Proton Driver by pengxiuhui

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									 Muons, Inc.




  Dielectric-filled RF
         cavity
               Milorad Popovic
                   FNAL


06/11/2009           LEMCW09     1
 Muons, Inc.




   Loaded Pillbox Cavity
                     Milorad Popovic

               (with Mike, Chuck, Katsuya, Al and Rol)




                       Muon Collider Design Workshop, Jefferson Lab
12/09/2008                                                            2
    Muons, Inc.
                            Motivation
   To fit pressurized cavities in HCC, size of cavity has to be reduced
800 MHz (from Katsuya)
   Maximum RF cavity radius = 0.08 m, (pillbox cavity 0.143)
   Radius of effective electric field (95 % from peak) = 0.03 m
400 MHz:
   Maximum RF radius = 0.16 m (pillbox cavity 0.286)
   Radius of effective electric field = 0.06 m
   Optimum electric field gradient = 16 MV/m


                For Pill Box Cavity, resonant frequency is




                         Muon Collider Design Workshop, Jefferson Lab
   12/09/2008                                                           3
Muons, Inc.


        Dielectric Loaded RF Cavities
New type of cavity is suggested.
The idea came from conversation with Chuck and
Yonehara.
I was told that Al suggested something like this.

                       Cu/Steel

                        ceramics
                        Vaccum/H/He




12/09/2008      Muon Collider Design Workshop, Jefferson Lab   4
    Muons, Inc.
                  HCC Concept




 Central Orbit and Beam Envelope                           Set of Coils



Basic Building Block can be Cavity + Coil


   12/09/2008           Muon Collider Design Workshop, Jefferson Lab      5
 Muons, Inc.
                            MANX + RF ?




                                Detector
             Cryostat           s                Cavity + Coil
             Vessel



                                                                           MICE will have
                                                                           ~?MV @200MHz



              Feedthrough                  Power in
              s                            Signals
                                           out
12/09/2008                  Muon Collider Design Workshop, Jefferson Lab                    6
  Muons, Inc.




• May be ceramics can play additional role,
making volume of Hydrogen smaller and making
cavity stronger so the walls do not have to be as
thick as without ceramics.
• RF power can be fed using loop between two
rings.
• Cavities can be put next each other so the
side wall can be made thin
• May be we should do experiment in the MTA,
with solenoid!




 12/09/2008      Muon Collider Design Workshop, Jefferson Lab   7
 Muons, Inc.
               Other Applications
  May be we can use this type of cavity for
Neuffer’s Phase Rotation Canal. This was
Cary Yoshikawa suggestion. The canal needs
many cavities in range from ~300 to 200MHz.
We can use, let say two sizes of Pill Box
Cavity (same size different dielectric!) and
adjust frequency in between using different
iner radius, re-entrant nose cones!




12/09/2008           Muon Collider Design Workshop, Jefferson Lab   8
   Muons, Inc.       Cavities for Neutrino Factory



Schematic of the Neutrino Factory front-end transport system.
Initial drift (56.4 m), the varying frequency buncher (31.5m),
The phase-energy (-E) rotator (36m) , a cooling section.
(A 75m cooling length may be optimal.)
         Parameter        Drift      Buncher            Rotator               Cooler
 Length (m)               56.4          31.5               36                  75
 Focusing (T)              2               2                2             2.5 (ASOL)
 Rf frequency (MHz)                 360 to 240 240 to 202                     201.25
 Rf gradient (MV/m)                    0 to 15             15                  16
 Total rf voltage (MV)                   126              360                  800
  12/09/2008                   Muon Collider Design Workshop, Jefferson Lab            9
Muons, Inc.
              PAC09 Paper




06/11/2009          LEMCW09   10
   Muons, Inc.
                              Did Not Get
                 FIRM NAME:                         RESEARCH INSTITUTION:
                               Muons, Inc.              Fermi National Accelerator Laboratory
   SBIR          ADDRESS:                           ADDRESS:
                                                            Milorad Popovic, subgrant PI
                            552 N. Batavia Ave.
                             Batavia, IL 60510




But Main Issues did not go away

Loss tangent tan d = 1/Qdielectric-1/Qair
Loss tangents of specially formulated alumina with TiO 2 have been reported to be close
to sapphire at 1e-5 . So it is easy to see that today’s ceramics may be used in this novel
idea without suffering a great deal in cavity Q at low frequencies.
 The other problem with ceramics in vacuum with beams is that of surface charging of
the ceramic. And again, much work has been done in coatings, from Chromium Oxide
to TiN to, more recently, ion implantation
Air gap between the dielectric and metal plates will be one of the issues that must be
tested experimentally

   06/11/2009                                     LEMCW09                                       11
Muons, Inc.
              ~40k$ Program




06/04/2009          MCTF Meeting   12
06/04/2009   MCTF Meeting   13
06/04/2009   MCTF Meeting   14
                            t(ns)    E(MV/m) ConvInsu
                                    1 104.27 23.366
                                  501 30.01801   4.6643
                                 1001 26.13199 3.898269
                                 1501 24.09519 3.509672
                                 2001 22.74676 3.257625
                                 2501 21.7529 3.074633
                                 3001 20.97312 2.932763
                                 3501 20.33563 2.817927
                                 4001 19.79908 2.722089
                                 4501 19.33756 2.64026
                                 5001 18.93382 2.569146
                                 5501 18.57586 2.506466
                                 6001 18.25497 2.45058
                                 6501 17.96468 2.400269
                                 7001 17.70002 2.354609
                                 7501 17.45714 2.312882
                                 8001 17.23295 2.274518
                                 8501 17.02498 2.23906
                                 9001 16.83119 2.206136
                                 9501 16.64992 2.175437
                                10001 16.47975 2.146709




06/04/2009   MCTF Meeting                      15
  Try to Establish Modeling Capability Locally
          (E-Cool people, Lionel Prost)




06/04/2009           LEMCW09                 16
             SuperFish




06/11/2009      LEMCW09   17
     Muons, Inc.
                   What is Next, 5-Years Plan
  The projected funding for the 5-year program proposed here..
…We will also accomplish sufficient hardware R&D (RF, magnets,
and cooling section prototyping) to guide, and give confidence in,
our simulation studies.

In order to produce a practical helical cooling channel, several technical issues need to be addressed, including:
magnetic matching sections for downstream and upstream of the HCC a complete set of functional and
interface specifications covering field quality and tunability, the interface with rf structures, and heat load limits
(requiring knowledge of the power lead requirements)

To prepare the way for an HCC test section we would:
   Develop, with accelerator designers, functional specifications for the magnet systems of a helical cooling
channel, including magnet apertures to accommodate the required rf systems, section lengths, helical periods,
field components, field quality, alignment tolerances, and cryogenic and power requirements. The specification
will also consider the needs of any required matching sections.
   Perform conceptual design studies of helical solenoids that meet our specifications, including a joint rf and
magnet study to decide how to incorporate rf into the helical solenoid bore, corrector coils, matching sections,
etc.


    12/09/2008                     Muon Collider Design Workshop, Jefferson Lab                                   18
  Muons, Inc.
                (near)FUTURE

oRF Workshop-This Summer
I hope, DC results with existing dielectric
oNuFact09-This Summer
I hope, RF(low power) results with low
loss dielectric




 12/09/2008        Muon Collider Design Workshop, Jefferson Lab   19
 Muons, Inc.

                   Test Cavity




12/09/2008     Muon Collider Design Workshop, Jefferson Lab   20

								
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