TESLA ACCELERATOR INSTALLATION
by Nebojša NEŠKOVIĆ
Abstract: The TESLA Accelerator Installation includes an isochronous cyclotron - the VINCY Cyclotron, a heavy ion source - the mVINIS Ion Source, and a light ion source - the pVINIS Ion Source. The diameter of the pole of the VINCY Cyclotron is 2000 mm. The bending constant of this machine is 145 MeV, while its focusing constant is 75 MeV. The radiofrequency system of the machine consists of two l /4-resonators with the eigenfrequency in the range from 17 to 31 MHz. The ions coming from the mVINIS Ion Source, or pVINIS Ion Source will be injected into the machine axially. They will be introduced into its median plane by a spiral inflector. The heavy ions accelerated in the machine will be extracted from it by a foil stripping system, or by an electrostatic deflection system. The light ions will be extracted from it by the foil stripping system. The extraction of the first ion beam from the VINCY Cyclotron will be performed by the end of June 1997. It will be the beam of protons with the energy of 30.2 MeV obtained from the beam of H 2 + ions extracted from the pVINIS Ion Source. This ion beam will be used first for the production of radioisotope 201Tl, to be employed for medical diagnostics. The first programs of use of the TESLA Accelerator Installation will be the following: modification and analysis of the physical properties of materials by ion beams, nuclear reactions with heavy ions at low and intermediate energies, radiation physics with light and heavy ions, radiolysis in condensed systems induced by heavy ions, physics of thin crystals, production of radioisotopes and radiopharmaceuticals, and biological effects induced by irradiation with light and heavy ions.
Key words: accelerators, cyclotrons, ion sources, applications of ion beams
PRODUCTION OF RADIONUCLIDES AND RADIOPHARMACEUTICALS IN THE VINČA INSTITUTE
PART I. PRODUCTION AND CONTROL OF THE PRODUCTS
by Nadežda VANLIĆ-RAZUMENIĆ
Abstract: The paper represents a comprehensive review of the activities of the "Vinča" Institute of Nuclear Sciences in developing a series of procedures for manufacture, purification and isolation of radionuclides, to be used either directly in technical applications, medicine, chemical and biological research, or to make labeled compounds and preparations, used as radiotracers for various applications, mostly for nuclear medicine (radiopharmaceuticals). Some radionuclides 131I, 198Au, 51Cr, 203Hg, 32P, 35S were obtained by neutron irradiation in the RA reactor, while 99mTc is obtained from the imported fission product 99Mo in the form of 99Mo/ 99mTc generators. Radiopharmaceuticals have been delivered to hospitals all over the country. Development of the manufacturing procedure of 35S enabled further development of a series of organic and inorganic 35S labeled compounds. Furthermore, synthetic procedures for numerous 14C labeled compounds were developed on the basis of the imported 14C barium carbonate as the starting substance. Compounds labeled with beta-emitters (14C and 35S) are used for chemical and biological research, except 32P which is used also in nuclear medicine. Technological procedures for fabrication of sealed radioactive sources for industrial and medical applications are also developed.
Key words: radioisotopes, radiopharmaceutical preparations, radionuclide production, technetium-99m, radiochemistry, nuclear medicine, radio-pharmaceutical control, RIA kits
SOME APPROACHES IN STUDYING EFFECTS OF RADIATION ON RATS AS MAMMALIAN SPECIES
by Olivera IVANIŠEVIĆ-MILOVANOVIĆ, Miroslav DEMAJO
Abstract: The character of changes which arise in a living organism after exposure to ionizing radiation is always the same, no matter on the type of radiation. The degree of damage depends on the dose of irradiation, the age of the organism and its physiological state. Mammals are most sensitive to irradiation during their intrauterine period of life, especially during organogenesis. Even low doses, to which the pregnant female is exposed, result in severe damages to the offspring. Significant from the point of biological and medical aspects, are those effects detectable at the endocrinological level. Of special significance are changes in the reproductive system in the offspring and filial generations that originate from irradiated ancestors. Applying hypothermia followed by hypoxia during irradiation showed a significant protective effect from irradiation damage. Thus, hypothermia applied on fetuses during irradiation, reduces mortality by 80%, while malformations are reduced by 50%. We may conclude that ionizing radiation, as an unspecific agent induces numerous changes in biological materials mediated by the ionization of water molecules, liberating an excess of harmful free radicals. Subjecting rats to hypothermia, which induces hypoxia, reduces the reactions of these free radicals with organic molecules, thus limiting the damages to tissues caused by radiation exposure.
Key words: X-rays, intrauterine irradiation, whole-body irradiation, head irradiation, hypothermia
ESTIMATION OF THE TEMPERATURE REACTIVITY COEFFICIENT AT THE PWR NUCLEAR POWER PLANT
by Ljiljana KOSTIĆ
Abstract: For monitoring temperature coefficient of reactivity of pressurized water reactors a method based on the correlation of fluctuations in signals of in-core neutron detectors and core-exit thermocouples and neural network paradigm is used. It is shown that the moderator temperature coefficient of reactivity can be predicted with the aid of the back propagation neural network technique by measuring the frequency response function between the in-core neutron flux and the core-exit coolant temperature.
Key words: moderator temperature reactivity coefficient, pressurized water reactor, neutron flux, coolant temperature, fluctuations, frequency response function, neural network, driving noise source