[en] The ninth International Symposium on Electron Beam Ion Sources and Traps and Their Applications - EBIS/T 2004 was held at the Tokyo Metropolitan University (TMU), 15-17 April 2004. There were about 40 participants and about 30 papers presented. The meeting has shown the remarkable progress in science and technology with the EBIS/T machines. In this meeting, besides the normal presentations related to the EBIS/T works, a special session was organized on the last day which was dedicated to Professors N Kobayashi and K Okuno, who have contributed to the EBIS/T development and to the physics of highly charged ions (HCI), to mark their retirement from the TMU in March 2004. In the evening of the first day, there was a laboratory tour where the participants enjoyed seeing the Tokyo EBIT facility and also a beer party in a small hall next to the laboratory. The banquet was held in a traditional Japanese restaurant in a village under Mt Takao with the Japanese meals and performances, after seeing the HCI-research activities in the TMU. The next EBIS/T symposium will be held in Heidelberg in the summer of 2007 as a satellite meeting of XXV ICPEAC. We are looking forward to the next exciting meeting there. Finally, we thank all of TMU staffs and students for their help during the meeting. (preface)

[en] The fraction of metastable-state Ar₂⁺(3p₄₁D) ions in Ar₂⁺ beam has been determined by an optical attenuation method (OAM) combined with the conventional beam attenuation method. The present OAM is based on observation of spatial decay of specified emission line intensities arising from charge-changed ions, along the beam axis in a target gas cell. The validity of the OAM is discussed in detail. The cross sections for one-electron capture by the ground-state Ar₂⁺(₃P) ions, σ²¹, and by the metastable-state Ar₂⁺(₁D) ions, σ²¹ *, from Na have been measured independently by the OAM. Both the cross sections are of the order of 10^-₁₄ cm₂ and σ²¹ * is about 1.3 times as large as σ²¹ at the collision energy of 1.5 keV. (author)

[en] A new electron beam ion trap (Tokyo-EBIT) has been completed in Institute for Laser Science, University of Electro-Communications, Tokyo. The maximum parameters of the electron beam are designed to be 340 keV and 300 mA. The preliminary experiments have been performed in 1997. We report here the recent results and planned experiments such as electron-ion collision experiments, atomic structure measurements by X-ray and visible spectroscopy and ion-surface interaction experiments. (author)

[en] We are developing an ion trap system for nuclear physics research at INS using lasers and a Penning trap. It has several important features, no specificity to ion species, fast response due to dynamic trapping and hopefully high trapping efficiency. (author)

[en] A strong anharmonicity has been observed in the oscillation of ion clouds in an rf ion trap when two species of ions are stored simultaneously. This anharmonic term in the trapping potential is shown to be induced by the presence of two different species of ions. (author)

[en] Emission spectra between 2800 and 6000 A have been observed at the ionic energies from 0.2 to 12 keV. Absolute measurements of emission cross-sections have been made for the emission lines coming from ArII excited states at 4 and 8 keV with a crossed-beam technique. Processes of single-electron capture into the ArII 4p- and 4p'-states, with exothermicity of a few eV, take place dominantly (--10¹⁵ cm²), while the endothermic processes producing ArII in the 4d- and 5s-states occur with small cross-sections. Sum of the cross-sections for electron capture into the excited states observed is comparable with the total single-electron capture cross-section estimated from attenuation measurements of ion currents. Possible errors and uncertainties are discussed. (author)

[en] We have been using the Tokyo electron beam ion trap to investigate the relativistic and the quantum electrodynamical effects on the atomic structure of few electron heavy ions. In this paper, we present 1s binding energy measurement for hydrogen-like rhodium which was performed as one of such systematic studies. It has been obtained by measuring the X-ray transition energy for radiative recombination into the 1s vacancy of bare rhodium and subtracting the electron beam energy from it. For further investigation, a bent crystal spectrometer for hard X-rays is being developed. The design of the new spectrometer and the preliminary result with it are also presented

[en] Excitation cross-sections are obtained for each term of the ArII nl-states (nl = 4p, 4p' and 4d) at 4 and 8 keV. The relative population distribution among the terms of a given nl-state can be interpreted in terms of statistics based on the building-up principle of molecule under radial coupling scheme. The relative population distribution among the multiplets in a given term is proportional to their statistical weight; spin-orbit recoupling at large internuclear separations is responsible for the population mechanism. The energy dependence of excitation cross-sections is discussed in connection with the Landau-Zener theory. (author)

[en] Double charge transfer spectra of NO²⁺ were observed using 1.5-keV H⁺ projectiles. The vibrational progression of the X²Σ⁺ state was resolved. For the unresolved vibrational peaks of the A²Π state, peak-fitting procedures determined their energies and intensities. From the present observation, the ν=0 energy of the A²Π state given by threshold photoelectrons coincidence method was corrected, which confirmed the independent recent work by Eland et al. This correction was concluded from the smooth vibrational distributions, suggesting the Franck-Condon behavior. So Franck-Condon analyses were performed to deduce the bond lengths for the X²Σ⁺ and A²Π states, in a similar manner developed for photoelectron spectroscopy. For the X²Σ⁺ state, the error of the bond length thus estimated is 0.005 A compared with the rotational data. For another quantitative check, high-level ab initio calculations have also been done. The theoretical Franck-Condon profiles well reproduced the experimental spectra, verifying the validity of the Franck-Condon principle

[en] A highly efficient focusing device using RF multipole field 'sextupole-ion-beam-guide (SPIG)' has been developed for the ion guide isotope separator on-line (IGISOL). The SPIG, placed after the nozzle, consists of the six circular rods uniformly distributed on a circle in the plane perpendicular to the symmetry axis. Under the combined action of the sextupole RF electric field produced by the rods and helium gas flow, a good focusing and cooling of ions from the Ion Guide with highly efficient transmission are achieved in the SPIG. The experimental results using a discharge ion source show that almost nearly 90 % of the ions out of the nozzle can be transported through the SPIG, and the width of the kinetic energy distribution after the SPIG is about 0.8 eV (FWHM). These experimental results coincide well with the Monte-Carlo simulation results and the simulation also predicts the size of the spatial distribution in the plane perpendicular to the symmetry axis is smaller than 1 mm^φ at the end of the SPIG. (author)