[en] Short communication

[en] No-carrier added ⁷⁵Se (T_1/2 = 120 d) was produced with a high-current Cu₃As-target via the ⁷⁵As(p,n)-reaction. A two-step thermochromatographic method using O₂ as the purging gas was developed to separate radioselenium which was taken up in 6 M HCl. A 4 h irradiation with protons (E_p = 17 → 0 MeV) at a beam current of 20 μA led to about 37 MBq (1 mCi) of no-carrier added ⁷⁵Se. The product was of high radionuclidic purity and predominantly consisted of ⁷⁵SeO^2-₃. After reduction with SO₂, the radioactive species was efficiently extracted in benzene and showed high chemical reactivity. The extraction behaviour of radioselenium in benzene was found to be strongly influenced by the arsenic concentration in the solution. (orig.)

[en] Short communication

[en] We have measured the cross sections, averaged over a ²³⁵U fission neutron spectrum, for the two high threshold reactions: ⁷⁵As(n,p)⁷⁵mGe and ⁷⁵As(n,2n)⁷⁴As. The measured averaged cross sections are 0.292±0.022 mb, referred to the 3.95±0.20 mb standard for the ²⁷Al(n,p)²⁷Mg averaged cross section, and 0.371±0.032 mb referred to the 111±3 mb standard for the ⁵⁸Ni(n,p)^58m+gCo averaged cross section, respectively. The measured averaged cross sections were also evaluated semi-empirically by numerically integrating experimental differential cross section data extracted for both reactions from the current literature. The calculations were performed for four different representations of the thermal-neutron-induced ²³⁵U fission neutron spectrum. The calculated cross sections, though depending on analytical representation of the flux, agree with the measured values within the estimated uncertainties. (author)

[en] There has been universal agreement among the cosmologists and astronomers that most of the mass of the universe is dark. There are overwhelming evidences to believe that dark matter candidates are mostly nonbaryonic, the baryonic component is roughly 20%. The most promising nonbaryonic cold dark matter candidates are the Weakly Interacting Massive Particles (WIMP) which arise in super symmetric theories of physics beyond the standard model

[en] A 4⁺, 1.3 s isomer has been found at 102.6 keV in ⁷⁶Br using the ⁷⁵As(α,3n) reaction. A previously reported band structure is interpreted to decay into this isomer. (Auth.)

[en] In this paper few reaction cross-sections are measured using neutron activation technique. The cross-sections were measured at 14.0 MeV and compared with the existing data available in EXFOR (Exchange Format) data base. These are the base materials and used as structural material in reactor. The measured cross-section is important for the fusion reactor as well as for the Advance Accelerator based Sub-Critical Systems. Theoretical calculations for these data was done using TALYS-1.6 nuclear data evaluation code. Detail nuclear model consideration will be discussed at the time of presentation

[en] Based on a theoretical evaluation of the charged particle induced reactions leading to ⁷⁵Br the four most promising reactions, ⁷⁶Se(p,2n)⁷⁵Br, ⁷⁶Se(d,3n)⁷⁵Br, ⁷⁵As(³He,3n)⁷⁵Br and ⁷⁵As(⁴He,4n)⁷⁵Br, were selected for excitation function measurements. From the measured excitation functions the production rates and radionuclide purities were calculated. The proton induced reaction on ⁷⁶Se showed the highest production rate (118 mCi/μAh) while the contamination of the undesired nuclide ⁷⁶Br is limited to 1.4%. (author)

[en] Short communication

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