Re: [Brahms-dev-l] problem with FS TOF1 deltaTime vs Ytrack...

From: flemming videbaek <videbaek@rcf.rhic.bnl.gov>
Date: Fri Dec 03 2004 - 09:20:43 EST
Hi
when you see a problem in some diagnostics plots - your have to ask
yourself -where
the problems can be.

i) Is the problem already know ?
   One way to check this is to read the e-log for the approproate run to see
if problems
   have been noted, at that run or somewhat later. This is also the palce
(usualy) to see if changes
   has been made to hardware.

ii) Is the problem persistent? That is for what kind of range of runs does
it exists. This is usualy a
good diagnotics tool, that can help too.

iii) Is it a detector/hardware issue ?
    to address this you have to look at near to raw data. This are being
monitored in a simple way
    per run. One place to start is in
    http://brahms-web.brahms.bnl.gov/shift/MonitorSummary/run04/R010443/
    where output plots for all monitored runs are present.

   What would you expect? well you can start saking your local people who
build and are responsible for tof1, and 2 what the plots mean.
  In short since the H1slat hit distribution look rather smooth it is
probably ok, albeit you may note that
  the tup-tdown vs slat seem to have the pek shifted out of range

   Since similar plots for many other runs look similar e.g look at 10264 it
probably IS ok.
   This may bring you to ask is the problem only for these runs or does it
aperar other places?

iv) It is a software issue?
   Software is not a black box that handles every condition. It  may also
fail, and may not have taken certtain conditions into account. Thus it can
eg. be that the limits of histograms, cuts prevents certain range of data to
be considered.


my own hunch - SOFTWARE -
Since I note from the plot above shows that the dt is out of range (or maybe
not there) you should
probably consider point iv), but only after having identified where the
problem appears?
Is there actually any run you looked at whwre it is ok ?

Flemming



----------------------------------------------------------------
Flemming Videbaek
Physics Department
Brookhaven National Laboratory

e-mail: videbaek@bnl.gov
phone: 631-344-4106
----- Original Message ----- 
From: "Casper Nygaard" <caz@fys.ku.dk>
To: <brahms-dev-l@lists.bnl.gov>
Sent: Friday, December 03, 2004 7:02 AM
Subject: [Brahms-dev-l] problem with FS TOF1 deltaTime vs Ytrack...


> Hi
>
> While doing the FS calibration for AuAu 200 Gev a problem was found.
>
> When looking at the slats 25-28 in TOF1 the correlation between deltaTime
> vs. Ytrack looks really weird.
>
> Attached is two plots, showing slat 24 which has the expected linear
> behaviour and slat 25 which just looks f***ed. Both plots are from the the
> runrange 10393-10394.
>
> Has anyone encountered this before? if so any comment would be nice :-]
>
> regards,
>
> Casper Nygaard
>
>


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