IBR-2 reactor operating start-up and first studies with its beams

Main results of start-up tests of pulsed periodic IBR-2 reactor are reported. Tests were concluded for the mean power levels up to 2MW at which the reactor was put in operation. Data on basic performances and parameters of the reactor as a pulsed neutron source are presented. Results of the first physical experiments on extracted IBR-2 beams are discussed. IBR-2 core is loaded by PuO2 fuel of 90 kg mass. Puel rods are cooled by sodium with 300 deg C inlet temperature. The reactor is surrounded by water neutron moderators which are scanned by 14 horizontal channels. Power pulse is formed by the basic mobile neutron reflector rotating with 1500 rev/min speed. Pulse-repetition rate changes discretely by means of additional reflector which rests or rotates with lower speed. Physical facilities are located in two experimental rooms. Spectrometers of elastic and inelastic neutron scattering are used in research program. Eight beams (9 facilities) are used currently for investigations of physics of elementary particles, condensed media and radiobiology. Four beams are under assimilation