PhaseⅠcommissioning of the SSRF storage ring at 3.0 GeV was ended with encouraging results. Distortions and calibrations of the linear optics during the storage ring commissioning are discussed in this paper.The cali...PhaseⅠcommissioning of the SSRF storage ring at 3.0 GeV was ended with encouraging results. Distortions and calibrations of the linear optics during the storage ring commissioning are discussed in this paper.The calibration procedure has reduced sextupole-additional focusing effects by minimizing closed orbit deviation and corrected quadrupole magnetic coefficients with the linear optics from closed orbit (LOCO) technique.After fitting the closed orbit response matrix,linear optics of the storage ring is substantially corrected,and the measured parameters agree well with the design.Four optics modes were commissioned,and relevant machine physics studies were carried out.Their results are summarized.展开更多
This paper presents a novel approach to seek the bar width for ripple filter used in pencil beam scanning proton therapy.A weight decay quadratic programming method is employed for the new optimization strategy.Compar...This paper presents a novel approach to seek the bar width for ripple filter used in pencil beam scanning proton therapy.A weight decay quadratic programming method is employed for the new optimization strategy.Compared to the commonly used iterative-least-square technique,the ripple filter derived by the proposed method not only has better depth dose uniformity,i.e.,the dose uniformity is within 0.5%,but also has triangle-like vertical cross-sectional shape which is suitable for manufacture.Moreover,the new method has such good robust characteristics that it is also applicable to the real application with unavoidable measurement errors and noises.The simulation results of this study may be helpful in improving the design of the ripple filter.展开更多
文摘PhaseⅠcommissioning of the SSRF storage ring at 3.0 GeV was ended with encouraging results. Distortions and calibrations of the linear optics during the storage ring commissioning are discussed in this paper.The calibration procedure has reduced sextupole-additional focusing effects by minimizing closed orbit deviation and corrected quadrupole magnetic coefficients with the linear optics from closed orbit (LOCO) technique.After fitting the closed orbit response matrix,linear optics of the storage ring is substantially corrected,and the measured parameters agree well with the design.Four optics modes were commissioned,and relevant machine physics studies were carried out.Their results are summarized.
文摘This paper presents a novel approach to seek the bar width for ripple filter used in pencil beam scanning proton therapy.A weight decay quadratic programming method is employed for the new optimization strategy.Compared to the commonly used iterative-least-square technique,the ripple filter derived by the proposed method not only has better depth dose uniformity,i.e.,the dose uniformity is within 0.5%,but also has triangle-like vertical cross-sectional shape which is suitable for manufacture.Moreover,the new method has such good robust characteristics that it is also applicable to the real application with unavoidable measurement errors and noises.The simulation results of this study may be helpful in improving the design of the ripple filter.
