FEL2013 - List of Authors (Yampolsky, N.A.)

Paper

Title

Page

Using a Lienard-Wiechert Solver to Study Coherent Synchrotron Radiation Effects

17

R.D. Ryne
LBNL, Berkeley, California, USA
B.E. Carlsten, N.A. Yampolsky
LANL, Los Alamos, New Mexico, USA

We report on coherent synchrotron radiation (CSR) modeling using a new first-principles Lienard-Wiechert solver (CSR3D) that simulates real-world number of particles (624 million to 6.24 billion for 100-pC to 1-nC bunch charges). Using this tool, we have verified the limits of applicability of the common 1-D CSR model, including effect due to transverse beam size and shape. We also have observed energy dependent, wavelength dependent, and transverse-size dependent effects on CSR enhancement from microbunching. Additionally, we describe statistics of CSR shot noise, including dependencies on beam energy and transverse position and resulting energy diffusion. We consider the full transverse equation of motion and also quantify the effect of emittance growth from the bunch’s transverse radiation force.

Slides MOOCNO04 [6.258 MB]

WEOANO04

Two-stream Instability at Soft X-ray Wavelengths for Increasing Brightness of Compton Sources

N.A. Yampolsky, G.L. Delzanno, C. Huang, D.Y. Shchegolkov
LANL, Los Alamos, New Mexico, USA

Two-stream instability at soft X-ray wavelengths for increasing brightness of Compton sources. We propose a novel scheme which may result in the next generation Compton source for soft X-rays. The scheme is based on creating an electron beam distribution consisting of several energy bands and allowing for the two-stream instability to develop resulting in a short scale density modulation. The multi-stream beam distribution is created within a single bunch through EEHG mechanism which results in well separated bands with close energies. The wavelength of the microbunching caused by the two-stream instability strongly depends on the beam parameters and can be reduced down to soft X-ray wavelengths that are not achievable with other mechanisms. The microbunching can be used for

Slides WEOANO04 [1.362 MB]

WEPSO19

A Full Beam 1D Simulation Code for Modeling Hybrid HGHG/EEHG Seeding Schemes for Evaluating the Dependence of Bunching Factor Bandwidth on Multiple Parameters

533

C.M. Fortgang, B.E. Carlsten, Q.R. Marksteiner, N.A. Yampolsky
LANL, Los Alamos, New Mexico, USA

Multiple seeding schemes are available for design of narrow-band, short-wavelength FELs. Analysis of such schemes often focus on the amplitude of the final bunching factor b, and how far it is above shot noise. Only under ideal conditions is the bandwidth of b FT limited. We have developed a 1D simulation tool that models complex hybrid seeding schemes using macro properties of the entire beam bunch to assess effects on both the amplitude and bandwidth of b. In particular the effects on bunching factor from using non-ideal beam driven radiators for downstream modulators, energy slew and curvature, and energy spread are investigated with the 1D tool.

Paper	Title	Page
MOOCNO04	Using a Lienard-Wiechert Solver to Study Coherent Synchrotron Radiation Effects	17
	R.D. Ryne LBNL, Berkeley, California, USA B.E. Carlsten, N.A. Yampolsky LANL, Los Alamos, New Mexico, USA
	We report on coherent synchrotron radiation (CSR) modeling using a new first-principles Lienard-Wiechert solver (CSR3D) that simulates real-world number of particles (624 million to 6.24 billion for 100-pC to 1-nC bunch charges). Using this tool, we have verified the limits of applicability of the common 1-D CSR model, including effect due to transverse beam size and shape. We also have observed energy dependent, wavelength dependent, and transverse-size dependent effects on CSR enhancement from microbunching. Additionally, we describe statistics of CSR shot noise, including dependencies on beam energy and transverse position and resulting energy diffusion. We consider the full transverse equation of motion and also quantify the effect of emittance growth from the bunch’s transverse radiation force.
	Slides MOOCNO04 [6.258 MB]

WEOANO04	Two-stream Instability at Soft X-ray Wavelengths for Increasing Brightness of Compton Sources
	N.A. Yampolsky, G.L. Delzanno, C. Huang, D.Y. Shchegolkov LANL, Los Alamos, New Mexico, USA
	Two-stream instability at soft X-ray wavelengths for increasing brightness of Compton sources. We propose a novel scheme which may result in the next generation Compton source for soft X-rays. The scheme is based on creating an electron beam distribution consisting of several energy bands and allowing for the two-stream instability to develop resulting in a short scale density modulation. The multi-stream beam distribution is created within a single bunch through EEHG mechanism which results in well separated bands with close energies. The wavelength of the microbunching caused by the two-stream instability strongly depends on the beam parameters and can be reduced down to soft X-ray wavelengths that are not achievable with other mechanisms. The microbunching can be used for
	Slides WEOANO04 [1.362 MB]

WEPSO19	A Full Beam 1D Simulation Code for Modeling Hybrid HGHG/EEHG Seeding Schemes for Evaluating the Dependence of Bunching Factor Bandwidth on Multiple Parameters	533
	C.M. Fortgang, B.E. Carlsten, Q.R. Marksteiner, N.A. Yampolsky LANL, Los Alamos, New Mexico, USA
	Multiple seeding schemes are available for design of narrow-band, short-wavelength FELs. Analysis of such schemes often focus on the amplitude of the final bunching factor b, and how far it is above shot noise. Only under ideal conditions is the bandwidth of b FT limited. We have developed a 1D simulation tool that models complex hybrid seeding schemes using macro properties of the entire beam bunch to assess effects on both the amplitude and bandwidth of b. In particular the effects on bunching factor from using non-ideal beam driven radiators for downstream modulators, energy slew and curvature, and energy spread are investigated with the 1D tool.