Phone meeting Feb. 06, 2004
Attending: H. Kirk, Michael Iarocci --BNL
Adrian Fabich, Friedrich Haug--CERN
Harold begin the meeting by describing for CERN the general strategy of our
power supply/cryogenic system. He described how the system had evolved from
one in which the pulsed solenoid was originally conceived (and spec'ed) for
operation at 30 deg K and requiring a 300V/7200A power supply in order to
generate 15T peak axial field. Due to safety concerns and costing trade
this system has evolved toward operations at 69 deg K with a 600V/7200A
With operations set at 600V/7200A the total stored energy of the system will
be 22 MJ and the solenoid will experience a temperature rise from 69 deg
100 deg K.
Peter then discussed the current thinking involving testing the magnet
at the conclusion of fabrication but before shipping to CERN. Either a
flood/wait/drain/pulse sequence will be followed or a more intricate system
will be used which will serve as a prototype for the systems operations at
Peter then described the flow chart he has produced and previously presented
to the Muon Collaboration at the Riverside meeting. Key points involve the
flowing of LN2 from a supply Dewar to the solenoid via a control valve
allow the LN2 to flow at a carefully adjusted rates. The strategy is to
flowing the LN2 at 0.1 kg/sec rate and then cutting back toward 0.01 kg/sec
as the magnet cools and LN2 begins to collect inside the magnet. At this
point a vacuum pump will be activated to pull a 0.2 atmosphere partial
so that the LN2 and magnet can be sub-cooled to 69 deg K. In general,
should be leaving the exit port of the solenoid.
Harold pointed out that the major issues to be resolved are 1st) develop a
consensus agreement that the proposed system is viable and buildable; and 2)
develop a clear understanding as to which components of the system can be
provided by CERN and which components should be developed and built by
BNL/MIT. A loose agreement was forged that CERN would look into
bulk items such as Dewar's, vacuum pump, and transfer lines while
concentrate on the smaller components such a valves and control system
components. In particular it was felt that the process control system could
best be assembled in the US as part of the solenoid testing at MIT.
No show stoppers were identified in this round but it was agreed that this
meeting was but a first step and further iterations will be necessary.
and Friedrich stated that they would be visiting the nTOF area the next week
in order to better ascertain the requirements for the layout of the
Friedrich inquired about TIS involvement to date and Harold stated that a
preliminary meeting had already taken place and that the minutes of that
meeting would be forwarded.