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Author

J.G. Karssenberg

Bio: J.G. Karssenberg is an academic researcher from University of Twente. The author has contributed to research in topics: Optical cavity & Undulator. The author has an hindex of 3, co-authored 4 publications receiving 45 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, a paraxial optical propagation code that can be combined with various existing models of gain media, for example, Genesis 1.3 for FELs, is presented.
Abstract: Modeling free-electron laser (FEL) oscillators requires calculation of both the light-beam interaction within the undulator and the light propagation outside the undulator. We have developed a paraxial optical propagation code that can be combined with various existing models of gain media, for example, Genesis 1.3 for FELs, to model oscillators with full paraxial wave propagation within the resonator. A flexible scripting interface is used both to describe the optical resonator and to control the codes for propagation and amplification. To illustrate its capabilities, we numerically investigate two significantly different FEL oscillators: the free-electron laser for infrared experiments (FELIX) system and the vacuum-ultraviolet (VUV)-FEL oscillator of the proposed high-gain fourth generation light source. For the FELIX system, we find that diffraction losses are a considerable part of the single-pass cavity loss (at a wavelength of 40 µm). We also demonstrate that a resonator with hole coupling may be a viable alternative to a standard resonator with transmissive optics for the high gain VUV-FEL oscillator.

26 citations

Proceedings Article
28 Aug 2006
TL;DR: A paraxial Optical Propagation Code (OPC) based on the Spectral Method and Fresnel Diffraction Integral is presented, which in combination with Genesis 1.3 can be used to perform either steady-state or time-dependent FEL oscillator simulations.
Abstract: Modeling free-electron laser (FEL) oscillators requires calculation of both the light-beam interaction within the undulator and the propagation of the light outside the undulator. We present a paraxial Optical Propagation Code (OPC) based on the Spectral Method and Fresnel Diffraction Integral, which in combination with Genesis 1.3 can be used to perform either steady-state or time-dependent FEL oscillator simulations. A flexible scripting interface is used both to describe the optical resonator and to control the codes for propagation and amplification. OPC enables modeling of complex resonator designs that may include hard-edge elements (apertures) or hole-coupled mirrors with arbitrary shapes. Some capabilities of OPC are illustrated using the FELIX system as an example.

13 citations

Proceedings Article
28 Aug 2006
TL;DR: The Conceptual Design Report for the 4th Generation Light Source (4GLS) at Daresbury Laboratory in the UK was published in Spring 2006 as discussed by the authors, which includes a low-Q cavity (also called a regenerative amplifier) FEL to generate variably-polarised, temporally coherent radiation in the photon energy range 3-10eV.
Abstract: The Conceptual Design Report for the 4th Generation Light Source (4GLS) at Daresbury Laboratory in the UK was published in Spring 2006. The proposal includes a low-Q cavity (also called a regenerative amplifier) FEL to generate variably-polarised, temporally-coherent radiation in the photon energy range 3-10eV. A new simulation code has been developed that incorporates the 3D FEL code Genesis 1.3 and which simulates in 3D the optical components and radiation propagation within the non-amplifying sections of an optical cavity*. This code is used to estimate the optimum low-Q cavity design and characterise the output from the 4GLS VUV-FEL.

6 citations

Proceedings Article
01 Jan 2007
TL;DR: An extension to the OPC code is presented that allows it to model mirror distorions of the high average power vacuum ultra violet FEL oscillator of the 4th generation light source to indicate that the high gain oscillator is quite resilient to thermal mirror deformation and operation well into the kW range of average power can be expected.
Abstract: Several high power free-electron lasers (FELs) are currently under design, operational or being upgraded. One central issue is the beam outcoupling and mirror deformation due to absorbed power. Here we present an extension to the OPC code that allows it to model mirror distorions. We use this code to model the high average power vacuum ultra violet FEL oscillator of the 4th generation light source. Both Genesis 1.3 and Medusa are used to calculate the gain provided by the undulator. Our findings indicate that the high gain oscillator is quite resilient to thermal mirror deformation and operation well into the kW range of average power can be expected.

2 citations


Cited by
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01 Jan 2006

49 citations

Journal ArticleDOI
TL;DR: In this paper, an analytic model of an APPLE-II undulator is presented to model arbitrary elliptical polarizations, which is used to treat general elliptical polarity.
Abstract: Free-electron lasers (FELs) have been built ranging in wavelength from long-wavelength oscillators using partial wave guiding through ultraviolet through hard x-ray that are either seeded or start from noise. In addition, FELs that produce different polarizations of the output radiation ranging from linear through elliptic to circular polarization are currently under study. In this paper, we develop a three-dimensional, time-dependent formulation that is capable of modeling this large variety of FEL configurations including different polarizations. We employ a modal expansion for the optical field, i.e., a Gaussian expansion with variable polarization for free-space propagation. This formulation uses the full Newton–Lorentz force equations to track the particles through the optical and magnetostatic fields. As a result, arbitrary three-dimensional representations for different undulator configurations are implemented, including planar, helical, and elliptical undulators. In particular, we present an analytic model of an APPLE-II undulator to treat arbitrary elliptical polarizations, which is used to treat general elliptical polarizations. To model oscillator configurations, and allow propagation of the optical field outside the undulator and interact with optical elements, we link the FEL simulation with the optical propagation code OPC. We present simulations using the APPLE-II undulator model to produce elliptically polarized output radiation, and present a detailed comparison with recent experiments using a tapered undulator configuration at the Linac Coherent Light Source. Validation of the nonlinear formation is also shown by comparison with experimental results obtained in the Sorgente Pulsata Auto-amplificata di Radiazione Coerente SASE FEL experiment at ENEA Frascati, a seeded tapered amplifier experiment at Brookhaven National Laboratory, and the 10 kW upgrade oscillator experiment at the Thomas Jefferson National Accelerator Facility.

32 citations

Journal ArticleDOI
TL;DR: In this paper, an analytic model of an APPLE-II undulator is presented to model arbitrary elliptical polarizations of free-electron laser output radiation, including planar, helical, and elliptical undulators.
Abstract: Free-electron lasers (FELs) have been built ranging in wavelength from long-wavelength oscillators using partial wave guiding through ultraviolet through hard x-ray that are either seeded or start from noise (SASE). In addition, FELs that produce different polarizations of the output radiation ranging from linear through elliptic to circular polarization are currently under study. In this paper, we develop a three-dimensional, time-dependent formulation that is capable of modeling this large variety of FEL configurations including different polarizations. We employ a modal expansion for the optical field, i.e., a Gaussian expansion with variable polarization for free-space propagation. This formulation uses the full Newton-Lorentz force equations to track the particles through the optical and magnetostatic fields. As a result, arbitrary three-dimensional representations for different undulator configurations are implemented, including planar, helical, and elliptical undulators. In particular, we present an analytic model of an APPLE-II undulator to treat arbitrary elliptical polarizations. To model oscillator configurations, and allow propagation of the optical field outside the undulator and interact with optical elements, we link the FEL simulation with the optical propagation code OPC. We present simulations using the APPLE-II undulator model to produce elliptically polarized output radiation, and present a detailed comparison with recent experiments using a tapered undulator configuration at the Linac Coherent Light Source. Validation of the nonlinear formation is also shown by comparison with experimental results obtained in the SPARC SASE FEL experiment at ENEA Frascati, a seeded tapered amplifier experiment at Brookhaven National Laboratory, and the 10-kW Upgrade Oscillator experiment at the Thomas Jefferson National Accelerator Facility.

26 citations

Journal ArticleDOI
TL;DR: In this article, the main processes for XFELO design, and parameter optimization of the undulator, X-ray cavity, and electron beam are described, which can be combined with the GENESIS and OPC codes for the numerical simulations of the X FELO.
Abstract: The Shanghai Coherent Light Facility (SCLF) is a quasi-continuous wave hard X-ray free electron laser facility, which is currently under construction. Due to the high repetition rate and high-quality electron beams, it is straightforward to consider X-ray free electron laser oscillator (XFELO) operation for the SCLF. In this paper, the main processes for XFELO design, and parameter optimization of the undulator, X-ray cavity, and electron beam are described. A three-dimensional X-ray crystal Bragg diffraction code, named BRIGHT, was introduced for the first time, which can be combined with the GENESIS and OPC codes for the numerical simulations of the XFELO. The performance of the XFELO of the SCLF is investigated and optimized by theoretical analysis and numerical simulation.

21 citations