Affiliation:
1. MOE Key Laboratory of Fundamental Physical Quantities Measurement and Hubei Key Laboratory of Gravitation and Quantum Physics, PGMF and School of Physics, Huazhong University of Science and Technology , Wuhan 430074, People’s Republic of China
Abstract
The drop tower is an important experimental facility to provide a microgravity environment on the ground. The National Precise Gravity Measurement Facility has built a vacuum drop tower at Wuhan in China. The vacuum drop tower has a falling-height of 20 m, a free falling-time of 2.0 s, and a pressure of ∼6.15 Pa after 1 h pumping. The microgravity level of the vacuum drop tower is analyzed in this paper. The error sources include the aerodynamic drag, the difference of gas pressure around the gaps, the misalignment, the rotation, the magnetic field, etc. The evaluated microgravity level of the vacuum drop tower is better than (4.80 ± 3.31) × 10−7g, which is mainly limited by the aerodynamic drag and the rotation of the capsule. In addition, the microgravity level is measured to be better than 3.22 × 10−5g by using the quartz-flexure accelerometer. The vacuum drop tower provides a ground-based public service platform with a microgravity environment on the order of magnitude of 10−7g for further experiments.
Funder
National Key Research and Development Program of China
Young Top-Notch Talent Cultivation Program of Hubei Province