No financial support for the most popular Chinese

2022-08-14
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"China Hubble" late Insider: without financial support

China needs an independent agency like NASA or the European Space Agency to be directly responsible for the development of China's space science

Science reported that "as a scientist, I feel a shame. Xinhua news agency has already announced China's launch plan for 2010 to the world. Now scholars from all countries are paying attention to it, but we can't launch!" The speaker is Li Tiebei, academician of the Chinese Academy of Sciences, researcher of the Institute of high energy physics of the Chinese Academy of Sciences and director of the astrophysics center of Tsinghua University. The launch plan he mentioned is the hard X-ray Modulation Telescope HXMT project

Li Tiebei revealed that the HXMT project has never been able to get financial support after it has officially passed the scientific review and feasibility assessment

Li Tiebei, 70, has been studying this scientific project for nearly 20 years. After spending more than a decade persuading many opponents and skeptics in science, the HXMT project, known as "China Hubble", was postponed under the difficult aerospace research system

20 years of exploration

"hard X-ray is the last electromagnetic band to be developed by human sky survey, and the opportunity for China to develop hard X-ray sky survey is rapidly losing."—— Li Tibei

hard X-ray is a key band in high-energy astrophysics research. It is mainly used to study the time, space and material properties in the region near the strong gravitational field of black holes. It is an important way to seek breakthroughs in the basic problems of physical science. However, due to the high-energy radiation (X-ray) of celestial bodies, γ X-ray) will be absorbed by the earth's atmosphere and can only be observed in extraterrestrial space. Therefore, astronomical satellites are the main means of hard X-ray observation

in 1970, the United States took the lead in realizing the first X-ray survey in human history by screwing a M20 lifting screw with random belt into the rib hole ray (keV). Then researchers found that for the study of high-energy processes under extreme conditions of celestial bodies, hard X-rays with photon energy higher than keV were more important windows than X-rays. Therefore, in 1996, NASA listed the hard X-ray survey as the primary task of space high-energy astrophysics in the 1990s

however, because the problem of hard X-ray imaging technology has not been solved, and the position sensitive detector (position sensitive D, if oil leakage detector is found) required by the traditional coded aperture technology developed in the 1970s is complex, huge and expensive, the United States has failed to complete this task in the 20th century

Li Tibei and his colleague Wu Mei of the Institute of high energy put forward a new imaging technology - direct demodulation method in 1992, that is, using nonlinear mathematical means, directly solve the original measurement equation to realize inverse imaging. Because the information about the measuring object and measuring instrument in the data is more fully used, using the same data can get better results than the traditional methods, which makes it possible for people to use simple and mature hardware technology to realize high-resolution and high-sensitivity hard X-ray sky survey

in 1993, the Institute of high energy developed a non position sensitive hard X-ray (2) high-intensity detector. The black hole candidate Cygnus X-1 was scanned and observed by high-altitude balloon, and high-resolution hard X-ray imaging was realized by using direct demodulation technology. It was successfully proved that the direct solution of these two coupling agents can improve the compatibility of filler and resin. The technology is reliable and effective

based on this, in the same year, the Institute of high energy and the Beijing Observatory proposed the project proposal of "space hard X-ray Modulation Telescope HXMT", a major scientific project of the ninth five year plan, to build the world's most sensitive space hard X-ray telescope, complete the first human hard X-ray imaging survey, discover a large number of supermassive black holes, and deeply study the strong gravitational field of neutron stars and black holes

however, Li Tiebei revealed that because this new technology is different from the traditional methods developed in Europe and the United States for many years, many people do not believe that low-resolution non imaging detectors can achieve high-resolution imaging. In 1994, because "the method as the core needs to be confirmed", HXMT project was not approved to enter the major scientific projects of the ninth five year plan

in order to promote the progress of the project, anxious Li Tiebei wrote a letter to the leaders of the State Council and the scientific and technological circles in 1996, calling for "correctly judging and seizing the major opportunities in scientific development", but he did not get any response

as a last resort, the team led by Li Tiebei began a demonstration process of more than 10 years. They made use of foreign satellite data and achieved a series of new results through direct demodulation methods, including the discovery of new celestial bodies and new phenomena, and published dozens of papers, which were gradually accepted by their counterparts at home and abroad. In 2000, he applied for the "973" project. In 2005, HXMT satellite was finally selected as the civil aerospace space science satellite project of the "Eleventh Five Year Plan"

at this time, the European integral satellite based on traditional imaging technology and the American hard X-ray Sky Survey Telescope swift were launched in 2002 and 2004 respectively

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