LARGE AMPLITUDE WAVES IN A COLLISION-FREE PLASMA. I. SINGLE PULSES WITH ISOTROPIC PRESSURE

Journal Article · Sat Jan 16 04:00:00 EST 1960 · Nuovo Cimento (Italy) Divided into Nuovo Cimento A and Nuovo Cimento B

OSTI ID:4143604

Banos, A Jr; Vernon, R

An infinite expanse of low density, fully ionized plasma, magnetically inmobilized in a constant and uniform field of magnetic induction is considered. In the absence of collisions it is assumed that the ion and electron motions take place in planes perpendicular to the magnetic field. Transformation is made to a "shock" frame of reference moving at constant speed at night angles to the magnetic field, and a search is made for the class of non-trivial, timeindependent. one-dimensional, sell-consistent solutions of the Maxwellian set and of the equations of motion of the charged particles; that is, the propagation of transverse pulses and waves whose characteristic length is much smaller than the collision mean free path is studied. Upon making appropriate simplifications, evolved is a system of equations in which collisions are neglected, charge neutrality is assumed, and both ions and electrons behave like two-dimensional fluids obeying isentropic relations with gamma = 2 and exhibiting rigorously isotropic pressure tensors. With these simplications and assumptions, the system of equations can be solved completely by a simple numerical quadrature. Both symmetric pulses and periodic waves are obtained, with characteristic lengths of the order of the plasma "skin depth", or mean gyromagnetic radius for particles traveling with the Alfven speed. In Part I, is de scribed the solitary pulses, which are the only solutions satisfyiny the conditions of the undisturbed plasma ahead of the wave train. Two basic parameters are required for a complete specification of the problem: the Alfven Mach number alpha , which gives a measure of the speed of propagation, and the ratio beta of the total plasma pressure to the magnetic pressure, which specifies the initial state of the plasma. It is shown that, for given beta , stationary solutions exist only for a limited range of speeds alpha . (auth)

• Research Organization: Univ. of California, Los Angeles
• NSA Number: NSA-14-013401
• OSTI ID: 4143604
• Journal Information: Nuovo Cimento (Italy) Divided into Nuovo Cimento A and Nuovo Cimento B, Journal Name: Nuovo Cimento (Italy) Divided into Nuovo Cimento A and Nuovo Cimento B Vol. Vol: (10) 15; ISSN NUCIA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ALFVEN NUMBER
ALFVEN SPEED
ALFVEN WAVES
COLLISIONLESS PLASMA
DENSITY
DIFFERENTIAL EQUATIONS
ELECTRONS
EXPANSION
FLUIDS
INDUCTION
INTERACTIONS
IONIZATION
IONS
MACH NUMBER
MAGNETIC FIELDS
MAXWELL EQUATIONS
MOTION
ORBITS
OSCILLATIONS
PHYSICS
PLASMA
PLASMA WAVES
PRESSURE
PULSES
SHOCK WAVES
THERMODYNAMICS
VELOCITY