E-rhic-ir-l mailing list

[Bill Christie <christie AT bnl.gov>]

Dear All,
    Below please find the minutes from our eRHIC IR Design meeting that 
was held on Friday, 8/10/2018. Please note that our next meeting will be 
on Friday August 24th, at 3 pm.
    Greetings,
        Bill

  Minutes from the eRHIC IR Design meeting held on 8/10/18
 
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* We started with a brief discussion of the agenda for the meeting.

* We then had a brief discussion concerning the philosophy of the 
"Design Study" that we'll be embarking on to investigate optimizing and 
eventually changing the Baseline IR Design which is in the pCDR. The 
Design Study philosophy was discussed during the 7/27/18 IR Design mtg, 
and text to reflect it written into the minutes from the meeting. The 
consensus from our discussion was that the text in the minutes 
accurately reflected what we'd discussed, and the approach that we'll take.

* Walk through Holger's slides that we didn't get to in the 7/27 mtg. 
File 2018-07-27_Q1PF_stepped.pdf
    - Slide #1: Introduction to Bob's design 1807
        - Q1 magnet broken up into two magnets, Q1A and Q1B
        - If this change works it decreases the cost of the Q1 magnet 
concept significantly.
    - Slide #2: Geometry of Q1APF
    - Slide #3: Magnetization
        - Need to keep the magnetic field in the region of iron between 
the hadron and electron beams from saturating the iron (i.e. below about 
1.8 T). Looks "tight" in current study.
    - Slide #4: Gradient Quality
    - Slide #5: Q1B, all looks OK. No cross talk.
    - Slide #6: Q1PF (a tapered magnet design in the pCDR)
        - tapered helical coil
        - shows a simulation result for the pCDR design
    - A fairly long discussion on how to deal with the magnetic field 
in the region iron between the hadron and electron beams. Currently 
shows about 2 T in the iron by the hadron beam. Holger will study this 
issue further.

* Update from the EIC User's meeting
    - Elke indicates that there was little to nothing that came up at 
the meeting that would impact our IR design efforts.
    - Christoph points out that there was the first meeting of the 
combined (BNL & JLab) IR Design working group, put together under the 
auspices of the EIC Users group.
        - Christoph sent the mailing list for this joint IR Design 
group to our group mailing list after the meeting.
        - Christoph also sent the slides that were shown at this first 
mtg of the group to our mailing list. The file is attached to these minutes
        - Comments that it needs more people involved
        - Backgrounds would be an important topic for people to work on
        - Also Synchrotron radiation related issues important to get 
effort.
    - Ferdi makes point that we should work between BNL and JLab to 
come up with a document that details the design requirements for the IR 
design that are driven by the Physics program requirements.
        - Elke adds that the people planning to do physics need to 
get/be involved in the development of these requirements.
            - Points out that perhaps she and Alexander will go to JLab 
and get discussions started along these lines.
    - This leads to a discussion about how to make the BNL/JLab EIC 
Collaboration meetings more productive and useful.
        - An idea to have a Workshop on the IR Design requirements, 
driven by the Physics program requirements.
            - Not just a bunch of presentations. Perhaps a short 
presentation from both BNL and Jlab on a few slides detailing the IR 
Design requirements, followed by a discussion and work to combine, to 
the extent possible, the IR design requirements into a single joint EIC 
IR Design requirements list. Acknowledged that not all requirements 
would necessarily be the same, but if they aren't, a clear statement 
detailing why they aren't would also be useful.
    - Date for the next EIC Machine Collaboration meeting is October 
29th (and 30th?)
    - Vadim reminds the group about the joint magnet design R&D proposal.
            - Also brings up joint Background studies

* Bob brings up suggestion that, as Holger looks into the issue with the 
saturating iron in the proposed split Q1 design, that he provides the 
group with some feedback on what crossing angle leads to a "comfortable" 
design regarding the iron saturation.

* Discussion of the next meeting:
    - Will occur in two weeks, on August 24th, at the usual 3 pm time.
    - Draft Agenda:
        - Update from Holger on his efforts to solve the "saturation" issue
        - Update from Bob on the magnet lengths. Revisit rear (incoming 
proton beam) "stepped" magnet design.
        - Update from Doug on Integration issues and progress
        - Update on the beam pipe design and Impedance simulations (if 
available)
                        End of meeting

Attachment: 2018-07-27_Q1PF_stepped.pdf
Description: Adobe PDF document

Attachment: IR_Lumi_WG_summary_01aug18.pptx
Description: application/vnd.openxmlformats-officedocument.presentationml.presentation