FEL2015 - List of Authors (Novokhatski, A.)

Paper	Title	Page
MOP054	Wake Field Potentials of 'Dechirpers'	157
	A. Novokhatski SLAC, Menlo Park, California, USA
	Funding: This work was supported by Department of Energy Contract No. DOE-AC03-76SF00515. A corrugated structure, which is used on 'dechirpers' is usually a pipe or two plates with small corrugations (bumps) on the walls. There is a good single-mode description of the wake potentials excited by a relativistic bunch if the wave length of the mode is much longer than the distance between the bumps in the pipe. However, ultra-short bunches, which are now used in FELs, excite much higher frequency fields and the corresponding wake potentials will be very different from single-mode description. We made analyzes of these wake potentials based on a numerical solution of Maxwell's equations. The behavior of the wake fields of ultra-short bunches in corrugated structures is not much different from the fields excited usually in accelerating structures where the wake potentials are described by the exponential function. As we increase the bunch length, the wake potentials slowly transform to the form of a single mode. For a practical application we present results for a 'dechirper', which will be soon installed at LCLS. We also carried out calculations for a similar device, that was installed and measured at the Pohang Accelerator Laboratory, Korea. We find very good agreement with the experimental results.
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MOP055	The Effect of Wakefields on the FEL Performance	161
	A. Novokhatski, F.-J. Decker, Y. Nosochkov, M.K. Sullivan SLAC, Menlo Park, California, USA
	Funding: This work was supported by Department of Energy Contract No. DOE-AC03-76SF00515. If a beam travels near collimator jaws or other discontinuities of the beam pipe, it gets the energy loss and the transverse kick due to the back reaction of the beam field diffracted on the collimator's jaws. The wake field effect from collimators may not only bring an additional energy jitter and change the trajectory of the beam, but may also lead to degradation of the performance of Free Electron Laser (FEL) It may be possible due to the special character of the wake fields: the response reaction depends on the longitudinal position of the particles in the bunch. We describe a model of the wake field radiation, simulation results and comparison with measurements.
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Paper

Title

Page

Wake Field Potentials of 'Dechirpers'

157

A. Novokhatski
SLAC, Menlo Park, California, USA

Funding: This work was supported by Department of Energy Contract No. DOE-AC03-76SF00515.
A corrugated structure, which is used on 'dechirpers' is usually a pipe or two plates with small corrugations (bumps) on the walls. There is a good single-mode description of the wake potentials excited by a relativistic bunch if the wave length of the mode is much longer than the distance between the bumps in the pipe. However, ultra-short bunches, which are now used in FELs, excite much higher frequency fields and the corresponding wake potentials will be very different from single-mode description. We made analyzes of these wake potentials based on a numerical solution of Maxwell's equations. The behavior of the wake fields of ultra-short bunches in corrugated structures is not much different from the fields excited usually in accelerating structures where the wake potentials are described by the exponential function. As we increase the bunch length, the wake potentials slowly transform to the form of a single mode. For a practical application we present results for a 'dechirper', which will be soon installed at LCLS. We also carried out calculations for a similar device, that was installed and measured at the Pohang Accelerator Laboratory, Korea. We find very good agreement with the experimental results.

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

MOP055

The Effect of Wakefields on the FEL Performance

161

A. Novokhatski, F.-J. Decker, Y. Nosochkov, M.K. Sullivan
SLAC, Menlo Park, California, USA

Funding: This work was supported by Department of Energy Contract No. DOE-AC03-76SF00515.
If a beam travels near collimator jaws or other discontinuities of the beam pipe, it gets the energy loss and the transverse kick due to the back reaction of the beam field diffracted on the collimator's jaws. The wake field effect from collimators may not only bring an additional energy jitter and change the trajectory of the beam, but may also lead to degradation of the performance of Free Electron Laser (FEL) It may be possible due to the special character of the wake fields: the response reaction depends on the longitudinal position of the particles in the bunch. We describe a model of the wake field radiation, simulation results and comparison with measurements.

Export •

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