Hi peter,
everything is clear but I have not seen the results yet. I'll play with
that calib file. Do not worry about the "true" time for the flasher. We
would anyways have offsets (cable lengths!).
In conclusion: if you use t0=time for events at center of the paddle then
the derived offsets have a larger uncertainty because you or your
algorithm are not able to define the center of the paddle properly.
Is that so ?
-- t
________________________________________________________________________________
Tancredi Botto, phone: +1-617-253-9204 mobile: +1-978-490-4124
research scientist MIT/Bates, 21 Manning Av Middleton MA, 01949
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
On Sun, 9 Feb 2003, Peter Karpius wrote:
> Tancredi-
>
> Since attenuating the flasher I have made an attempt to calculate
> the offsets using the macro flasher_tdc_offsets.C with run 3408 (the
> attenuated flasher run). I have attached the calibration file
> blastcal:3408. Because the testing is a pain with ntuples I copied and
> then slightly modified raw_tdc.C so that it still plots raw data but also
> now lists raw data and raw data plus offsets read in from a calib file.
> It also recalculates the offsets directly from the raw data. This file
> is in my directory /home/blast/karpiusp/recon/cvs/run/rawtdcoff.C (it does
> not write a new calib file) These offsets were found by setting the avg
> TDC target channel to 2000.
>
> At this point, we have a simple macro using good flasher data, we do not
> have true time (and I don't know how to get it!), but if we only care
> about sums and diffs then I don't see why these offsets aren't correct (as
> long as we recalculate them if we change the programmable delays!)
>
> I have two classes on Tuesday (one of which requires a presentation for
> which I have to prepare) so I am afraid that I can not make the
> analysis meeting. I have attached two postscript files outlining some
> important points. Please let me know if anything is unclear.
>
>
> Pete
>
>
> ----------------------------------------------
> Pete Karpius
> Graduate Research Assistant
> Nuclear Physics Group
> University of New Hampshire
> phone: (603)862-1220
> FAX: (603)862-2998
> email: karpiusp@einstein.unh.edu
> http://pubpages.unh.edu/~pkarpius/homepage.htm
> ----------------------------------------------
>
>
>
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