Low-divergent, quasi-stationary neutral beams are often applied in modern magnetic fusion devices as a diagnostic tool providing unique information about plasma parameters. The most important requirements to these beams are sufficiently large current and energy of the particles, so that the beam could penetrate to plasma core. At the same time, duration of the beams should be long enough, close to that of a plasma shot, amounting to, at least, a few seconds for large machines. We developed neutral beam injector which is capable to meet above mentioned requirements. Plasma emitter in the injector is provided alternatively radio frequency or arc discharge in hydrogen (deuterium).