报道了基于常温射频直线加速器建成的10 MeV光子FLASH放疗射线源样机，采用高平均电流电子束轰击高速旋转辐射转化靶，在距离靶点1 m远处的固体水模内，X射线剂量率达到80.5 Gy/s，达到未来临床实验与推广所需剂量率阈值。

干涉图像区域分割属于重要的干涉图像预处理步骤，目的是从干涉图像中提取出有效数据区域。干涉图像区域分割广泛存在于各种数字波面干涉仪的实验测试和数据处理中，对于精确波前复原以及相位解包裹可靠实施具有重要影响。介绍了3类常见干涉图像的区域分割技术，包括单帧干涉图、同步移相干涉图和横向剪切干涉图，并系统总结了相关研究进展、展望了该领域研究趋势。

In this study, an optical setup for generating terahertz (THz) pulses through a two-color femtosecond laser filament was carefully designed to achieve a precise overlap of two-color laser pulses in space and time. β-barium borate (BBO), α-BBO, and a dual-wavelength plate were used to compensate the phase delay of the two-color lasers. Tilting of α-BBO could further realize the precise spatial overlap of the two beams by counteracting the walk-off effect. The maximum output THz pulse energy reached 21 μJ in argon gas when using a commercial Ti:sapphire laser with a pulse energy of 6 mJ at a 1 kHz repetition rate. The corresponding conversion efficiency exceeded 0.35%.In this study, an optical setup for generating terahertz (THz) pulses through a two-color femtosecond laser filament was carefully designed to achieve a precise overlap of two-color laser pulses in space and time. β-barium borate (BBO), α-BBO, and a dual-wavelength plate were used to compensate the phase delay of the two-color lasers. Tilting of α-BBO could further realize the precise spatial overlap of the two beams by counteracting the walk-off effect. The maximum output THz pulse energy reached 21 μJ in argon gas when using a commercial Ti:sapphire laser with a pulse energy of 6 mJ at a 1 kHz repetition rate. The corresponding conversion efficiency exceeded 0.35%.

报道了基于光阴极S波段电子直线加速器建成的9 MeV高能微焦点射线成像系统“精卫”，X射线束横向尺寸小于100 μm，7 h剂量波动低至1.6%。初步开展成像实验结果表明：双丝像质计清晰分辨13D号丝，丝直径0.05 mm，CT测试卡测得空间分辨率优于10 lp/mm，装置同时兼容电子束能量6～18 MeV可调。

中国工程物理研究院太赫兹自由电子激光装置（CAEP THz FEL, CTFEL）是国内唯一运行的基于超导加速器的高平均功率自由电子激光太赫兹源，具有频率连续在线可调(0.1～4.2 THz)、高峰值功率(＞0.5 MW)、高平均功率(＞10 W)、高重频(54.17 MHz)、短脉冲(～ps)、窄线宽（～2%）、全相干和线性偏振等特点。自2017年出光以来，已稳定运行了四年多，并开展了诸多应用实验研究。为进一步满足用户需求，CTFEL计划升级为一台红外太赫兹自由电子激光装置，电子束能量提升至最大50 MeV，频谱范围拓展至0.1～125 THz，同时，建设材料光谱和生物医学两个实验站。

FLEET流场测速时，荧光丝的形态和特征影响流场速度测量的精度和覆盖范围，而这些参数又取决于FLEET光学系统参数，有必要对FLEET光学系统参数对荧光丝的影响规律进行研究。本文研究了光学系统的主要参数飞秒激光脉冲能量和聚焦透镜焦距对荧光丝长度、光丝峰值强度、功率密度、信噪比的影响，并在最优实验参数条件下，对不同压强下空气飞秒荧光丝的寿命进行探测。实验表明，飞秒荧光丝的激发存在功率密度阈值，本实验中大致在2×10¹³ W/cm²，光学系统参数优化应以飞秒荧光丝信噪比高且光丝强度分布均匀为基准。飞秒荧光丝的寿命约为几微秒，因此，两次测速采样的时间间隔应小于微秒量级。本文研究结果可以为FLEET光学系统主要参数确定提供依据。