Hi Roberto

You should not need to wash the flight tube again.   If there is a problem,
you should bake the vacuum system.  This means you need to use a heating
tape or other heat source to heat up the metal surfaces to a temperature of
about 200 C.

The peak shape is unlikely to be affected by contamination of the flight
tube unless the contaminant is forming an insulating layer which is
charging up. Unless the delta was subject to mis-use before it was shut
down,  baking should remove any problem.

The most probable cause of bad peak shape is that the magnet is out of
position with respect to the flight tube.  If there are no indicating
marks,  place the magnet in position over the flight tube as symetrically
as possible. Then test the peak shape.  Shift the magnet a little then
retest the peak shape.  When you find the position with the best peak
shape, mark it.

Other things to check  :

That the ion source is located correctly in the  housing.

The ion source is properly tuned.

Does the system use an electromagnet or permanent magnet?  If it is an
electromagnet,  email me as there are some other things you can check.

Boa Sorte

Joe Cali



PS  Could one of the members of isogeochem with psychic abilities please
tell us what Michael O'Leary's message said.    :-)


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Joseph A. Cali                           |                               |
Research School of Earth Sciences | Phone :  61-6-2493246         |
Australian National University    |   Fax :  61-6-2493246         |
Canberra, Australia,  0200        | Email :  [log in to unmask]  |
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