Re: Meeting Wed Apr 24 9:00 (fwd)

[Elton Smith <elton@jlab.org>]

---------- Forwarded message ----------
Date: Tue, 23 Apr 2002 10:49:31 -0400
From: Carl Zorn <carl.zorn@jlab.org>
To: Elton Smith <elton@jlab.org>
Subject: Re: Meeting Wed Apr 24 9:00

Tuesday, April 23, 2002

Once again, I must offer an apology on behalf of Stan.  As you may know, 
Stan has been out of town for this past week and will continue to be 
this week.   He is aware of the need to come up with a detailed plan 
(including costs) for the forward chambers.   I'm sure he will direct 
his energies towards this project as soon as he returns.   Brian has 
some ideas of his own, but he tells me that without Stan's presence, he 
cannot produce a reasonable proposal.

Both Brian and I will attend the meeting.  I am still intrigued by 
Dave's proposal to simplify Andi's problem of the "nose cone" by 
replacing it with a small forward detector.  In looking through my 
collection of literature, there are numerous cases where people have 
used small scintillator packages of unusual geometry to act as 
hodoscopes, TOF, etc.  As I see it now, it would consist of one or more 
thin circular plates (fast blue scintillator) with a series of curved 
grooves cut into their surface.  Several green waveshifting fibers glued 
into those grooves would collect, absorb and re-transmit the light.  
Since Andi will have a fast and highly efficient cryogenic photodetector 
(highly optimized for green light) upstream of this, the green fibers 
could be coupled to clear fibers to take the light the last few meters 
to the VLPCs.  Based on the literature and our own experience, I would 
think that this detector could form a fast and efficient trigger.

In the end though, this is all just a suggestion for the pot.  It would 
not be a surprise to me if a better solution exists.

All the best,


                Carl