在电子驻波直线加速器上获得小束斑电子束

近年来高效率探测器阵列数字辐射照相技术已经用于无损探伤实时在线图象处理检测。厚在则重的关键部位的微小缺陷，需要用加速器产生的高能电子束作为焦点打靶产生Ｘ射线进行无损探伤检测。

SMALL SPOT OF ELECTRON BEAM IN STANDING WAVE (SW) LINAC

Digital radiograph(DR) using high efficiency detectors array has been adopted recently to online real-time graph processing of nondestructive testing. The detection of little defect in somethick and heavy key units needs the X-ray produced by bombardment of focused high energy electron beam from accelerator on a target. For research on high resolution on-line real-time DR graphprocessing of nondestructive testing, a focusing unit is used to compress beam diameter after the 4MeV SW linac. Calculation shows that under the separated system condition, electrons must passtwo layers of Ti windows and gas before focued to small spot beam. When focusing unit and accelerator are connected in the same vacuum system, the beam spot can be compressed to about } =0. 2 mm and the X-ray dose produced by bombarding target satisfies DR detection. In addition, afurther approach is proposed to acquire small spot electron beam by improving the structure of accelerator and controlling emittance growth.