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					Simulation of the 8 GeV beam extraction from
   the Recycler Ring using bent crystal and
 application of crystals for X-Ray accelerator
               Fermi National Accelerator Laboratory
                    Accelerator Physics Center
                PARTI Summer Internship Program
ALEXEI SYTOV
Belarusian State University,
Research Institute for
Nuclear Problems

Supervisor in Belarus                      Supervisors:
VICTOR TIKHOMIROV                          NIKOLAI MOKHOV,
                                           YOUNG-MIN SHIN
                                                         1
  Different effects in crystal




Straight crystal      Bent crystal




                                     2
   Beam extraction from the Recycler Ring*

                                                    *V. Shiltsev, FNAL,
                                                 No. DE-AC02-07CH11359;
                                                   A.I. Drozhdin, FNAL,
                                                 No. DE-AC02-07CH11359.



Crystal and beam parameters:              Extraction efficiency is
 Pc = 8.88889GeV                          defined like the ratio
 Crystal length = 1mm
 R = 2m
                                          between the number of
 Bending angle = -0.5mrad                 particles successfully
 Crystal thickness = 1mm                  passed the septum-magnet
 Crystal transverse coordinate            and get to the beam Dump
 Xcr = -12.7383mm
                                          and all the particles.
 Crystal ideal alignment θcr = 0.86mrad                            3
                          Impact parameter distributions
                           With scattering in crystal                         Without scattering in crystal
                             Only                                                Only
        1/N dN/dX, mm-1




                                                            1/N dN/dX, mm-1
                           STRUCT*                                             STRUCT*
                           STRUCT+                                             STRUCT+
                            my code                                             my code


At septum-
  magnet
 entrance
                                                    X, mm                                                 X, mm
                             Only                                                Only



                                                            1/N dN/dX, mm-1
        1/N dN/dX, mm-1




                           STRUCT*                                             STRUCT*
                           STRUCT+                                             STRUCT+
                            my code                                             my code

 At beam
  Dump


                                                    X, mm                                                X, mm
                                  *A.I. Drozhdin, FNAL, No. DE-AC02-07CH11359.                                4
                                  Phase space
                  At septum-magnet entrance               At beam Dump
       θx, mrad




                                               θx, mrad
STRUCT+
 my code
       θx, mrad




                                               θx, mrad
  Only
STRUCT*
       θx, mrad




                                               θx, mrad

 Both
pictures


                                       X, mm                             X, mm
                                                                                 5
                       *A.I. Drozhdin, FNAL, No. DE-AC02-07CH11359.
       Particle loss vs crystal alignment
Channeling critical angle ~ 71μrad    R.m.s. angle of scattering at crystal
Volume reflection angle ~ 142μrad     (like amorphous target) > 160μrad

Monte Carlo error~5%          count




    Channeling
                                                     Volume
                                                    reflection
 Crystal with cut

                                                               θcr, mrad
                                                                              6
                        A technique to improve crystal channeling
                         efficiency of charged particles till 99%*
                                                       Crystal
                                 Beam            cut                                         z
                                              0 z1     z2        z3
                                                                                      zc
channeling efficiency




                                                Crystals with cut                               Crystal with cut
                                                 (different cut                               (best cut parameters)
                                                  parameters)



                        Crystal without cut
                                                                            Crystal without cut

                                                            θr.m.s., μrad                                 θr.m.s., μrad
            *V.V.Tikhomirov. JINST, 2 P08006, 2007.                                                              7
                          X-Ray accelerator*

   Particle motion in the channeling
   regime
   Need 40keV high peak power X-Rays
(provided by FELs for ex. LCLS in SLAC)
   Gradients>10GeV/cm
   Muons preferred (μ+ rad. length 109 cm)
*Tajima, Cavenago, Phys. Rev. Lett. 59 (1987)

    z-component of electric field               y-component of magnetic field

   Ez, V/cm
                                            Hy, V/cm




                                   x, cm                                  x, cm
         z, cm
                                                       z, cm                      8
                             First shot of muon acceleration
                   Energy vs longitudinal coordinate                 Energy vs longitudinal coordinate
    E, GeV




                                                            E, GeV
                                                    z, cm                                           z, cm
                       Final energy distribution                            Particle trajectories



                                                            x, Å
1/N dN/dE, GeV-1




                                                                                                     z, cm




                                                                                                     9
                                                   E, GeV
              My mission at Fermilab
To adapt my simulation code for 8 GeV protons motion in crystal and
to combine it with STRUCT.
To simulate the experiment of beam extraction from the Recycler
Ring.
To modify my code of particle motion in crystal for simulation of
X-Ray accelerator.
To simulate the X-Ray accelerator with application of specific electric
fields configuration in crystal provided by X-Rays.

                      In perspective:
To understand and simulate the electric fields configuration in crystals
depending on different parameters.
To consider the possibility of application nanotubes for the channeling
regime for both beam extraction and X-Ray accelerator cases.
Try to apply the idea of the cut increasing the channeling efficiency
till 99,9% proposed by my supervisor in Belarus V. Tikhomirov.
New: To apply the idea of radiation cooling for accelerating muon
beam in crystal.                                                    10
Thank you for attention!




                           11
                          Impact parameter and angle distributions
                           Initial angle distribution                                Impact parameter distribution




                                                                   1/N dN/dX, mm-1
     1/N dN/dθx, mrad-1




                                                        θx, mrad                                                X, mm




                                                                   1/N dN/dX, mm-1
1/N dN/dθx, mrad-1




                                                 1st crystal                                                 1st crystal
                                                  entrance                                                    entrance
                                                 2nd crystal                                                 2nd crystal
                                                  entrance                                                    entrance




                                                        θx, mrad                                                X, mm 12
       Multiple Volume Reflection (MVR)*



                                   Axes form
                                 many inclined
                                reflecting planes


    Z
      Θx Θy
                                    *V. Tikhomirov,
Y                                 PLB 655 (2007) 217;
                                 V. Guidi, A. Mazzolari
                                  and V. Tikhomirov,
                                 JAP 107 (2010) 114908
                                                 13
              X
First MVROC observation                   MVR of
 W. Scandale et al, PLB 682(2009)274   negative pions




 MVROC indeed increases reflection angle 5 times

				
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posted:12/2/2012
language:English
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