ON MINIMIZATION OF IMPACT OF MAGNETIC ELEMENTS ADJUSTMENT TOLERANCES ON BEAM ORBIT DEVIATIONS IN SYNCHROTRONS

Рассматривается задача минимазации отклонений орбиты пучка заряженных частиц в синхротронах, вызванной погрешностью юстировки квадруполей. Разработан метод оптимизации траектории орбиты, основанный на применении роевых вычислений и метода градиентного спуска. Приведены результаты численных экспериментов. The problem of minimizing the deviations of the orbit of a beam of charged particles in synchrotrons caused by the alignment error of the quadrupoles is considered. A method for optimizing the orbit trajectory based on the use of swarm computations and the gradient descent method has been developed. The results of numerical experiments are presented.

Mechanical requirement and influence on the design and manufacturing of beam position monitor of Taiwan photon source

The beam position monitors (BPMs) with submicron-level resolution act as the major eyes of storage ring in detecting the position of electron beams and are used for feedback system to guide the beam orbit to the desired track. Compared to major improvements on backend electronics, the physical devices generate and transmit signals had little improvement due to the lack of control on manufacturing processes including all mechanical tolerance requirements. The design started with ANSYS to simulate mechanical deformation. Due to the small size (submillimetre) and complicated assembly of feedthrough structure, it is difficult to achieve 1 % tolerance (submicron) in all aspects including machining and brazing. The smallest tolerance for machining is 5 µ and the overall tolerance will be 30 µm. The influence of the tolerance on mechanical will be shown on time-domain reflectometry measurement. The resulted heat-related issue will also be discussed and addressed since the problem happened at SLAC (private communication with Albert Sheng at Stanford Linear Accelerator Center) and DIAMOND (presented at the RF Button Heating Mini-Workshop at EPAC 2008). Manufacturing steps will be described. The consequence of mismatch on manufacturing will be discussed. All related measurement and simulation data are presented in this paper.