High Brightness Photo Injectors for Brilliant Light Sources

High Energy Density Physics

et al. 2019

Self Cite

To understand astrophysical magnetic-field amplification, we conducted a feasibility study for a laboratory experiment of a nonresonant streaming instability at the Photo Injector Test Facility at DESY, Zeuthen site (PITZ). This non-resonant streaming instability, also known as Bell's instability, is generally regarded as a candidate for the amplification of interstellar magnetic field in the upstream region of supernova-remnant shocks, which is crucial for the efficiency of diffusive shock acceleration. In the beam-plasma system composed of a radio-frequency electron gun and a gas-discharge plasma cell, the goal of our experiment is to demonstrate the development of the non-resonant streaming instability and to find its saturation level in the laboratory environment. Since we find that the electron beam will be significantly decelerated on account of an electrostatic streaming instability, which will decrease the growth rate of desired non-resonant streaming instability, we discuss possible ways to suppress the electrostatic streaming instability by considering the characteristics of a field-emission-based quasi continuous-wave electron beam.

Section: Overview Of the Photo Injector Test Facility At Desy-zeuthenmentioning

confidence: 99%

Preliminary study for the laboratory experiment of cosmic-rays driven magnetic field amplification

Jao

Vafin

High Energy Density Physics

et al. 2019

Self Cite

“…The spatial and temporal shapes of this laser are both Gaussian distribution. While in order to reduce the nonlinear space charge effect on beam emittance, the laser pulse should have a uniform distribution with hard edges in space and time [24][25][26][27]. Therefore, a spatiotemporal reshaping is required.…”

Section: Drive Laser Systemmentioning

confidence: 99%

Commissioning the photoinjector of a gamma-ray light source

Phys. Rev. Accel. Beams

Liu

Tian

et al. 2019

“…We will not go into further details on the PITZ gun and its operation parameters. For a thorough description, the interested reader is referred to [1][2][3].…”

Section: The Pitz Photoinjectormentioning

confidence: 99%

“…RF photoinjectors can provide highly charged electron beams with very low transverse emittance [1][2][3][4][5][6][7][8]. This is a crucial property, in particular, for coherent light sources since the radiated light intensity tends to grow near-quadratically with decreasing beam emittance [9].…”

Section: Introductionmentioning

confidence: 99%

“…In the following, we will introduce a simulation approach dealing with these beam dynamics and particle emission issues for RF photoinjectors operated in the source limited as well as in the space charge limited emission regime. We will refer primarily to the PITZ photoinjector of DESY [1][2][3]. For this injector, a large database of measurements exists which can be used to assess the validity of our simulations.…”

Section: Introductionmentioning

confidence: 99%

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Modeling and simulation of RF photoinjectors for coherent light sources

Nuclear Instruments and Methods in Physics Research Section A:

Krasilnikov

Stephan

et al. 2018

We propose a three-dimensional fully electromagnetic numerical approach for the simulation of RF photoinjectors for coherent light sources. The basic idea consists in incorporating a selfconsistent photoemission model within a particle tracking code. The generation of electron beams in the injector is determined by the quantum efficiency (QE) of the cathode, the intensity profile of the driving laser as well as by the accelerating field and magnetic focusing conditions in the gun. The total charge emitted during an emission cycle can be limited by the space charge field at the cathode. Furthermore, the time and space dependent electromagnetic field at the cathode may induce a transient modulation of the QE due to surface barrier reduction of the emitting layer. In our modeling approach, all these effects are taken into account. The beam particles are generated dynamically according to the local QE of the cathode and the time dependent laser intensity profile. For the beam dynamics, a tracking code based on the Lienard-Wiechert retarded field formalism is employed. This code provides the single particle trajectories as well as the transient space charge field distribution at the cathode. As an application, the PITZ injector is considered. Extensive electron bunch emission simulations are carried out for different operation conditions of the injector, in the source limited as well as in the space charge limited emission regime. In both cases, fairly good agreement between measurements and simulations is obtained.