Meetings are held in Room 84, Trailer City on Thursday at 1:30 P.M.

ATTENDEES: S. Benson, G. Biallas, C. Bohn, E. Feldl, L. Harwood, G. Krafft, W. Merz, C. Murray, G. Neil, M. Wiseman

Decisions/Comments:

A goal is to more easily match the Optical Chicane Bend family to the other families of dipoles on the same power supply string. We will try to fit racetrack style window frame magnet style dipole into the beam line positions by restricting the width of the optical chicane vacuum pipe to four inches rather than six. We will then layout the racetrack style window frame magnet (with upgrade ability) into the layout to determine if the magnets can fit into those positions. See new action items.

Design the Optical Chicane Bend family with shunt currents that can create excursions over a greater range than the range selected by D. Douglas, say +-1.5% for magnet variation between families and an additional +-1% for momentum change from lasing.

The use of aluminum vacuum chambers would have no advantage in eliminating any significant magnetic effects. The solid steel already damps 60 Hz ripple by a factor of 6 and ripple at other frequencies is damped by a factor of 1/ƒ^-2

A prototype of the Reverse Bends will be built that can provide accurate information on end effects on the racetrack-window frame style of magnet. The prototype will be made of 1006 steel, have #10 square conductor in the same coil window as the final Reverse Bends but be made as a rectangle (in the top view) rather than the wedge shape to allow magnet measurement to be more accurate. The magnet will serve as a test bed for other enhancements L. Harwood wants to test out.

Design the beam tube in the 180 Degree Bends to be 6 inches wide.

Action Items:

J. Parkinson/C. Murray/B. Yunn - Maintain latest layout/ define the vacuum tube at all discontinuities, refine impedance analyses and write the Tech. Note. Definition of discontinuities in process. Continuing

C. Bohn - Establish a clean statement of the energy range of the machine. Status: Need help from Biallas/Harwood to plot cost vs. maximum energy for the magnetic optics. Division Leadership Group wants to see this data. Presentation to M7 delayed while need for taps on the added turns is assessed.

D. Douglas - Check if the existing QJs can be used in the new injection line. No news

G. Biallas - Get the BT contracts signed. Contracts needed to be changed to new DIMAD configuration.

T. Siggins/K. Jordan - Review proposed Shielded Viewers for vacuum construction properties. T. Siggins reviewing the drawings.

G. Biallas - Define the trim quad for start of engineering design. No progress.

G. Biallas - Start definition of a girder for the wiggler, diagnostics and quad telescopes that maintains position of the elements within 50 µm (0.002 in.) during change-out of the wiggler. S. Benson has set up a meeting with W. Oren & C. Curtis.

L. Harwood - Determine if placing additional dipole(s) around the first dipole of the dump chicane after the cryomodule is the best method of bending pulsed 42 MeV beam into the dump during cryomodule phasing. Inserting a different, more powerful magnet into the position is being considered.

G. Biallas/L. Harwood - Provide a good value for field enhancement factor for the style of magnets we are anticipating. Verify the K value of 0.45 that D. Douglas uses in his optics calculations. Calculations with existing data give values of field enhancement factor of 1.4 to 1.1 gaps. We will make the prototype for better resolution. See decisions.

C. Bohn - Have B. Yunn establish the vacuum specification for the remainder of the vacuum system using the criteria of ion trapping. Started.

G. Biallas - Examine the categories on the Web and propose alterations. New organization on the web site may be easier to utilize. No action.

New Action Items:

C. Bohn - Have B. Yunn examine the impedance effects of a 4 inch wide pipe in the optical chicane area. (C. Murray to provide cross sections.)

C. Murray - Layout the Optical Chicane Bends in a the proposed 4 inch beam pipe configuration with fully upgradable coils.

W. Merz - Determine from the actual response of power supplies with respect to jitter, short term drift and long term drift.

New Action Items from the Diagnostics/Commissioning Meeting:

none

Completed Action Items:

D. Douglas - Check the width of the beam in the 45° either side of the 90° point in the 180° Dipoles. Analysis done, 5 inch beam tube possible for +-200° of phase change under worst conditions. See decisions. Complete.

E. Feldl - Make the prototype weak QB. Complete. Awaiting repair of card in CAMAC module and an additional two weeks of testing required on the quads of the NP Accelerator. Prototype set of the proposed coils is being made.