Observation of focusing effect in optical transition and diffraction radiation generated from a spherical target

Abstract

For the first time the focusing effect in optical transition and diffraction radiation generated by 1.28 GeV electrons in a tilted spherical target has been observed experimentally. A comparison of detected as well as simulated radiation spatial distributions produced by a flat and a spherical target has been made. It is shown that the application of such targets has allowed us to increase the radiation spectralspatial density at the target focus without applying any additional focusing devices.

Smith-Purcell radiation from concave dotted gratings

“…control is the modification of the wave front, which already was implemented by altering the target geometry (geometric phase shift) [14,15]. However, it can also be introduced via planar phase shifts between diffraction elements of the dotted grating.…”