Stochastic particle instability for electron motion in combined helical wiggler, radiation, and longitudinal wave fields

Journal Article · Thu Jul 01 00:00:00 EDT 1982 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.26.410· OSTI ID:6868729

Davidson, R C; McMullin, W A

The relativistic motion of an electron is calculated in the combined fields of a transverse helical wiggler field (axial wavelength is lambda/sub 0/ = 2..pi../k/sub 0/) and the constant-amplitude, circularly polarized primary electromagnetic wave (delta-circumflexB/sub T/,..omega..,k) propagating in the z direction. For particle velocity near the beat wave-phase velocity ..omega../(k+k/sub 0/) of the primary wave, it is shown that the presence of a second, moderate-amplitude longitudinal wave (delta-circumflexE/sub L/,..omega..,k) or transverse electromagnetic wave (delta-circumflexB/sub 2/,..omega../sub 2/,k/sub 2/) can lead to stochastic particle instability in which particles trapped near the separatrix of the primary wave undergo a systematic departure from the potential well. The condition for onset of instability is calculated, and the importance of these results for free-electron-laser (FEL) application is discussed. For development of long-pulse or steady-state free-electron lasers, the maintenance of beam integrity for an extended period of time will be of considerable practical importance. The fact that the presence of secondary, moderate-amplitude longitudinal or transverse electromagnetic waves can destroy coherent motion for certain classes of beam particles moving with velocity near ..omega../(k+k/sub 0/) may lead to a degradation of beam quality and concomitant modification of FEL emission properties.

• Research Organization: Plasma Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
• OSTI ID: 6868729
• Journal Information: Phys. Rev. A; (United States), Vol. 26:1
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
FREE ELECTRON LASERS
INSTABILITY
STOCHASTIC PROCESSES
DYNAMICS
ELECTROMAGNETIC FIELDS
ELECTRON BEAMS
RELATIVISTIC RANGE
WIGGLER MAGNETS
BEAMS
ELECTRICAL EQUIPMENT
ELECTROMAGNETS
ENERGY RANGE
EQUIPMENT
LASERS
LEPTON BEAMS
MAGNETS
MECHANICS
PARTICLE BEAMS
420300* - Engineering- Lasers- (-1989)