E-rhic-ir-l mailing list

["Christie, William" <christie AT bnl.gov>]

Dear All,
          Below please find the minutes from our eRHIC IR Design meeting that 
was held on Friday, 1/11/2019. Please note that it was decided that our next 
meeting will be Friday, January 25th, starting at 2:30 pm.
          Greetings,
              Bill

        Minutes from the eRHIC IR Design meeting held on 1/11/19
       
---------------------------------------------------------------------------------
* We started with a brief discussion of the agenda for the meeting.
       - Discussion of Bob's December IR Design layout and parameters, led by 
Bob (file 1901-ir-changes.pdf, attached)
       - Update by Steve T. on his effort to determine if an Electron ring 
Match solution is possible. (Nothing ready for this meeting).
       - Update from Guillaume on his updates and insights on matching the IR 
design into the Hadron rings (file 2018design-IPmoved.png, attached)
       - A quick look at some new integration drawings from Doug (file 6IR 
iso View 2019-01-08.pptx, attached)
       - Summary of a recent EIC User group IR Working group mtg by Alexander
       - AOB

* Bob Walks us through his slides:
     - Overview of recent changes, comparing the old with the new parameters.
     - On Slide #6, two possibilities are shown, one with three magnets, and 
one with four magnets.
         - Ferdi proposes that we go with the three magnet choice (9/21 
version).
            - Holger points out that he has concerns about this choice. Will 
require some magnet simulations to resolve/study.
               - We set a goal to, if possible, make a decision on the 
choices presented on slide #6 (3 vs 4 magnets).
     - Slide #8, Guillaume points out that the Q1B magnet, as listed on the 
slide, is off by 1 m. Also points out that there is a missing "unpowered" 
dipole in the line.
     - Slide #9, Adjusted Betas compared to pCDR.
       - Error on the slide, Q2pR needs to be longer (not Q1pR as listed on 
slide).
         - A decision needs to be made on how much longer to make Q2pR. Bob, 
Brett, and Holger to decide.
     - End of presentation

* Guillaume presents his Slide:
     - Looking at matching the hadron IR design to the RHIC ring.
     - Reiterates that decision was made to move IR towards inside of RHIC 
ring by 1 m.
     - He moved the point where he matches into the Hadron ring to D8 (~ 130 
m).
        - This impacts the number of RHIC magnets that can be "reused".
           - Needs to make a few new magnets.
     - This brings up a discussion about what the angles of the electron and 
hadron beams are with respect to the current RHIC beam through the IRs. The 
opening angle between the beams is 25 mr, but the actual angles needs to be 
settled on by the group.
        - Bill proposes, as a starting point in settling this questions about 
the angles of the beams, that he put the angles currently used by Doug in his 
integration studies into the minutes. Doug emphasizes that these angles, and 
the exact distance that the IR is moved towards ring center can likely be 
changed IF NEEDED.
         - The angles in Doug's current studies are:
             Hadron beam is at 18 mr
             Electron beam is at 7 mr
             Total crossing angle of 25 mr
  - Looking at the rear side
        - Need to see to it that there is a Spin rotator on the rear side of 
the IR before the start of the electron ring.
     - End of presentation

* Doug presents just a few of his slides:
     - Indicates that he's put the quads into cryostats (i.e. RHIC quads)
           - sort of arbitrarily spaced in current drawings
     - RCS ring is 0.5 m higher in elevation that the hadron ring.
     - Bill suggests that, when he has time, that Doug take a look to see if 
this IR design can fit into the 8:00 IR region.
     - End of presentation

* Summary of recent EIC IR working group meeting by Alexander:
     - A virtual organization
       - A mailing list of many people
     - Goal is to organize a group to work together
     - 3 Sub groups
        - IR Design
        - Polarimetery
        - Luminosity
     - 1st meeting on February 15th
        - Focused on luminosity monitors
            - Talks by Elke, mirror talk by JLab, Angelika, and Bill Smidtke 
planned.
     - End of summary

* Date and draft agenda for next meeting:
        Next meeting in two weeks (January 25th, starting at 2:30 pm):
     - Draft Agenda:
        - IR Design Discussion, status on decisions to be made (3 vs 4 
magnets, Q2pR length, beam angles)
        - Steve T. on existence of a matching solution for electrons
        - Update from Guillaume
        - Update by Doug
        - AOB
                        End of meeting

Attachment: 1901-ir-changes.pdf
Description: 1901-ir-changes.pdf

Attachment: 2018design-IPmoved.png
Description: 2018design-IPmoved.png

Attachment: 6IR Iso View 2019-01-08.pptx
Description: 6IR Iso View 2019-01-08.pptx