排序方式: 共有18条查询结果,搜索用时 15 毫秒
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Laser-driven ultrafast X-ray sources are widely used for diagnostic radiography. However, there is a large divergence of fast electrons when they are generated by an intense short-pulse laser interacting with a foil target.We design a nanowire array target to achieve a more compact point X-ray source. Fast electrons are confined and guided by the nanowire array structure in order to generate a Kαsource with a small spot size. In our work, the smallest measured source size is comparable to the laser spot size, while the conversion efficiency can reach2.4 × 10-4. 相似文献
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为了提高高功率激光光束质量和改善近场均匀性,在SILEX-Ⅰ超短脉冲激光装置的泵浦光系统上进行实验,研究了一种双光子吸收材料的光限幅特性及对激光近场的改善情况。利用泵浦光SAGA激光器输出的激光进行光限幅特性实验。结果表明:该材料具有明显的光功率限幅特性,且透过率较高,当入射光强小于0.60 GW/cm2时,透过率大于90%。在SILEX-Ⅰ装置的泵浦光系统进行联机实验,研究了该材料对激光近场均匀性的改善。实验结果表明:经过材料后,激光近场均匀性和调制度有明显改善。 相似文献
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Influence of water environment on paint removal and the selection criteria of laser parameters 下载免费PDF全文
Li-Jun Zhang 《中国物理 B》2022,31(6):64205-064205
Laser paint removal in a water environment does not diffuse ablation pollution products into air. Characteristics of water, such as high specific heat and heat flux, generate different effects of the laser paint removal than in an air environment. In this study, the effects of air and water environments on the mechanism and effect of laser paint removal are analyzed and compared experimentally and theoretically. In air, thermodynamic ablation causes removal of paint, whereas in water, stress coupled with plasma shock waves cause tear and splash removal of paint layers after fracture and damage. Fracture and pressure thresholds of the paint and substrate, respectively, indicate the optimum energy density range for laser paint removal in water, providing a reference for engineering applications. 相似文献
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赵磊 徐妙华 张翌航 张喆 朱保君 姜炜曼 张笑鹏 赵旭 仝博伟 贺书凯 卢峰 吴玉迟 周维民 张发强 周凯南 谢娜 黄征 仲佳勇 谷渝秋 李玉同 李英骏 《物理学报》2018,67(22):222101-222101
在利用超强激光驱动中子源的研究和应用研究中,中子源的产额及其角分布至关重要.我们在星光Ⅲ号激光装置上采用气泡探测器对强激光驱动的中子源的产额及其角分布进行了测量.利用超强皮秒激光与碳氘薄膜靶相互作用产生高能氘离子束撞击次级碳氘靶,通过氘-氘核反应产生准单能快中子.实验发现中子束的发射具有一定的方向性,在入射氘离子的传输方向上中子束具有更高的强度,测量得到的中子束最大强度为5.13×107 n/sr.利用实验测量的氘离子能谱和角分布对中子束角分布进行了理论计算,结果与实验测量基本一致. 相似文献
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