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Pre- Linac simulations in G4beamline Kevin B. Beard Muons,Inc . & Alex Bogacz & Yves Roblin Jefferson Lab. LEMC2009 workshop 8-12 Jun 2009. pre-accelerator linac - not very relativistic. Morteza Aslaninejad , Cristian Bontoiu J ü rgen Pozimski , Ajit Kurup - PowerPoint PPT Presentation
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Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
Pre-Linac simulations in G4beamline
Kevin B. BeardMuons,Inc.
&Alex Bogacz & Yves Roblin
Jefferson Lab
LEMC2009 workshop 8-12 Jun 2009
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
0.6 GeV/pass 3.6 GeV
0.9 GeV244 MeV
146 m
79 m
2 GeV/pass
264 m
12.6 GeV
Etotal: 244 MeV → 900 MeV
P: 220 MeV/c → 894 MeV/c
KE: 138 MeV → 794 MeV
M = 105.658 MeV
pre-accelerator linac - not very relativistic
Morteza Aslaninejad, Cristian Bontoiu
Jürgen Pozimski, Ajit Kurup
Imperial College, London, UK
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
30-30 S [cm] View at the lattice beginning
15
0-1
50
dP
/P *
10
00
,
Longitudinal phase-space tracking
IDS rmsA = (2.5)2
normalized emittance: x/y mmra
d
4.8 30
longitudinal emittance: l
lp z/mc)
momentum spread: p/p
bunch length: z
mm
mm
27
0.07
176
150
0.17
442
ELEGANT (Fieldmap) OptiM (Matrix)
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
Solenoid Linac (244 -909 MeV)
6 short cryos
15 MV/m
8 medium cryos
17 MV/m
11 long cryos
17 MV/m
1.1 Tesla solenoid 1.4 Tesla solenoid 2.4 Tesla solenoid
Transverse acceptance (normalized): (2.5)2= 30 mm rad
Longitudinal acceptance: (2.5)2 pz/mc= 150 mm
1460
Sat Dec 13 22:36:02 2008 OptiM - MAIN: - D:\IDS\PreLinac\Sol\Linac_sol.opt
120
50
BE
TA
_X&
Y[m
]
DIS
P_X
&Y
[m]
BETA_X BETA_Y DISP_X DISP_Y
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
Why another simulation?
• OptiM – fast, interactive, design, matrix based 0th order design tool, symplectic soft edge solenoids, very good at tuning (free)
• GPT – good at tracking ($)
• G4beamline – tracking, Geant4 particle decays & interactions, energy depositions, showers, etc., not so good at tuning (free & open source)
•http://g4beamline.muonsinc.com
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
Solenoid Model (Superfish)
outer coil
inner coil
shield
2e
pc
22 2
edge z 0
-
1 k a= B (s) ds B L
2 8e
pc 0k = B
‘Soft-edge’ Solenoid
21Ls
a
z 0
1B (s) = B tanh
2
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
Two-cell cavity (201 MHz) – COMSOL
Morteza Aslaninejad
Cristian Bontoiu
Jürgen Pozimski
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
Field maps
Ez
single RF cell
Ez
solenoid
Bz
double RF cell
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
LEMC2009 workshop 8-12 Jun 2009
g4beamline 2.08
valve assembly
conductors
counterwoundsolenoid
RF cellVirtual detectors
flux return shield
stainless pipe
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
LEMC2009 workshop 8-12 Jun 2009
upper middle
lower
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011Muons, Inc.
LEMC2009 workshop 8-12 Jun 2009
ΔE ≈ -2qEzo L cos(π/ 2β) cos(φ) β2/(π (1-β2)
L=2λ c=λf z=cβt
+L/2
-L/2
0o≡on crest
Ez(z,t) ≈ qEzo cos(2πf t + φ) cos(π z/L)
ΔE ≈ -2qEzo L cos(π/ 2β) cos(φ) β2/(π (1-β2)
ΔE ≈ ∫ Ez(z,z/cβ) dz
Ti ≈ Ti-1+ (zi - zi-1)/(cβi-1)
Simple Phasing via spreadsheet
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011Muons, Inc.
Linac parameters
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011Muons, Inc.
LEMC2009 workshop 8-12 Jun 2009
phases from spreadsheet
phases partially adjusted
Longitudinal
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
Muons, Inc.
LEMC2009 workshop 8-12 Jun 2009
Comparison of GPT, OptiM, g4beamline
z[cm]
KE[MeV]
KE[MeV]
z[cm]
OptiM
G4beamline w/adj. φ's
G4beamlinew/OptiM's φ's
GPT
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011Muons, Inc.
LEMC2009 workshop 8-12 Jun 2009
Ez
Ez
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
LEMC2009 workshop 8-12 Jun 2009
Sep 14, 2010Muons, Inc.
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011Muons, Inc.
LEMC2009 workshop 8-12 Jun 2009
Pz
t
Synchrotron motion
t
~ 1 synch period
~ oncrest
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011Muons, Inc.
LEMC2009 workshop 8-12 Jun 2009
GPT
G4beamline
z[m]z[m]
y[m]
Transverse motion
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011Muons, Inc.
LEMC2009 workshop 8-12 Jun 2009
G4beamline improvements from this work:
•fieldmap timeOffset fixed•(simple bug fix)
•pillbox autoTune being added•(tune for max,min ΔE or Δt rather than assume Δv=0)
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011
Linac – near term plans
greatly improve RF phasing capability of G4beamline
optical rematch of linac to cooling channel
optimize longitudinal and transverse acceptance
determine energy deposition in components
prepare the transfer line to RLA I
Operated by JSA for the U.S. Department of Energy
Muons, Inc.Winter MAP Mtg, Mar. 2nd, 2011Muons, Inc.
LEMC2009 workshop 8-12 Jun 2009
Sep 14, 2010