The progress of gravitational wave detection in China and its further physical application

Contemporarily, a gravitational wave is one of the most important approaches to gather information from the enormous universe. In short, a gravitational wave is a wave that carries energy, and it is created by the acceleration of massive celestial body propagation with a speed of light. This paper discusses the recent progress of gravitational wave detection in China and clarifies our own opinion on future development. Specifically, a basic description is first presented about the definition and basic knowledge for gravitational wave models and detection methods. Subsequently, this section contains the plan and achievement of the Chinese gravitational wave observatory. Finally, the usages and applications of the gravitational wave to help to detect more phenomena in the universe are demonstrated. These results shed light on a clearer picture of gravitational waves, which may offer a better understanding of the background, principle of detection, and the uses of gravitational waves, i.e., emphasizes its importance in modern astrophysics scientific researches.

Research on the analytical development and progress of gravitational wave detection technology

This article demonstrates the basic principle and the recent progress of gravitational wave detection based on information retrieval and literature review. The article describes and illustrates the gravitational wave, including the description of the adopted field equation and its properties. There is also a demonstration of the principle behind the first direct gravitational wave detection. Some other potential ground-based detectors, e.g., KAGRA and space-borne detectors, are also listed and contrasted. Since gravitational waves tend to retain themselves from interacting with matter, which travels from a much earlier time than Electromagnetic waves and should be a vital component to Cosmology studies, the space-borne detectors Taiji and LISA will also interlace with each other to explore deeper space in the 2030s, which would be significant progress in gravitational wave Astronomy. This article employs literature analysis that examines papers that discuss the nature of gravitational waves and their detection. These analyses will shed light on gravitational wave detection development.

Research on Semi-Physical Simulation Testing of Inter-Satellite Laser Interference in the China Taiji Space Gravitational Wave Detection Program

To guarantee a smooth in-orbit space gravitational wave detection for the Taiji mission, a semi-physical simulation test of inter-satellite laser interference is carried out. The semi-physical simulation test consists of three aspects: the establishment of the inter-satellite laser link, interferometry of the inter-satellite ranging, and simulation of the space environment. With the designed specifications for the semi-physical simulation platform, the test results for the inter-satellite laser interference can be obtained. Based on the semi-physical simulation test, the risks of inter-satellite laser interference technology can be mitigated, laying a solid foundation for the successful detection of in-orbit gravitational waves.

Low Power Cusped Field Thruster Developed for the Space-Borne Gravitational Wave Detection Mission in China

The microthruster is the crucial device of the drag-free attitude control system, essential for the space-borne gravitational wave detection mission. The cusped field thruster (also called the High Efficiency Multistage Plasma Thruster) becomes one of the candidate thrusters for the mission due to its low complexity and potential long life over a wide range of thrust. However, the prescribed minimum of thrust and thrust noise are considerable obstacles to downscaling works on cusped field thrusters. This article reviews the development of the low power cusped field thruster at the Harbin Institute of Technology since 2012, including the design of prototypes, experimental investigations and simulation studies. Progress has been made on the downscaling of cusped field thrusters, and a new concept of microwave discharge cusped field thruster has been introduced.

Drop tower tests of Taiji-1 inertial sensor substitute

Taiji-1, which is the first technical verification satellite of China’s Space Gravitational Wave Detection Program, was successfully launched on August 31, 2019. The mission aimed to investigate the key technologies used in space gravitational wave detection. The inertial sensor, which was one of the main payloads, measured the residual acceleration of the satellite, and verified the drag-free control technology. Its performance was crucial to the success of the Taiji-1 mission. To ensure its performance in orbit, the inertial sensor was fully evaluated prior to launch. Owing to the gravitational acceleration on the ground, it is impossible to verify all the properties of the inertial sensor in a routine laboratory. A feasible method to conduct such tests is to use a drop tower. To guarantee the safety of the inertial sensor, a substitute was used with similar structure and circuit design. A total of 20 falls in three groups were completed, a set of research methods was established, and the importance of conducting simulations before the drop tests was verified. For the first time, the switch of different circuit gains in a drop tower test has been achieved and the National Microgravity Laboratory of China (NMLC) drop tower’s residual accelerations in three dimensions were measured. The results demonstrated that the microgravity level of the drop tower can reach about 58 μg0 in the fall direction and 13 μg0 along the horizontal axes.