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Re: 4 (5?) bumps but a definite improvement



Hi Simon:

Good point.  Thanks.  I was not sure whether it was the intrinsic
meantimer resolution or not and hence my comment that the BCAL
resolution looked too good to be true.  As it was, it was :-)

George

>>> Simon Taylor <staylor@jlab.org> 04/08/07 3:22 PM >>>
Hi, George.

The 160 ps number is the resolution in the difference in timing between
two adjacent T-counters, so I think the number you want to use is
160/sqrt(2)=113 ps, which leads to a BCAL contribution of 153 ps.

Simon

On Fri, 6 Apr 2007, George Lolos wrote:

> Hi Blake:
>
> Well, there's a big improvement already.  However, the spikes you
> mentioned - and seen so clearly in the sigma plots - pull the fit to
> higher sigma and one can see this that the fit line is consistently
> above the valey values between the peaks.    With better statistics
and
> with the pesky peaks removed, the fit will improve.  However, even as
> is, for cell 8 and 1 GeV, we get a sigma of 0.190 ns.  If the sigma of
> the timing tagger counters is .160 ns, then the BCAL contribution is
> .102 ns, a bit too good to be true but well on the way to
acceptability
> when all the analysis is done.
>
> George
>
> >>> Blake Leverington <leverinb@uregina.ca> 04/06/07 4:59 PM >>>
> Hi David,
>
> I redid similar plots to what you did on April 4th but now using the
> tagger as a reference time( i.e (ts7+tn8)/2 + tphoton ) and things
look
> much better. However... :) ...I can clearly see 4 bumps that I am not
> sure where they are coming from. I sort of see gaps in the
> tn8+tphoton:Ephoton spectra as if we're missing the t-counter there or
> something.
>
> You can see the results here:
>
http://www.jlab.org/Hall-D/software/wiki/index.php/BCal_Beam_Test_Plots%2C_April_6%2C_2007
>
> -Blake
>
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