Establishment Method Of Longer Laboratory Baselines For Verificating EDMs

The research on laboratory methods for verifying EDMs is at the initial stage by far, by which only the additive constants and cyclic errors of EDMs can be got; but the multiplication constants are got reliably only in longer baseline according to the theoretic analysis and the real practice. In other words, the longer laboratory baseline is the premise and foundation for indoor verification of EDM, which is a worldwide hot issue that needs to be explored furtherly. There are two ideas to establish longer laboratory baseline at present. One is optical fiber-based and the other is based on two large plane mirrors. But the achievements on both of them can not be used in practice yet. So how to establish a laboratory baseline for verifying EDMs is meaningful in theory and in practice currently.In this paper, a novel approach using cube corner prisms establishing a laboratory baseline has been proposed based on the following research work: (1) the feasibility of establishing a laboratory baseline using cube corner prisms has been analyzed. For cube corner prisms have some appropriate advantages, such as their reflected rays paralleling to incident rays, cube corner prisms being adjust-free, optical pathlength being a constant etc. After analyzing the energy loss, influence of atmosphere condition and wavelength, stability of the system and calibration of the baseline, it has been concluded that it is feasible to establish a 1km long laboratory baseline using 25 cube corner prisms on 40 meters distance. (2)The analysis method of the uncertainty of the system has been presented. It has been concluded that the uncertainty of the system in 1km baseline is 0.67mm and this result may meet the requirement for verifying EDMs. (3) To test the theory, some experiment schemes has been made, which manifested that the method for establishing longer baselines for EDMs verification in this paper is feasible and realiable. However, the baseline length only reaches 200m owing to some experiment limitations. The experiments demonstrate that the distance is repeatable in this system and the system is relatively stable and can be operated easily. The approach should be promising with the help of financial invest in the future.The main contents of this dissertation are as follows:1. The achievements and problems in EDM laboratory verification in the past research work has been analyzed.2. A novel scheme based on cube corner prisms for the establishment of a laboratory baseline has been proposed.3. The feasibility of establishing a laboratory baseline using cube corner prisms has been analyzed and the uncertainty of the system has been discussed.4. The experiment schemes have been confirmed and the results of the experiments have been analyzed.5. The principles of designing field baseline seldom reported in China have been induced systematically.6. A suggestion has been presented that the definitions of additive constant and multiplication constant should be given in verification certifications and these two constants should be calculated with weight.