Azimuthal asymmetry of coherent Cherenkov radiation from a tilted bunch

Publication date: Available online 4 December 2018Source: Physics Letters AAuthor(s): S.Yu. Gogolev, A.P. PotylitsynAbstractModern accelerator technologies may provide electron beams consisting of ultrashort bunches with transverse sizes, which are much larger than bunches with longitudinal sizes. The spectral-angular characteristics of coherent Cherenkov radiation (CChR) produced by the former type have thus been considered. We simulated the characteristics of CChR and those from a single charge on the basis of the polarisation current model, which allowed us to consider finite sizes for the target Cherenkov radiator. We calculated the angular distribution of the CChR from a bunch tilted by angle ψ, with respect to the velocity direction, with the assumption of a 3-D Gaussian charge distribution in the bunch. Contrary to the azimuthally symmetrical distribution of conventional ChR, a strong azimuthal asymmetry was observed in the CChR from the tilted bunch. The maximal yield of the CChR may be achieved if the tilt angle ψ coincides with the Cherenkov angle Θch=arccos⁡(1/nβ), βc is the charge velocity and n is the refraction index.

Source: Physics Letters A - December 5, 2018 Category: Physics Source Type: research