GKICK DISPERSION implementation in LIAR Preliminary DFS results for Curved LINAC

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GKICK DISPERSION implementation in LIAR
Preliminary DFS results for Curved LINAC
Francois Ostiguy Kirti Ranjan
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• Francois has put earth-curvature related
  important parameters in LIAR
• Initial dispersion (hx , hx , hy , hy ) and
  its propagation through LINAC
• GKICK arbitrary dispersion-free geometrical
  angle (change in reference coordinates of the
  beam)
• some issue about the geometrical transformation
  - further checks are needed
• Option of angle in VKICK presently its fixed
  dispersion less kick. Since its alternative
  is present so its not of high pripority issue.
• While doing that, many features of the LIAR
  also become evident

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TESTING GKICK

• Lattice ILC BCD Like, but with GKICK placed
  together with the YCOR and given same kick angle
• 1 Q / 32 Cavities (1 Q/ 4 CM)
• QUAD package (Quad, BPM, YCOR, XCOR) is at the
  centre of the CM
• YCOR and GKICK are placed at the CMs w/ Quad
  Package
• GKICK provides the reference trajectory ( to
  incorporate curvature) so that all the beam line
  elements get placed on that reference.
• YCOR launches the beam on to that reference
  trajectory
• Three cases are simulated
• A.) GKICK is OFF , but YCOR is ON gt Terrible
  case
• B.) GKICK is ON , but YCOR is OFF gt Terrible
  case
• C.) GKICK is ON and YCOR is ON gt Nominal case

Initial conditions y0 , yp0, etay 0, etayp 0
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20 FODO cells
Y-orbit(m) vs. BPM index
Y-emit(m) vs. BPM index
Y-dispersion(m) vs. BPM index
Yp-dispersion vs. BPM index
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Full ILC LINAC
Initial conditions y0 , yp0, etay 0, etayp 0
Y-orbit(m) vs. BPM index
Y-emit(m) vs. BPM index
Y-dispersion(m) vs. BPM index
Yp-dispersion vs. BPM index
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DFS in Curved LINAC
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Length (m) 10417.20 Begin
Energy (GeV) 15.00 Final Energy (GeV) 251.80

Misalignment Values BPM Resolution m
1.0e-6 BPM Offsets wrt
Girder m 200e-6
"front-end"BPM Offsets wrt Quads m 30e-6
Quad Offsets wrt Girder m
300e-6 Quad Fractional Strength Errors
0.0 Quad Tilt errors rad
300e-6 Cavity Offsets wrt CM m
300e-6 Cavity Pitches wrt CM
rad 300e-6 CM Offsets wrt
Survey Line m 200e-6 CM Pitches
wrt Survey Line rad 20e-06 All
the errors on 1st 25 CM (7 BPMs) are RESET to ZERO
Kloss (V/C/m) 1.48E13 Charge (Npart)
2.0E10 Average phase - 5.1 degrees
N_quad 240 N_struc 7680 N_bpms
241 N_Xcor 240 N_Ycor
241 N_gkicks 240 (Curved)


0 (straight)
ILC wakes ON
DFS Number of DFS regions
18 Overlap in DFS regions
0.5 Number iterations
DFS per region 2 DFS Max relative
energy change 0.2 DFS Max absolute
energy change GeV 18 DFS Endpoint for
Region 1 EChange (Q) 4
Flat Steering Number of steering regions
7 Overlap in steering regions
0.1 Number iterations steering per region
3 Number "front-end" BPMs 7
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Lattice ILC BCD Like, but with GKICK placed
together with the YCOR and given same kick angle
( YCOR and GKICK are placed at the CMs w/ Quad
Package )
Initial conditions y0 , yp0, etay 0, etayp 0
Y-orbit( m) vs. BPM index
STRAIGHT
NO errors introduced
CURVED
Y-projected normalized emittance (nm) vs. BPM
index
NO errors introduced
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DFS Y-projected normalized emittance (nm) vs.
BPM index
No DFS applied
FLAT Y-projected normalized emittance (nm) vs.
BPM index
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MEAN Y-projected normalized emittance (nm) for
20 seeds vs. BPM index
FLAT STEERING
DFS
CURVED
CURVED
STRAIGHT
STRAIGHT
No DFS applied
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Different Initial Conditions
Three cases are simulated A.) y0 , yp0, hy
0, hyp 0 B.) y 18.146E-6m , yp 2.4347E-6,
hy 0, hyp 0 C.) y 18.146E-6m, yp
2.4347E-6, hy 0.96510E-3m, hyp
-15.3113E-6
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20 FODO cells
Y-orbit(m) vs. BPM index
Y-emit(m) vs. BPM index
Case B Case C coincides
Y-dispersion(m) vs. BPM index
Yp-dispersion vs. BPM index
Case A Case B coincides
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Full ILC LINAC
Y-orbit(m) vs. BPM index
Y-emit(m) vs. BPM index
Case B Case C coincides
Y-dispersion(m) vs. BPM index
Yp-dispersion vs. BPM index
Case A Case B coincides