Thursday, October 25, 2018 11am ET

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Logistic information

 BlueJeans calling instructions:
 Toll-Free Number (U.S.&  Canada):  888-240-2560
 International toll number:         408-740-7256
 Bluejeans CODE:                    734 609 7559
 Bluejeans link: https://bluejeans.com/7346097559

Agenda

  1. Prototype testing status (Ernie)
  2. MOLLER nomenclature (David) - Nomenclature pdf
    1. Do we just make a decision? What about consistency between systems?
    2. "Upstream" and "Downstream" instead of "Hybrid"
    3. Coil and sector sequencing from beam left going clockwise
      1. coils A-G
      2. sectors 1-7
    4. subcoils by electrical path in a given coil
    5. "Zones" defined by different NI
      1. A-D from upstream to downstream
      2. possibly an additional zone E in the "segmented" version
    6. subcoil string to define the set of subcoils in each coil in series
    7. Scope (in section 3)
      1. This is "magnets"
      2. "Spectrometer" needs to include more
  3. cross-sections - cross-sections pdf
    Stacked Cross sections
  4. Downstream torus questions (David) - DS thoughts pdf
    1. Versioning generally is an issue as we go forward (item 1)
    2. Trade off studies - what has been done, what to do? (item 2)
    3. Water flow (items 13, 14, 15, 16, 17, 18, 19 )
  5. Propose to deal with offline and/or at a later meeting
    1. Details of prototype winding (items 5, 6)
    2. Strongback design (items 7, 8, 20, 21)
    3. insulation (items 9, 10, 11)
    4. water flow (items 12, 22)
  6. phase space study (Juliette) - phase space pdf

Minutes

Attendance: Randy, David, Roger, Juliette, Ruben, Probir, Sandesh, Rakitha, Jason, Ernie, KK, Kent, Jim

  1. Prototype testing status (Ernie)
    1. Pump came in
    2. getting hardware to set it up - waiting for little parts
    3. hoping to be complete next week
    4. pressure check and flow test each one
    5. water in one at a time, power to nominal numbers without water in adjacent coils
      1. if not powered, don't need to cool
      2. but if do add water into adjacent coils, does that help?
      3. try to match the flow rate? No - put certain pressure
      4. can throttle it back but can't go higher
    6. need to measure the flow rate each flowpath
      1. 2 subcoils have 2 flowpaths
    7. temperature
      1. have control of the chiller
      2. thermocouples on inlet and outlet to measure Delta T
      3. won't get coil close to 70 C because of epoxy
      4. risk of cracking epoxy between coils
      5. B stage, not vacuum impregnated
      6. check if epoxy is cracked - only visually
      7. thermal imager - tells you temperature of epoxy on outside
        1. tells you a distribution, can try to calibrate with inlet and outlet
        2. had to cover with tape at JLAB b/c acted like a mirror
  2. MOLLER nomenclature (David) - Nomenclature pdf
    1. Do we just make a decision? What about consistency between systems?
    2. "Upstream" and "Downstream" instead of "Hybrid"
    3. Coil and sector sequencing from beam left going clockwise
      1. coils A-G
      2. sectors 1-7
      3. in detectors - subsectors (open, closed and transition)
      4. region refers to along z (detector region, target region, etc)
    4. subcoils by electrical path in a given coil
    5. "Zones" defined by different NI
      1. A-D from upstream to downstream
      2. possibly an additional zone E in the "segmented" version
    6. subcoil string to define the set of subcoils in each coil in series
    7. Scope (in section 3)
      1. This is "magnets"
      2. "Spectrometer" needs to include more
        1. downstream of target, upstream of detectors
        2. water system up to where it attaches to the JLAB tower
        3. MIT - design chillers
        4. already considered Hall A infrastructure etc.
        5. same thing on DC power side - work with MIT as well
    8. meet with Cameron and Sakib, meet with detector group
  3. cross-sections - cross-sections pdf
    Stacked Cross sections
    1. V5 is a new version
    2. tradeoff of prototype vs. number of flow paths, number of ceramic breaks
    3. blocky model - where is space available?
      1. taller conductor
      2. depending on hole size, you can optimize current density vs. pressure, etc.
      3. same winding as prototype
      4. allow water flow without getting into the particle envelopes
      5. should we look at the other large conductor model?
      6. envelopes and coil with proper slices coming from Stonybrook
  4. Downstream torus questions (David) - DS thoughts pdf
    1. Versioning generally is an issue as we go forward (item 1)
    2. Trade off studies - what has been done, what to do? (item 2)
      1. quadrupoles (KK)
      2. permanent magnets (Willy Falk had looked at this)
      3. single magnet
        1. need the pre-focussing
        2. see first director's review (Kent's slides)
      4. make front magnet like a potato chip (optimization)
        1. change the distance between the pancakes
        2. shape of the upstream toroid is providing prefocusing for mid-angle tracks
        3. this is not an easy problem - extreme angles, extreme energies
        4. worried about tolerances
      5. hybrid and upstream
      6. segmented
      7. iron in coils
      8. superconducting magnets
      9. 5 or 9 vs 7 coils
        1. why did we choose 7?
      10. What are the important things?
        1. Where can we go outside of the blocky model, if anywhere?
          1. can't interfere with the particle envelopes
      11. certainly for Director's review have to show why this design
    3. Water flow (items 13, 14, 15, 16, 17, 18, 19 )
      1. critical parameters
        1. 15 ft/sec
        2. max temp 70 C
        3. max current density 21 A/mm^2
        4. low number of water flow paths
      2. different types of conductor
      3. number of flow paths per subcoil
      4. different level of pressure headers
      5. could consider higher current densities
      6. Propose to deal with offline and/or at a later meeting
    4. Details of prototype winding (items 5, 6)
    5. Strongback design (items 7, 8, 20, 21)
    6. insulation (items 9, 10, 11)
    7. water flow (items 12, 22)
    8. adding more than 2 headers doesn't necessarily help
    9. Comparison
      1. first column is the prototype
      2. prototype with 2 headers is second column
      3. With V5 - the height is different could risk collapsing the walls
      4. need wall thickness for connecting
      5. off the shelf had a less than 1mm wall
      6. how do you actually make joints - brazed with pockucell 15 or 5?
        1. taper ends of ferrel to have a pressure drop over short ferrel
        2. really just aligning the thing
        3. what was done in the prototype - should find out because it could affect pressure drop
      7. will try to add the segmented coil to the spreadsheet
      8. large conductor model?
    10. Back to document
      1. segmented not easier to cool
      2. make a monolithic structure - pot all at once after B stage
      3. more flimsy without the epoxy
        1. vendor would rather use B stage and then pot at the end
      4. what keeps the coils from touching each other
        1. it has blocks in place before vacuum impregnation
        2. wrapped around coils with add'l fiberglass
      5. need to be able to move the coils slightly (BLAST, QTOR)
      6. make field uniform and zero it on the beamline
      7. map the field very carefully
      8. Hard mounting CLAS coils gave perfect alignment
      9. segmented coil doesn't win - how much more to do?
    11. new item 23
      1. does location of current make a difference in the MOLLER envelopes
  5. Roger has a new item
    1. putting in vacuum - power and current doesn't turn off instantaneously
    2. Paschen point for hydrogen - if leak in target
    3. sweet spot between vacuum and air
    4. interlock on magnet with hydrogen detectors?
    5. magnet never discharge?
    6. need to assign a risk factor and mitigation
  6. Measurement of the prototype coils
    1. how well designed are they?
  7. Magnet Advisory Group meeting
    1. after prototype testing?
    2. CD1 earliest is January/early February - before this
    3. just before the end of the year?
    4. 2-3 hour bluejeans meeting - call it an update
    5. Next year have the more "official" review
    6. Members
      1. Dieter Walz
      2. Vladimir Kashikin
      3. Steve Williamson
      4. Ruben's suggestion
      5. MIT guy
      6. Berkeley
      7. others?
    7. how much new
      1. prototype manufactured
      2. results of the tests
      3. segmented magnet
      4. steel in magnet not effective and not desirable for parity experiments
      5. haven't seen the large conductor or prototype
      6. solution to the winding of the prototype
      7. phase space studies
      8. summary of high current density magnets operation
    8. Summary
      1. convince that the coil as designed - happy with current
      2. have a CAD model that looks like it can be wound
  8. Next meeting
    1. week of the 5th - new time?
  9. phase space study (Juliette) - phase space pdf


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