| Paper | Title | Page |
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| MOPC146 | Development of Piezoelectric Pulse Gas Valve for Small ECR Ion Source | 418 |
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| In a conventional ion source, the source gas is continuously fed even in its pulse operation. This requires a high load to a vacuum pumping system. The situation is prominent when the gas load is relatively higher in such a high current ion source. In order to improve this situation, we try to supply gas only when it is needed by synchronizing the gas feed with the extraction of the ion beam. We have developed a small pulse-gas-valve using a commercially available disc-shape piezoelectric element. This valve is small enough to be mounted in our ECR ion source and is capable of very fast open-and-close operation of an order of kHz repetition. A small ECR ion source with this valve will be presented. | ||
| MOPP015 | Continuously Adjustable Permanent Magnet Quadrupole for a Final Focus | 583 |
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| A permanent magnet quadrupole with continuous strength adjustability has been fabricated. It has a five-ring-singlet structure, which was proposed by R. L.Gluckstern. Its small overall diameter allows an outgoing beamline to pass closeby. Since the permanent magnet pieces do not have any vibration source in themselves, this magnet could be used as a quadrupole in a final focus doublet. Such a quadrupole system is described. | ||
| WEPC164 | Development of Modulating Permanent Magnet Sextupole Lens for Focusing of Cold Neutrons | 2392 |
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| A modulating permanent magnet sextupole lens that can focus pulsed cold neutrons is under development. It is based on the extended Halbach configuration to generate stronger magnetic field. In order to adjust the strength, the magnet is divided into two co-axial nested rings, where the inner ring is fixed and the outer ring can be rotated. Synchronizing the period of the modulation with that of pulsed neutron beam suppress the chromatic aberration. We have fabricated a half-scale model and studied the strength, the torque and the temperature rise caused by eddy current. Now we are developing the full-scale model improving such problems. These two scale models of magnet are described. | ||
| THPP054 | Laser Cooling of Bunched Ion Beam at S-LSR | 3488 |
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S-LSR is an ion storage ring equipped with an electron cooler and a laser cooling system. The laser cooling experiments of coasting beams were carried out during last year*. Now we started bunched beam laser cooling. 40keV Mg+ beams are bunched by an untuned RF cavity for harmonic number 5-50, and is cooled by a single 280nm laser. Bunch length are measured by electrostatic pickups. When RF harmonic number is five, bunch lengths is shorten from 1m to under 0.14m by laser cooling. Since the bunch length after cooling is shorter than present monitor resolution, fluorescence measurement is in preparation. We have installed another small RF cavity for harmonic number 100. Synchrotron-betatron coupling will be induced by dispersion at the place of this cavity**. This effect is expected to realize three dimensional laser cooling. In this paper we present the result of bunched beam cooling and the trial to three dimensional laser cooling.
*M. Tanabe et al. Appl. Phys. Express, in press. |