共查询到19条相似文献,搜索用时 93 毫秒
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作为高功率激光系统的放大器的增益,是决定系统能否达到能量指标的关键因素,特别是主放大器,将有95%的总能量在这里获得.整个激光系统要达到设计要求的增益,主放大器本身的性能无疑是最关键的问题.神光Ⅱ实验装置中,使用了2×2列阵组合式同轴双程主放大器.允许四束φ200(mm)激光束并行通过.用组合式结构来提高泵浦效率,用双程放大来有效地提高能量抽取效率,降低造价.组合式双程放大器设计了独特的同轴型注入和引出光路,避免了大口径光开关的技术难点.利用空间滤波器来实现激光束的注入和引出.前级放大器输出激光束,经补… 相似文献
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《中国激光》2017,(3)
双脉冲双向传输放大构型可对两束激光脉冲沿主放大器空间对称的两个方向同时进行传输放大,有效增加了放大器的储能提取率,在惯性约束聚变激光驱动器领域具有很大的应用价值。通过建立等效光路,推导了两束激光脉冲在传输放大时波前畸变的叠加过程,并对神光-Ⅲ主机装置中的实测数据进行了数值模拟。结果表明,双向传输放大构型下两束激光脉冲的波前面形存在一定差异,波前像差集中在低频段,且三、四程放大时空间滤波器小孔处的激光脉冲和输出激光脉冲的波前畸变较大。为保证输出光束质量和光束通过空间滤波器小孔,必须对主放大器内的波前像差进行补偿控制。这些结论将为双脉冲双向传输放大构型的波前控制方案的设计提供理论指导。 相似文献
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神光Ⅱ升级装置终端光学组件的排布设计 总被引:2,自引:1,他引:1
设计高功率激光装置靶场终端光学组件(FOA)时考虑的重要因素足鬼像对光学元件的破坏.山于神光Ⅱ升级装置(SG-Ⅱ-U)的输出能量高、靶场空间小、鬼像分布情况复杂,导致了终端光学组件的设计难度很高.用自主研发的鬼像控制设计软件对神光Ⅱ升级装置靶场终端光学组件排布进行设计,给出了进行鬼像控制设计时需考虑的设计因素,并对比研究了两种靶场终端光学组件设计方案的优缺点,最后结合神光Ⅱ升级装置的特点,优化设计出神光Ⅱ升级装置靶场终端光学组件的最终排布方案. 相似文献
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报道了一种新型组合式同轴双程放大器-“神光-Ⅱ”实验装置的主放大器,净通光口径为φ200mm,以及在单束原型机上取得的判断实验和理论计算的结果。 相似文献
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片状放大器系统是神光Ⅲ装置主放系统的基本组成单元,也是最重要的组成单元,其可靠性水平直接影响到整个装置的可靠运行情况。首先对片状放大器系统的结构进行简要介绍,然后建立可靠性模型,给出了片状放大器系统可靠性仿真的算法和程序流程,最后给出了仿真结果,并对结果进行了简要分析。 相似文献
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The properties of singular value decomposition (SVD) are used to implement an SVD spatial domain pseudoinverse restoration filter. This type of filter is attractive for poor imaging conditions (low spatial resolution, high image noise) and is thus appealing for nuclear medicine images. The method might offer some advantages over more traditional frequency domain filter techniques since the restoration is performed on a local rather than global basis. High-contrast thyroid phantom images collected at different count densities and low-contrast liver phantom images were processed with the SVD filter. Restored images yielded improved spatial resolution, lesion contrast, and signal-to-noise ratio. The SVD pseudoinverse restoration filter implemented as an interactive process permits the operator to terminate filtering at a stage where the visually "best" image is obtained compared to the original data. Processed images suggest that the technique may have potential for improving lesion detection in nuclear medicine. 相似文献
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Moran PR 《IEEE transactions on medical imaging》1982,1(3):197-204
To filter an image by an aperture function A(r), or in Fourier space by its transform A(f), requires that A(r) and A(f) are physically realizable and mathematically exist as transform pairs. This constrains both functions to being square-integrable to guarantee their uniform convergence both in spatial and frequency domains. This paper presents a general method for deriving filter forms which maximize image SNR and also satisfy the existence constraints. We show that asymptotic limiting forms of the constrained filters reduce to the "ideal observer" result, but demonstrate that the "ideal" filter form has a divergent square integral in some simple cases important in medical imaging. We apply these properly constrained filter forms to radiographic image and CT image models, and derive the range of arguable signal-to-noise advantage, which "more" optimum filters may exhibit with respect to the simple "matched" filter limit. 相似文献
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《Solid-State Circuits, IEEE Journal of》2009,44(6):1697-1708