| Paper | Title | Page |
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| WEPAL057 | Methods to Detect Error Sources and Their Application at the TPS | 2305 |
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| For a low-emittance photon light source, beam stability is a very important property to attain a high-quality photon beam. While it is hard to avoid beam perturbations in a storage ring, it is more important to quickly find the source locations and to remove or eliminate the sources as soon as possible. In this report, we develop a method to identify the locations of multiple sources. For a source with a particular frequency, the relative phase between sources can also be obtained. This method has been a useful tool during TPS operation and its methodology and practical applications are described in this report. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL057 | |
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| WEPAL058 | Beam Loss Studies at the Taiwan Photon Source | 2309 |
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| PIN-photodiodes and RadFETs are installed in the storage ring of the Taiwan Photon Source (TPS) to study beam loss distributions and mechanisms. In the highest dose area, the radiation comes mainly from hard X-rays produced by synchrotron bending magnets. During beam cleaning and after replacing a vacuum chamber, losses due to inelastic Coulomb scattering occur mostly downstream from bending magnets while elastic scattering causes electrons to get lost mainly after an elliptically polarizing undulator which has a limited vertical aperture. During the injection period, the beam loss pattern can be changed by modifying injection conditions or lattice settings. The beam loss usually happens in the injection section and small-aperture section. The injection efficiency can be improved by minimizing the detected injection loss. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL058 | |
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| WEPAL059 | Observation and Suppression of Beam Orbit Drift Due to Path Length Changes and Thermal Effect in TPS | 2313 |
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| Tidal effect, ambient temperature fluctuation and other effects of the TPS site can cause the path length changes of the electron beam in the TPS storage ring. Off-energy orbit drifts from the path length change, if not varying the RF frequency, cannot be properly corrected by the horizontal correctors and this causes the fast orbit feedback system over its normal working range. RF frequency adjustment loop is therefore applied to compensate for the circumference change based on the accumulating corrector strengths of the fast orbit feedback system. Implementation and operational experiences will be discussed in the report. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL059 | |
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| WEPAL062 | Bunch Length Measurements with a Streak Camera in Low Alpha Lattice Operation at the TPS | 2316 |
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We developed and tested lattice with lower momentum compaction factor (low alpha) in TPS (Taiwan Photon Source) recently. Operating low alpha lattice can provide picosecond bunch length for time-resolved research and coherent IR/THz synchrotron light. The bunch length around 2.5 picosecond rms was measured by a streak camera* in low alpha mode while operating in the routine users mode** it was around 10 picosecond. This paper presents the related processes and measurements.
* L.Y. Liao et al., "Preliminary beam test of synchrotron radiation monitoring system at Taiwan Photon Source", IPAC'15. ** C.C. Kuo et al., "Commissioning of Taiwan Photon Source", IPAC'15. |
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| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL062 | |
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| THPAK055 | Suppression of Transverse Beam Instabilities by Stripline Kickers at TPS | 3346 |
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| Collective beam instabilities could limit the accelerator performance if proper countermeasures are not in place. Active beam feedback systems are commonly used to suppress beam instabilities. The resistive wall impedance including phase-II insertion devices at TPS are calculated with analytical formulas. The growth rate of transverse coupled bunch instabilities due to wall impedance is estimated by theory. The RF properties of existing stripline kickers in TPS are analyzed with a 3-D electromagnetic simulation code GdfidL. Based on the above analysis, the requirements for a beam feedback system are calculated and the results are reported. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK055 | |
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| THPMK015 | Low Momentum Compaction Lattice Operation of the Taiwan Photon Source | 4325 |
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| In order to provide short bunch length for picosecond time-resolved experiments and for coherent IR/THz radiation, low momentum compaction factor (alpha) lattices have been commissioned recently at the Taiwan Photon Source (TPS). The momentum compaction can be positive or negative and its value can be reduced by more than two orders of magnitude. In this paper, we discuss variable low alpha lattice optics, its beam dynamics issues, the measured momentum compaction and bunch lengths as well as beam orbit stability issues, etc. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK015 | |
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