Observations of the development of striations in large barium ion clouds

Striations are observed to develop within large (6–352 kg releases) barium ion clouds in a two-stage process. First the clouds split into sheets commencing at the trailing edge of the cloud. Then distortions or pinching effects within the individual sheets cause the formation of field-aligned raylike structures. In the clouds observed, the individual sheets were 200–1000 m in thickness and were spaced 700–2000 m apart. Quasi-sinusoidal waviness of spatially periodic thickenings exhibited a wavelength typically 700–1000 m. When rod-like structures appeared, these were typically 200–400 m dia and were spaced along the pre-existing sheet at 700–1000 m on centers.