E-rhic-ir-l mailing list

[Bill Christie <christie AT bnl.gov>]

Dear All,
    Below please find the minutes from our meeting on August 4th.
    Greetings,
        Bill

     Minutes from the eRHIC IR Design meeting held on August 4, 2017
---------------------------------------------------------------------------------------
Agenda:
   - Bob's Presentation
   - Update on effort to match IR to the rest of the Lattice
   - Geometry Update
 * Bob's Presentation:
   - presents argument why for ring-ring design one expects (possible?) 
epsilon_y_e << epsilon_x_e
   - makes point that with short, flat beams that one may be able to 
operate without crab cavities and lose only ~40% of the luminosity.
   - brief discussion of whether it could be possible to operate 
without a crossing angle, difficult is one wants a small beta*.
   -  Bob explains the choices of divergences, essentially balancing 
luminosity vs acceptance and measurement errors.
   - Elke emphasizes the point again that the possibility of running 
with small divergences in both directions (x & y) will be an important 
feature (choice #3 in Bob's list). Important for the p-e physics program.
   - Elke makes the point that the divergence of the Au beam is 
important as well, as it ties into the neutron acceptance. As important 
as the proton divergence is in p-e.
   - Bob presents slide defining three levels of cooling
   - Conclusion on cooling discussion, it gets down to how one wants to 
present it
   - Moderate cooling with CeC:
      - If CeC works then all good
      - If CeC doesn't work, assess different cooling techniques
End of Bob's presentation
 * Matching IR to rest of Lattice Update
   - One meeting has been held
   - Homework was assigned and done
   - Discussions at meeting
      - Parameters to use (language)
      - Which things to work on first
   - An ongoing effort
 * Geometry Update
   - Bill had talked with Ferdi about desire to have the geometry for 
the IR put into a drawing
   - Ferdi commented that too early to get designers involved, to 
involve them one needs precise numbers, inefficient at this point
   - Idea to try and draw up preliminary geometry drawings with simpler 
software packages
      - Suggestion to speck with Dejan about possibly getting Stephen 
involved in this

 * Discussion of next meeting
   - Schedule for two weeks from today (i.e. next mtg on August 18th  
at 2 pm)
                  - Cancel if deemed desirable
   - Update on geometry
   - update on the lattice matching effort.
                       End of Meeting