Diagnostic Techniques of the High Compression and Neutral Injection Experiments

Abstract

In the Multi-Stage Compression Experiment (Toy Top III) we wish to determine the energy and spatial distribution of the plasma components - ions and electrons - from the time of their initial injection into the machine through the heating and containment cycle. An ion analyzer, consisting of a magnetic momentum analyzer followed by an electrostatic analyzer, has been valuable in finding the energy distribution of the plasma ions. The density distri-of the plasma in the experiment's magnetic field has been largely determined with electrostatic extraction probes. Microwave radiometers and double probes have been utilized to find electron temperatures. Li6 (Eu) and plastic scintillation counters assess the total number and rate of production of neutrons from D-D reactions, which may be confirmed with nuclear emulsions. Electron temperatures in the Single-Stage High Compression Experiment (Table Top II) have been determined from an analysis of the escaping electron flux. The initial experiments on neutral atom injection into a mirror field geometry (ALICE) require a knowledge of the initial background gas density, neutral beam current, buildup of plasma density, loss rate from the confinement region, and the spatial distribution of the plasma. A magnetically shielded, nude Bayard-Alpert gauge determines the total initial gas pressure, the partial pressure of each atomic specie being found with a mass spectrograph. A copper target calorimeter indicates beam current; while neutral particle detectors on the chamber walls and screened Faraday collectors outside of the mirrors show the buildup and loss of plasma.