Re: [BLAST_ANAWARE] nwl, nwr from wire chambers

From: zhangchi (zhangchi@general.lns.mit.edu)
Date: Tue Feb 11 2003 - 10:35:08 EST


Hi, just a reminder,

A few days ago, Aaron spotted that the wire stagger in BlastLib2 and
blastmc v2 version (which was the version we used all the time) were of
the wrong signs. I corrected them in TBLWc1ChamberGeometry.cc and
wc_geom.f.

I assume everyone is working with these two files updated.

Chi

On Mon, 10 Feb 2003, Chris Crawford wrote:

> hi doug,
> the three runs, 3329-31 lasted from 3:36-6:36 am. each plot was only
> one sector. my naive interpretation is that the chambers were working
> well at the beginning, and there is a peak at around 18 hits, and
> another at 0 hits. then the peaks rise due to noise (space charge effect?).
> --chris
>
> Douglas Hasell wrote:
>
> > Hi Chris,
> >
> > I suppose I am a bit confused by your plots. I see what I
> > assume to be about 6 fills. The fills are characterised by a lot of
> > events with only a few hits in the wire chambers which then as the
> > fill progresses increases to reach stable values around 18 and 36 hits
> > which correspond to one or two track events. To interpret this one
> > could think that the chambers were collecting data as they were turned
> > on. ie triggers were coming in while the WC HV was being ramped so we
> > are inefficient at the beginning but this should only take 10-20
> > seconds. What is the time scale for your plot? The other conclusion
> > could be that the initial part of the fill is noisy and after a while
> > the halo or X-rays from a high current in the gas target are reduced
> > and the chamber behaves as it should.
> >
> > --On Monday, February 10, 2003 5:04 PM -0500 Chris Crawford
> > <chris2@lns.mit.edu> wrote:
> >
> >> hi,
> >> these graphs may be usefull in determining cuts on "nwl,nwr". they
> >> are
> >> the number of hits on left/right as a function of time (entry #) over
> >> three runs 3329,30,31. these were hydrogen runs taken in the last
> >> day or
> >> so, right inbetween deuterium runs. doug, does this look consistent
> >> with what you would expect? --chris
> >
> >
> >
> >
> > Cheers,
> > Douglas
> >
> > 26-415 M.I.T. Tel: +1 617 258 7199
> > 77 Massachusetts Avenue Fax: +1 617 258 5440
> > Cambridge, MA 02139, USA E-mail: hasell@mit.edu
>
>
>



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