An apparatus for determining the secondary electron emission properties of nonconductors
The apparatus described allows the measurement of the secondary emission coefficient and the secondary electron energy distribution from nonconducting surfaces. The potential of the nonconducting surface is stabilized by a cathode very close to it. The use of an oscillatory primary beam allows a measurement of the secondary emission coefficient. The application of a sinusoidally modulated voltage sawtooth allows the determination of the emitted electron energy distribution and measures the potential of the emitting surface. The performance of the apparatus is demonstrated by results obtained from an amorphous magnesium oxide coating.
AC Methods for the Determination of Photoelectron Energy Distributions
The sensitivity of the Spicer‐Berglund retarding‐potential method for the determination of photoelectron energy distributions may be improved by an order of magnitude by a more effective cancellation of the capacitative component of the signal. A double modulation technique, in which energy distributions can be traced from saturated photocurrents of the order of 10−11 A, is also described. This method can be employed to eliminate steady thermionic or photoelectric currents many orders of magnitude greater than that under investigation.
Der Elektronenstoß an Kristallschichten zum Nachweis optischer Energiestufen
ZusammenfassungEs wird eine zur Untersuchung des Elektronenstoßes an Kristallschichten geeignete Versuchsanordnung beschrieben. Aus Gegenfeldmessungen erhält man die korrigierten Elektronengeschwindigkeiten.Das erste Absinken der Elektronenreflexion entspricht bei NaCl, KCl, KJ, LiF, NaF und CaF2 den optisch bekannten Durchlässigkeitsgrenzen.Die Elektronenreflexion ist nur im Bereich kleiner Geschwindigkeiten elastisch, beim Erreichen der optischen Durchlässigkeitsgrenze wird sie unelastisch.