WANG Wen-ming1,2, DAI Ke1,2, ZHANG Yan-jun1, ZHANG Wei-qun1

(1. Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China;

2. Graduate University of Chinese Academy of Sciences, Beijing 100039, China) 

Abstract: In order to reduce the magnetic field at the storage bulb to the lowest, a magnetic shield is designed for a new hydrogen maser. The estimation and design, including the consideration to the holes and seams, are presented. The simulation and experiment have tested and verified the feasibility of the designed magnetic shield.

Key words: magnetic shield; hydrogen maser; magnetic permeability