The 4π-fragment-spectrometer FOBOS developed for heavy-ion research at beam energies of 10–100 AMeV has been commissioned for physical experiments at the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research in Dubna. Based on the logarithmic detector principle, it is able to register charged fragments from protons up to heavy residual nuclei in a large dynamical range. Position-sensitive avalanche counters, axial ionization chambers and CsI(Tl) scintillation detectors are arranged in three concentric detector shells. An array of phoswich detectors is used as a more granular forward detector at narrow polar angles. The modular concept of FOBOS allows for different experimental application in the field of exclusive fragment spectroscopy at medium multiplicities. For illustration, the fragment spectroscopy studies concerning the spontaneous fission process and the fragmentation of hot nuclei by means of the FOBOS set-up are considered.

The projectile-like fragment Separator COMBAS is being designed at the Flerov Laboratory of Nuclear Reactions, JiNR Dubna, for providing radioactive nuclear beams. COMBAS is a compact achromatic beam line with a high resolving power of 4360. It accepts fragments within 6.4 msr solid angle and with a momentum spread of 10%. The method of isotopic Separation is based on a combination of magnetic rigidity and energy loss analysis. The sepürated radioactive bearn is planned to be transported either into a time-projection charnber in the regime gas target - gas detector or to a secondary target positioned in the centre of the FOBOS 4n-array or to another Set-up. The FOBOS detector is intended for heavy ion reaction studies in the bombarding energy range of 10-100 AMeV at the cyclotron U-400M of the FLNR. Presently, only pnmary cyclotron beams are used because COMBAS is not yet complete. FOBOS consists of a gas-detector bali of 30 position-sensitive avalanche counters and 30 axial ionization chambers behind them and an outer scintillator shell of 210 CsI(T1) counters surrounding the gas detectors. An array of 96 phoswich counters Covers the very forward angles. All charged reaction products can be measured in a wide dynamic range and in a geometq covering a substantial part of 4n. First data have ben taken concerning kission and emission 0f intermediate-mass fragmenis in the reactions 'Li (43 AMeV) on 232~11 and 14~ (34 AMeV) Ig7~u.