Construction and development of pulsed periodic-action reactors in JINR

Design and operation of pulsed IBR-type reactors using time-of-flight methods for the nucleus neutron spectroscopy and investigations into solid-state physics are described. Revolving reactivity modulator consisting in the first designs of a fissile material and in the last one (IBR-2) - of the neutron moderator, appears to the basis of the reactor design. The first 1 kW average capacity IBR reactor produced pulses with the duration of 40 μs and 5-83 s-1 frequency neutron flux density made up 1013 cm-2xs-1. Booster regime was used at the IBR-30 reactor with the average capacity of 25 kW, for which linear electron accelerator was applied. Neutron fluxes with the density of 1016 cm-2c-1, pulse duration of 215 μc and frequency of 5 s-1 are produced at the IBR-2 reactor with the average capacity of 2MW and capacity in pulse - 1500 Mw. The reactor has 14 neutron-guides for beam rejection and will operate in future in combination with a strong-current electron accelerator LIU-30