Study of the particle radiation near the Vavilov–Cherenkov radiation threshold

The Cherenkov radiation phenomenon is widely used in physics applications, mainly in particle identification or particle energy determination. The classical theory of Cherenkov radiation introduced by Tamm and Frank is sufficient for practical needs. r, it is not well known that another theory derived by Tamm exits. It predicts the interference character of the radiation and the classical Cherenkov ring as the main interference maximum is considered. Unlike the first theory, there is no threshold, the radiation under classical threshold is caused by a boundary effect in the medium crossed by the particle, known as transition radiation. The interference begins to be observable near the threshold where the difference between both theories is well noticeable.