Experimental results are presented for the heating of a 4 m long plasma confined by a uniform magnetic field of 4-5 kG by an intense relativistic electron beam. The initial plasma density ranged from approximately 5 x 10 to the 13th power cu cm to approximately 3 x 10 to the 15th power cu cm, the lower density cases being partially ionized and the higher density cases highly ionized. In all cases, the energy coupled from the beam to the plasma is greater than can be explained by binary collisions between beam electrons and the plasma particles. Over most of the density range tested, 5 x 10 to the 13th power cu cm to 1.5 x 10 to the 15th power cu cm the plasma heating cannot be explained by classical processes. These results are found to be explained quantitatively by the use of a full nonlinear treatment of the electron-electron two stream instability in the kinetic regime. A review of beam plasma interaction theory and previous experiments is presented to facilitate comparison with the present results.

An intense (5 x 105 Amp/cm2), relativistic (5 MeV), electron beam will be used to investigate the heating of small volumes (~5 to 10 cm3) of dense plasma (1017-- 1018 electrons/cm3) to kilovolt temperatures via the electrostatic two-stream instability.

The TRITON experiment for the study of plasma heating by intense, relativistic electron beams is described. A 1.2 MV beam of 150 kA of electrons is injected into a 4 M long theta pinch. The rationale for the design of this experiment is discussed in terms of the existing theory of the intense beam plasma interaction. (Author).

An exploratory experiment has been performed on the propagation of intense relativistic electron beams through an ionized medium. The beam was produced on the Cornell facility and consisted of a 50 kAmp stream of 350 keV electrons. The initial plasma was produced by a conical theta pinch gun located 1.5 m downstream of the diode and it is estimated that the initial electron density at beam injection was about 10(exp 13) cu cm. Beam propagation was observed photographically, on an X-ray diode at the end of the tube, and on magnetic loops along the tube. Results suggest that the bulk of the beam propagates down the tube at speeds of 1.8 x 10(exp 8) m/sec. The magnetic probe signals indicate that there is appreciable counter streaming current within the plasma volume.