Toward the realization of crystalline beams-----Overall investigation of the fundamental properties of ultracold ion beams-----

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Theoretical Results :1.We have derived the orbit equations that govern the motion of individual particles forming a coasting crystalline beam in a storage ring.2.The necessary condition has been obtained to suppress the occurrence of severe collective instability during a beam cooling process.3.A novel dispersive effect peculiar to bunched crystalline beams has been discovered.4.In order to study the fundamental properties of ultracold ion beams systematically, we have developed a molecular dynamics (MD) code in which not only the exact lattice structure of a storage ring but also the dissipative interactions between laser photons and fast stored ions can be considered.5.Employing the new MD simulation code, we have confirmed the effectiveness of the resonant coupling method. In addition, it has been demonstrated that one- or two-dimensional crystalline beams could be formed in a properly-designed storage ring by combining existing accelerator technologies.Experimental Results :1.We have designed and constructed a linear Paul trap dedicated to beam-physics purposes, in particular, the study of space-charge effects. In order to reproduce lattice-dependent phenomena in a particle accelerator, a radio-frequency power supply system that can generate an arbitrary pulse waveform has been developed.2.Preliminary experiments have been done to check the performance of our system. Measurement data obtained with a MCP detector indicate that it is possible to confine a large number of ions in our trap for a sufficiently long time.3.Several compact atomic ovens have been constructed to produce Ca plasmas. We have succeeded in confining an almost pure ^<40>Ca^+ plasma by applying proper bias voltages to the quadrupole electrodes.4.We have equipped our trap system with a laser cooler that controls the phase-space density of a Ca plasma.