Experiments on the spherical expansion of a plasma into an underdense plasma are described. The initial spherical plasmas are stable anode spots that expand into the ambient region. The anode spots are formed in low pressure noble gas plasmas that have been impregnated with acetone. The formation mechanism is interpreted in terms of electron attachment on the acetone molecules.

This paper describes an inexpensive versatile electronic circuit which will anow a conventional oscilloscope or an XY recorder to be used as a transistor curve tracer. It can also be used to obtain Langmuir probe characteristics in plasma physics experiments.

No abstract

No abstract

A technique to easily and quickly obtain, display, and analyze the transistor characteristics of pnp and npn bipolar junction transistors with a Macintosh personal computer is reported. Both the necessary hardware and software are described.