The differential elastic and total reaction cross sections of the K+-meson interactions with 12C and 40Ca at  the beam momentum 0.635, 0.715 and 0.8 GeV/c are calculated. To this end the microscopic optical potential derived within the high-energy approximation is applied. It includes dependence on the kaon-nucleon amplitude of scattering and the density distribution function of point nucleons of a target-nucleus. Basing on the high-energy approximation the Klein-Gordon-Fock equation reduces to the Shroedinger equation form. It is shown that little differences between approaches of such reductions do not lead to a visible changes in elastic scattering, but the effect of relativization itself occurs very important. The successful agreement with the experimental data on the K+A elastic scattering is shown. The total reaction cross sections are shown can be explained by addition to the volume potential the term in the form of its derivative, having the maximum in a periphery, and which contribution is adjusted to the experimental data.

    A three-dimensional neutronic code POWEX-K has been developed, and it has been coupled with the sub-channel thermal-hydraulic core analysis code SV based on the Single Mass Velocity Model. This forms the integrated neutronic/thermal hydraulics code system POWEX-K/SV for the accident analysis. The Training and Research Reactors at Budapest University of Technology and Economics (BME-Reactor) has been taken as a reference reactor. The cross-section generation procedure based on WIMS. The code uses an implicit difference approach for both the diffusion equations and thermal-hydraulics modules, with reactivity feedback effects due to coolant and fuel temperatures. The code system was applied to analyzing power excursion accidents initiated by ramp reactivity insertion of 1.2 $. The results show that the reactor is inherently safe in case of such accidents i.e. no core melt is expected even if the safety rods do not fall into the core.

Keywords: Gauss-Seidel iteration; reactivity accident, single mass velocity model, thermalhydraulic.

Nuclear Analytical Methods for Trace Element Studies in calcified Tissues
    Various nuclear analytical methods have been developed and applied to determine the elemental composition of calcified tissues (teeth and bones). Fluorine was determined by prompt gamma activation analysis through the 19F(p, alpha-gamma)16O reaction. Carbon was measured by activation analysis with He-3 ions, and the technique of Proton-Induced X-¬ray Emission (PIXE) was applied to simultaneously determine Ca, P, and trace elements in well-documented teeth. Dental hard tissues: enamel, dentine, cementum, and their junctions, as well as different parts of the same tissue, were examined separately. Furthermore, using a Proton Microprobe, we measured the surface distribution of F and other elements on and around carious lesions on the enamel. The depth profiles of F, and other elements, were also measured right up to the amelodentin junction.

Secondary Neutron Production in Tissue during High Energy Bremsstrahlung and Hadron Therapy
    The total yield of photo-neutrons from soft-tissue-equivalent material irradiated with ?remsstrahlung of end-point energy from 6 to 28 MeV has been measured using the 35 MeV University of Melbourne Betatron and a 4p Halpern-type neutron detector. The results are compared with calculations based on the cross sections for neutron production of the constituent elements of tissue (H, C, N and O). It is shown that the less common isotopes of the constituent elements (2H, 13C, 15N, 17O,18O) must be included to obtain agreement with the measured yields.
Moreover, we have also estimated the secondary neutron yields from tissue under irradiation with Hadrons (protons, alphas, carbon and neon ions, etc.) of up to 400 MeV per nucleon energies. Our results indicate that at least 4.2 neutrons , with energies greater than 5 MeV,  are produced for every carbon ion of 400 MeV / u energy incident on tissue. This number reduces to 3, 1.4 and 0.3 respectively at carbon energies of 300, 200 and 100 MeV /u. The energy range of carbon ions considered here, 100 MeV/u to 400 MeV/u, corresponds to that being actually used in therapy. It is suggested that due to the very high number of the secondary neutrons being produced in patients during therapy with Hadrons, especially with heavier ions, extreme care should be taken while deciding to treat patients with C-ions, especially the younger patients who have many years of their lives ahead of them

Studying the Effect of 1974 french Atomic Tests in The Pacefic on Australian Atmosphere- A Novel Approach to Nuclear Metrology
    A novel approach has been selected to study the effects of French Atomic Tests series of 1974 on the Australian atmosphere. This is to investigate the changes in the elemental concentrations of the atmospheric particulates collected in Australia just before and after the onset of the atomic tests in the Pacific. The atmospheric particulates were collected on Polystyrene filters in high volume air samplers placed all along the Australian East Coast at locations in Port Moresby (New Guinea), Townsville, Brisbane, Sydney, Melbourne and Hobart. The elemental concentrations in the filters were measured by using the technique of charged particle activation analysis. A number of elements, such as S, Ca, Ti, Cr, Fe, Ni, Cu, Zn, Se and Hg ranging in concentrations from 0.001- 3.27 micrograms / cubic metre, were detected. The changes observed in the concentrations of these elements in the two sets of samples, taken just before and just after the Atomic Tests, are attributed to synoptic rather than Nuclear Fall-Out effects. The advantages of this novel approach for nuclear metrology, especially by making use of the latest analytical techniques, such as ICP-MS which can determine all the elements and isotopes from Li up to U simultaneously, would be highlighted.

    The lecture presents a review of cyclic accelerators and their energy limitations. A description is given of the phase stability principle and evolution of the synchrotron, an accelerator without energy limitation. Then the concept of colliding beams emerged to yield doubling of the beam energy as in the Tevitron 2 trillion electron volts (Tev) proton collider at Fermilab and the Large Hadron Collider (LHC) which is now planned as a 14-Tev machine in the 27 Kilometer tunnel of the Large Electron Positron (LEP) collider at CERN. Then presentation is given of the Superconducting Supercollider (SSC), a giant accelerator complex with energy 40-Tev in a tunnel 87 Kilometers in circumference under the country surrounding Waxahachie in Texas, U.S.A. These superhigh energy accelerators are inteded to smash protons against protons at energy sufficient to reveal the nature of matter and to consolidate the prevailing general theory of elementary particles.

    A new irradiation facility has been designed, constructed and located at the Experimental Nuclear Physics Department, NRC, AEA, Cairo. The facility is based on an Am-Be (a, n) source with activity of about 175 GBq results in a neutron yield of about 2.5*106 fl/S. The geometrical arrangements of the facility consider the safety aspects and protection rules. This new irradiation facility uses fast and epithermal neutrons that can be used in basic research and industrial applications. The aim of the present work is to develop methods able to use fast and epi-thermal neutron activation analysis to estimate the hydrogen content in bulk samples through neutron reflection and transmission processes.

Keywords: neutron flux, neutron reiketion, neutron transmission, hydrogen content determination.

    Poly(3-hydroxybutyrate) PHB is a biotechnologically produced polyesters, highly crystalline, totally biodegradable with low versatility in mechanical properties. To overcome this proplem it is performed a reactive blending producer with a glassy acrylic polymer, Poly(methylmethacrylate) (PMMA) with different concentrations. positron annihilation lifetime (PAL) spectroscopy has been used to study the effect of PMMA concentrations on the free volume hole properties of PHB. PAL spectra were analyzed using PALSFit program into three components which reflected three different morphologies of the polymer structure. The ortho-postronium (o-Ps) parameters revealed an inflection at (75/25 wt/wt) PHB/PMMA blend. Pure PHB and (75/25 wt/wt) PHB/PMMA blend have been measured as a function of temperature from -30 oC to 90 oC. The data clearly revealed the glass transition temperature (Tg) at zero oC. An attempt is done to find a correlation between the electrical properties of PHB with different concentrations of PMMA and the positron annihilation parameters.

    Polyoxymethylene (POM) Copolymer is notable for their high degree of crystallinity, which gives them: high strength, stiffens and hardness, good chemical and environmental resistance and low moisture absorption. Structure changes in ?-irradiated samples were investigated by positron annihilation lifetime spectroscopy (PALS) and means of X-ray measurement. The PAL measurements were performed using fast-fast coincidence at room temperature at doses (0.6, 2, 5, 10, 20, 80, 160, 200 and 500 KGy). The observed lifetime spectra were resolved using (LT 0.9) program into three components. The size and the fractional of the free volume holes were estimated from the positron annihilation parameters . The ortho-positronium lifetime and its intensity show two inflection points at (20, 80 KGy). The mechanical properties of ?-irradiated samples of POM copolymer were also measured by Lietz microhardness tester as an attempt to find a correlation between the macroscopic properties of POM and microscopic parameters. Moreover, The experimental results suggest that the chemical structure plays a main role in the result of the radiation reaction, which is related to cross-linking and degradation reactions.

    Positron annihilation lifetime (PAL), infrared spectroscopy (IR) and electrical conductivity studies were carried out on a series of polycrystalline spinel ferrite with composition Li0.5-0.5xCuxFe2.5-0.5xO4 where (x = 0.2, 0.4, 0.6, 0.8, 1). The lattice parameter a , the radius of the tetrahedral A- sites (rA) and the radius of the octahedral B- sites (rB) were studied as a function of composition. The compositional dependence of the dc electrical conductivity ?dc showed a maximum at x= 0.4 then decreases with increasing Cu2+ ions content. This behavior was explained on the basis of the hopping conduction mechanism.
For lifetime measurements, a conventional fast –fast coincidence system with a resolution of 220 ps was used. The recorded lifetime spectra were analyzed in terms of two lifetime components ?1 and ?2 with their relative intensities I1 and I2. The variation in lifetime value is relevant to defect type, while changes in the intensity reflect amount of  defect concentration. The variations in positron lifetime parameters with Cu2+ ion substitution are attributed to positron trapping in tetrahedral and octahedral sites. Positrons initially get trapped in the vacancies in the octahedral sites. With doping by Cu2+ ions tetrahedral vacancies dominate as positron trapping sites. With further doping, some of the octahedral sites become vacancies and trap positrons.