Overview of final* concept

1
Overview of final concept
Bunch compressor
45 deg. spectro
cavity
gun
3.9 GHz
3 ILC cryomodules
18
4
57
10
61
user area
injector
transportline
main linac
disp. area
as of last week version
2
ILCTA layout

• Injector
• rf-gun
• TESLA high gradient accelerating cavity
• Bunch compressor,
• Eventually
• 3rd harmonic cavity (f3.9 GHz)
• Dog-leg deflecting mode cavity
• Main linac
• Eventually 3 ILC-type modules
• Initially one module
• Transport line
• Focusing/steering elements,
• Standard diagnostics (screens BPM)
• Area for diagnostics and/or accelerator physics
  experimentrequiring multi-bunches
• Initially transport line will be long (when only
  one ILC module)
• Dispersive area
• Diagnostics (energy energy spread measurement)
• User area
• Free beamline for advanced accelerator and
  diagnostics RD only single bunch mode operation
  possible (low power)

3
Optimization of a short injector (E cathode 40
MV/m, Q3.2 nC)

• Objective minimize emittance at 8 m from
  cathode (assume round beam and do not include
  matching section)
• Free parameters laser spot size, gun phase,
  solenoid fields, E-fieldand location of SCRF
  cavity

parameter value
slaser (mm) 2.04
fgun (deg) 15
B1 (T) 0.150
B2 (T) 0.155
Epeak (MV/m) 30.6
zcav (m) 1.85
4
Optimization of a short injector (E cathode 40
MV/m)
K20.4 MeV
5
Injector
14 m
Bunch compressor
gun
cavity
3.9 GHz TM010
OTR
3.9 GHz TM110
BPM
BPM
BPM ICT
OTR
OTR
OTR
OTR
YaG
YaG/OTR
BPM
BPM
OTR
Slit(s) OTR ICT
Slit(s) OTR/CTR ICT Streak camera port
quadrupole
skew quadrupole
dipole
6
Injector length needed reusing A0 components

• Real-estate neededDistances were provided by B.
  Popper (SMTF injector phase A drawing of Dec.
  21st, 2005)
• Cavity center is 1.85 m from cath. (Astra sim.)
• 3.9 Ghz exit at 1.852.736 4.586 m
• Entrance of module should be at
  4.5866.53711.123 m 11.5 m from cath.
• round-to-flat beam transform 1 meters
• HOM dogleg 1 meter
• SO TOTAL INJECTOR LENGTH is 12.5 m
• Reuses A0 quads -- not sure about steerers

2.736 m
Typical DESY assemblyeverything is
welded(includes 1 ICT, 2 six-ways Xs 1 BPM
chamber)
6.537 m
7
Transport section (straight ahead)
8
Compression Performance (1 nC example)
9
Compression Performance (1 nC example)
Peak current at 1 nC 2 kA!
10
Dogleg and off-axis beamline

• Double bend achromat to offset the beam in an
  off-axis dispersionless beamline
• R56 should be small to avoid influencing the
  bunch length
• Bending angle effective length of dipole
  (curvature radius) still need to be chosen
  right now 22.5 deg, Leff0.3 m (current offset if
  1 m)

11
Diagnostics using the DMC
Beam spot on FDL3 for various scenario Cavity
ON cavity vertically deflecting Eta NOT 0
dispersion leak in the hori-zontal plane.
Cavity OFF Eta0
Cavity on Eta0
Cavity on Eta NOT 0
12
ILC Module post module lattice
Disp. Section
ILC module chain
Spectr.
III
III
IV
dump
Lattice rev. AUG-06-2006
13
Can be used as an AARD facility
45 deg. spectro
Bunch compressor
cavity
cavity
High Energy bunch compressor
gun
3.9 GHz
3 ILC cryomodules
experimental area could have 3 parallel beamline

• Example with 1st module at 18 m
• Two stage bunch compression should allow peak
  current of 5 kA
• High energy bunch compressor followed by cavity
  operated a zero-crossing to remove correlated
  energy spread
• In principle this layout has comparable
  performance to state-of-art linac-driver for
  short wavelength SASE free-electron lasers

14
Summary on-going work

• Finally all parties agreed on a possible layout
  at ILCTA
• Preliminary look at indicate no show stopper
• Layout fit building,
• Head room for upgrade (e.g. new gun location)
• Immediate work if focused on ILC-type
  applications, and simulation of related
  experiment (e.g. wakefield studies will be
  performed)
• The facility is good-enough to support an
  advanced RD program
• First parasitically to ILC-related studies
• Then dedicated to AARD with addition of new hall