Search academic texts

Information × Registration Number 0216U010219, 0115U003806 , R & D reports Title Investigation of ionization loss of high-energy electron-positron pairs which have nonequilibrium electromagnetic field popup.stage_title Head Trofymenko Sergii, Registration Date 23-12-2016 Organization National Science Center "Kharkiv Institute of Physics and Technology popup.description2 The major aim of the present stage was the investigation of ionization loss of ultrarelativistic electron-positron pairs in thin layers of substance under conditions when the elctromagnetic field around the pairs is significantly nonequilibrium. For this reason there was considered a process in which the pair traverses a thin plate situated in vacuum on some distance from a thick target, in which the pair is created. The consideration of the problem is made without application of parallel electron and positron velocities, which is usually used in theoretical investigations of pairs ionization loss. It is shown that in this case both the effects of pair ionization loss reduction comparing to the sum of independent electron and positron losses and the effect of increase of the pair loss in the plate comparing to this quantity are possible. The effect of ionization loss reduction manifests itself within distances between the plate and the target which are proportional to the square of the pair energy and significantly exceed the corresponding distances in the case of the "classical" Chudakov effect of pair ionization loss reduction in boundless medium. Within such distances the increase of the pair ionization loss in the plate takes place with the increase of the gap between the plate and the target in which the pair is created. It is shown that the asymptotic value of the pair ionization loss at large distances between the plate and the target can differ from the sum of independent electron and positron losses in this process and depends on the pair divergence angle. The conditions for manifestation of the effect of exceeding by the pair loss of this sum are found. It is shown that such effect is the most visible at the energy of the pair of the order of 100 MeV and its value grows with the increase of the pair divergence angle. Product Description popup.authors popup.nrat_date 2020-04-02 Close