Date: Thu, 13 Apr 2000 21:12:29 -0400 (EDT)
From: James J. Kelly <jjkelly@physics.umd.edu>

Subject: Version2.1

	Please post and announce the Version 2.1 of the simulation
program.  New features include:

1) recoil proton tracked to rear charged-particle tagger
2) adjustable resolution of reconstructed trigger time
3) adjustable resolution for time and pulse height for each pmt
4) rectangular beam raster
5) np scattering based upon helicity amplitudes obtained from
   Arndt subroutines
6) Fermi gas model for scattering from carbon
7) multiple scattering of neutron in front array

Some new features still need work, but should be useful in their
present form.  Several bugs have also been corrected.


Subject: Maximum Cross Section Parameter

	The maximum cross section is used for the rejection algorithm for
the primary vertex.  It should be slightly above the largest cross section
for (e,e'n) within the kinematic acceptances.  Setting it too large
reduces the efficiency of the simulation (too many trials), but setting
it too small distorts the cross section distribution.  I have not tried
to optimize that parameter for kinematics 1 or 3, but you will note that
the maximum cross section encountered during the simulation is written
on the summary output.  Therefore, one can adjust the input value based
upon that output.

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James J. Kelly			email:	jjkelly@physics.umd.edu
Dept. of Physics		phone:	(301) 405-6110
University of Maryland		fax:	(301) 405-8558
College Park, MD 20742		Web:	www.nscp.umd.edu/~kelly		
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