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Assuming f0(980) and a0(980) are mainly qqqq low mass scalar mesons and mixed with qq high mass scalar mesons, we analyzed the mixing effects for φ → f0(980)γ, φ → a0(980)γ, f0(980) → γγ and a0(980) → γγ. Used the vector meson dominance model (VDM), these decay amplitudes are expressed by coupling parameters B describing the S(qqqq scalar meson)‐V(vector meson)‐V(vector meson) coupling and B′ describing the S′(qq scalar meson)‐V‐V coupling. If the magnitudes for B and B′ are ∼ 2.8GeV−1 and ∼ 12GeV−1, respectively, the mixing angle between a0(980) and a0(1450) are ∼ 9°, and the mixing parameter λ01 causing the mixing between I = 0 qqqq state and qq state is ∼ 0.24GeV2 , the experimental data for these radiative decays are interpreted consistently.

To improve the purity of the ion beams new type of pulsed power ion accelerator named “bipolar pulse accelerator” was proposed. The accelerator consists of two acceleration gaps (an ion source gap and a post acceleration gap) and a drift tube, and a bipolar pulse is applied to the drift tube to accelerate the beam. In the accelerator intended ions are selectively accelerated and the purity of the ion beam is enhanced. As the first step of the development of the accelerator, a Br-type magnetically insulated acceleration gap is developed. The gap has an ion source of coaxial gas puff plasma gun on the grounded anode and a negative pulse is applied to the cathode to accelerate the ion beam. By using the plasma gun, ion source plasma (nitrogen) of current density around 100 A/cm2 is obtained. In the paper, the experimental results of the evaluation of the ion beam and the characteristics of the gap are shown with the principle and the design concept of the proposed accelerator.

To apply an intense pulsed ion beams produced in plasma focus (PF) to material processing, characteristics of the beam was evaluated. In the experiment a Mather type PF was used which was pre-filled with N 2 (5.5 Pa) to produce nitrogen ions. To clarify the mechanism of the production of impurity ions, two types of anode (type A; rod type and has an anode tip on the top, type B; hollow shape top) were used. In both type peak discharge currents of 550 kA were obtained at 1.5 µs after the rise of the current. From the measurement by Thomson parabola spectrometer large quantity of copper ions were observed when type A is used and the purity for type A and type B were evaluated to be 26 % and 90 %, respectively. To enhance the energy and the charge state of the nitrogen ions the PF with type B anode was pre-filled with mixture of nitrogen and hydrogen (N 2 20, H 2 180 Pa). From the TPS measurement, multiply ionized nitrogen ions (N1−5+) of energy more than several MeV were observed with protons of maximum energy 1 MeV. Thin layer of amorphous silicon was irradiated by the ion beams produced in PF and we found that the layer was crystallized.