ICAR:U of C Activities

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ICARU of C Activities

• Kwang-Je Kim
• September 3, 2003

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U of C KJK

• Part A Ionization cooling theory
• K.-J. Kim and C.-x. Wang (ANL)
• Part. B Smith-Purcell Laboratory
• O. Kapp, A. Crewe,Y.-e Sun (student),Yau Wah
• Part C Graduate Physics Course Accelerator
  Physics and Technologies for Linear Colliders
• Kwang-Je Kim
• Part D Participation to flat beam generation
  experiment at FNPL
• Y.-e Sun (student)

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Part A Ionization Cooling Theory

• Theoretical effort by K.-J. Kim and C.-x. Wang
• A comprehensive linear theory for ionization
  cooling taking into account
• Transport in cooling lattice (Hamiltonian)
• Dissipation and fluctuation in absorbers
• Emittance exchange via dispersion and wedge
  absorbers
• Beam angular momentum
• Moments expressed in terms of five invariant
  emittances

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Emittance Exchange
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Equation of Motion

• Phase space vector

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Hamiltonian of the Focusing System

• Lab frame

solenoid
quadrupole
r.f.
dipole

• Rotating frame

,
,
,
,
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Emittance Evolution Near Equilibrium Parametrized
by Five Invarients
Guidance for developing cooling channel with
emittance-exchange
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Further Theoretical Topics

• Recursive evaluation of beam transport lattice
  consisting of extended elements ( such as
  solenoids used in ionization cooling channels)
• Rigorous treatment of magnetic field expansion
  for curved reference orbitsProvided
  bench-marking of ICOOL
• Extensive Publications including two PRLs

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Selected papers on related developments

• C.-x. Wang and K.-J. Kim, COOL03, NIM A (2003)
• Beam envelope theory of ionization cooling
• C.-x. Wang and K.-J. Kim, PRL 88(18) 184801
  (2002)
• Linear Theory of Ionization Cooling in 6D
  Phase Space
• C.-x. Wang and K.-J. Kim, NIM A503 401 (2001)
• Linear theory of transverse and longitudinal
  cooling in a quad. channel
• C.-x. Wang and K.-J. Kim, PRE 63 056502 (2001)
• Recursive solution for beam dynamics of
  periodic focusing channels
• C.-x. Wang, NIM A503 409 (2001)
• Dispersions in a bent-solenoid channel
• C.-x. Wang and L.C. Teng, PAC01(2001)
• Magnetic Field Expansion in a Bent-Solenoid
  Channel
• K.-J. Kim and C.-x. Wang, NIM A472 561(2001)
• Progress in the Linear Beam Dynamics Study of
  Ionization Cooling Channel
• K.-J. Kim and C.-x. Wang, PRL 85(4) 760 (2000)
• Formulas for Transverse Ionization Cooling in
  Solenoidal Channels

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Part B Smith-Purcell Laboratory

• An electron microscopebased Smith-Purcell
  generator for a compact far IR source
• Retrofitted the sample chamber of a Cambridge
  S-200 scanning electron microscope with a grating
  
• Radiation transported via a polyethyene window to
  a bolometer
• Observed spontaneous Smith-Purcell radiation
  after carefully eliminating the effects due to
  blackbody radiation. (c.f., Dartmouth claim on
  high-gain behavior)
• We are evaluating
• Several options for electron sources (heated
  tungsten tip, Lab6, Thermionic field emission)
• Electron beam recovery system
• Preparing proposals for other funding agencies

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Part C A Graduate Physics Course Physics and
Technologies for Linear Colliders

• Physics 575 during winter 2002
• Lectures by experts in the field
• S. Holmes, K.J. Kim, T. Raubenheimer, J.
  Rosenzweig, L. Emery, J. Wang, L. Lilje, F.
  Zimmermann, V. Shiltsev, W. Gai
• Lecture notes in the course web page
• http//hep.uchicago.edu/kwangje/phy575.html

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Part D Flat Beam Generation

• A novel beam manipulation technique proposed by
  Y.Derbenev
• A flat beam ratio (FBR) of 50 has been achieved
  at FNPL ( FNAL-NIU Photocathode Laboratory).
• Yin-e Sun is investigating effects reducing FBR
• Energy spread, space-charge effects, breaking of
  cylindrical symmetry
• To improve the flat beam ratio to gt100.

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Schematic rendition of the layout at Fermilabfor
flat beam experiment
A cos kz A sin (kzp/2) flat beam
vortex beam
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FermiLab/NICADD PhotoInjector
Layout taken from PAC01 paper of D. Edwards etc.
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Flat electron beam profile at 9.6m from the
cathode (XL6) and horizontal and vertical
beamlets used for emittance measurements
downstream at XL7 and XL8. The transverse
emittance ratio is about 41 in the example shown
here.








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Major Budget Items

• Part A Fund transfer to ANL to support C.-x.
  Wang
• Part B Partial (40-50) salary support for O.
  Kapp, equipments and supplies, technician charges
• Part CTravel support for lecturers
• Part DStipend for a graduate student
• Domestic and international travels