Die plötzliche Kernladungsänderung als Anregungsmechanismus optischer Übergänge

Abstract

Abstract The sudden change of nuclear charge (β-decay) produces a finite probability for the excitation of the outer electron shell. The emission spectrum of a gaseous Xe133-source exhibits light from the daughter Cs+, excited by the sudden change of nuclear charge, as shown by a spectral analysis. The probability for this excitation, p ∼ 6 · 10-2 per β-decay, is found in coincidence with the β-particles from the upper part of the β-spectrum; this value is lowered if also the low-energy part of the β-spectrum is included in observation; this seems to indicate a breakdown of the sudden approximation around 20 keV. The absolute values of p for Kr85 and Xe133 are discussed. The photon yield from the Kr85-decay in solid state for high Eβ is not a constant, as it is in the gaseous state, but decreases with Eβ , suggesting nonradiative transitions induced by the β-recoil.