THE ADIABATIC MOTION OF CHARGED PARTICLES IN ELECTROMAGNETIC FIELDS

Technical Report · Sun Jan 01 04:00:00 EST 1961

OSTI ID:4781503

Northrop, T G

The equations of motion of a charged particle in an electromagnetic field were used to obtain the so-called guiding center'' motion. In a slowly varying field the particle motion is approximately a rapid rotation about a circle whose center (the guiding center) has velocity components along and at right angles to the magnetic field. The equations governing the guiding center motion were obtained deductively for the general time-dependent field. Several unfamiliar drifts appeared because the time dependence and the perpendicular electric field were assumed, for the sake of generality, to be zero order in the radius of gyration rather than first order. These less familiar drifts are illustrated via practical examples where they occur. The modifications of the guiding center equations needed for particles of relativistic energy are given. The three adiabatic invariants of the particle motion are defined and the invariance proven for the general case of time dependent fields. Several applications were made of the guiding center equations of motion and the adiabatic invariants. Finally, deviations from the adiabatic predictions are discussed. (auth)

• Research Organization: California. Univ., Berkeley. Lawrence Radiation Lab.
• DOE Contract Number: W-7405-ENG-48
• NSA Number: NSA-16-031016
• OSTI ID: 4781503
• Report Number(s): UCRL-9517
• Country of Publication: United States
• Language: English

Related Subjects

CHARGED PARTICLES
DIFFERENTIAL EQUATIONS
ELECTROMAGNETIC FIELDS
MOTION
PHYSICS
ROTATION
VARIATIONS
VELOCITY