Paper 
Title 
Other Keywords 
Page 
MOBAU01 
SelfForceDerived Mass of an Electron Bunch

electron, acceleration, synchrotron, synchrotronradiation 
1 



The properties of Lorentz transformations for energy and momentum in electromagnetic systems are illustrated in a simple example involving a short electron bunch moving in a bending magnet. The famous 4/3 problem in electromagnetic mass is discussed.



Slides



MOPPH010 
ThreeDimensional Analysis of the Surface Mode Supported by a Reflection Grating

electron, laser, polarization, freeelectronlaser 
38 

 K.J. Kim
ANL, Argonne, Illinois
 V. Kumar
RRCAT, Indore (M. P.)


In a SmithPurcell FreeElectron Laser (SPFEL), the electron beam interacts with the surface mode supported by a metallic reflection grating to produce coherent radiation. All the previous analyses of SPFEL had considered the localization of the surface mode only in the direction perpendicular to the grating surface and assumed translational invariance along the direction of grooves of the grating. In this paper, we include the localization of the surface mode along the direction of grooves and study the threedimensional structure of the surface mode in order to include diffraction effects in the analysis of SPFELs. Full threedimensional MaxwellLorentz equations are derived for the selfconsistent nonlinear analysis of SPFELs.



MOCAU05 
Space Charge Effect in an Accelerated Beam

acceleration, spacecharge, radiation, electron 
200 

 Z. Huang, G. V. Stupakov
SLAC, Menlo Park, California


It is usually assumed that the space charge effects in relativistic beams scale with the energy of the beam as the inverse relativistic factor gamma factor squared. We show that for a beam accelerated in the longitudinal direction there is an additional space charge effect in free space that scales as the ratio of the accelerating field to the gamma factor. This space charge field has the same origin as the "electromagnetic mass of the electron" discussed in textbooks on electrodynamics. It keeps the balance between the kinetic energy of the beam and the energy of the electromagnetic field of the beam. We then consider the effect of this field on a beam generated in an RF gun and calculate the energy spread produced by this field in the beam.



Slides


