摘要
颗粒污染物是高功率激光装置光学元件损伤的诱因之一,掌握污染物产生规律是解决污染诱致损伤问题的基础。针对本色氧化工艺处理前后的5052铝合金样品,研究了激光辐照样品诱致亚微米和微米尺寸气溶胶颗粒的产生规律,分析了激光能量密度、脉冲数目、激光光斑直径、表面粗糙度等参数对颗粒物数量的影响。结果表明:颗粒物数量和激光光斑面积呈正相关;激光能量密度低于烧蚀阈值时,颗粒物产生于第一个脉冲辐照过程,高于烧蚀阈值时,表面颗粒物数量随着激光能量密度增加而逐渐增加;随着激光脉冲数目的增加,本色氧化5052样品产生颗粒物的数量逐渐增加,而5052样品产生颗粒物的数量变化不明显。两种不同表面工艺样品产生颗粒物的规律存在较大差别;低于烧蚀阈值时,两种样品产生的颗粒物数量相当;在烧蚀阈值附近时,颗粒物数量存在陡增现象;高于烧蚀阈值时,本色氧化5052样品产生的颗粒物数量显著多于5052样品。研究结果为高功率激光装置中铝合金表面处理和洁净控制提供了参考依据。
Objective With the continuous advancement in laser-driven inertial confinement nuclear fusion research, laser damage to optical components caused by particle pollutants has become a bottleneck limiting the output capacity of high-power laser drivers. In a high-power laser system(HPLS), stray light and ghost spots can have a high energy density, and the surface of the mechanical components is easily exposed to stray light to produce metal particles, which diffuse into the optical path and result in a large number of aerosols. Aerosol pollutants can not only fill the gaps of the porous sol-gel coating on optical surfaces to reduce transmittance but also easily damage the optical element under laser irradiation. Therefore, suppressing particle pollutants is crucial to improve the output capacity of HPLSs. The aluminum alloy is commonly used as the mechanical component in high-power laser facilities;thus, we experimentally study the generation of aluminum alloy particles irradiated by a nanosecond laser in this article. The effects of laser parameters and sample surface treatments on particle generation are investigated in detail, and the suppression methods of particle generation are discussed to control online cleanliness in HPLSs.Methods The nanosecond laser was passed through a window glass of the cavity to irradiate the surface of a metal sample with an incident angle of 0°.Clean nitrogen gas was continuously filled into the cavity through the gas inlet to remove particles generated by the laser radiation to exit the cavity through the exhaust hole at the back of the cavity.Because of the rapid gas flow rate from the cavity vent hole,the exhaust gas was divided into two parts:one part was directly discharged into the surrounding atmosphere,and the other part was fed into a particle counter to measure the number of the particles with various sizes.Therefore,the number of particles produced by laser irradiation in the experiment was 3.16 times that of data directly measured using the particle counter.Micron and s
作者
李畅
庞向阳
孙明营
刘文凤
乔战峰
朱健强
Li Chang;Pang Xiangyang;Sun Mingying;Liu Wenfeng;Qiao Zhanfeng;Zhu Jianqiang(Key Laboratory of High Power Laser and Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2021年第14期148-158,共11页
Chinese Journal of Lasers
基金
中国科学院战略性先导科技专项(XDA25020202)
中国科学院青年创新促进会项目(N2018282)。
关键词
激光光学
颗粒污染物
洁净控制
激光辐照
铝合金
激光诱致损伤
laser optics
particle pollutants
clean control
laser irradiation
aluminum alloy
laser induced damage
