Die Pendelvervielfachung von Sekundärelektronen (Multipactoreffekt) als Zündbedingung von Hochfrequenzentladungen

It is experimentally shown that the breakdown voltage of high frequency discharges at very low pressures becomes identical with the initial voltage of secondary electron resonance mechanism (“multipacting”). This result is discussed by means of a formerly published theory of multipacting. Experimental results of other authors are also judged by comparing them with the predictions of this theory.     

Der Einfluß der Auffängertemperatur auf die Ausbeute beimβ-Rückstoß von ThB

Zeitschrift für Physik A Hadrons and nuclei - Durch neue Versuche über die Ausbeute beim β-Rückstoß von Th B wird gezeigt, daß ähnlich wie bei den...     

Der Einfluß eines elektrischen Feldes auf die Absorptionskante von ZnS

In the electric field as has been shown theoretically byFranz andKeldysh there is in crystals an absorption edge shift towards longer wave-lenghts. This effect has been studied and verified on CdS byBöer and co-workers and has led to a more profound understanding of many problems of CdS single crystals conductivity. This paper is a first report on the absorption edge shift of ZnS single crystals in the electric field.     

Der Einfluß von Gitterstörungen auf die optischen Eigenschaften von Metallschichten

By condensation of metals from the vapour onto a cooled substrate an especially high degree of disorder can be frozen in. Such strongly disordered films show essential changes of their properties. This paper deals with optical studies of such films of Bi, Ga, Sn and Ag. Reflectivity and transmission and their changes during annealing are measured in the spectral range from 0,25 to 4 microns. There is reasonable agreement with results of other measurements e.g. Hall-voltage, electrical resistance and electron diffraction. Optical constants and their changes during annealing are calculated in the range from 0,8 to 4 microns by approximation formulas. The high disorder produces similar anomalies of the optical constants as observed so far at extremely thin films. Concentrations and collision frequencies of free electrons are determined by means of the Drude theory. These values, obtained by a purely optical method are compared to results of electrical measurements and show satisfactory agreement.     

Untersuchungen zur Mehrfach-Emission von Sekundärelektronen

CuBe- and NaCl-targets are bombarded by single electrons (100–600 eV). The secondary electrons accelerated by 40 kV strike the crystal of a scintillation counter, backed by a multichannel analyser. The probabilityP _n of emission ofn=0, 1, 2, 3, ... secondaries can be found from the pulse height distribution. The probability distributionP _n =f(n) shows a characteristic deviation from aPoisson's distribution. There was no evidence that there is a preference for even numbers ofn as found byBarrington andAnderson.     

Die Pendelvervielfachung von Sekundärelektronen im Dezimeterwellengebiet

The conditions as deduced from theory for the existence of secondary electron resonance mechanism (dynamic multiplication of secondary electrons) are tested in the decimeter wave range. A re-entrant cavity resonator is used for this the field length of which can be varied at its field maximum. For the voltage amplitude at the start of multiplication the quadratic dependence on the length of field — as postulated by theory — is completely confirmed. For the voltage amplitude at the instant of break-off the experiments, however, yield for small lengths of field higher values than calculated.