论文标题
在脱落的情况下，通过轨道响应测量对圆形晶格的反向建模
Inverse modeling of circular lattices via orbit response measurements in the presence of degeneracy
论文作者
论文摘要
在圆形晶格中，BPM和转向器相对于四倍体的数量和相对位置可能会导致在加速器光学的反向建模的情况下导致退化。此外，梁位置监测器引入的测量不确定性可以通过反向建模过程以禁止成功估计模型误差的方式传播。在这一贡献中，研究了BPM和Steerer放置对反问题调节的影响。 Jacobian的分析版本将四极梯度误差与BPM连接起来，并通过轨道响应矩阵获得了增益错误。已经证明，这种分析版本的雅各布式可以代替拟合过程中数值获得的雅各布。该方法首先通过模拟测试，并通过对GSI的SIS18同步加速器的测量数据进行了验证。结果与标准数值雅各布方法进行了交叉检查。确定了在SIS18上观察到的调节差异的四极误差。
The number and relative placement of BPMs and steerers with respect to the quadrupoles in a circular lattice can lead to degeneracy in the context of inverse modeling of accelerator optics. Further, the measurement uncertainties introduced by beam position monitors can propagate by the inverse modeling process in ways that prohibit the successful estimation of model errors. In this contribution, the influence of BPM and steerer placement on the conditioning of the inverse problem is studied. An analytical version of the Jacobian, linking the quadrupole gradient errors along with BPM and steerer gain errors with the orbit response matrix, is derived. It is demonstrated that this analytical version of the Jacobian can be used in place of the numerically obtained Jacobian during the fitting procedure. The approach is first tested with simulations and the findings are verified by measurement data taken on SIS18 synchrotron at GSI. The results are crosschecked with the standard numerical Jacobian approach. The quadrupole errors causing tune discrepancies observed at SIS18 are identified.
