脉冲展宽分幅相机的最优空间分辨能力分析  

Analysis of Optimal Spatial Resolution Capability of Pulse-Dilation Framing Camera

作　　者：陈欢 白雁力 李姮 高海英 Chen Huan;Bai Yanli;Li Heng;Gao Haiying(School of Electronic Engineering and Automation,Guilin University of Electronic Technology,Guilin 541004,Guangxi,China;School of Information and Communication,Guilin University of Electronic Technology,Guilin 541004,Guangxi,China)

机构地区：[1]桂林电子科技大学电子工程与自动化学院,广西桂林541004 [2]桂林电子科技大学信息与通信学院,广西桂林541004

出　　处：《激光与光电子学进展》2024年第8期158-164,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(11865007);广西自然科学基金面上项目(2022GXNSFAA035561);广西自动检测技术与仪器重点实验室主任基金(YQ22101)。

摘　　要：短磁聚焦脉冲展宽分幅相机是一种具有长漂移区的二维超快诊断设备。通常采用轴上和离轴的点空间分辨率对其近轴空间分辨能力和工作面积进行评估,但由于像场弯曲会引起高斯像面的空间分辨不均匀,因此难以评价相机的整体空间分辨能力,所以研究一种能量化空间分辨能力的方法具有重要意义。为探讨新方法,采用COMSOL软件建立模型,基于场曲特性重建三维成像曲面,采用标准差分析成像曲面与高斯像面之间的偏离程度,通过融合点空间分辨率和整体调制度构建高斯像面空间分辨率,并运用相对误差量化高斯像面空间分辨均匀性。研究结果显示,在组合磁透镜的孔距为200 mm、漏磁缝隙为10 mm、轴向宽度为100 mm、漂移区长度为400 mm、成像半径为21 mm、阴极为-3.75 kV的情况下,随着成像磁场变化,成像曲面与高斯像面之间的偏离程度,以及高斯像面空间分辨率均呈开口向上的抛物线形状,并在成像磁场为41.97 Gs(1 Gs=10^(-4)T)时,两像面偏离程度标准差达到最小,为2.82 mm,高斯像面空间分辨率提升至最优,为292.80μm,表征空间均匀性的调制度差值降低至最小,为330%。本文研究为评估短磁聚焦脉冲展宽分幅相机的最优空间分辨性能提供了一种可量化的参考方法。The pulsedilation framing camera,with a short magnetic focus,is a twodimensional,ultrafast diagnostic device with a long drift region.It evaluates the paraxial spatial resolution and detection area by the point spatial resolution of the onaxis and offaxis,respectively.However,because of the spatial nonuniformity of the Gaussian image plane caused by the field curvature,the overall spatial resolution of the camera is difficult to evaluate.Therefore,this study proposes a new method to quantify the spatial resolution of a pulsedilation framing camera.The proposed method is based on a model constructed using the COMSOL software.In this model,the threedimensional imaging surface is reconstructed based on the characteristics of the field curvature.The degree of deviation between the imaging surface and the Gaussian image plane is analyzed by standard deviation(SD),and the spatial resolution of the Gaussian image plane is obtained by combining the point spatial resolution and the overall modulation.The spatial resolution uniformity of the Gaussian image plane is quantified using relative error.The results of our study show that,when the lens aperture is 200 mm,slit width is 10 mm,axial width is 100 mm,length of drift region is 400 mm,imaging radius is 21 mm,and the cathode voltage is−3.75 kV,with the change in magnetic field,the degree of deviation between the imaging surface and the Gaussian image plane,and the spatial resolution of the Gaussian image plane both have an upward parabolic shape.When the imaging magnetic field is 41.97 Gs(1 Gs=10^(-4) T),the SD of the deviation of the two image planes is minimized to 2.82 mm,the spatial resolution of the Gaussian image plane is optimal at 292.80 m,and the modulation difference characterizing the spatial uniformity is minimized to 330%.In conclusion,this study proposes a quantifiable reference method for evaluating the optimal spatial resolution performance of a pulsedilation framing camera with a short magnetic focus.

关 键 词：超快诊断技术 脉冲展宽分幅相机 短磁聚焦 高斯像面 空间分辨能力 

分 类 号：TN143[电子电信—物理电子学]