Measurement of the current distribution on monopoles in a large volume of hot plasma

Measurements have been made of the amplitude and phase distributions of the current on monopoles of various lengths (¿0/4 < h < 11/2¿0) embedded in a large volume of hot plasma. The change in the current distributions was observed as the ratio of the plasma frequency (¿p) to the antenna frequency (¿) was varied. When ¿p < ¿, the plasma behaves like a dielectric with a relative permittivity ¿r=1¿¿p2/¿2. The electrical length of the antenna is shortened as the plasma density is increased. At ¿p ¿ ¿, the antenna becomes electrically very small, and the antenna current tends to show a triangular distribution. When ¿p > ¿, the antenna-current distribution undergoes an anomalous change. An oscillating nature in the amplitude distribution and the reversal of phase change in the phase distribution are observed.