ATTENDEES: S. Benson, G. Biallas, D. Douglas, G. Krafft, J. Parkinson

Decisions/Comments:

In the meeting of 5/9/96, C. Bohn made it clear that D. Douglas is owner for the Beam Transport effort and shall sign off all specs and requirements.

D. Douglas issued a new DIMAD as of 5/15/96, incorporating the latest suggestions from the visit of J. Flanz. Changes were:

- The reverse bend dipoles now have two flavors, differing by about 2 degrees on the edge angle.

- The specification of the dipole system demands that the bend radius in the reverse bends be the same as that of the 180° Dipoles when the field integrals are set to their design values. He suggests shimming or machining after first measurement to achieve this.

- Slight changes in the angles of the beam through the reverse bends

D. Douglas concluded with some reservations that the end dipoles may be usable in the 74 MeV configuration.

D. Douglas requested that the 180° Bends, the Reverse Bends and the Optical Chicane Dipoles be powered in one string with shunts that give +-1%, 2% and 3% adjustment to the types respectively. He suggested the 180° Bends match Integral Bdl to 1%, match to the reverse bends by 0.1% and track to the Reverse Bends by 0.5%

J. Flanz suggested that the one pillar near the final reverse bend of the first loop is too close to the magnet for comfort. It has to be subject to very close tolerances during building or may have to be moved.

D. Douglas suggested that the vacuum tube through the 180° Bends should continue the 8 inches from the inner reverse bends. The vertical extent of the beam is at a minimum in the 180° Bends, so the greater thickness of the vacuum tube walls will not be a problem

Items to Pass on to the Diagnostics/Commissioning Meeting:

D. Douglas commented that air core corrector dipoles at the entrance and exit of the 180° Dipoles will give him a powerful tool to adjust phase of the beam magnetically. (a ±2 mrad kick yields ±2 cm using both dipoles) He suggests we may be successful in the RF experimental program by placing a series of shims of up to 2.5 cm. thickness on the entrance and exit edges of the dipoles to make the macro changes in path length that involve a zero crossing and going to an acceleration mode. The full adjustment would then be 14 cm or 250°. This would eliminate the movable stand and extra bellows - a substantial savings in cost and effort.

The feedback from J. Flanz on the dump after the second loop is that an in-line dumplet may be good enough.

Action Items:

G. Biallas/J. Parkinson - Do the appropriate calculations and get Sign-off on relaxed vacuum requirements near cryomodule by R. Sundelin & P. Kneisel. We need the hard interlock values for closing valves. No progress.

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. C. Murray will go back to this task tomorrow.

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. One price estimate received. No Progress.

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

G. Biallas - Ask David Douglas about reversing the dipole at the Injector dump to deflect the beam twice the angle and eliminate the additional bend dipole. Proposal has merit, but requires wider short injector dipole. Awaits Leigh's design of the dipole.

G. Biallas - Get the BT contracts signed. G. Biallas has to check task list.

T. Siggins/K. Jordan - Review proposed Shielded Viewers for vacuum construction properties. No progress.

E. Feldl - Make the prototype weak QB. Stacking to begin Friday 5/17/96.

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. No progress.

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.

New Action Items:

D. Douglas - Check the width of the beam in the 45° either side of the 90° point in the 180° Dipoles.

New Action Items from the Diagnostics/Commissioning Meeting:

None

Completed Action Items:

D. Douglas - Continue to refine lattice. Complete, testing to start.

J. Parkinson/S. Benson - Investigate the "easy way" the ALS aluminum vacuum chambers were made. Complete.

G. Biallas - Inquire of D. Douglas if the vertical corrector after the second arc can go slightly down stream and can the dump dipole move somewhat up stream to take its place. Complete. Dipole cant be there.

D. Douglas - Determine with D. Douglas what dipoles will be powered in what strings. Complete.

G. Biallas - Inquire if F. Ellingsworth can be lent out at this time. Revert to M. Wiseman to get design personnel on board.

C. Bohn - Determine with D. Douglas which magnetic elements can be started in engineering design. Complete. Complete, unless lattice tests prove otherwise, the lattice as released on 5/15/96 can be used for all magnets.

G. Biallas - Publish with the layout drawing, a summary of the magnetic elements and if and how they are powered in strings. Now available in the Biallas's shared folder

D. Douglas/C. Bohn - Add the bunch lengths to zones on the layout drawing in the main beam line and the Injector respectively. Court is doing this with a tabulation. Complete.