Summary Meeting Wed Sep 6 9:00

[Elton Smith <elton@jlab.org>]

Summary for Meeting Wed Sep 6 9:00


1. Solenoidal Magnet Transfer - Paul Brindza

- John McClelland (Los Alamos) has obtained Dennis Kovar's approval to
transfer the MEGA magnet to J-Lab. 
- Larry Cardman will need to write a letter to him specifying that Jlab
has put aside resources to move the magnet.
- An MOU must be drafted with details of the move, to be circulated and
agreed upon by Jlab and Los Alamos.

We discussed ingredients that would be addressed by the MOU. Paul will
attempt a draft.

MOU topics:

a. Need to make solenoid "ready for move." This includes completing all
safety requirements to obtain a "free release" from Los Alamos. 

Scenario: Los Alamos will be responsible for making the solenoid ready,
supported by Jlab to optimize easy of future use. Critical here is the
time schedule, which must be carefully considered.

b. Packing, preparation for move. 

Scenario: Jlab is responsible for packing and preparation for move,
assisted by Los Alamos to coordinate with mechanical, electrical, etc
services. Time frame should also be addressed.

c. Actual Move.

Scenario: Jlab is responsible for actual move, becoming "owner" as soon as
magnet leaves the site.

d. Preparing location at Jlab.

Storage must be designated by Jlab, which is consistent with the timeline
outlined in previous sections.

2. Solenoid Magnetic Field - Paul Brindza

Paul has received information about the MEGA magnet fields, both
calculations and fringe field measurements. Based on his own calculations,
Paul believes that he understands the calculations (which was not computed
out to large enough distances) and actual measurements, both which match
his own calculations (within a factor of 2) for relevant comparisons.

For the configuration of the MEGA magnet and a 2 T field, fringe fields
radially out from the center of the magnet (leaking though the iron) range
from about 600 G at 250 cm to 200 G at 500 cm. The location of the
Cerenkov counter pmts are off scale in these calculations, but VERY rough
extrapolation by eye suggests 150-200 G at that location.

The general agreement serves as a basis for believing the current
calculations.

3. F1 TDC Chip - Fernando Barbosa

Elton will attend the Workshop on Skewed Parton Distributions, and visit
SACLAY on the return trip. Claude Marchand, now working with COMPAS, has
been testing the F1 TDC chip and we will try to gain as much information
about it during the visit.

Fernando:

20 F1 chips ordered and received.
 - 8 low resolution channels/chip
 or 4 high resolution channels/chip

Proposal: Use VME-64 in a 6U form factor for prototyping. Present schedule
should allow serious work to begin in a month or two.
Dave Doughty expressed concern that VME-64 does not have the readout
performance which we will require. Due to the unknown future of VMEP or
other formats, it seems reasonable to begin with VME-64, with the intent
of studying transfer rates and establishing precise specifications for
Hall D.

Before prototype is implemented, would like for Fernando to give a
presentation outlining prototyping plans and establish goals for the
outcome of the tests.

Questions for COMPAS/Claude:
- Analog layout and performance on COMPAS boards
- formats actually used by COMPAS
- readout capability of COMPAS boards
- degradation of chip performance on actual boards.



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