Measurements with electrostatic probes in the L-1 stellarator

Methods for electrostatic-probe measurements of the parameters of the plasma injected into the L-1 stellarator with spark sources are described. For measurement of the plasma potential, the electron temperature, the ion temperature, the ion concentration, fluctuating ion beam on the walls of the chamber, and the quasipermanent ion beam, individual Langmuir probes, emitter probes, multigrid electrostatic probes, and double probes were used. Construction of the probes and the electrical measurement circuit is described. The potential of the methods under conditions characteristic of the L-1 stellarator is discussed. A brief review is given of the basic results of the measurements. (tr-auth)