Date: Mon, 30 Jul 2001 11:22:55 -0400
From: Michael Schmidt <schmidt@hepvms.physics.yale.edu>
To: cdf-ops-managers@fnal.gov
Cc: feild@cdfsga.fnal.gov, jdl@fnal.gov, ykkim@fnal.gov, pjw@fnal.gov
Subject: Prescales for minimum bias triggers

Ops managers,

I notice that the shift crews are allowed to change the
prescales for a run by hand. Please ask them if they change
the prescales at Level 1 for zero or minimum bias triggers
to please use a value that is close to what they want (e.g.
100) but avoid values that contain factors of 2 or 3
(36 = 2*2*3*3) (i.e. 101 would be good to use).

This avoids `beats' in the
triggers accepted vs. BC bunch and makes the L1A accepts
and livetime per bunch be meaningful. I think the CLC guys
would also wish for this practice to be followed.

See run 121963 and the logbook entry: Sun Jul 29 22:25:54.
(Note that the original prescales did not contain factors
of 2 or 3).

Thanks!

Michael