Prospects for the use of X-ray tubes with a field-emission cathode and a through-type anode in the range of soft X-ray radiation

The use of field emission cathodes in X-ray tubes requires the placement of the cathode assembly with a small gap from the anode, and this hampers the output of radiation. The greatest difficulties arise in the generation of a relatively soft spectrum with wavelengths of 1–10 nm: in this case, the accelerating voltage does not exceed several kilovolts and the interelectrode gap does not exceed several hundred microns. In this work, the possibility of using submicron films based on beryllium as through-type anodes for emitting the Be$K_{\alpha}$ line ($\lambda$ = 11.4 nm) and the accompanying bremsstrahlung spectrum is experimentally demonstrated. In particular, the characteristic radiation of a tube with a field emission blade-type cathode and a Be-film anode, introduced into a grazing incidence grating spectrometer, was detected. The characteristics of beryllium films necessary for designing high-power X-ray tubes of this type are determined.