The presented review describes the current state of the art, methods, and techniques for producing neutron fluxes, as well as physical processes occurring in neutron tubes during their operation. Some attention is paid to the choice of structures and the principle of construction of the neutron generator schemes. Assessments are provided for the prospects of creating compact neutron generators with a neutron flux in the full solid angle of 1010 to 1012 n/s. It is demonstrated that conical targets are of interest not only in the context of nuclear fusion, but are also promising in the development of pulsed neutron generators. This review covers different plasma generators, including sources of particles, neutrons, and high-energy fluxes.