Video meeting Feb. 18, 2004
Attending: H. Kirk, J. Gallardo--BNL
A. Fabich, J. Lettry, H. Ravn, P. Sievers,R. Wilfinger--CERN
Kirk McDonald--Princeton
Roger Bennett-RAL
M. Zisman--LBL
Presentations:
http://pubweb.bnl.gov/people/kirk/e951/video_meetings/04_Feb18
KMcD: riverside presentation includes scheme proposed by JL
pump: US and UK vendors contacted.
driving pressure p=1/2 rho v^2 = 25 bar
gear pump as used in E951 not useful for v=20 m/s
centrifugal pump already purchased
The meeting began with Kirk McDonald giving an update on the Princeton prototype
Hg jet. He stated that although it was originally envisioned to be a vertical
system it has been decided to retrofit it for horizontal operations so as to be
a better test of our proposed horizontal system
for the CERN experiment. A key component of the system is the pump
for delivering the Hg jet. Kirk gave key parameters which included: 1.6 l/s flow
rate; 4.3 kW (5.7 HP) power; and 27 atoms. (410 psi) pressure. He has purchased
(and it has been delivered) a 20 HP, 480V centrifugal pump from R.S. Corcoran.
The document mercury_pump.pdf shows many of the specs and characteristics of
this pump.
Adrian then explored the subject of electromagnetic pumps. The main advantage of
such pumps is that they operate without the flowing liquid being touched by
anything except the pipe through which the fluid flows. There are no seals in
the system and it is considered to be very reliable. It is relatively free of
system vibrations which were a considerable nuisance in the Grenoble high-field
tests. Although it appears that these types of pumps can deliver high volumes of
material, it was not clear whether the pressure and therefore the Hg velocities
that we seek can be achieved. Other properties of these types of pumps appear to
be long (10's of seconds to minutes) start up time for fluid delivery and an
associated heating of the material during operation. More homework is required.
A discussion ensued concerning the layout of the ntof experiment and some of the
beam parameters. Among the many points:
1) It is believed that the experiment should be designed with the removal
of the jet/optics system at the conclusion of the experimental run.
2) It is not yet clear whether the pulsed solenoid itself needs to be
immediately removed. Kirk McDonald made the point that it might be
wise to at least envision the possibility of a subsequent run to follow
up on successes and/or failures of the initial run.
3) For a run period Harold mentioned the possibility of 200 pulses in 1
month of running. Jacques, however, said that our proposal would
more like be considered less constraining of the ntof schedule if
we ran for 2 weeks instead. This would require about 15 pulses per
day which should in principle be achievable.
4) Harold mentioned that the pulse intensity could vary from 4 x10**12
protons (4 TP) per PS spill to a maximum of 32 TP per spill. For
activation calculations he intends to use as an average 16 TP per
spill.
5) Windows for the experiment were discussed. Harold mentioned Al windows
which are common eg at BNL. Jacques pointed out that Al is
incompatible with Hg and that Stainless Steel may be more appropriate.
Kirk McDonald recalled that a TiAl alloy was investigated for the first
running of E951 at BNL and that George Greene had done some tests with
Hg/TiAl compatibility with a positive outcome. It would be good to
resurrect that result.
`
The next meeting will be a phone meeting on Feb. 25. The main subject matter
will be activation calculations.