共查询到20条相似文献,搜索用时 156 毫秒
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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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原子(分子)团簇是有几个到几千乃至几万个原子(分子)通过物理或化学结合力形成的相对稳定的微观集合体,是介于原子分子和宏观固体物质之间的一种特殊的过渡物质结构。原子团簇尺寸比激光波长短,与强激光相互作用比原子或小分子更为激烈。团簇能够吸收相当大部分的激光能量,并产生超热电子和高电荷态的离子,高电荷态的离子会激发辐射出光子。 相似文献
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为了探索飞秒激光与固体靶相互作用中高能质子的产生和加速机制,在超短超强激光装置“SILEX-I”上进行了飞秒激光与平面固体薄膜Cu靶的相互作用中高能质子空间分布、能谱和产额的实验研究。实验采用固体核径迹探测器CR39和Thomson离子谱仪相结合的方式,在固体靶背表面法线方向测量了质子空间分布、能谱和产额。实验结果表明:质子沿着靶背法线方向发射,质子空间分布呈圆环状,存在一定的立体角;质子在一定能量处出现截断;截断能量的大小与靶厚度有关。经分析,高能离子的产生和加速是多种作用机制共同作用的结果,其中静电场中的TNSA加速机制则占主导地位。 相似文献
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为了探索飞秒激光与固体靶相互作用中高能质子的产生和加速机制,在超短超强激光装置“SILEX-I”上进行了飞秒激光与平面固体薄膜Cu靶的相互作用中高能质子空间分布、能谱和产额的实验研究。实验采用固体核径迹探测器CR39和Thomson离子谱仪相结合的方式,在固体靶背表面法线方向测量了质子空间分布、能谱和产额。实验结果表明:质子沿着靶背法线方向发射,质子空间分布呈圆环状,存在一定的立体角;质子在一定能量处出现截断;截断能量的大小与靶厚度有关。经分析,高能离子的产生和加速是多种作用机制共同作用的结果,其中静电场中的TNSA加速机制则占主导地位。 相似文献
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通过对由三个氘原子组成的氘团簇离子(d+3)与三个分立的氘核(3d+)在轰击吸氘固体靶时所发生的DD聚变反应率的差别的研究,进而揭示氘团簇离子在与固体靶中的氘核发生聚变反应时所体现出的团簇效应.实验结果显示,在10—40keV/d能区,每个氘团簇中的氘核(d+3/3)所产生的聚变反应率高于具有相同速度的独立氘核(d+)所产生的聚变反应率.反之,在50—100keV/d能区,独立氘核比之于氘团簇中的单个氘核所产生的聚变反应率要高.两者之间的比值具有非常明显的能量相关性.这种团簇特性与团簇离子本身特性及固体靶环境等多方面因素有关.对其作用过程和实验中观测到的现象的实质做了具体讨论. 相似文献
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We experimentally demonstrated remote sensing of the constituents of microparticles in air by combining laser-induced breakdown spectroscopy (LIBS) and lidar, using femtosecond terawatt laser pulses. Laser pulses of 70 fs duration and 130 mJ energy generated filaments when focused at a focal length of 20 m and the pulses irradiated artificial saltwater aerosols in air at a 10 Hz pulse repetition rate. Na fluorescence was observed remotely at a distance of 16 m using a 318 mm diameter Newtonian telescope, a spectrometer, and an intensified CCD camera. These results show the possibility of remote measurement of the constituents of atmospheric particles, such as aerosols, clouds, and toxic materials, by LIBS-lidar using femtosecond terawatt laser pulses. 相似文献
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M. B. Agranat N. E. Andreev S. I. Ashitkov A. V. Ovchinnikov D. S. Sitnikov V. E. Fortov A. P. Shevel’ko 《JETP Letters》2006,83(2):72-74
Characteristic K α x rays arising when a metallic target is irradiated by femtosecond infrared pulses that are generated by a terawatt chromium-forsterite laser system (1240 nm, 90 mJ, 80 fs) are studied. The absolute yield (up to 3 × 108 photons/sr pulse) and the coefficient of the transformation of laser radiation to K α radiation (maximum value ≈0.03%) are measured for an iron target. The dependence of the radiation intensity on the angle of incidence of p polarized laser radiation is analyzed. The mechanisms of the production of fast electrons responsible for generating characteristic x rays are discussed. 相似文献
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R.W. Schoenlein S. Chattopadhyay H.H.W. Chong T.E. Glover P.A. Heimann W.P. Leemans C.V. Shank A. Zholents M. Zolotorev 《Applied physics. B, Lasers and optics》2000,71(1):1-10
The generation of femtosecond X-ray pulses will have important scientific applications by enabling the direct measurement of atomic motion and structural dynamics in condensed matter on the fundamental time scale of a vibrational period. Interaction of femtosecond laser pulses with relativistic electron beams is an effective approach to generating femtosecond pulses of X-rays. In this paper we present recent results from proof-of-principle experiments in which 300 fs pulses are generated from a synchrotron storage ring by using an ultrashort optical pulse to create femtosecond time structure on the stored electron bunch. A previously demonstrated approach for generating femtosecond X-rays via Thomson scattering between terawatt laser pulses and relativistic electrons is reviewed and compared with storage-ring based schemes. 相似文献
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The multiple filamentation of terawatt femtosecond(fs) laser pulses is experimentally studied in a natural environment.A more than 30-m long plasma filament with a millimeter diameter is formed by the collimated fs laser pulse freely propagating in an open atmosphere. This study provides the first quantitative experimental data about the electron density of a long range light filament in the atmosphere. The electron density of such a filament is quantitatively detected by using an electric method, showing that it is at the 10~(11)-cm~(-3) level. 相似文献
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Dorchies F Blasco F Bonté C Caillaud T Fourment C Peyrusse O 《Physical review letters》2008,100(20):205002
We present the first experimental evidence of the subpicosecond duration of x-ray pulses emitted from laser-irradiated clusters, demonstrating the suitability of such a debris free target for ultrafast x-ray science applications. The K-shell emission (approximately 3 keV) from large Ar clusters (6 x 10(5) to 4 x 10(6) atoms) is time resolved, when irradiated by ultrashort (40 fs to 5 ps) and intense laser pulses (10(15-17) W/cm2). The observations are supported by hydrodynamical and collisional-radiative calculations, that reproduce the extremely short x-ray pulse duration. 相似文献
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数值研究了双色激光脉冲与一维氩原子相互作用的谐波发射功率谱.双色激光脉冲由800 nm和1600 nm的两束激光组成,脉冲持续时间为9.7 fs.计算结果表明,相对相位为π时,谐波截止频率从单色场情形的58 eV大幅度地展宽到316 eV,获得频宽为93 eV的软X射线连续辐射谱.此外,还采用短程的普薛耳-特勒势和长程的软化库仑势进行比对,数值结果表明该连续辐射谱的存在具有普适性.通过半经典的“三步”模型和时频分析小波变换方法对该连续辐射谱进行分析,发现其主要由单一的“短”量子路径生成,直接叠加频率从22
关键词:
红外双色激光脉冲
连续辐射谱
阿秒脉冲 相似文献