Multilateral surface analysis of the CeB6 electron-gun cathode used at SACLA XFEL

The CeB6(001) single crystal used as a cathode in a low-emittance electron gun and operated at the free-electron laser facility SACLA was investigated using cathode lens electron microscopy combined with X-ray spectroscopy at SPring-8 synchrotron radiation facility. Multilateral analysis using thermionic emission electron microscopy, low-energy electron microscopy, ultraviolet and X-ray photoemission electron microscopy and hard X-ray photoemission spectroscopy revealed that the thermionic electrons are emitted strongly and evenly from the CeB6 surface after pre-activation treatment (annealing at 1500°C for >1 h) and that the thermionic emission intensity as well as elemental composition vary between the central area and the edge of the old CeB6 surface.

FORMATION OF INTENSIVE BEAMS OF CHARGED PARTICLES IN A TRANSAXIAL CATHODE LENS

The paper proposes a method for taking into account the effect of space charge on the quality of focusing of charged particles and investigates the problem of the formation of an intense flux of charged particles using a transaxial cathode lens, which is a special case of cathode lenses with two planes of symmetry. The article solves a self-consistent problem by representing the distribution functions of potentials and space charge in the form of power series in small parameters. The author uses an improved and proven method for studying cathode lenses, based on taking into account the longitudinal component of the total aberration. The necessary equations and formulas are obtained for calculating the parameters and designing a source of charged particles based on a transaxial cathode lens.