Futoshi Minato

Generation of radioisotopes with accelerator neutrons by deuterons

A new system proposed for the generation of radioisotopes with accelerator neutrons by deuterons (GRAND) is described by mainly discussing the production of 99Mo used for nuclear medicine diagnosis. A prototype facility of this system consists of a cyclotron to produce intense accelerator neutrons from the natC(\(d\),\(n\)) reaction with 40 MeV 2 mA deuteron beams, and a sublimation system to separate 99mTc from an irradiated 100MoO3 sample. About 8.1 TBq/week of 99Mo is produced by repeating irradiation on an enriched 100Mo sample (251 g) with accelerator neutrons for two days three times. It meets about 10% of the 99Mo demand in Japan. The characteristic feature of the system lies in its capability to reliably produce a wide variety of high-quality, carrier-free, carrier-added radioisotopes with a minimum level of radioactive waste without using uranium. The system is compact in size, and easy to operate; therefore it could be used worldwide to produce radioisotopes for medical, research, and industrial...

Estimation of Production Yield of 99Mo for Medical Use using Neutrons from natC(d,n) at Ed=40 MeV

We estimated the production yield of 99 Mo from 100 Mo( n ,2 n ) 99 Mo using neutrons produced by bombarding a natural carbon target, nat C, with 40 MeV 5 mA deuterons. We used the latest data for the angular and energy distributions of neutrons from nat C( d , n ) and the evaluated cross section of 100 Mo( n ,2 n ) 99 Mo given in the Japanese Evaluated Nuclear Data Library to estimate the 99 Mo yield. The 99 Mo yields were obtained for different distances d between the carbon target and the 100 Mo sample, and for different 100 Mo sample radii and thicknesses. We typically obtained a 7.1 TBq activity of 99 Mo at the end of neutron irradiation for two days for a 100 Mo sample (251 g) placed at d =2 cm. The obtained 99 Mo activities show that a substantial fraction of the current 99 Mo demand in Japan could be met by adopting the proposed production method.

New Production Routes for Medical Isotopes 64Cu and 67Cu Using Accelerator Neutrons

We have measured the activation cross sections producing 64Cu and 67Cu, promising medical radioisotopes for molecular imaging and radioimmunotherapy, by bombarding a natural zinc sample with 14 MeV...

Fission barriers in the neutron-proton isospin plane for heavy neutron-rich nuclei

We discuss the sensitivity of fission barrier for heavy neutron-rich nuclei to fission paths in the two-dimensional neutron-proton quadrupole plane. To this end, we use the constrained Skyrme-Hartree-Fock + BCS method, and examine the difference of fission barriers obtained with three constraining operators, that is, the neutron, proton, and mass quadrupole operators. We investigate {sup 220}U, {sup 236}U, and {sup 266}U, that is relevant to r-process nucleosynthesis. We find that the fission barrier heights are almost the same among the three constraining operators even for neutron-rich nuclei, indicating that the usual way to calculate fission barriers with the mass quadrupole operator is well justified. We also discuss the difference between proton and neutron deformation parameters along the fission paths.

First Measurement of the Radionuclide Purity of the Therapeutic Isotope 67Cu Produced by 68Zn(n,x) Reaction Using natC(d,n) Neutrons

We have for the first time studied the radionuclide purity of the therapeutic isotope 67Cu produced by the 68Zn(n,x)67Cu reaction. The neutrons were obtained by the natC(d,n) reaction using 40 MeV ...

Collective excitations of Λ hypernuclei

Abstract We discuss low-lying collective excitations of Λ hypernuclei using the self-consistent mean-field approaches. We first discuss the deformation properties of Λ hypernuclei in the sd -shell region. Based on the relativistic mean-field (RMF) approach, we show that the oblate deformation for 28 Si may disappear when a Λ particle is added to this nucleus. We then discuss the rotational excitations of Mg Λ 25 using the three-dimensional potential energy surface in the deformation plane obtained with the Skyrme–Hartree–Fock method. The deformation of Mg Λ 25 is predicted to be slightly reduced due to an addition of a Λ particle. We demonstrate that this leads to a reduction of electromagnetic transition probability, B ( E 2 ) , in the ground state rotational band. We also present an application of random phase approximation (RPA) to hypernuclei, and show that a new dipole mode, which we call a soft dipole Λ mode, appears in hypernuclei, which can be interpreted as an oscillation of the Λ particle against the core nucleus.

Application of random phase approximation to vibrational excitations of double-

Using the Hartree-Fock plus random-phase-approximation (HF+RPA), we study the impurity effect of

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hypernuclei

hyperon on the collective vibrational excitations of double-

Nuclear Level Densities with Microscopic Statistical Method Using a Consistent Residual Interaction

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