China has conquered the heart of high-power laser

  • Detail

After half a century: China has conquered the "heart" of high-power lasers. Hundreds of weak lasers will amplify their energy by 1trillion times after passing through glass. Finally, they will converge to ignite the artificial "little sun" -- laser inertial confinement fusion device, which is expected to realize the ultimate dream of continuous access to clean energy after the completion and operation of Sinochem in 2019

in order to obtain a powerful laser that can trigger hydrogen isotope nuclear fusion, it is necessary to develop a neodymium glass that can deliver energy to the laser. It is the "heart" of high-power lasers. A group of scientists from the Shanghai Institute of Optics and mechanics of the Chinese Academy of sciences have worked silently for half a century to realize this dream

now, they are the only team in the world that has mastered the whole process of manufacturing large-size and high-performance laser neodymium glass. Yesterday, they won the 2016 Shanghai special prize for technological invention

neodymium glass "enables" laser to trigger fusion reaction

neodymium glass research has gone through half a century, four technical iterations and two academicians of the Chinese Academy of Sciences. Team members always have a belief: no matter how difficult it is, it must be done

1 joule of water can be placed in the cooling water tank at different temperatures, which can make the 1 watt bulb glow normally for 1 second. One nanojoule, only one billionth of one joule, is so weak that it is almost imperceptible. However, after one or two thousand pieces of neodymium glass absorbing energy are "energized", this beam of low light will be strong enough to trigger a fusion reaction

"neodymium glass is very strange. Under the irradiation of xenon lamp, neodymium ions will absorb the energy of light and transition from low-energy state to high-energy state." Hulili, the project leader of neodymium glass and researcher of the Institute of Optics and mechanics, explained that when the laser passes through the neodymium glass full of energy, it will absorb the energy in the glass and become stronger. "Thousands of pieces of laser neodymium glass in the device repeatedly 'relay' the laser, and finally make the laser meet the needs of scientists."

this powerful laser can help scientists carry out basic research on high-energy density physics. Neodymium glass array is also used in Pudong Zhangjiang super short laser device, which has set a world record for instantaneous laser output power; Laser neodymium glass can also be used in fusion research. China's "Shenguang" device is one of the best fusion "igniters" in the world

since 1964, Shanghai Institute of Optics and mechanics has started the research on neodymium glass, and has two academicians of the Chinese Academy of Sciences, Gan Fuxi and Jiang Zhonghong. The team members are currently stable at more than 80. From the first generation of silicate neodymium glass to the present phosphate neodymium glass, it has experienced four generations of technological upgrading. Hulili said that compared with silicate neodymium glass, phosphate neodymium glass is very "delicate": when used, the temperature and humidity should be accurately controlled, otherwise the glass will be moldy, and it is also very difficult to melt. "But its energy amplification ability is 10 times that of silicate neodymium glass, and high-power laser devices cannot be separated from it."

no matter how difficult it is, it must be done! Without it, the impact of China's Laser Science on the forefront of the world will only be on paper

the manufacturing process is unique in the world.

behind the word "conquer" are sleepless thinking, starting from scratch after repeated failures, countless emergency meetings and abandoned rest days. Along with the life course of getting married and having children, young people regard the technology to be tackled as another child

Why is it difficult to make phosphate neodymium glass? It needs to meet 28 technical parameters at the same time, almost all of which are difficult to cross: high-purity raw materials are easy to absorb water, and have a "lively" character. Even the "lazy" platinum will be "pulled" off its horse. However, there is no impurity in laser Nd glass. High power laser devices often need thousands of pieces of neodymium glass. They must have the same specifications and performance so that twoorthree laser paths can finally converge accurately on targets of only millimeter magnitude

according to the traditional method, it takes an average of two days to smelt a piece of neodymium glass. As early as the 1990s, three companies in the United States, Japan and Germany jointly invested in R & D and spent six years mastering the continuous smelting technology of neodymium glass

"China cannot buy neodymium glass from abroad, nor can it obtain relevant technology. Foreign countries have imposed an embargo on us." Hulili said that to make China's scientific research go to the forefront of the world, the only way is to break through this "bottleneck" difficulty

2002, with the support of major national science and technology projects, hulili led a team to start the journey of overcoming the continuous melting technology of 0.2~0.7 nucleating agent for neodymium glass

"this is really difficult!" Hulili said that it has challenged the limit of continuous melting of optical glass, with large size, many and extremely high requirements for indicators

remove water, platinum and impurities... It will take twoorthree years to overcome each pass. Behind the word "conquering", there are sleepless thoughts, starting again after failures, countless emergency meetings and abandoned rest days. "The whole team gave up even the Spring Festival holiday for seven consecutive years." Hulili said that only when the purplish red glass about 1 meter long and half a meter wide came off the production line and passed the test, everyone would feel a little relaxed

pure purplish red glass is wrapped with a light green glass edge. Neodymium glass should be placed in front of the girls' dressing table. However, in the eyes of professionals, it is a complete optical device - even the glue used to bond the two glasses must strictly comply with the technical parameters of neodymium glass

chenshubin, the second person completing the project and senior engineer of the Institute of Optics and mechanics, explained that after receiving energy, the neodymium glass will produce some random light scattering. The bonded glass should not only absorb "stray light", but also eliminate stress, otherwise the neodymium glass will break

every small point determines the success or failure of the whole development process. "In this team, many young men joined in as soon as they graduated. They have worked in a technology for more than ten years and have really achieved the best." Hulili said that some people have grayed their hair at a young age. "Along with the life process of getting married and having children, they regard the technology they want to tackle as another @ relevant experiment: a child."

continuous and stable support for overcoming difficulties at ease

the team is very pleased that over the years, they have never worried about funds and experimental sites. Only when we have a comfortable environment for scientific research can we accomplish this great event

walking into a building in Jiading North District of the Institute of Optics and mechanics, the world's only large caliber high-quality Nd glass continuous smelting production line is preparing for the next start-up. This production line can produce 1200 neodymium glasses a year. Chenshubin said that compared with the era of hand-made neodymium glass, the production efficiency has been increased by 10 times, and the yield has also been greatly improved

several years ago, international organizations found optical and Mechanical Institute and hoped to purchase products. "When they know that a scientific research institution in China has mastered a full set of production processes, and the product indicators are all excellent, they admire it in addition to admiration." Hehongbo, director of the scientific research department of the Institute of Optics and mechanics, said that the direct sales of neodymium glass has reached 376million yuan at present. It has opened up a situation in the high-tech field, and its far-reaching impact is inestimable

hulili is very pleased that, with the support of the national major science and technology project, the Ministry of industry and information technology and Shanghai Municipal Commission of economy and information technology, the team has never worried about funding for so many years. "The Institute of Optics and mechanics also gives priority to providing us with better experimental sites as much as possible." She said that only with an environment of peace of mind to do research can this great event be accomplished

Copyright © 2011 JIN SHI