| Paper | Title | Page |
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| MOPC060 | Transverse Resistive-wall Wake of a Round Pipe with Finite Thickness and its Effect on the ERL Multi-bunch Beam | 202 |
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We already started to study the effect of resistive-wall wake on the multi-bunch beam in an ERL (energy recovery linac)-based light source*, because resistive-wall beam breakup(RWBBU) could be caused by the cumulative transverse wake generated by interaction between the resistive vacuum pipe and the intense multi-bunch beam. However the resistive-wall wake function of a round pipe used so far for studying the RWBBU was valid only in a limited time range and improper to the RWBBU simulation for a longer time period. Therefore we analytically derived an exact expression of resistive-wall impedance of a round pipe with finite thickness over all the frequency range and numerically calculated the resistive-wall wake functions of several different pipes from the exact impedance expression. The calculated wake functions enabled us to study and simulate the beam behavior in an ERL made of the pipes accurately. We will present the transverse resistive-wall wake of a round pipe with finite thickness and its effect on the ERL multi-bunch beam.
*N. Nakamura et al., Proceedings of PAC07, Albuquerque, June 2007, pp. 1010-1012. |
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| MOPC061 | Progress in R&D Efforts on the Energy Recovery Linac in Japan | 205 |
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| The future synchrotron light sources, based on the energy recovery linacs (ERL), are expected to be capable of producing super-brilliant and/or ultra-short pulses of synchrotron radiation. The ERL-based light sources are under development at such institutes as the Cornell University, the Daresbury Laboratory, the Advanced Photon Source, and KEK/JAEA. The Japanese collaboration team, including KEK, JAEA, ISSP, and UVSOR, is working to realize the key technologies for the ERLs. Our R&D program includes the developments of ultra-low-emittance photocathode DC guns and of superconducting cavities, as well as proofs of accelerator-physics issues at a small test ERL (the Compact ERL). A 250-kV, 50-mA photo-cathode DC gun is under construction at JAEA. Two single-cell niobium cavities have been tested under high electric fields at KEK. The conceptual design of the Compact ERL has been carried out. We report recent progress in our R&D efforts. | ||
| WEPC091 | Beam Injection by Use of a Pulsed Sextupole Magnet at the Photon Factory Storage Ring | 2204 |
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| We will install a pulsed sextupole magnet (PSM) in order to test a new injection system for the top-up injection at the Photon Factory storage ring (PF ring) in the spring of 2008. A parabolic magnetic field of the PSM can give an effective kick to the injected beam that passes a distant region from the field center. And there is little modulation of the orbit of the stored beam because it passes around the center of the PSM. To achieve the beam injection at the PF ring, the PSM has a length of 0.3m, a magnetic field of 400 Gauss at a peak current of 3000A and a pulse width of 2.4μsec in a half-sine form. We already made the PSM and measured the magnetic field. We will report the result of the PSM beam injection at the PF ring. | ||
| WEPC092 | A Pulsed Quadrupole Magnet Injection at the PF-AR Storage Ring | 2207 |
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| We have examined a beam injection system that used a pulsed quadruple magnet (PQM) at the PF-AR storage ring since the spring of 2004. The system is operating well and the accumulation of the beam up to 60mA in the single bunch operation is possible by the current state. The beam injection system that uses the PQM does not require a conventional injection bump orbit, and has the feature that only one PQM in the injection part is needed. An injected beam is kicked to be proportional to the distance from the center and captured afterwards. On the other hand, the pulse kick hardly influences the stored beam at the magnetic field center of the PQM. We report on the result of collecting the basic data of the influence on the PQM beam injection at the PF-AR storage ring. |