We have cleaned out the ion pumps on our VG354. We removed the titanium(?)
mesh, small hands are useful! WE didn't bother removing teh magnets. I
think we used isopropyl alcohol or acetone. It took a lot of flushing and
light rubbing with lab tissues to remove all of the particles. We did this
after discovering that light tapping on the ion pump caused dramatic drops
in the vacuum. Presumably loose particles were being liberated?
What about the IG filaments?
At 09:51 12/11/99 +0000, you wrote:
>Dear List Members -
>I'm looking for advice on Ion pumps.
>The source ion pump our VG354 thermal ionisation mass spec appears to have
>partially stopped working, leaving the vacuum just below 10-6 mBar. I've
>baked out the system with no improvement. The pump controller is common to
>a smaller ion pump on the analyser bench which appears to be working
>correctly so I suspect the actual pump itself. There are also worrying
>flickers on the meter of the power supply if we monitor the current being
>drawn by the pump.
>Does anyone know if the pump can be dismantled and cleaned ?
>Any advice on dealing with this type of problem would be gratefully
>Dr Andy Midwood,
>Macaulay Land Use Research Institute,
>Tel: +44 (0) 1224 318611
>Fax: +44 (0) 1224 311556
>Email: [log in to unmask]