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U.S.-LARP and CARE Steve Peggs

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U.S.-LARP and CARE Steve Peggs Powered By Docstoc
					                brookhaven - fermilab - berkeley - stanford


                          U.S.-LARP and CARE
                                    Steve Peggs

                      Mission, budget, org chart
                      Accelerator Systems
                      - Commissioning, “outreach”
                      Interaction Region upgrade
                      - External review & EPAC 04 comments
                      Magnet Program
                      - Quadrupoles & dipoles
                      Two questions
                      Summary comments


CARE-HHH-APD, Nov 8, 04                 Steve Peggs          1
                          Mission Statement (“elevator” version)



    Four U.S. labs (Brookhaven, Fermilab, Berkeley, & Stanford)
       collaborate with CERN in LARP:

    1) To help make more luminosity, earlier

    2) To collaborate in an interaction region upgrade to make
       even more luminosity, later

    3) To use, develop, and preserve unique U.S. resources and
       capabilities
                       (physicists, engineers, & infrastructure)




CARE-HHH-APD, Nov 8, 04                Steve Peggs                 2
                          Budget profile – April 2004




                                                        After adding
                                                        Phase II
                                                        collimator R&D
                                                        (SLAC)

                                                        $11 M
                                                        “guidance” for
                                                        FY06 &
                                                        beyond still
                                                        holds good




CARE-HHH-APD, Nov 8, 04               Steve Peggs                 3
                          Organization Chart




CARE-HHH-APD, Nov 8, 04          Steve Peggs   4
                          Accelerator Systems tasks




   Add 3rd commissioning task, “Systems Hardware Commissioning”?

CARE-HHH-APD, Nov 8, 04              Steve Peggs                   5
                            Commissioning


At the recent LARP Collaboration Meeting Roberto Saban stated the
need for about 40 FTE-years of resources, half engineers, half super-
techs, at the interface of the magnet, cryogenic, and quench protection
systems

BNL & FNAL directorates agree that this is within the LARP mission

If LARP plays a role, we must seek additional funds

Where are the engineers - BD, TD, C-AD, …. ?

For ALL commissioning tasks, it is time to begin naming names




CARE-HHH-APD, Nov 8, 04           Steve Peggs                        6
                                 “Community outreach”



      LARP takes “outreach” education seriously, to our own community:

      Introduce U.S. ATLAS & U.S. CMS to some of the physical
      challenges that make LHC “not a light switch”

                   - e.g., persistent currents & snap-back

      Establish mutual support with International Linear Collider
      accelerator physics & technology

      Explore complementary relationship with CARE




CARE-HHH-APD, Nov 8, 04                   Steve Peggs                7
                          From Tevatron to LHC




                                                 9 kW !?

CARE-HHH-APD, Nov 8, 04           Steve Peggs        8
                          Persistent currents



                          Vortex currents circulate quantum
                          fluxoids pinned in a Type II SC filament

                          A quadratic fluxoid density gradient
                          drives a current gradient ...

                          Like eddy currents, “persistent currents”
                          - depend on the “external” field history
                          - decay (SLOWLY) with time
                          - unwind with vicious transients!




CARE-HHH-APD, Nov 8, 04       Steve Peggs                            9
                                Snapback transients




        “Snap-back” is not SO fast, but the chromaticity jump is huge

CARE-HHH-APD, Nov 8, 04               Steve Peggs                       10
                          Interaction Region Upgrade




    Quad or Dipole first? Single bore or twin bore?
    Large crossing angles with superbunches or crab cavities?
    Long range (parasitic) Beam-Beam collisions?
CARE-HHH-APD, Nov 8, 04              Steve Peggs                11
                          LARP External Review - June 2004

 “LAPAC suggests that the main issue is demonstration that (Nb3Sn)
 quads can be made in both long and short lengths.”

 “... demonstration of a working long quadrupole, the first of its kind
 in the world, will be a key element in the decision to start … the LHC
 luminosity upgrade.”

 “(Dipole) work is focused on the „dipole first‟ scenario, which must meet
 the most severe requirements; an open mid-plane design … 15 T, 10 m”

 “Since the new IR layout … is not known, … recommend against going
 further than … to deliver a low cost and simple (dipole) demonstration
 model …”

 We don‟t fully agree with the reviewers, but the comments are telling

CARE-HHH-APD, Nov 8, 04              Steve Peggs                         12
                          Ruggiero et al, EPAC 04


 “Nb3Sn technology
 - appears to be the only candidate for a substantial improvement
 - could open upgrade scenarios such as 'dipole-first'”
 “Important issues related to long Nb3Sn magnets need to be addressed
 by vigorous R&D”
 “The effective Nb3Sn filament diameter (>100 ) is too large” (Material
 development required.)
 “The choice of the coil aperture is driven more the power density
 limit than by the beam acceptance”
 “An estimate of the radiation parameters of the magnets requires
 extensive simulations based on detailed knowledge”


CARE-HHH-APD, Nov 8, 04             Steve Peggs                       13
                          LARP Magnet Program

DOE Guidance
“It is our firm intention that the LARP activities serve to explore the limits
    of the technologies described herein. While the end products of LARP
    will be applied to the LHC, LARP is not intended to be an engineering
    and construction service organization to that facility.”

“LARP is not intended to replace existing base program support at the
  various laboratories in superconducting magnet development and
  other ongoing areas.”

LARP Proposal
“have fully developed and proven accelerator-ready magnet designs,
  ready for production, by about 2012, as required to support the LHC
  physics program.”
CARE-HHH-APD, Nov 8, 04               Steve Peggs                         14
                            Magnet Program Goals


• Improve long-term physics research opportunities of the LHC by
  providing magnet options for an LHC luminosity upgrade

          Large aperture, high gradient quadrupoles (main emphasis)

          High-aspect ratio, large aperture separation dipoles

• Deliverable is a successful R&D program, leading to accelerator-ready
  magnet design(s) (production magnets are outside LARP scope)


    FY05                               FY08               FY10      FY12
            Research
                                          Focused Development Prototype
            Technology Base-Building



CARE-HHH-APD, Nov 8, 04                 Steve Peggs                        15
                                 Task Distribution



           3000
         $k
           2500

           2000
                                                      Quads
                                                      Dipoles
           1500
                                                      Long Mag
           1000                                       Sub-scale
                                                      Cond/Cable R&D
            500                                       Cond Proc

               0
                          FY05      FY06




CARE-HHH-APD, Nov 8, 04                 Steve Peggs                    16
                          3-Year Quad Model R&D Goals


• Fabricate, test and evaluate two shell-type coil designs: 4-layer (TQ1)
  and 2-layer (TQ2)

• Fabricate, test and evaluate two alternative mechanical structures
  based on bladder-key-Al shell and collar-yoke-skin

• Develop and study narrow and wide cables for both coil designs

• Study and optimize strand parameters for quadrupole models

• Develop and evaluate coil fabrication technologies

• develop infrastructure for fabrication and test of long (up to 4-m long)
  quadrupole coils

• Field quality issues deferred (output, not input)

CARE-HHH-APD, Nov 8, 04               Steve Peggs                      17
                           FY04 Quadrupole Development


• Design Studies
   – Dual-bore
   – Aperture
   – Geometries                                                                                               0    22   44


                                                     0   10   20   30       40




                                                                                 Rel. field errors (x10E-5)                      Rel. field errors (x10E-5)


                                                                        0    2 4   6   8 10 12 14 16 18 20
                                                                                                                        0    2   4   6   8   10 12 14 16 18 20




• Support Structure
   – Key-bladder-shell
   – Coil-yoke-skin


 CARE-HHH-APD, Nov 8, 04               Steve Peggs                                                            18
                      Racetrack Quadrupole with Sub-scale Coils


                              Clear bore: 110 mm
                              Magnet short sample
                                  Iss = 11.4 kA
                                  Bpeak = 11.2 T (in the end)   F┴ F║
                                  Gss = 95 T/m
                              Stored energy at Iss = 175 kJ
                              Inductance at Iss = 2.7 mH




 Later … ?

CARE-HHH-APD, Nov 8, 04                  Steve Peggs                    19
                          FY04 Dipole Development

• Based on “Dipole-first” IR design
   – Large aperture, asymmetric
   – Non-cos-theta
   – Split coil geometry
High field (~15T), long (~10m), large
radiation heat load (~9 kW) into 70 K




                                                     Calculations from Mokhov
                                                    show that the concept works

CARE-HHH-APD, Nov 8, 04               Steve Peggs                             20
                                 Dipole Status


   Peak power in coil will not cause magnet to quench.
   ~ 1/2 of heat load into 70K (tungsten rod) will try to increase significantly
   Residual dose => lifetime > 20 years
   OVERALL: could operate in LHC
   Remaining issues: (many) in particular total refrigeration load
   Split D1 into two magnets:
         D1A - smaller aperture, higher field, ~ short
         D1B - full aperture, lower field, ~ long
         focus on D1A
   Internal review of dipole program in December 04.

CARE-HHH-APD, Nov 8, 04                 Steve Peggs                       21
                          Two questions for this workshop


  1) What is the “road map” for establishing the IR upgrade layout?


  2) Whether/how/when to launch an integrated analysis of a straw
      layout, with both Magnet and Accelerator scientists & engineers?
  “An estimate of the radiation parameters of the magnets requires
      extensive simulations based on detailed knowledge”

        sample optics, apertures,
        energy deposition (liners etc?)
        quench analysis,
        component survival?
           heat removal analysis

CARE-HHH-APD, Nov 8, 04                 Steve Peggs                   22
                           Summary Comments

     1) Need LHC operating experience to optimize the IR upgrade
        design
     2) Explore the complementary roles of LARP and CARE
     3) Relationship of LARP program and base program:
           - Develop technology for future U.S. machines (BROAD)
           - Focused to meet LHC upgrade in 2012 (NARROW)
     4) Can long Nb3Sn magnets be built long?
         - Will they quench (9 kW)?
         - Can the heat be removed (at all/economically)?
         - Will they survive eg 7 years?
     5) “Outreach” to our own communities – ATLAS, CMS, ILC


CARE-HHH-APD, Nov 8, 04              Steve Peggs                   23
                          Other “LARP” presentations/posters




         Session 2          Electron Cloud           Jie Wei
         S3                 IR Layouts               Tanaji Sen
         S 3 Poster         Dipoles                  Peter Wanderer
         S4                 Beam-Beam                Tanaji Sen
         S6                 Electron Cloud           Miguel Furman
         S 6 Poster         Electron Cloud           Ubaldo Iriso




CARE-HHH-APD, Nov 8, 04                Steve Peggs                    24

				
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