[en] A study has been made of possible quadrupole and sextupole tuning configurations for the TARN to obtain various working lines in the νsub(x)-νsub(z) tune diagram, which may be useful in the experiments on injection and stacking to be done with this facility. These lines will give a large tune spread to stabilize the transverse collective instability. (author)

[en] Ion storage ring named TARN has been successfully operated at INS, which stores the low velocity ions (--7 MeV/u) in the betatron and synchrotron phase spaces by the amount of a few hundred turns. The operation results of the ring are described as well as the possible use of the ring for the study of beam dynamics in the storage ring of HIF scenario. Design outlines of NUMATRON, high energy heavy ion accelerator project in Japan, are given especially from the point of view of its usefulness for HIF accelerator study. (author)

[en] A correction system of chromaticities with use of sextupole magnets has been installed in TARN. Twelve magnets are devided into two families, SF and SD, which locate places with different twiss parameters to adjust chromaticities in horizontal and vertical directions indepent on each other. The sextupole magnet can excite the integrated sextupole strength (B''ds) of 66 kG/m for the excitation current of 400 A to attain enough chromaticity size for N⁵⁺ with kinetic energy of 8.55 MeV/u. With the sextupole system, working line nearly parallel to the difference resonance νsub(x) - νsub(z) = 0 has been realized. The chromaticities for this working line calculated by an analytical method with use of sextupole strength are -2.48 and -2.27 for horizontal and vertical directions, respectively, which are quite in good agreement with experimentary measured ones of -2.47 and -2.23. (author)

[en] In a circular accelerator, the resonance is one of the most important phenomena. The experiment for studying the charactristics of the resonance has been done in a storage ring, so called TARN, at INS. By ajusting the machine parameters so as to cross the 3rd order resonance, 3Qx = 7, in stacking process, we examined the correlation between the beam loss due to the effect of this resonance and the distance from the resonance point. The concept of the instability of the betatron oscillation by Courant and Snyder and the analytical treatment of resonances by Guignard were applied for discussing our data, and the stopband width of this 3rd order resonance is estimated about deltaQ = 0.001. (author)

[en] An accelerator complex consisting of storage rings of ions and electrons with their booster synchrotron of combined-function type is proposed as one of the candidates of the facility for the new campus of Kyoto University. Maximum energies for ions and electrons are 290 and 1500 MeV, respectively. Aimed beam intensities are 10¹⁰ and 4x10¹¹ per pulse for ions and electrons, respectively. With use of this accelerator complex, merging of highly ionized ions and trial of laser beam cooling to ultimate low temperature might be possible. The possibility of laser cooling with use of free electron laser is also to be studied

[en] General descriptions of the NUMATRON design and related technical developments at INS, University of Tokyo, are reported. A test accumulation ring for NUMATRON project, TARN, was constructed for integrating various technical developments. Recent results of injection test using this ring are also described. (author)

[en] A combination of multiturn injection and RF stacking is proposed as an efficient beam injection method in storage rings for heavy ion fusion program. Five turn injection in each transverse phase space and four RF stackings give total stacking turns of 100 which is a result of compromizing the tolerable emittances and momentum spread in the ring. Space charge limit and coherent beam instabilities are investigated and it is found that the most severe limit is transverse coherent instability but it will be managed by the use of sextupole and octupole magnetic fields. Assuming a charge exchange cross section as 1 x 10^-15 cm², the e-folding life time is estimated at 180 ms, while the stacking time is 40 ms. (author)

[en] The number of betatron oscillations per revolution (ν-value) can be measured experimentally by an RF knock-out method. The principle of the method is formulated. The RF knock-out system for TARN was desgned and constructed. Its design and specifications are described in detail. The experimental results with H₂⁺ and He²⁺ beams with the kinetic energy of 7 MeV/u are compared with the calculation with the computer program SYNCH. The νsub(x) and νsub(z) were measured to be 2.29 and 2.12, respectively, for the excitation currents of the quadrupole magnets; I sub(D) = 121 A (G sub(D) = 0.212 kG/cm) and I sub(F) = 74.5 A (G sub(F) = 0.131 kG/cm). The calculation indicates that the corresponding values are 2.21 and 2.19, respectively, which are in fairly good agreement with the experimental ones. (author)

[en] A measuring system for the field of a quadrupole magnet with a small bore radius in a drift tube linac is fabricated. The induced voltage at a rotating coil, the rotating axis of which is adjusted to the magnet axis, is analysed by a Fast Fourier Transformer (FFT). The measuring time can be made shorter with the use of an FFT. By calibration in a uniform field, the field gradient can be evaluated without the use of coil dimension. The accuracy of the measurement is better than +-8%. This system is applied to a permanent quadrupole magnet and its field gradient and sextupole components are measured to be 2.1 kG/cm and 0.81 G/cm₂. (author)

[en] Eight dipole magnets of window-frame type with zero field gradient have been fabricated for TARN. Various characteristics of the field were examined by a measuring system with a Hall and an NMR probes. The accuracy of the measurement was better than 1 x 10^-4 at the maximum field strength of --9 kG, and the uniformity of the field in the radial direction was better than +-2 x 10^-4 over the whole useful aperture. The deviations both of the field strengths and of the effective lengths among the eight magnets are smaller than +-2 x 10^-3. The sextupole component of the field and the variation of the effective length over the beam orbits contribute to chromaticities of the ring as the amount of -1.59 and 0.93 in the horizontal and vertical directions, respectively. (author)