Research in the field of new UV-radiation sources is topical due to several reasons. First, there is a decision to get rid of mercury-containing light sources, both in industry and in the private life (Minamata Convention on Mercury). Second, the UV-radiation sources with improved spectral characteristics are needed for photochemical processes, disinfection, medical treatments.  Cathode-ray radiation sources represent one of possible solutions. The electron-beam excitation of a luminophore is well-known in CRT having a long application history in TV sets and information displays. By replacing the phosphor with a UV-emitting one, it is possible to create sources of UV-radiation. Many types of UV-band luminophores are already known with an efficiency of cathodoluminescence up to 9% [1] and even 20%. The theoretical limit is 40-50%.  The use of the non-heated field emission cathode allows decreasing the power consumption of the device and increases its service life. Carbon fiber based field emission cathodes for cathode-ray light sources have been already proposed and investigated [2]. Lithium Tetraborate (LTB) based phosphors are promising due to the stability under the electron beam. Some of LTB phosphors have been synthesized and tested.