Re: [BLAST_SHIFTS] 9/27/02 evening shift summary

From: Jan van der Laan (janvdl@MIT.EDU)
Date: Sat Sep 28 2002 - 13:36:31 EDT


At 11:20 PM 02/09/27 -0400, you wrote:

Hello, All:

The goal of this shift was to determine whether or not the signal to noise

..................................


Another thing to note is that, after a fill, when the wire target was
being moved back in, the trigger rate would occasionally sky-rocket, even
though the wire was being moved back into the same place as for previous
runs.  We decided that it might mean that the wire unit is still not
returning 100% to its desired position.  Anyway, I found it must better to
move the target into -1.5mm, wait, and then step it into -1.3mm (which
seems to give a nice rate of about 30-40Hz).

THis well can be caused by the beamhalo, not totally intercepted by the
halo-scapers/slits.
Once the halo is gone everything is fine from that point off.
(a way of testing this, is by skipping the insert of the slits after filling;
and also by putting in the slits aas far as they start to reduce the beam , and move
them dirrectly after that some mm's out.
The difference in signal brinign the wire in , would give information
about thisa phenomenum)


A. Maschinot


greetinds, take care

Jan van der Laan



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