250 MeV Injector for the PSI FEL/LEG Project

The purpose of this page is to give i) a constant update of the current state of the affair and ii) all the information in order to build the Injector.

Simulation code used

Simulation software: IMPACT-T, written by Ji Qiang (LBNL), modified by Andreas Adelmann and Christof Kraus (PSI)
Visualization: H5PartROOT
Setup: based on FEL-PM84-005-01 (Marco Pedrozzi)

IMPACT-T Model Details

The complete IMPACT-T model of the 250 MeV injector is broken into two parts: the gun and everything else.
The gun simulation is run separately to generate a .hf5 file, which is used as input to the rest of the injector simulation.

Results

Full Injector

Plots of RMS beam parameters and the longitudinal electric and magnetic field seen by the beam bunch center.

standard plot:
RMS Size
Emittance
Magnetic Field
standard plot:
Kinetic Energy
RMS Energy Spread
Electric Field
standard plot:
RMS Beam Length
Current
IMPACT-T results
(ROOT macro)

Field data: (text file)
Beam RMS data: (text file)

pdf

pdf

pdf

Plots of the x and y slice emittance using various percentages of the beam.

standard plot:
Normalized x Emittance
standard plot:
Normalized y Emittance
IMPACT-T results
(ROOT macro)

Slice data: (text file)

pdf

pdf

Comparison to BET Model

Comparison of RMS beam parameters and longitudinal electric and magnetic field from IMPACT-T and BET for injector model up to the beam buncher.

standard plot:
Emittance
RMS Size
standard plot:
Magnetic Field
standard plot:
Electric Field
standard plot:
RMS Beam Length
Current
Energy
RMS Energy Spread
IMPACT-T results
compared to BET
(ROOT macro)

BET RMS data:
(text file)

pdf

pdf

pdf

pdf

Beam Buncher (chicane)

The final section of the injector is a four dipole beam buncher (chicane). Below are results isolating just this section of the machine. (Note that coherent synchrotron radiation (CSR) effects are not yet included in this calculation.)

Beam phase space before and after the buncher.

standard plot:
x Phase Space (x-pz)
standard plot:
y Phase Space (y-py)
standard plot:
z Phase Space (z-pz)
Before chicane
pdf

pdf

pdf
After chicane
pdf

pdf

pdf

Beam longitudinal profile before and after the buncher.

Before Buncher

standard plot:
Longitudinal Beam Profile
text file
After Buncher

standard plot:
Longitudinal Beam Profile
text file

pdf

pdf

Report

Will come up soon! Last update:

Andreas.Adelmann@psi.ch