基于激光尾波加速的涡轮叶片高能X射线CT  

Micro-focus computed tomography for turbine blade based on all-optical bremsstrahlung source

作　　者：郭博 刘得翔 吴双华 马跃 华剑飞[1] 鲁巍[1] Guo Bo;Liu Dexiang;Wu Shuanghua;Ma Yue;Hua Jianfei;Lu Wei(Department of Engineering Physics,Tsinghua University,Beijing 100084,China;Technology Transfer and Industrialization Center,Beijing Academy of Quantum Information Sciences,Beijing 100193,China)

机构地区：[1]清华大学工程物理系,北京100084 [2]北京量子信息科学研究院技术与产业开发中心,北京100193

出　　处：《强激光与粒子束》2021年第7期100-103,共4页High Power Laser and Particle Beams

基　　金：清华大学自主科研计划资助项目。

摘　　要：发展微焦点高能X射线源技术是实现高精度高能工业CT突破的关键,基于激光尾波加速驱动高能轫致辐射源开展了微焦点高能X射线源产生以及对涡轮叶片高能CT成像研究。利用一台20 TW钛蓝宝石超快超强激光器,通过电离注入的方式获得了(140±44)pC的高能电子束,并使用1.5 mm厚钨靶产生了累积源尺寸为25μm的高能轫致辐射X射线。利用该微焦点高能X射线源,采用基于压缩感知的CT重建算法,在获取较少角度投影(31个角度)的情况下,获得了对涡轮叶片叶榫结构的CT重建。Computed tomography is a major technique for nondestructive detection of internal defects of dense materials and large-size devices.It is widely used in material science,railway,aerospace,national defense,military industry and other industries.At present,conventional high-energy industrial computed tomography system uses the X-ray source based on traditional thermionic RF electron gun,which can only provide millimeter source size,thus limiting its imaging spatial resolution.A high-energy micro-focus X-ray source is the key means to realize high-resolution high-energy industry computed tomography.As an emerging accelerator technology,the laser wakefield accelerator is a promising candidate for the micro-focus high-energy industrial computed tomography.This article reports experimental results of a micro-focus X-ray source based on laser wakefield acceleration and a computed tomography for a turbine blade.Using a 20 TW Ti:sapphire laser system,an electron beam with a charge of(140±44)pC is generated through ionization-induced injection,and then an all-optical bremsstrahlung X-ray source with an accumulated source size of 25μm is obtained by using a 1.5 mm tungsten target.Using this source,a preliminary compressed-sensing-based computed tomography for a turbine blade is performed.

关 键 词：激光尾波加速 微焦点X射线源 全光轫致辐射源 高能工业CT 电离注入 

分 类 号：TG115.28[金属学及工艺—物理冶金]