E-rhic-ir-l mailing list

[Bill Christie <christie AT bnl.gov>]

Dear All,
    Below please find the minutes from the eRHIC IR Design mtg that was 
held on January 12th. Please note that I still need to get the minutes 
out from our meeting last Friday (1/26/18) which I hope to get out today.
    Greetings,
        Bill

    Minutes from the eRHIC IR Design meeting held on 1/12/18
-------------------------------------------------------------------------------
* The meeting started by a discussion and agreement on the Agenda for 
the mtg.
    - Conclusion from the discussion between Ferdi and Christoph about 
the stay clear acceptance for the synchrotron radiation fan.
    - Short presentation and discussion of a proposed geometry for the 
outgoing hadron end of the central beam pipe from Charles.
    - A presentation/update by Alexander on status of implementing the 
latest beam and magnet parameter file into the simulations. Also discuss 
status of importing a "STEP" file from Charles that details the central 
beam pipe, and outgoing electron side geometry, with the WCT, into the 
simulation framework.
    - Discussion of the text from Elke regarding IR design constraints 
imposed by physics program.

* Presentation by Bob "1801-update-v3.pdf"
   - Slide 1 shows the C1 magnet. Point made that, with the acceptance 
for the synchrotron radiation allowed to be reduced from 15 to 13.5 
sigma, the additional iron between the two beams simplifies the magnet 
design considerably.
    - Slide 2 shows the B0 magnet with a change from a rectangular 
opening for the passage of the two beam to an elliptical opening. I 
believe that the point here was that this also simplified the design of 
the magnet.
    - Details change from Combined function magnets (only for Electron 
beam) to single function magnets, and benefits.
    - Elke points out that the B0 magnet change will impact the physics 
acceptance, and has to be looked into.
    - A few slides showing the overall layout with these changes.
    - A table of Magnet and beam parameters for the electron ring are 
shown. Point made that at the next meeting (1/26) this table will have 
to be presented again after some updates/checks.
    - Ferdi suggests that a consideration should be given to shortening 
some of the magnets, given their modest B-field gradients.
    - point came up in discussion that the current dynamic aperture is 
~ 7 sigma, which is too low.
    - Update by Steve at next meeting.

* Conclusion that the 13.5 sigma aperture proposed for the synchrotron 
acceptance is OK

* We move on to look through Charles slides "Charles_slides_1_12_18"
    - N.B. For some reason Charles slides got merged into the body of 
an E-mail on my laptop. I took them out, and placed them in the pptx 
file attached to these minutes)

* We move on to look through Alexander's slides " 
ayk-2018-01-12-bnl-ir-meeting.pptx"
    - Starts with a slide showing the current "Beast" detector model.
    - It shows four magnets on proton downstream side.
    - Next slide shows examples of "importable" objects received from 
Brett, Holger, and Charles. Comments that most objects import correctly, 
but still some issues with a few.
    - Last slide lists some observations. One of the points is that 
there WILL BE conflicts between the IP vacuum chamber and the detector. 
This will take a few iterations.
    - Guillaume will send the magnet positions and strengths for the 
incoming proton beam. Will be provided in "survey frame".

* Move on to Elke's Physics requirements text. Link to text is 
https://www.dropbox.com/s/6692p8otvcy383l/detector.eRHIC.docx?dl=0
    - Looks good. Final draft soon.
    - Comments welcome.
* Discuss Agenda topics for the next (1/26/18) IR Design mtg.
    - "Final" presentation of tables with magnet and beam parameters 
for both the electron and proton beams.
    - Update on Simulations
    - Update from Charles on Vacuum design.
        End of meeting.

Attachment: Charles_slides_1_12_18.pptx
Description: application/vnd.openxmlformats-officedocument.presentationml.presentation

Attachment: 1801-update-v3.pdf
Description: Adobe PDF document

Attachment: ayk-2018-01-12-bnl-ir-meeting.pptx
Description: application/vnd.openxmlformats-officedocument.presentationml.presentation