The beam-based alignment system is given in HLS (Hefei Light Source), in which a switchable shunt resistorwas installed on quadrupole to bypass a small percentage of the magnet current. The system can measureBPM-to-qu...The beam-based alignment system is given in HLS (Hefei Light Source), in which a switchable shunt resistorwas installed on quadrupole to bypass a small percentage of the magnet current. The system can measureBPM-to-quadrupole offset which can be used to position the beam in the magnetic center of quadrupoles. In measurement,some methods ( linear fitting with single corrector, parabola fitting with single corrector, linear fitting withlocal bump, and parabola fitting with local bump ) are used. These measurement results are given, and comparedamong the methods mentioned above.展开更多
This paper derives the closed-form expressions for nonparaxial phase flipped Gaussian （PFG） beams propagating in free space, through a knife edge and an aperture, which enable us to study nonparaxial propagation pro...This paper derives the closed-form expressions for nonparaxial phase flipped Gaussian （PFG） beams propagating in free space, through a knife edge and an aperture, which enable us to study nonparaxial propagation properties of PFG beams and to compare nonparaxial results with paraxial ones. It is found that the f parameter, offsetting distance of the knife edge and truncation parameter affect the nonparaxial beam propagation properties. Only under certain conditions the paraxial approximation is applicable. The results are illustrated by numerical examples.展开更多
文摘The beam-based alignment system is given in HLS (Hefei Light Source), in which a switchable shunt resistorwas installed on quadrupole to bypass a small percentage of the magnet current. The system can measureBPM-to-quadrupole offset which can be used to position the beam in the magnetic center of quadrupoles. In measurement,some methods ( linear fitting with single corrector, parabola fitting with single corrector, linear fitting withlocal bump, and parabola fitting with local bump ) are used. These measurement results are given, and comparedamong the methods mentioned above.
基金Project supported by the National Natural Science Foundation of China(Grant No10574097)
文摘This paper derives the closed-form expressions for nonparaxial phase flipped Gaussian （PFG） beams propagating in free space, through a knife edge and an aperture, which enable us to study nonparaxial propagation properties of PFG beams and to compare nonparaxial results with paraxial ones. It is found that the f parameter, offsetting distance of the knife edge and truncation parameter affect the nonparaxial beam propagation properties. Only under certain conditions the paraxial approximation is applicable. The results are illustrated by numerical examples.
