The mechanism of Vavilov-Cherenkov radiation
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e Mechanism of Vavilov–Cherenkov Radiation “When, in around 1860, the law of conservation of energy was eventually generally recognized, it very quickly became a cornerstone of the whole of natural science. Since then any new theory, especially a physical one, has been above all evaluated with respect to its agreement with the law of conservation of energy.” M. Laue, “Inertia and Energy,” Sov. Phys. Uspekhi, vol. LXVII, issue 4, p. 729 (1959).
A. P. Kobzev Frank Laboratory for Neutron Physics, JINR, Dubna, Moscow oblast, Russia Abstract—The mechanism of generation of Vavilov–Cherenkov radiation is discussed in this article. The developers of the theory of the Vavilov–Cherenkov effect, I.E. Tamm and I.M. Frank, attributed this effect to their discovery of a new mechanism of radiation when a charged particle moves uniformly and rectilinearly in the medium. As such a mechanism presupposes the violation of the laws of conservation of energy and momentum, they proposed the abolition of these laws to account for the Vavilov–Cherenkov radiation mech anism. This idea has received a considerably wide acceptance in the creation of other theories, for example, transition radiation theory. In this paper, the radiation mechanism for the charge constant motion is demon strated to be incorrect, because it contradicts not only the laws of conservation of energy and momentum, but also the very definitions of uniform and rectilinear motion (Newton’s First Law). A consistent explanation of the Vavilov–Cherenkov radiation microscopic mechanism that does not contradict the basic laws is pro posed. It is shown that the radiation arises from the interaction of the moving charge with bound charges that are spaced fairly far away from its trajectory. The Vavilov–Cherenkov radiation mechanism bears a slowing down character, but it differs fundamentally from bremsstrahlung, primarily because the Vavilov–Cherenkov radiation onset results from a twostage process. First, the moving particle polarizes the medium; then, the already polarized atoms radiate coherently, provided that the particle velocity exceeds the phase speed of light in the medium. If the particle velocity is less than the phase speed of light in the medium, the polarized atoms return energy to the outgoing particle. In this case, radiation is not observed. Special attention is given to the relatively constant particle velocity as the condition of the coherent composition of waves. However, its motion cannot be designated as a uniform and rectilinear one in the sense of its definition by Newton’s First Law, and it also contradicts the laws of conservation of energy and momentum. DOI: 10.1134/S1063779610030044
1. INTRODUCTION More than 70 years have passed since the macro scopic theory of the Vavilov–Cherenkov effect [1] was developed. In the course of these years, a great number of different studies have been carried out in this field and hundreds of experimental and theoretical works have been published, various types of Cherenkov counters have been successfully run in man
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