Magnetic focusing of electron beams in the presence of transverse velocity components
Abstract
The behavior of nonlaminar electron beams having an originally Gaussian current density distribution in a uniform magnetic field is studied by analytical and numerical methods. The effects of transverse velocity components in the beam are described by a fictitious, equivalent perveance which is proportional to the square of the rms value of the transverse beam velocity. Simple expressions are given for the magnetic field required to achieve a certain beam transmission through a tunnel of given diameter, and for the optimum beam filling factor. In the appendix a simple experimental method for the determination of the rms value of the transverse beam velocity is described.
- Publication:
-
IEEE Transactions on Electron Devices
- Pub Date:
- May 1981
- DOI:
- 10.1109/T-ED.1981.20369
- Bibcode:
- 1981ITED...28..473H
- Keywords:
-
- Electron Beams;
- Magnetic Lenses;
- Velocity Distribution;
- Charge Distribution;
- Current Density;
- Electron Energy;
- Lorentz Force;
- Magnetic Field Configurations;
- Normal Density Functions;
- Plasma Waves;
- Space Charge;
- Electronics and Electrical Engineering