Nuclear States with Abnormal Radii

The radius of a nuclear state is one of the most important its characteristics. Presently there were developed some methods exploiting special features of the nuclear reactions leading to short – lived excited states and allowing determination of their radii. Evidence of existing nuclear excited states with enhanced radii (size isomers) was obtained

Study of internal structures of 9,10Be and 10B in scattering of 4He from 9Be

A study of inelastic scattering and single-particle transfer reactions was performed by an alpha beam at 63 MeV on a 9$Be target. Angular distributions of the differential cross sections for the 9Be(4He,4He')9Be*, 9Be(4He,3He)10Be and 9Be(4He,t)10B reactions were measured. Experimental angular distributions of the differential cross sections for the ground state and a few low-lying states were analyzed in the framework of the optical model, coupled channels and distorted-wave Born approximation. An analysis of the obtained spectroscopic factors was performed.Comment: 16 pages, 7 figures, 3 tables, regular paper, mispritns are corrected in new versio

Production of ²³⁵Np, ²³⁶Pu and ²³⁷Pu via nuclear reactions on ^235,236,238U and ²³⁷Np targets

A summary of methods for cyclotron production of 235Np (396.1d), 236Pu (2.858y) and 237Pu (45.2d) via nuclear reactions with protons and 3He-ions on 235,236,238U and 237Np targets in wide energy ranges is given. Methods for the chemical separation and purification of these nuclides from the irradiated uranium and neptunium targets are described. Cross sections, yields and radionuclidic purities of 235Np, 236Pu and 237Pu are presented and compared with literature data on the nuclear reactions leading to these radionuclides. The nuclear reactions with the so far highest known yields of 235Np, 236Pu and 237Pu are determined: 236U(p, 2n)235Np, 237Np(p, 2n + pnβ-)236Pu and 237Np(p, n) 237Pu, respectively. The highest radionuclidic purity of 235Np, 236Pu and 237Pu tracers can be reached with the 236U(p, 2n)235Np, 236U(p, nβ -)236Pu and 237Np(3He, t) 237Pu reactions, respectively. In addition new cross sections and yield data of the 236U(3He, p3n)235Np reaction in the energy range 42.4-60 MeV are given.</p

Measurement of the 20 and 90 keV resonances in the 18O(p,α)15{}^{18}{\rm O}(p,\alpha){}^{15}N reaction via THM

The $^{18}{\rm O}(p,\alpha)^{15}{\rm N}$ reaction is of primary importance in several astrophysical scenarios, including fluorine nucleosynthesis inside AGB stars as well as oxygen and nitrogen isotopic ratios in meteorite grains. Thus the indirect measurement of the low energy region of the $^{18}{\rm O}(p,\alpha)^{15}{\rm N}$ reaction has been performed to reduce the nuclear uncertainty on theoretical predictions. In particular the strength of the 20 and 90 keV resonances have been deduced and the change in the reaction rate evaluated.Comment: 4 pages, 4 figures, submitted to PR

Molecular Structures in T=1 states of 10B

Multi-center (molecular) structures can play an important role in light nuclei. The highly deformed rotational band in 10Be with band head at 6.179 MeV has been observed recently and suggested to have an exotic alpha:2n:alpha configuration. A search for states with alpha:pn:alpha two-center molecular configurations in 10B that are analogous to the states with alpha:2n:alpha structure in 10Be has been performed. The T=1 isobaric analog states in 10B were studied in the excitation energy range of E=8.7-12.1 MeV using the reaction 1H(9Be,alpha)6Li*(T=1, 0+, 3.56 MeV). An R-matrix analysis was used to extract parameters for the states observed in the (p,alpha) excitation function. Five T=1 states in 10B have been identified. The known 2+ and 3- states at 8.9 MeV have been observed and their partial widths have been measured. The spin-parities and partial widths for three higher lying states were determined. Our data support theoretical predictions that the 2+ state at 8.9 MeV (isobaric analog of the 7.54 MeV state in 10Be) is a highly clustered state and can be identified as a member of the alpha:np:alpha rotational band. The next member of this band, the 4+ state, has not been found. A very broad 0+ state at 11 MeV that corresponds to pure alpha+6Li(0+,T=1) configuration is suggested and it might be related to similar structures found in 12C, 18O and 20Ne.Comment: 10 pages, 10 figures, accepted in Physical Review

Production of a C-15 radioactive ion beam based on O-18(n, alpha)

.In the context of the SPIRAL2 radioactive beam facility the production rate of the neutron-rich C-15 nucleus by O-18(n,) has been investigated. In a water target of 20 cm(3), enriched in O-18 and placed behind the neutron converter, a rate of a few 10(10) nuclei per second can be reached with 1mA of 40MeV deuterons. A O-18(n,) cross-section based on the activation method is proposed. It is intermediate between the highest and lowest evaluations available to date.Peer reviewe

Measurement of the Low-Energy Antideuteron Inelastic Cross Section

In this Letter, we report the first measurement of the inelastic cross section for antideuteron-nucleus interactions at low particle momenta, covering a range of 0.3 = 17.4 and 31.8 is obtained. The measured inelastic cross section points to a possible excess with respect to the Glauber model parametrization used in GEANT4 in the lowest momentum interval of 0.3Peer reviewe