Zhao Wang 1,2Rui Cheng 1,2,3,a)Guodong Wang 1,2Xuejian Jin 1,2[ ... ]Jie Yang 1,2,3
Author Affiliations
Abstract
1 Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 Advanced Energy Science and Technology Guangdong Laboratory, Huizhou 516003, China
4 College of Physics and Electronic Engineering, Northwest Normal University, Lanzhou 730070, China
A novel experimental method is proposed for observing plasma dynamics subjected to magnetic fields based on a newly developed cylindrical theta-pinch device. By measuring simultaneously the temporal profiles of multiple parameters including the drive current, luminosity, plasma density, and plasma temperature, it provides a basis for observing the plasma dynamics of the theta pinch, such as shock transport and magnetohydrodynamic instability. We show that the plasma evolution can be distinguished as three phases. First, in the radial implosion phase, the trajectories of the current sheath and shock wave are ascertained by combining experimental data with a snowplow model (Lee model) in a self-consistent way. Second, in the axial flow phase, we demonstrate that m = 0 (sausage) instability associated with the plasma axial flow suppresses the plasma end-loss. Third, in the newly observed anomalous heating phase, the lower-hybrid-drift instability may develop near the current sheath, which induces anomalous resistivity and enhanced plasma heating. The present experimental data and novel method offer better understanding of plasma dynamics in the presence of magnetic fields, thereby providing important support for relevant research in magneto-inertial fusion.
Matter and Radiation at Extremes
2023, 8(4): 045901
Author Affiliations
Abstract
1 Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
2 University of Chinese Academy of Sciences, Beijing 100049, China
3 School of Science, Xi'an Jiaotong University, Xi'an 710049, China
4 Department of Engineering Physics, Tsinghua University, Beijing 100084, China
The research activities on warm dense matter driven by intense heavy ion beams at the new project High Intensity heavy-ion Accelerator Facility (HIAF) are presented. The ion beam parameters and the simulated accessible state of matter at HIAF are introduced, respectively. The progresses of the developed diagnostics for warm dense matter research including high energy electron radiography, multiple-channel pyrometer, in-situ energy loss and charge state of ion detector are briefly introduced.
Warm dense matter Intense heavy ion beams HIAF Electron radiography 
Matter and Radiation at Extremes
2018, 3(2): 85
Author Affiliations
Abstract
Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
Recent research activities relevant to high energy density physics (HEDP) driven by the heavy ion beam at the Institute of Modern Physics, Chinese Academy of Sciences are presented. Radiography of static objects with the fast extracted high energy carbon ion beam from the Cooling Storage Ring is discussed. Investigation of the low energy heavy ion beam and plasma interaction is reported. With HEDP research as one of the main goals, the project HIAF (High Intensity heavy-ion Accelerator Facility), proposed by the Institute of Modern Physics as the 12th five-year-plan of China, is introduced.
heavy ion beam high energy density physics ion beam and plasma interaction radiography 
High Power Laser Science and Engineering
2014, 2(4): 04000e39
Author Affiliations
Abstract
1 中国科学院上海光学精密机械研究所高功率激光物理联合实验室, 上海 201800
2 中国工程物理研究院上海激光等离子体研究所, 上海 201800
Damage experiments are conducted by irradiating fused silica with the multiple wavelength laser near field. The multiple wavelength laser consists of 1053、 527、 351 nm laser. It designs a definition of damage threshold based on laser near-field irradiation and extracts damage areas from damage images by the marker-based watershed algorithm with gray control. The initial damage threshold is defined as the fluence of critical site between damage region and no damage region, which is calculated by comparing the damage image with the multiple wavelength laser near field. The research shows that the damage of fused silica is induced by the three wavelength lasers. The 351 nm laser plays a leading role. The initial damage threshold is 8.22 J/cm2. With multiple irradiation of fused silica in multiple wavelength laser, the damage growth of exit surface is exponential, and the coefficient of damage growth is 0.59.
激光光学 激光诱导损伤 激光近场 分水岭标记算法 复合波长 laser optics laser induced damage laser near field marker-based watershed algorithm multiple wavelength 
Collection Of theses on high power laser and plasma physics
2013, 11(1): 0114001
作者单位
摘要
中国科学院 上海光学精密机械研究所, 高功率激光物理联合实验室, 上海 201800
自动准直系统是将采集的图像进行特定算法处理获取光束的位置信息, 驱动电机调整光斑到指定的位置, 其中图像质量对光束定位的精确性影响很大, 为尽量避免受严重噪音和光束畸变影响的图像进入图像处理流程而产生准直结果的错误判断, 保证自动准直系统图像处理结果的精确性, 试图提供一种较为简单的判断依据, 采用基于Monte-Carlo模拟方法, 建立了远场准直过程中三种主要噪音的干扰评估模型, 以测量不确定度作为定量判断处理图像与否的特征参数, 将该结果做成统计图表作为判断依据。结果表明, 在设定合理测量不确定度阈值的情况下, 该特征参数能够较好地排除不良图像, 从而提高准直结果的可信度。
图像处理 测量不确定度 Monte-Carlo模拟 可信度 自动准直 image processing uncertainty of measurement Monte-Carlo simulation reliability automatic alignment 
强激光与粒子束
2013, 25(4): 867
作者单位
摘要
1 中国科学院上海光学精密机械研究所高功率激光物理联合实验室, 上海 201800
2 中国工程物理研究院上海激光等离子体研究所, 上海 201800
3 复旦大学信息科学与工程学院, 上海 200433
4 上海交通大学理学院物理系, 上海 200240
皮秒参数测量系统用于提供皮秒拍瓦激光系统的各项状态参数,协助激光系统达到预期的技术指标。针对皮秒拍瓦激光系统的技术指标,皮秒参数测量系统将提供压缩脉冲的能量、脉宽、远场、信噪比等参数。为了判断参数测量系统的工作性能,采用均方根(RMS)误差来描述测量系统的可靠性。经过实验测试,能量测量单元的测量范围为10~1000 J,标定实验数据的RMS误差为2.2%。脉宽测量单元的时间测量范围为0.5~18.0 ps,时间分辨率为0.07 ps,测试数据的RMS误差为3%。远场测量单元的空间测量范围为150倍衍射极限(DL),空间分辨率为0.3倍DL,测试数据的RMS误差为0.15%。信噪比测量单元的时间测量范围为30 ps,时间分辨率为0.3 ps,动态范围为106。基于拍瓦实验提供的测试数据表明,皮秒参数测量系统能够稳定可靠地提供以上参数的实时测试数据,实现拍瓦装置的运行状态诊断功能。
超快光学 精密测试 自相关 单次脉冲 
中国激光
2013, 40(1): 0108003
作者单位
摘要
1 中国科学院上海光学精密机械研究所高功率激光物理联合实验室, 上海 201800
2 中国工程物理研究院上海激光等离子体研究所, 上海 201800
在复合波长(波长分别为1053、527、351 nm)情况下,利用激光近场对熔石英样品进行损伤实验。设计了一种基于激光近场辐照的损伤阈值定义方法,并利用带有灰度抑制的分水岭标记算法对损伤图像进行损伤区域提取,通过对比损伤图像与相应光束近场能量分布,计算出损伤区域与非损伤区域临界处的光能量密度,即为熔石英样品的损伤阈值。实验结果表明,复合波长激光诱导熔石英损伤是3种波长激光共同作用的结果,但351 nm激光对损伤起主要作用,初始损伤阈值为8.22 J/cm2;在复合波长激光多次辐照样品的情况下,熔石英样品后表面的损伤成指数形式增长,损伤增长系数为0.59。
激光光学 激光诱导损伤 激光近场 分水岭标记算法 复合波长 
光学学报
2013, 33(1): 0114001
作者单位
摘要
中国科学院上海光学精密机械研究所高功率激光物理联合实验室, 上海 201800
为了准确测量皮秒量级超短脉冲的信噪比,扩大测量仪器的可测动态范围,针对高功率超短激光脉冲在相关过程中产生参量荧光的问题,研制了一台重复频率扫描测量的三阶相关仪,并在皮秒域短脉冲光学参量啁啾脉冲放大(OPCPA)抽运源上开展了测量技术研究。研究实验表明,通过采用大角度非共线匹配方式,消除了参量荧光对测量过程的影响,进而通过结构优化降低了背景噪声的影响,使可测动态范围达到107左右。由于互相关技术的非对称性,该测量系统可同时提供时间波形的分析功能。测量结果显示,激光脉冲前沿与双曲正割(sech)型曲线比较吻合,而脉冲后沿与高斯型曲线吻合得比较好。
非线性光学 三阶相关 信噪比 时间波形 
中国激光
2012, 39(12): 1208002

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