ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
A new e-beam probe is developed to study the potential structure inside a SEIC device [G. H. Miley et al., Fusion Technol. 19, 840 (1991)]. The device has a spherical grid negatively biased inside a spherical vacuum chamber. Ions oscillate through the highly transparent grid, forming a single potential well inside the cathode. The potential in turn attracts electrons from ionization of background gas. The measurement of this complex potential profile is the objective of this work. The e-beam probe offers advantages over the e-emitting probes and the laser heterodyne method. It minimizes perturbations (versus a physical probe) and detects smaller charge density variations than possible with laser techniques. The present e-beam probe utilizes a higher voltage and a modified focus compared to the earlier version used by Swanson [Swanson et al., Phys. Fluids 16, 1939 (1973)]. The characteristic e-beam deflection patterns observed are compared to predictions from an impulse approximation model.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1143622
