[RASMB] Elevated temperature operation with a turbomoledcular pump.

[Leech, AP]

Walter Stafford wrote:
> Dear RASMB-ers
> 
>     I have been testing a turbomolecular pump as a replacement for the 
> standard diffusion pump on the XL-I. I am writing to report the results 
> of that experiment.

Hello Walter and RASMBers,

I have asked our service engineers a couple of times why Beckman had not
investigated this option, without any really cogent reply, so I thought
up a few potential objections myself:

1. Modifications to power supply/control are more complex than one
might think (eg power failure cases);

2. Turbo pumps are notoriously sensitive to "bits" of solid material,
as the clearances of the blades are very small for good performance.
Dust etc entering from the chamber could be a problem for long term
reliability;

3. Turbo pumps have been known to fail catastrophically, shedding bits
of metal into the vacuum space.

I would be interested to know if the ATP80 is a specially robust model
of turbo, whether you included any screens or filters etc. Otherwise I
think it is a long overdue development, and I'd be happy to get one
(subject as ever to budget constraints!)

Best regards to all,

Andrew

-- 
Dr Andrew Leech                   *  Laboratory Manager
Technology Facility               *  Molecular Interactions Laboratory
Department of Biology (Area 15)   *  Tel   : +44 (0)1904 328723
University of York                *  Fax   : +44 (0)1904 328804
PO Box 373,  York  YO10 5YW       *  Email : apl3 at york.ac.uk