RE: electron detector measurements

[Mulhauser Francoise <francoise.mulhauser@psi.ch>]

Hi Torsten,

Thanks for the comments. I believe you have answered all the
questions-comments yourself.

Indeed, the center detectors (two concentric wire chambers) have not been
touched and are well adjust, as you said it. My only major concern was the
behaviour of the outside detector, due to the additional weight of the
neutron detectors.  

I think your approach is good and there is nothing to change in it.

best regards
Francoise

-----Original Message-----
From: Schaarschmidt Torsten
To: Mulhauser Francoise; 'Brendan Kiburg'
Sent: 21/10/05 16:00
Subject: AW: electron detector measurements

Dear Francoise,

I think there is a little missunderstanding. From my point of view,
there is no question about, to do a re-measurement of the whole
structure and reference the center-points to our
outside-referencepoints. That is what we did yesterday.
I was questioning the re-assambling, because last time we did that job,
we had to align the inner parts first, before we even could start the
base-measurment. If nothing or not much changed, we would start without
aligning the inner parts. In view of the urgency of the matter, we did
start anyway, but checked the centers of the aluminium structure and the
2nd tube. These centers are all on the same spot with a range of +/-1mm,
and I believe this is quit good and everything should be fine for
aligning the detector next week in the area.
I also asked Brendan, what is important of the detector and has to be on
the beam. He confirmed, that the inner part has to be on the beam.

Hopefully, all missunderstandings are elimineted.

Greetings
Torsten



-----Ursprüngliche Nachricht-----
Von: francoise.mulhauser@gmail.com
[mailto:francoise.mulhauser@gmail.com] Im Auftrag von Francoise
Mulhauser
Gesendet: Freitag, 21. Oktober 2005 08:20
An: Brendan Kiburg; torsten.schaarschmidt@psi.ch
Betreff: electron detector measurements

Dear Brendan and Torsten,

Sorry for my lack of answer yesterday. My mail was send to my laptop
before I could read it. I saw it last night.

The electron detector top half was removed totally, whereas the bottom
half was left in place. However, in the bottom half, we removed half of
the electron scintillator, add the neutron detector and replace the
scintillator. In the process, we have move the distance from the center
to the scintillator, because we have moved the shime.

---> I believe that the bottom half may very well be distorted in
comparison with before. Specially because of the weight of the new
neutron detectors, the fact that one side has two and one side has one,
and the fact that when remounting the system, we did not necessarely
keep the original scintillator orientation.

The top part was also dismounted and remounted. You can even see the
fact that  we mounted one bar upside down, because the holder for the
survey point is wrong.

Now, to answer you question.... I believe that if you have seen some
distorsion between the various reference point on the detector, then it
means that you have to re-aligned the detector relative to the rail.
This is what I would suggest.

I can be reach correctly by mail today, until 17:00.

best regards
Francoise