Publications by authors named "R I Pomatsalyuk"

Based on analytical description of isotope production by bremsstrahlung (X-ray) radiation, an algorithm is proposed for calculating the optimal dimensions of a cylindrical target of given mass positioned at a given distance from a bremsstrahlung converter to ensure the maximum yield of the isotope product. The expressions are derived for the total activity and its distribution along the target axis. A technique of γ-spectrometric measuring the activity of a thick production target is proposed.

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Based on a developed analytical model, a method is proposed for measuring the photonuclear cross section averaged over bremsstrahlung flux without application of additional target-monitor of photon flux. The method involves the use of a thin isotopic target, that completely overlaps the photon beam (a photonuclear converter), as well as an algorithm for processing the data on the yield of a reaction under study in such a target. The novel technique was validated on the reactions Mo(γ,n)Mo and Ni(γ,n)Ni in the range of photon end-point energy of 40.

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An analytical method is used to describe isotope production at an electron accelerator. The key characteristics that determine the total target activity and its distribution have been established. The expressions for the reaction yield depend explicitly on the irradiation regime and parameters of the giant dipole resonance.

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When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure, and mapping out the strength and the isospin structure (neutron-proton (np) versus proton-proton (pp) pairs) of these virtual excitations is thus critical input for modelling a range of nuclear, particle and astrophysics measurements.

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We report high-precision measurements of the deeply virtual Compton scattering (DVCS) cross section at high values of the Bjorken variable x_{B}. DVCS is sensitive to the generalized parton distributions of the nucleon, which provide a three-dimensional description of its internal constituents. Using the exact analytic expression of the DVCS cross section for all possible polarization states of the initial and final electron and nucleon, and final state photon, we present the first experimental extraction of all four helicity-conserving Compton form factors (CFFs) of the nucleon as a function of x_{B}, while systematically including helicity flip amplitudes.

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