Hi Ray,

	I was designated secretary today.  Here is my summary of the
meeting.  I also have transparencies that were shown and will send them to
you in lab mail.  Is it desirable to scan such documents and put them on
the web page?

						Dan Kaplan

1.  Al Moretti discussed x-ray emission by RF cavities.  An 805-MHz test
of a 6-cell cavity for the Linac upgrade was performed in 1989 at 1.52
Kilpatricks and the radiation levels vs. polar angle were measured.  He
showed a plot in which the emission is strongest at 90 degrees to the beam
and seems to be negligible on the beam axis.  At 90 degrees the level was
200 R/hr at a distance of 40 cm.  Given the lower duty cycle, he thinks
the levels should be comparable for a MuCool 16-cell cavity.  While the
levels improve slowly with time, having dropped a factor of 10 in two
years of Linac operation, this will do us no good as we don't plan to wait
2 years! 

Questions: Will these x rays contribute significantly to

a) the heat loading of the LH2 absorbers?

b) heating of the solenoid?

c) backgrounds in the TPC due to shine from the magnet material?

	Al then discussed the layout of Lab G for the RF-cavity test.  The
big magnets will be cleared out by early October.  Then the PET test
apparatus will need to be removed.  More shielding may be needed.  There
exist a labyrinth and interlocks that should be suitable for our test.  Al
has worked out the manpower requirements to set up and carry out the test 
and has sent a request to Bob Noble.

	He has ordered 3 Be windows with Be retaining rings They cost $7k
each.  He will send 2 to LBL and keep 1 for cryo tests here.  He wants to
check the windows at LN2 temperature for flatness, brittleness, and how
well the bond to the stiffener ring holds up under thermal stress. 

2.  Al Russell presented a concept for splitting our beam out from the
CPT/CKM beam.  This can be done in the usual way using a kicker magnet
followed by a Lambertson.  The needed kick depends on the size of the
beam, the septum thickness in the Lambertson, and the distance between the
kicker and the Lambertson.  Assuming a 30m distance, the kicker needs a
maximum field ranging from a couple of hundred gauss up to 570 gauss,
depending on the length of the kicker and the beam emittance.  The MI beam
has a 1.59-us abort gap out of a cycle time of 11.1 us.  3 cycles will
give us the desired ping length of about 30 us. The kicker turn-on and
turn-off should each occur within the 1.59-us gap.  This is believed to be
no problem for available power supplies.  Dave Finley mentioned that this
performance can be achieved even if the cables to the power supply are as
long as 150 ft, so there is no egregious constraint on the supply
location.  Tom Kobilarcuk confirmed that the plans for the CPT/CKM beam
includes a beam dump, so beam can be available for us whether or not CPT
and CKM are running. 

3. Steve Kahn gave a status update on his GEANT simulation of the
instrumentation channel, including some information he had already
presented at the Brookhaven MuCool meeting.  His simulation now includes a
description of the material and magnetic fields in the channel.  He has
optimized the matching to the beam to reduce non-decay losses from the
previous 25% to 3%, occurring mostly at the exit of the channel.  Even
with the material turned off, the beam transverse phase space grows
through the channel.  He suspects this may have to do with the spikes in
B_x in his description of the field in the bent solenoids.  Dave Carey
suggested integrating the kick in that region to see if the phase-space
growth is affected.  When he turns on the material (beryllium windows,
scintillator, low-pressure methane in the TPC), the simulation shows
energy loss through the channel as it should.  He expects this to be
alleviated when he adds the RF.  Still to be done: add RF, go to DPGEANT,
put code into CVS, add the beamline simulation.  He intends to play with
the beamline, degrader, matching solenoid, etc. to try to optimize the
match into the instrumentation channel.