基于低温扭秤技术检验弱等效原理的实验方案研究

项目名称： 基于低温扭秤技术检验弱等效原理的实验方案研究

项目编号： No.11475066

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 数理科学和化学

项目作者： 杨山清

作者单位： 华中科技大学

项目金额： 90万元

中文摘要： 等效原理是广义相对论的基本假设之一，而目前几乎所有涉及到四种相互作用的大统一理论均要求等效原理在一定程度上破缺。因此，一个高精度的等效原理实验检验具有重要的科学意义。目前地面实验的最高精度已经达到了10^(-13)，是采用扭秤方案完成的，但实验精度的进一步提高主要受到了扭秤热噪声的限制。由于热噪声与环境温度成正比，因此降低环境温度即采用低温扭秤技术则是下一步提高实验精度的主要方向。低温扭秤虽然具有极高的潜在灵敏度，但是其对实验条件的要求也极为苛刻，这些仍然是学术界没有解决的问题。因此本项目拟开展低温扭秤检验等效原理的实验方案及前期研究，旨在通过理论建模分析给出整个低温扭秤平台的优化设计和可行性报告。同时，通过前期的相关实验掌握低温下扭丝的耗散规律、并解决低温下背景磁场屏蔽与温度稳定性的控制等关键问题，为下一步在10^(-14)～10^(-15)的更高精度下检验弱等效原理是否成立奠定基础。

中文关键词： 引力实验；低温扭秤；弱等效原理；精密测量

英文摘要： Equivalence Principle(EP)is one of the hypothesis of the General Theory of Relativity, but almost all the unified theories that may unify the four fundamental forces of nature predict the violation of the EP.Therefore,any experimental effort devoted to validating these expectations will help to understand the fundamental nature of gravity. Up to now, the WEP has been tested with a accuracy of about 10^(?13) by Eot-Wash group with a rotational torsion balance. Unfortunately, the advanced improvement of sensitivity of the torsion balance was naturally limited by the thermal noise of the torsion fiber.Because the square of the torque noise of the fiber is direct proportion the environment temperature, the cryogenic torsion pendulum is becoming an major candidate for advancing the sensitivity. Though the pendulum has a best potential sensitivity in measurement, the requirement for the experimental conditions is very strict and this is still an open question in international field. In this project, we want to do some researchs about the design of the experimental scheme for the cryogenic torsion pendulum platform and develop a feasibility report. At the same time, we want to do some previous experiments in crygenic condition for finding the dissipation of the torsion fiber, shielding the magnetic field and the controling the stability of the temperature, and so on. This research is a groundwork for us for aiming to test the WEP at the highest accuracy of 10^(-14)～10^(-15) in next step.

英文关键词： gravitational experiment;cryogenic torsion balance;weak equivalenc principle;precision measurement