Investigation of bismuth nuclei fission into three fragments with comparable masses by means of GeV energy photons

We present the results of experimental studies of the process of fission of ²⁰⁹Bi nuclei into three mass-comparable fragments by bremsstrahlung photons with maximum energies of 2 GeV and 4.5 GeV with use of nuclear photoemulsion implanted with bismuth nuclei. We compare the results with those obtained with proton beams.