Publication Date


Advisor(s) - Committee Chair

F.M. Carter, N.F. Six, William Buckman,

Degree Program

Department of Physics and Astronomy

Degree Type

Master of Science


The objective of this study was to build preliminary devices . which could be used to measure electron reflection coefficient values using crossed electric and magnetic fields. The technique for using crossed fields to measure reflection coefficients was developed at Air Force Cambridge Research Laboratories. The reflection coefficient is the ratio of the number of electrons in a reflected beam to the number of electrons in an incident beam striking a surface.

The work described herein was a part of a project authored by AFCRL under contract AF19 (628)-5940; Project 8605 (with Western Kentucky University being the contractor) which was entitled. "An Investigation of the Reflection of Slow Electrons from Surfaces."1 Earlier researchers working on the problem of measuring reflection coefficients generally had used large electron optical systems with target collection chambers.2 Since their findings varied so considerably (Figure 1) it was decided to try a new approach. The results shown are curves describing the values obtained when electrons bombarded tungsten metal with energies ranging between .1 and 3.5 electron volts.

Basically the devices discussed within this paper consist of two parallel electrodes to provide a uniform electric field and an electron gun to inject electrons with known energy levels into the field perpendicular to the electrodes. Each device utilized a Faraday cup to collect the electrons after the application of an external uniform magnetic field which bent the originally straight electron beam into a trochoidal path.


Engineering Physics | Physical Sciences and Mathematics | Physics