From naranjo Tue Nov  9 18:51:02 2004
Date: Tue, 9 Nov 2004 18:51:02 +0000
To: michael.loughlin@ukaea.org.uk, APX077@coventry.ac.uk,
        nigel.hawkes@npl.co.uk, colin.murray.01@bbc.co.uk
Cc: puherman@ritva.physics.ucla.edu, camara@physics.ucla.edu,
        shopkins@scs.uiuc.edu
Subject: SL + neutron detector coincidences
Reply-To: Brian Naranjo <naranjo@physics.ucla.edu>

Fellow sonofusionists,

In BBC 03,
  - number of SL PMT pulses above 1 PE threshold = 10689
  - number of unsaturated neutron/gamma hits = 5865
  - total run time = 18.1 seconds

Of the three events shown having coincident timing within 500 ns,
I believe only trigger 166 is a truly random event.  Using
the Poisson distribution, the expected number of random
coincidences is
 10689 (1-Exp[-(5865/18.1) 500e-9]) ~= (10689 5865 500e-9)/18.1 = 1.7,
in statistical agreement with observation.

Brian
