| Paper | Title | Page |
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| WEPCH025 | COD Correction at the PF Ring by New Orbit Feedback Scheme | 1978 |
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| When we correct the global COD (closed orbit distortion), if we use the modified conversion matrix calculated by the eigen vector method with constraint conditions (EVC), the local orbit correction can be simultaneously done to fix the light source point in the insertion device. In the EVC, the local orbit correction is combined to the global orbit correction by the Lagrange's undetermined multiple method. In this paper, we show the machine study results at the PF Ring. | ||
| THPCH052 | Dependence of Transverse Instabilities on Amplitude Dependent Tune Shifts | 2904 |
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| In the Photon Factory electron storage ring, transverse instabilities have been observed in multi-bunch operation mode. The instabilities can be suppressed by amplitude dependent tune shifts, which are induced by the sextupole, octupole and higher order magnetic field. Since four octupole magnets have been installed in the PF ring, we can control the tune shifts, which is caused by the octupole magnetic field, independently of chromaticities, which is caused by sextupole magnetic field. In order to research the suppression mechanism of the instabilities, we measured the dependence of the instabilities on the tune shifts, which are induced by the octupole field. The threshold of the tune shifts, which suppress the instabilities, were observed in the measurement, and it depended on the filling pattern of the bunch train and the beam current per bunch. In addition, we will present the results of the measurement before and after the reconstruction for the straight-sections upgrade at the PF ring, which was carried out in 2005. | ||
| THPLS036 | Results of the Straight-sections Upgrade of the Photon Factory Storage Ring | 3365 |
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At the 2.5-GeV ring of the Photon Factory (PF), a large reconstruction of the lattice around the straight sections* has been accomplished in 2005. As a result, four short straight sections of 1.5 m have been newly created, and the lengths of the existing straight sections have been much improved. For example, the length of the longest straight section has been extended to 9 m from 5 m. The optics has been optimized for installing short-period narrow-gap (in-vacuum) undulators at the new straight sections. The reconstruction work on the ring was held from March to September 2005. In the range over two-thirds of the storage ring, all the quadrupole magnets and all the beam ducts have been renewed and rearranged. Commissioning of the storage ring was started from the end of September 2005 and continued for one month. The operation for the user experiment was resumed from the end of October on schedule. Though we made no in-situ baking after the installation for the beam ducts, the vacuum scrubbing by the synchrotron radiation is running very well. The product of the beam lifetime and the beam current exceeded 700 A min for the operation current 450 mA at the end of December 2005.
*S. Asaoka et al. "New Upgrade Project for the Photon Factory Storage Ring", AIP Conf. Proc. 705, p161 (2004). |
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| THPLS107 | Possibility of the Beam Injection Using a Single Pulsed Sextupole Magnet in Electron Storage Rings | 3526 |
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| Recently, we succeeded in the beam injection using a single pulsed quadrupole magnet (PQM) at the Photon Factory Advanced Ring (PF-AR). The PQM enables us to inject the beam into the storage ring without the local bump by several pulsed dipole magnets. In addition, since the stored beam is not kicked when the beam passes through the magnetic center of the PQM, we can avoid the coherent beam oscillation, which is often produced by the unclosed local bump. It is important for the top-up injection in electron storage rings as synchrotron radiation sources. However, in the case of the PQM, we have the problem that the beam profile slightly changes turn-by-turn after the excitation of the PQM. In order to solve it, we investigated the possibility of the beam injection using a single pulsed sextupole magnet (PSM) instead of the PQM. Here, we will present the simulation of the beam injection using the PSM. |