Radiation Physics Department

(Head – Dr. Sci., Professor P. G. Lytovchenko)

Department was created in 1960 as a department of the Institute of Physics of the Ukrainian Academy of Sciences.

Main directions of scientific activity: 

• Fundamental researches of the nuclear radiation effect on the physical properties of atomic and binary semiconductors and devices on their base.
• Research of radiation and growth defects in semiconductors and kinetics of defect-impurities complexes alteration.
• Neutron transmutation doping of semiconductors and study of their properties.
• Development and manufacture of different types of semiconductor detectors for dosimetry and spectrometry of nuclear radiation.

The most important scientific results: 

Time decrease of the oxygen precipitation is stated to take place in irradiated silicon. This phenomenon is caused by additional introduction of the centers of precipitate nuclei with the participation of the primary radiation defects generated by irradiation. The acceleration of oxygen precipitation in irradiated silicon is determined by the general concentration of introduced point radiation defects, i.e. by the irradiation fluence. Time of 50% - oxygen precipitation under annealing (600 - 800 °C) in silicon, irradiated by the neutron fluence £10¹⁶ n/cm²  is stated to decrease almost by the order and in silicon irradiated by the neutron fluence Ф>10¹⁶ n/cm² the process of the oxygen precipitation becomes homogeneous and kinetics of preci­pitation is conditioned mainly by the radiation defects introduced by the previous neutron irradiation.

·        The cyclic loading by the ultrasound of GaP devices with the high density  is proved to decrease the microplasma amount. Such extinguishing is a result of the mobile dislocations interaction with non-equilibrium defects agglomeration. Such an effect is particularly distinctly displayed on the specimens with radiation defects.

·      The phenomenon of superconductivity is discovered in Indium Arsenide (InAs) irradiated by 80MeV alpha-particles.

·      Radiation hardness is shown to increase (approximately 10 times to gamma-irradiation and 2 times to neutron irradiation) in neutron transmutation doped silicon due to the sinks, created under the neutron irradiation and technological annealing of silicon.

·      In Radiation Physics Department different types of semiconductor detectors for nuclear-physical experiments of KINR are developed and produced.  Semiconductor detectors are also supplied to Flerov’s Laboratory of Nuclear Reactions (Joint Institute for Nuclear Researches (Dubna, Russia).