Re: [Beamtest Analysis] - Attn:Dave and Simon - odd tphoton spectra(fwd from Simon)

[Elton Smith <elton@jlab.org>]

Hall D barrel calorimeter:


---------- Forwarded message ----------
Date: Mon, 27 Nov 2006 08:45:43 -0500 (EST)
From: Simon Taylor <staylor@jlab.org>
To: Blake Leverington <leverinb@uregina.ca>
Cc: David Lawrence <davidl@jlab.org>, halld-bcal@jlab.org
Subject: Re: [Beamtest Analysis] - Attn:Dave and Simon  - odd tphoton
    spectra

Hi, Blake.

I believe the explanation is this:
The last timing calibration for the tagger counters was done relative to
signals in the veto (using one of the special veto-triggered runs).  The
times you plot are relative to the (presumably) production trigger.  The
T-counters are not guaranteed to be exactly in time in hardware at the
trigger level.

Simon

On Fri, 24 Nov 2006, Blake Leverington wrote:

> Hi Dave and Simon,
>
> Hope you guys had a good weekend stuffing yourselves!
>
> I've been doing some more analysis looking at the tdc and so on to try
> and clean up the adc spectra for the BCal. I noticed when I plot adcsumN
> vs. tphoton and Ephoton vs. tphoton I get the plots at the bottom of
> http://www.jlab.org/Hall-D/software/wiki/index.php/BCAL_Beam_Test_Plots%2C_November_20%2C_2006
>
> The scale is blown up but I think something strange is going on like the
> offsets aren't correct for the tagger. Or is this normal and something I
> have to live with?
>
> Thanks,
> -Blake
>