Engineering topics

Romesser, T.

Publications and source records attributed to Romesser, T..

5 records

NASA NTRS1975

Experimental observation of the ion-ion beam instability in a cylindrical geometry

The ion-ion beam instability is investigated in a cylindrical geometry. In the presence of a cylindrically symmetric ion beam a coherent ion-ion beam instability is observed for a well-defined range of beam velocity. This instability gives rise to cylindrical standing waves whose frequency depends upon beam velocity. The beam distribution function is measured to be a ring in velocity space. The dispersion relation appropriate for the cylindrical standing waves is solved numerically and is shown to be in good agreement with the experimentally observed instability.

Romesser, T.↗

NASA NTRS1975

Plasma confinement by a picket-fence

It is shown that a current-produced line cusp field in a 'picket fence' configuration will confine both primary ionizing electrons and plasma. The 'picket fence' consists of a planar array of equally spaced water-cooled copper tubing with the current alternating in direction. The loss rates of both plasma and primary electrons are shown to be inversely proportional to the fence current. Plasma confinement is found to be much weaker than electron confinement.

Leung, K. N.↗

NASA NTRS1974

Ion-ion beam instability in a cylindrical geometry

The ion-ion instability is studied in a cylindrical double-plasma device. Low-frequency cylindrical standing waves are found which are one-dimensional in character with frequency proportional to beam velocity. An approximate dispersion relation for the cylindrical standing waves is derived.

Hershkowitz, N.↗

NASA NTRS1974

Observations of ion-acoustic cylindrical solitons

Experimental observations of cylindrical solitons in a collisionless plasma are presented. The data obtained show that cylindrical solitonlike objects exist and that their properties are consistent with those of one- and three-dimensional solitons. It is found that compressive density perturbations evolve into solitons. The number of the solitons is determined by the width and amplitude of the applied pulse.

Hershkowitz, N.↗

NASA NTRS1972

Multiple soliton production and the Korteweg-de Vries equation.

Compressive square-wave pulses are launched in a double-plasma device. Their evolution is interpreted according to the Korteweg-de Vries description of Washimi and Taniuti. Square-wave pulses are an excitation for which an explicit solution of the Schrodinger equation permits an analytical prediction of the number and amplitude of emergent solitons. Bursts of energetic particles (pseudowaves) appear above excitation voltages greater than an electron thermal energy, and may be mistaken for solitons.

Hershkowitz, N.↗