A new device intended for UV-light generation and based on cold electron emission is proposed and analyzed theoretically. The device operation is based on the excitation by the field emitted electrons of the surrounding nitrogen (N-2) molecules, which in turn emit UV Light. The device should operate at low pressures compatible with field emission. The proposed device involves electrons moving in crossed electric E and magnetic B fields. Equations for the electron time evolution (both radial and angular position) are obtained. When moving inside the device, the electron has a periodical cycloid-like trajectory which is always confined between two coaxial cylinders. The inner cylinder has the same radius and position with the circular array of emitters used for electron generation. The position of the outer cylinder (and so the width of the confinement zone) is controlled by E and B. The described analytical-numerical approach is used to analyze the device operation as function of model parameters.