FEL2015 - List of Keywords (resonance)

Paper	Title	Other Keywords	Page
MOP004	Influence of Horizantal Constant Magnetic Field on Harmonic Undulator Radiations and Gain	undulator, radiation, electron, FEL	34
	H. Jeevakhan, P.K. Purohit NITTTR, Bhopal, India G. Mishra Devi Ahilya University, Indore, India
	Harmonic undulators has been analyzed in the presence of constant magnetic field along the direction perpendicular to the main undulator field. Effect of constant magnetic field magnitude on trajectory of electron beam , intensity of radiation and FEL gain at fundamental and third harmonics has been evaluated. Performance of harmonic undulator in the presence horizontal component of earth's magnetic field is the practical realization of the suggested scheme.
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MOP029	PAL XFEL Pulse Modulator System Test Results Using a High Precision CCPS	klystron, controls, power-supply, high-voltage	89
	S.H. Kim, H.-S. Kang, G.H. Kim, I.S. Ko, S.J. Kwon, H.-S. Lee, S.S. Park, Y.J. Park PAL, Pohang, Kyungbuk, Republic of Korea M.-H. Cho POSTECH, Pohang, Kyungbuk, Republic of Korea K.Y. Jang, H.S. Shin POSCO ICT, Gyeonggi-do, Republic of Korea D.S. Kim, S.Y. Lee, M. Seo Dawonsys, Siheung-City, Republic of Korea
	PAL XFEL is supposed to install 51 units of the pulse modulator power supplies for a 10-GeV linear accelerator using S-band (2856 MHz) cavities. The requirements of the modulator stability really become very tight. The stability on beam voltage is required to be less than 50 ppm. In order to obtain the high precision stability from the modulator system, we have newly produced a capacitor charging power supply (CCPS) and obtained the target stability with 10 ppm (STD) accuracy from measuring PFN (Pulse Forming Network). The CCPS generates a maximum output voltage of 50 kV at average current of 2.4 A with 4 units of the CCPS. The modulator peak output capacity is 400 kV, 500 A and 7.5 us at a pulse repetition rate of 60 pps using CCPS, a modified type-E PFN, and a pulse transformer. In this paper, the test results of the modulator system will be described.
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MOP041	Turbo-ICT Pico-Coulomb Calibration to Percent-level Accuracy	impedance, laser, plasma, network	118
	F. Stulle, J.F. Bergoz BERGOZ Instrumentation, Saint Genis Pouilly, France
	We report on the calibration methods implemented for the Turbo-ICT/BCM-RF. They allow to achieve percent-level accuracy for charge and current measurements. Starting from the Turbo-ICT/BCM-RF working principle, we discuss scientific fundaments of calibration and their practical implementation in a test bench. Limits, both principle and practical, are reviewed. Achievable accuracy is estimated.
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MOP066	Electron Bunch Length Measurement using an RF Deflecting Cavity	cavity, electron, simulation, space-charge	188
	S. Park, E.-S. Kim Kyungpook National University, Daegu, Republic of Korea S. Bae, K.H. Jang, Y.U. Jeong, H.W. Kim, J. Mun, N. Vinokurov KAERI, Daejon, Republic of Korea
	Recently, the RF photogun based-ultrafast electron diffraction (UED) system has been developed in KAERI. In the system, the emitted electron bunches are experimentally confirmed to be accelerated up to 3 MeV at 5MW of RF power. And the time duration of the each bunch is initially designed to be less than 50 fs at the sample position. To analyses the performance of the system and to measure exactly the length of the electron bunches, we developed a rectangular type of S-band deflecting cavity working on TM120 mode. The principle of electron deflecting in the cavity, design & mechanical fabrication process and test results will be present in the conference.
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MOP068	First Simulation Results on Free Electron Laser Radiation in Displaced Phase-combined Undulators	undulator, radiation, electron, FEL	196
	N.S. Mirian UVSOR, Okazaki, Japan E. Salehi AUT, Tehran, Iran
	This report deals with self amplified spontaneous emission free electron laser (FEL) amplifier where the FEL emission is obtained from displaced phase combined undulators. Magnetic field of this adjustment methods in three dimensions is presented. The electron dynamics is investigated. The simulation method and results are explained. The radiation properties of the fundamental resonance and third harmonic through the phase combined undulators are compared with the normal undulator with the same undulator deflection parameter
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MOP074	Efficiency Enhancement of a Harmonic Lasing Free-Electron Laser	wiggler, electron, radiation, FEL	209
	N.S. Mirian UVSOR, Okazaki, Japan B. Maraghechi, E. Salehi AUT, Tehran, Iran
	The harmonic lasing free-electron laser amplifier, in which two wigglers is employed in order for the fundamental resonance of the second wiggler to coincide with the third harmonic of the first wiggler to generate ultraviolet radiation, is studied. A set of coupled nonlinear first-order differential equations describing the nonlinear evolution of the system, for a long electron bunch, is solved numerically by CYRUS code. Thermal effects in the form of longitudinal velocity spread are also investigated. The second wiggler field decreases linearly and nonlinearly at the point where the radiation of the third harmonic saturates to enhance the efficiency. The optimum starting point and the slope of the tapering of the amplitude of the wiggler are found by a successive run of the code. It is found that tapering can increase the saturated power of the third harmonic considerably.
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MOP075	Three-dimensional Simulation of a Harmonic Lasing Free-Electron Laser Amplifier	wiggler, radiation, electron, FEL	213
	E. Salehi, B. Maraghechi AUT, Tehran, Iran N.S. Mirian UVSOR, Okazaki, Japan
	Three-dimensional simulation of harmonic lasing Free-electron laser is represented in the steady-state regime. Here, the third harmonic of the first wiggler is adjusted at the fundamental resonance of the second wiggler by reducing the magnetic field strength of the second wiggler. The hyperbolic wave equations can be transformed into parabolic diffusion equations by using the slowly varying envelope approximation. A set of coupled nonlinear first-order differential equations describing the nonlinear evolution of the system is solved numerically by CYRUS3D code. This set of equations describes self-consistently the longitudinal spatial dependence of the radiation waists, curvatures, and amplitudes together with the evaluation of the electron beam. Thermal effects in the form of longitudinal velocity spread are also investigated. In order to reduce the length of the wiggler, the prebunched electron beam is considered.
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Paper

Title

Other Keywords

Page

MOP004

Influence of Horizantal Constant Magnetic Field on Harmonic Undulator Radiations and Gain

undulator, radiation, electron, FEL

34

H. Jeevakhan, P.K. Purohit
NITTTR, Bhopal, India
G. Mishra
Devi Ahilya University, Indore, India

Harmonic undulators has been analyzed in the presence of constant magnetic field along the direction perpendicular to the main undulator field. Effect of constant magnetic field magnitude on trajectory of electron beam , intensity of radiation and FEL gain at fundamental and third harmonics has been evaluated. Performance of harmonic undulator in the presence horizontal component of earth's magnetic field is the practical realization of the suggested scheme.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP029

PAL XFEL Pulse Modulator System Test Results Using a High Precision CCPS

klystron, controls, power-supply, high-voltage

89

S.H. Kim, H.-S. Kang, G.H. Kim, I.S. Ko, S.J. Kwon, H.-S. Lee, S.S. Park, Y.J. Park
PAL, Pohang, Kyungbuk, Republic of Korea
M.-H. Cho
POSTECH, Pohang, Kyungbuk, Republic of Korea
K.Y. Jang, H.S. Shin
POSCO ICT, Gyeonggi-do, Republic of Korea
D.S. Kim, S.Y. Lee, M. Seo
Dawonsys, Siheung-City, Republic of Korea

PAL XFEL is supposed to install 51 units of the pulse modulator power supplies for a 10-GeV linear accelerator using S-band (2856 MHz) cavities. The requirements of the modulator stability really become very tight. The stability on beam voltage is required to be less than 50 ppm. In order to obtain the high precision stability from the modulator system, we have newly produced a capacitor charging power supply (CCPS) and obtained the target stability with 10 ppm (STD) accuracy from measuring PFN (Pulse Forming Network). The CCPS generates a maximum output voltage of 50 kV at average current of 2.4 A with 4 units of the CCPS. The modulator peak output capacity is 400 kV, 500 A and 7.5 us at a pulse repetition rate of 60 pps using CCPS, a modified type-E PFN, and a pulse transformer. In this paper, the test results of the modulator system will be described.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP041

Turbo-ICT Pico-Coulomb Calibration to Percent-level Accuracy

impedance, laser, plasma, network

118

F. Stulle, J.F. Bergoz
BERGOZ Instrumentation, Saint Genis Pouilly, France

We report on the calibration methods implemented for the Turbo-ICT/BCM-RF. They allow to achieve percent-level accuracy for charge and current measurements. Starting from the Turbo-ICT/BCM-RF working principle, we discuss scientific fundaments of calibration and their practical implementation in a test bench. Limits, both principle and practical, are reviewed. Achievable accuracy is estimated.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP066

Electron Bunch Length Measurement using an RF Deflecting Cavity

cavity, electron, simulation, space-charge

188

S. Park, E.-S. Kim
Kyungpook National University, Daegu, Republic of Korea
S. Bae, K.H. Jang, Y.U. Jeong, H.W. Kim, J. Mun, N. Vinokurov
KAERI, Daejon, Republic of Korea

Recently, the RF photogun based-ultrafast electron diffraction (UED) system has been developed in KAERI. In the system, the emitted electron bunches are experimentally confirmed to be accelerated up to 3 MeV at 5MW of RF power. And the time duration of the each bunch is initially designed to be less than 50 fs at the sample position. To analyses the performance of the system and to measure exactly the length of the electron bunches, we developed a rectangular type of S-band deflecting cavity working on TM120 mode. The principle of electron deflecting in the cavity, design & mechanical fabrication process and test results will be present in the conference.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP068

First Simulation Results on Free Electron Laser Radiation in Displaced Phase-combined Undulators

undulator, radiation, electron, FEL

196

N.S. Mirian
UVSOR, Okazaki, Japan
E. Salehi
AUT, Tehran, Iran

This report deals with self amplified spontaneous emission free electron laser (FEL) amplifier where the FEL emission is obtained from displaced phase combined undulators. Magnetic field of this adjustment methods in three dimensions is presented. The electron dynamics is investigated. The simulation method and results are explained. The radiation properties of the fundamental resonance and third harmonic through the phase combined undulators are compared with the normal undulator with the same undulator deflection parameter

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP074

Efficiency Enhancement of a Harmonic Lasing Free-Electron Laser

wiggler, electron, radiation, FEL

209

N.S. Mirian
UVSOR, Okazaki, Japan
B. Maraghechi, E. Salehi
AUT, Tehran, Iran

The harmonic lasing free-electron laser amplifier, in which two wigglers is employed in order for the fundamental resonance of the second wiggler to coincide with the third harmonic of the first wiggler to generate ultraviolet radiation, is studied. A set of coupled nonlinear first-order differential equations describing the nonlinear evolution of the system, for a long electron bunch, is solved numerically by CYRUS code. Thermal effects in the form of longitudinal velocity spread are also investigated. The second wiggler field decreases linearly and nonlinearly at the point where the radiation of the third harmonic saturates to enhance the efficiency. The optimum starting point and the slope of the tapering of the amplitude of the wiggler are found by a successive run of the code. It is found that tapering can increase the saturated power of the third harmonic considerably.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

MOP075

Three-dimensional Simulation of a Harmonic Lasing Free-Electron Laser Amplifier

wiggler, radiation, electron, FEL

213

E. Salehi, B. Maraghechi
AUT, Tehran, Iran
N.S. Mirian
UVSOR, Okazaki, Japan

Three-dimensional simulation of harmonic lasing Free-electron laser is represented in the steady-state regime. Here, the third harmonic of the first wiggler is adjusted at the fundamental resonance of the second wiggler by reducing the magnetic field strength of the second wiggler. The hyperbolic wave equations can be transformed into parabolic diffusion equations by using the slowly varying envelope approximation. A set of coupled nonlinear first-order differential equations describing the nonlinear evolution of the system is solved numerically by CYRUS3D code. This set of equations describes self-consistently the longitudinal spatial dependence of the radiation waists, curvatures, and amplitudes together with the evaluation of the electron beam. Thermal effects in the form of longitudinal velocity spread are also investigated. In order to reduce the length of the wiggler, the prebunched electron beam is considered.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)