trips the circuit.  Before I start I'm hoping someone out there
might have some insight about how this circuit works and what it is
looking at.

Thanks in advance for any insight!

Scott McMaster, P.Eng
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Manager, McMaster Accelerator Laboratory
McMaster University, Hamilton, Ontario