PACS: 74.20.-z

Physical processes are considered at Meissner effect. A new explanation is offered for reasons behind the surface shielding current occurrence at transition into superconducting state in constant external magnetic field. It is shown, that transition into superconducting state in a magnetic field should be accompanied by characteristic radiation.

1. For long time it was believed that the total absence of electric resistance is the main and only characteristic ability of superconductors. In 1933 Meissner and Ochsenfeld had experimentally discovered that when transiting into superconductive state by cooling, in not strong, permanent magnetic field (Н<Н_с), the magnetic field that was originally penetrating the sample is ejected from the sample (В=0 inside the superconductor) [1]. In the same time an electric current arise in a thin boundary layer of superconductor. Magnetic field of this current completely compensates the external magnetic field. Also in this region the magnetic field decreases from its maximum value on the surface to zero inside the superconductor.