One-dimensional kinetic description of nonlinear traveling-pulse and traveling-wave disturbances in long coasting charged particle beams
This study makes use of a one-dimensional kinetic model to investigate the nonlinear longitudinal dynamics of a long coasting beam propagating through a perfectly conducting circular pipe with radius rw. The average axial electric field is expressed as < Ez >=-(∂/∂z)<Φ>=-ebg0∂λb/∂z-ebg2r2w∂3λb/∂z3, where g0 and g2 are constant geometric factors, λb(z,t)=∫dpzFb(z,pz,t) is the line density of beam particles, and Fb(z,pz,t) satisfies the 1D Vlasov equation. Detailed nonlinear properties of traveling-wave and traveling-pulse (soliton) solutions with time-stationary waveform are examined for a wide range of system parameters extending from moderate-amplitudes to large-amplitude modulations of the beam charge density. Two classes of solutions for the beam distribution function are considered, corresponding to: (i) the nonlinear waterbag distribution, where Fb=const in a bounded region of pz-space; and (ii) nonlinear Bernstein-Green-Kruskal (BGK)-like solutions, allowing for both trapped and untrapped particle distributions to interact with the self-generated electric field < Ez >.
- Research Organization:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC02-09CH11466
- OSTI ID:
- 1233865
- Alternate ID(s):
- OSTI ID: 1221815; OSTI ID: 1254755
- Report Number(s):
- PPPL-5136; PRABFM; 094201
- Journal Information:
- Physical Review Special Topics - Accelerators and Beams, Vol. 18, Issue 9; ISSN 1098-4402
- Publisher:
- American Physical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Nonlinear Bernstein--Greene--Kruskal wave equilibria subject to global energy and momentum conservation constraints
Influence of the trapped-electron distribution on the sideband instability in a helical wiggler free-electron laser