Focusing of parametric X-ray radiation

The possibility of focusing parametric x rays (PXRs) without x-ray optics has been shown. Parametric x rays are emitted by channeled relativistic charged particles moving along a bent crystal. Parametric x rays emitted from the entire length of the bent crystal are focused at two points on the bending axis of the crystal. The Huygens picture of formation of focused PXRs is given. The width of the spectral peak of this radiation has been estimated. Certain properties of focused PXRs are estimated for typical experimental conditions, and possibilities for the application of focused PXRs are discussed. An experiment for the observation of focused PXRs has been proposed. It has been shown that focused PXRs can be observed for a proton energy of several tens of GeVs or higher.