M = 1 Diocotron Mode Damping in the Electron Diffusion Gauge (EDG) Experiment
Abstract
The evolution of the amplitude of the m = 1 diocotron mode is used to measure the background neutral pressure in the Electron Diffusion Gouge (EDG), a Malmberg-Penning trap. Below 5 x 10(exp -8) Torr, the dependence on pressure scales as P(exp 1/4), and is sensitive to pressure changes as small as delta P = 5 x 10(exp -11) Torr. Previous studies on the EDG showed that the diocotron mode is more strongly damped at higher neutral pressures. Both the diocotron mode damping rate and the plasma expansion rate depend similarly on experimental parameters, i.e., conditions which favor expansion also favor suppression of the diocotron mode. The sensitivity of the mode evolution is examined as a function of the resistive growth driving conditions, which are controlled by the amount of wall resistance connected to the trap.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 24, 2002
- Accession Number
- ADP012524
Entities
People
- Kyle A. Morrison
- Ronald C. Davidson
- Stephen F. Paul
- Thomas G. Jenkins
Organizations
- Princeton University