Phenix Newsletter 1992
Oct_09.html
S. Aronson: Magnet
B. Jacak: Si + Beam/Beam
E. O'Brien: Tracking
E. Kistenev: EM Calorimeter
P. McGaughey: e-mu coincidence
W. Zajc: Physics comments
C. Maguire: PISA
M. Chen: HBD test
o 2:00 - 4:30: Individual group meetings
Progress report, R&D plan, cost estimate, etc.
o 4:30 - 6:00: CDG + EC meeting on the Detector elements to be
listed in the CDR, urgent tasks, etc.
o 6:00 - : Supper at B. Jacack's House
October 19 (Monday)
o Entire day: Individual group meetings
Agreement on the contents to be written in CDR,
CDR responsibility distribution
o 4:00 - 6:00: CDG + EC meeting (continued discussion from Sunday) on
the Detector elements to be listed in CDR, urgent
tasks, etc.
October 20 (Tuesday)
o 9:00 - 10:30: Individual group meetings
Summaries on 1) R&D schedules, 2) Responsibility
distributions for sub-element construction and R&D,
3) Detector elements to be listed in CDR (the real
detector to be built), 4) CDR writing plan.
o 10:30 - 4:00: Joint meeting
Reports from the individual subgroups
o 4:00 : End of the collaboration meeting
======================================================================
TRAVEL SCHEDULES:
----------------
Shoji will be traveling extensively in October. His plans are as
follows:
10/16 - 21: Santa Fe
10/23 - 27: Korea
10/29 - 31: Japan
Shoji, Sam, Glenn, and Leo will all be at the Santa Fe meetings.
======================================================================
Local LLNL PHENIX Magnet Meeting Notes from Sept 23, 1992.
---------------------------------------------------------
(from Jim Thomas)
Attendees: Engineering: Joe Ryland, Art Harvey, Winston Wong, Bob
Highland, Joel Bowers, Donn Bupp, Allen House, Bob Yamamoto.
(Missing VIP: Ross Sleuter). Physics: Shaheen Tonse, Jim Costales,
David Krofcheck, Ron Zasadzinski, Jim Thomas
Bob Yamamoto has recruited a strong team of Engineers to work on the
PHENIX magnet. Some are old hands at PHENIX and some are quite new. A
general round of introductions was held and suggested the following
engineering assignments:
Art Harvey - Senior magnet engineer. Will work on cooling,
water flow, and engineering analysis for coils.
Winston Wong - Designer. Proposes to design central magnet coils,
fixturing for coils, and fixturing for epoxy
potting of coils.
Donn Bupp - Designer. Proposes to design muon piston coil.
Joel Bowers - Engineer. Will work on steel for magnets and support
structure.
Bob Highland - Designer. Proposes to design support structure and
return steel for both the central and muon magnets.
Ross Sleuter - (absent) Engineer. Magnetic field analysis.
Joe Ryland - Retired engineer. Will serve as the coordinator for
large procurements and fabrication.
Allen House - Engineer. Will do finite element analysis on support
structure. Also, is doing Muon Chamber design for GEM.
Bob Yamamoto - Group Leader. Overall responsibility for Engineering
design, costing, and analysis.
With the addition of another Designer or perhaps Designer-Detailer,
Bob thought this group was the right team for the job.
Bob mentioned that he, Ross S., and Joel B. will be going to Santa Fe
to attend engineering meetings. In addition, Joel may be going to the
Efremov institute in November. This would be a GEM mission but he may
also make PHENIX contacts.
Bob then reviewed the status of the magnet design for the physicists
in the room. He emphasized that the goal is to stay as "low tech" as
possible especially when it comes to winding the coils.
The muon coil is a conical, 2 layer, coil with a quadrafillar winding.
Copper coils will be used as a compromise between space and
convenience. Water will enter at the front and back of the windings
(towards the central magnet and as far away from the central magnet as
possible) but the electrical connections will be made only at the back
of the coils. Having the hydraulics at the two ends of the coil
lowers the pressure drop through the coils, allows more water to flow,
and hence lowers the temperature of the coils, and ultimately allows
us to run more current in the coils. This coil will be wound on an
epoxy shell so that it can slip over the iron piston ... rather than
trying to wind a coil directly onto a 70 ton piece. The coils will be
wrapped in mylar and then a dacron sleeve to insulate them. The mylar
is tough and resists tearing while hammering (physicists call it
"winding") the coil. But the mylar doesn't pot into epoxy very well
and so a Dacron sleeve is added. The Dacron is very absorbent and
will hold the epoxy around the coil as it sets into its final
configuration.
The biggest challenge in winding the muon coil is figuring out how to
join the two layers of coils at the front of the coil. (The electrical
connections are at the back so current travels down the outer layer
and returns up the inner layer.) This transition is crucial and will
probably determine how the coil is wound. Art Harvey has worked out a
possible scheme and we are building a quarter scale model of the muon
magnet to test it out.
Bob showed a sample of the "dead soft" copper to be used in the full
sized coil. (2 centimeters square with an approximately 1 cm hole
down the center for a cross-section that is 50% open.) It looks more
like a "crow bar" than a magnet coil. It is very stiff; even with a
large hole down the center for water cooling. The water lines will
have to come in along the eight spokes that support the muon magnet
flux return lamp shade.
The flux returning lamp shade will be made in 8 pieces or facets.
Each weighs 10 to 12 tons. The backs of these facets are bolted to
the first 30 cm of Mu ID steel. (This 30 cm of steel comes in one
giant piece.) The spokes, or impellors, to support the facets would
preferably be made out of Stainless steel so they could be welded but
since the physics prefers low Z material, they are looking at Al. This
causes some concern about strength (especially the method of bolting
in place) but appears to be do-able.
For now, we assume that the engineers responsibility ends after the
first 30 cm of muon ID steel. The thinking is that the remaining Mu
ID steel is part of the detector and not the magnet. This needs input
from Leo and Sam.
It was generaly agreed that the muon piston magnet needs the most work
since it is so intimately integrated into PHENIX.
Bob Highland then commented on how to support all this steel. The
muon piston is a 70 ton conical piece of steel. (Apparently, a French
company has been found who can make it in a single piece.) It will
rest on a three sided cradle that holds the bottom three facets of the
lampshade. These bottom facets will be welded in place to give the
whole structure the necessary strength. The cradle will be stationary
because the muon magnet doesn't have to move. (However, the central
magnet DOES move.) The cradle then supports the impellors (solid
sheets of aluminum running the full length of the piston) that hold up
the lampshade. There are some obvious questions which remain to be
answered (and will take a thorough discussion between Eng. and Phys.)
For example, how do you get the bottom tracking chamber sections in
and out? How fragile are the detectors? The overall assembly
scenario is still being worked out. Additional questions are: What
are the loads on the facets of the lampshade? What pressure goes onto
the piston? What are the magnetic loads and forces on the steel?
Other forces? We are assuming only gravity for now.
Winston Wong discussed the status of the central coils. These are
double sided pancakes with bifilar winding (two conductors to go on
top of each other). The windings are electrically in series but
hydraulically in parallel, like the muon magnet coil, for the same
reasons. Three pancakes together make a single coil that is
parallelogram shaped to get the maximum amount of Cu into the allowed
space. The pancakes for the inner coils will weigh approximately 200
kilograms and the pancakes for the outer coil will weigh about 700
kilograms each. Each coil is identical but they increase in size.
The major technical challenge is to find a way to make the transition
from the inner to outer layer of the bi-filar coil pack at the center
of the coil. Art Harvey has found a way to wind the filaments for
these coils but he still worries about the Epoxy cracking while
handling the coils. May need to design special handling tools and
fixtures.
Art has a computer code that allows us to change the current density
in the coils etc. etc. for the purposes of evaluating structure,
cooling, temperature, weight, power dissipation, and cost issues. He
prefers not to make changes now but he has the capability to iterate
on the magnet parameters in an automated way. Previously, this was
done by hand.
Ross Sleuter was missed at this point because everyone was curious
whether the new coil shapes (parallelograms) would change the magnetic
field and/or the physics.
Joel Bowers offered a list of specifications that will have to be
defined soon by physicists and engineers, together. These include:
Defining the space envelope for each detector.
Support for each detector.
Stay out tolerance zone.
Stability and motion tolerance.
Static deflection and dynamic deflection requirements.
Alignment requirements.
Access requirements.
Temperature tolerance.
Electrical, gas, water, requirements.
Feedthoughs for all of the above. How many, where?
Line of sight (for alignment) requirements.
Maintenance period.
We then developed a list of questions to be answered in collaboration
with BNL engineers.
Can BNL do a ground motion and vibration study? We need this data for
input to the Dynamic motion study ... for performance issues such as
alignment and drift. Long term stability vs short term stability.
Also, these specs need to be called out by someone. LLNL will
construct a global motion model for the detector structure.
Where do pumps for the beam pipes go? Other access issues for beam
pipe are important to the design of the central magnet. Can we support
the beam pipe on the side opposite the muon arm? Perhaps translate the
central magnet to get to the flange that allows breaking vacuum.
Specifications for uniformity of the steel.
We need to work on the motion of the central magnet. Need "jockying"
room for alignment, jacking, and shimming as re-install the central
magnet (eg. after maintenance).
The Tungsten nose cone. How does it attach and what can the designers
do to it?
What range of motion is required for the adjustment of the muon
chambers? Who designs this, the magnet people or the muon chamber
people?
Finally, the discussion turned to the possibility of building the
magnet in Russia or China. Some concern was expressed about Quality
control; especially regarding materials and fabrication standards.
This will require input from the institutions involved. Bob Y.
proposed that the design proceed as if we were going to build the
magnet in the US but we should seek guidance from Russian and Chinese
engineers as soon as possible so that we don't preclude the
possibility of working overseas. J. Thomas will arrange for the
Russians and Chinese to visit LLNL.
======================================================================
Mailing List Changes:
--------------------
(from Jim Thomas)
The following changes to the mailing list were made for the
distribution of this weeks Newsletter. Please review the list for
errors and fix the noted problems (usually, disk quotas exceeded) as
soon as possible. Please advise and help your friends if you see they
are in trouble.
ADDED the following users:
alley@icsun1.ic.ornl.gov 10/11/92
britton%vlsi01@msr.epm.ornl.gov 10/11/92
simon@p2vax.lanl.gov 10/11/92
simpson%vlsi01@msr.epm.ornl.gov 10/11/92
wintenbe%vlis01@msr.epm.ornl.gov 10/11/92
CHANGED the following users addresses:
evert@kosfuy.lu.se was evert.stenlund@kosufy.lu.se
hansak@kosufy.lu.se was hans-ake.gustafsson@kosufy ...
kosu_andosk@garbo.lucas.lu.se was anders.oskarsson@kosufy.lu.se
kosu_ingvar@garbo.lucas.lu.se was ingvar.otterlund@kosufy.lu.se
kosu_kaj@garbo.lucas.lu.se was kaj.soderstrom@kosufy.lu.se
sten@kosufy.lu.se was sten.garpman@kosufy.lu.se
CAUSES TIME-OUTS (usually due to disk quota exceeded, please fix ASAP):
(Mail is NOT delivered if systems time-out.)
utknp::arai
insvax::homma
utknp::ise
insbnl::sako
hirohi:sugitate
INCORRECT ADDRESSES don't know how to fix:
igw::psi%esx25net.ihepvx::zhaowq
igw::psi%esx25net.ihepvx::zhuyc
DEAD deleted these names:
baris%oasis@physics.yale.edu
berger@vsikp0.uni-muenster.de
oulette%oasis@physics.yale.edu
thomas@ecad1.ameslab.gov
tony@vxihep.ihep.cern.ch
tkshea@bnlcl6.bnl.gov
zimanyi%nbivax.dnet@igw.dnet
======================================================================
****************************************************************************
****************************************************************************
The Newsletter will appear weekly. Submissions should be sent to:
phenix@buddha.llnl.gov (internet)
igw::buddha::phenix (decnet)
phenix%buddha.llnl.gov@mitvma.bitnet (bitnet)
The submission deadline is Friday at 5:00 pm EDT for items to appear
in the next weeks Calendar and Newsletter. All submissions are
welcome; especially meeting announcements and minutes of meetings.
Please try to provide at least two weeks notice for all meetings.
Anyone may log onto the PHENIX account on Buddha and view the mail
contributions.
****************************************************************************
****************************************************************************