Background questions

From: Timothy Smith (tim_smith@mit.edu)
Date: Fri Jan 11 2002 - 11:39:14 EST


Hello Sean,

        The number I cite I think came from that report by Scott
Grant - the fast background routine. I believe that it is also the
same is the the 1998 and 1991 TDR.

        I think one of the chief things which make this number low
is the assuption that there is a coicidence trigger (that is the 500
events/second). Only when there has been a trigger is the DAQ gate
open. So there is only a small percentage of the time that a wire
could fire with "background".

                                        Tim
PS. Please post this type of question to BlastTalk - it is of
general intrest. TPS

On Thu, 10 Jan 2002, Sean Stave wrote:

> Tim:
>
> Hello. I have a few questions about the background rate that you had
> given me. I seem to remember that you mentioned that the background rate
> for the wires was about 0.01 hits/wire/event. Is this right? Also, how
> was it arrived at? Did you use the background routine and what beamline
> was in place? From reading the TDR, BLAST should have an event rate of no
> more than 500 true events per second giving about 5 background wire hits
> per second if I have the right definition of event. This seems low to me.
> I'm trying to arrive at the background rate that you had given me but
> can't seem to get that low. Some insight into the procedure you used
> would be great. Also, do you have any numbers on the background
> rate in the scintillators as well? Thanks.
>
> -Sean
>
>
>

-- 
____________________________________________________________________
 Timothy Paul Smith                               Research Scientist
 MIT Bates Lab                                     tim_smith@mit.edu
 21 Manning Rd.                                 tel:  (617) 253-9207
 Middleton, MA 01949                            fax:  (617) 253-9599



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