Status and Installation Plan for the Spectrometer Solenoid Magnets - PowerPoint by KevenMealamu

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									5-Year RF R&D Plan

NFMCC and MCTF Phone Meeting
     Friday, September 18, 2009

              Derun Li
 Lawrence Berkeley National Laboratory
              Recommendations from MUTAC 2008
• Recommendations from MUTAC Review 2008 on RF
  programs
       – Pursue a more aggressive program at MTA, taking advantages of
         its unique facilities to do experiments that compliment the
         MICE program


• In addition to 805 MHz experimental programs, we have
  been working on normal conducting 201-MHz cavity:
       –  Gradient of ~ 16 MV/m in a few Tesla magnetic fields
         environment
       – MICE cavity fabrication progressing well; the cavity gradient is
         limited to 8 MV/m due to available RF power
       – No SC coupling coil magnet yet

MCTF                                   5-Year RF R&D Plan

           Derun Li - Lawrence Berkeley National Laboratory, Sep. 18, 2009   Page 2
              Recommendations from MUTAC 2009
Three recommendations on RF R&D and 5-year plan:
1. Provide a resource loaded RF R&D schedule, highlighting
   prioritized activities and any potential for expediting the down-
   selection process.

2. Define a minimum RF specification to expedite the RF down-
   selection.

3. Modify the employed QA processes to change the 201 MHz Be
   windows to ensure more appropriate protection of the RF
   surfaces.
       –   MuCool prototype or MICE cavity?



MCTF                                   5-Year RF R&D Plan

           Derun Li - Lawrence Berkeley National Laboratory, Sep. 18, 2009   Page 3
                     Responses to MUTAC 2009
• Down-selection (2) in MUTAC Recommendation 1. & 2.
   – Major challenges of RF cavity in cooling channels:
          • RF gradient limit: RF gradients degradation of normal conducting cavities
            in external magnetic fields
          • RF breakdown and surface damage associated with the external magnetic
            fields
       – RF R&D plan
          • Understand the RF breakdown problem in magnetic field
               – Physics models
               – Experimental programs
       – Is this a show stopper ?
          • No ; different cooling channel?
       – Do we have (or presented to MUTAC) too many options?
          • No, pillbox-like closed (by Be windows) with different materials and
            coatings
          • Pressurized cavity

MCTF                                  5-Year RF R&D Plan

          Derun Li - Lawrence Berkeley National Laboratory, Sep. 18, 2009   Page 4
                     Summary of R&D Plans
• Continue experimental studies at 805-MHz
       – The 805-MHz pillbox cavity has been refurbished and should be ready
         soon for more button (new + old button configurations) tests for RF
         breakdown studies
       – High pressured cavity test at MTA (Muons, Inc. + FNAL): no SBIR Phase-
         II support, what’s next?
• 201-MHz cavity program
       ─ RF cavities for MICE : progressing well
       – SC coupling coil for MuCool RF breakdown studies at MTA:

           – Collaboration with ICST of HIT, Harbin for design and fabrication,
             making progress slowly;

           – 3.15 M RMB funding approved by HIT, contract to be rewarded
             soon (hopefully)
MCTF                                   5-Year RF R&D Plan

           Derun Li - Lawrence Berkeley National Laboratory, Sep. 18, 2009   Page 5
              Summary of R&D Plans (cont’d)
• RF breakdown studies
       — Magnetic insulation:
          – Box cavities at FNAL to study ExB effects; the cavity is almost
            ready.
       — Other options:
          •   All beryllium cavity
          •   ALD cavity: current work focus on SC RF cavity
• Theoretical studies on RF breakdown, physics model to
  understand RF breakdown in magnetic fields, in
  collaboration with SLAC
          • BNL (R. Palmer)’s model
               •   Be cavity
          • ANL (J. Norem)’s model
               •   ALD cavity
• SC RF cavity for acceleration
MCTF                                  5-Year RF R&D Plan

          Derun Li - Lawrence Berkeley National Laboratory, Sep. 18, 2009   Page 6
                Dielectric Loaded RF Cavity
Motivation:
• To fit pressurized cavities in HCC, size of cavity has to
   be reduced
•    Examples:
    – 800 MHz dielectric loaded cavity
        •   Maximum RF cavity radius = 8 cm, (pillbox cavity: 14.3 cm)
        •   Radius of effective electric field (95 % from peak) = 3 cm
    – 400 MHz dielectric loaded cavity
        •   Maximum RF radius = 16 cm
            (pillbox cavity: 28.6 cm)
        •   Radius of effective electric field = 6 cm

                                           Dielectric ring

MCTF                               5-Year RF R&D Plan

       Derun Li - Lawrence Berkeley National Laboratory, Sep. 18, 2009   Page 7
           Responsibility for MICE (RFCC Module)
 August 29, 2009                                                           SC coupling Coil
                                         Curved
                                        Be window




                                      201-MHz cavity                       Vacuum Pump

MCTF                                 5-Year RF R&D Plan

         Derun Li - Lawrence Berkeley National Laboratory, Sep. 18, 2009      Page 8
                                     Summary
• Muon Ionization Cooling Channel requires normal conducting RF
  cavity operating in a few Tesla magnetic field
       – Remains a challenge
• 201-MHz RF cavity for MICE progressing well
       – The first five cavities expect to be delivered to LBNL in Nov. 2009
       – Superconducting coupling coil contract to be awarded soon
• Plans for RF breakdown studies
       – Vacuum cavity
           • 805-MHz button cavity and box cavity tests
           • 201-MHz cavity test to be resumed soon
           • Beryllium cavity design starts soon
           • ALD processed cavity to eliminate field emission
           • Dielectric loaded cavity
       – High pressured RF cavity tests
MCTF                                   5-Year RF R&D Plan

           Derun Li - Lawrence Berkeley National Laboratory, Sep. 18, 2009   Page 9

								
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