Energy spectrum of electrons transmitted through curved dielectric tubes

The transmission coefficients and the energy spectra of electrons with an energy of 10–20 keV transmitted through curved glass and polyurethane tubes are measured with a cylindrical electrostatic analyzer. The spectra of X-ray excited by these electrons at the tube outlet are also measured. At larger beamdeflection angles, the spectral distribution of electrons at the curved tube outlet expands considerably, and the maxima of the spectral curves shift toward lower energies. The obtained results suggest that electrons propagating within a curved tube lose energy in the process of inelastic collisions with walls. The transmission coefficient, which is determined by measuring the electron current at the tube inlet and at its outlet, depends only slightly on the electron energy (in the studied energy range) and drop by a factor of more than two when the deflection angle is increased from 0° to 90°.