FW: Contribution to GLUEx electronics (fwd)

[Elton Smith <elton@jlab.org>]

Attached are questions from Jim Pinfold regarding definition of a couple
of electronic projects for GlueX.

Cheers, Elton.

Elton Smith
Jefferson Lab
elton@jlab.org
(757) 269-7625

---------- Forwarded message ----------
Date: Wed, 11 Aug 2004 13:44:41 -0600
From: James Pinfold <pinfold@phys.ualberta.ca>
To: 'Paul Smith' <ptsmith@indiana.edu>
Cc: 'Alex Dzierba' <dzierba@indiana.edu>,
     'Curtis Meyer' <cmeyer@ernest.phys.cmu.edu>,
     'Elton Smith' <elton@jlab.org>
Subject: FW: Contribution to GLUEx electronics


Hi Paul

As a result of our discussions and reviewing the literature available
(although this was by no means  an exhaustive review) we have concluded that
the electronics projects that we would like to contribute to are:

	A) Constant Fraction Discriminator circuits (TOF + Calorimeter)

	B) Preamps for the Wire chambers


We need some information to proceed:

A) Information required to design & construct constant fraction
discriminators circuits.

1)Space available in the PMT bases?
2)Input pulse height variation?
3)Input pulse rise time?
4)Input signal polarity?
5)Does the input have a DC offset or is it AC coupled?
6)Threshold level for input pulse acceptance is it fixed or variable?
7)What will be the minimum threshold set point?
8)Maximum event rate for inputs?
9)Will the pulse fraction for the constant fraction discriminator be the
same for the  different parts of the detector?
10)What is the shape of the output pulse from the constant fraction
discriminator (i.e. pulse width and amplitude)?
11)Does the output drive into a 50 ohm load or differential ECL?
12)What power, control and signal cables will be available?
13)Is radiation damage a factor for the electronics?
14)Is there a maximum power dissipation allowed per channel?


B) Information required for the design and construction of preamp circuits
for the wire chambers.	If not this is a list of information we will need to
know

1) Will a signal splitter after the preamp be required?
2) Input pulse rise time?
3) Input pulse amplitude?
4) Gain required for wire chamber signals?
6) What signal levels and pulse shaping will be required for the output of
the preamp?
7) Will a base line restorer and pole zero circuit be required for high
event rates?
8) What power supply voltages will be available for the preamp?
9) Radiation hardness?
10) Will the output signal have to drive a 50 ohm or similar cable?

Obviously, if there is some information we should be asking for, but did not
ask for, tell us anyway!

Cheers, Jim.