Subjects: Astronomy >> Astrophysical processes submitted time 2022-10-17 Cooperative journals: 《天文研究与技术》
Abstract： In order to reduce the relative change rate of the transition frequency of the hydrogen masers caused by the inhomogeneous C field, two designs of C field components, three-segment solenoids and four sets of coils, are proposed. Using the high-order expansion of the magnetic field on the axis, the ampere-turn ratio and the solenoid spacing were calculated when the three-segment solenoid with L=0.05-0.5 constructed a uniform magnetic field. The finite element analysis of the magnetic field is carried out with L=0.2-0.45, and the magnetic field non-uniformity distribution with different widths is given. Among them, the maximum non-uniformity with L=0.45 in the storage bubble area is 0.105%, and the corresponding relative change rate of transition frequency is1.02×10-13 . Using the same method, the ampere-turn ratio and spacing between coils when four or five sets of coils construct a uniform magnetic field are calculated, and the finite element simulation of the magnetic field in the coil is carried out, and the non-uniformity distribution is given. The maximum non-uniformity of the magnetic field in the storage bubble region in the four sets of coils is 0.066%, and the corresponding transition frequency relative change rate is 6.42×10-14
Subjects: Astronomy >> Astrophysical processes submitted time 2019-07-30 Cooperative journals: 《天文研究与技术》
Abstract： 激光导引星波前倾斜测量问题是限制自适应光学技术在天文领域广泛应用的关键问题之一。测量并改正激光上行到达角起伏是解决这一问题的有效方法。提出一种基于统计平均算法而不依赖自然导引星和辅助望远镜的测量方法，可以有效地测量出激光上行到达角起伏。利用具有子孔径阵列的哈特曼波前传感器对激光信标进行探测，选择部分子孔径进行倾斜量的统计平均以获得激光上行到达角起伏。仿真了统计平均算法的误差随子孔径数量的变化关系。结果表明，最小算法误差相对于望远镜全口径倾斜误差的下降比例与大气Fried常数无关，而与望远镜口径有关。望远镜口径越大，算法误差相对于全口径倾斜误差下降越多。当望远镜口径为10m时，最小算法误差下降为望远镜全口径倾斜误差的33%。
Hits
Hits
Downloads
Comment