集装箱检测系统用加速器电子枪的特性研究

 研究了固定式海关集装箱检测系统用9MeV电子行波直线加速器电子枪的结构特点和束流特性。该电子枪采用钪酸盐阴极，在灯丝电流为2.4A，阳极引出电压为-40kV的工作条件下，由电子枪发射到加速器入口处的脉冲电流强度为300mA，在加速器出口处，束斑截面小于φ2mm；打靶后，产生的X射线剂量率大于30cGy/(min× m)。电子枪的良好特性及束流强度保证了集装箱检测图像所需的高分辨率的要求。为保证满足更换电子枪时的安装要求，利用EGUN程序模拟计算了电子枪的结构及束流特性，为实际装配和使用提供了参考尺寸和调试参数。

Characteristics of electron gun used in the accelerator for customs inspection systems

The paper introduces the characteristics of the electron gun used in the 9MeV traveling wave electron linear accelerator for fixed customs container inspection system. With the scandate cathode, the electron gun meets the accelerator characteristics with the whole system not needing high-temperature roasting to degas. The electron gun can work normally at a vacuum of about 10－5Pa and can be reinstalled after exposure to air. In the accelerator, the electron gun emits a beam which strikes the target to produce an X-ray beam with a dosage rate of over 30Gy/(min*m) and a beam focus spot of less than φ 2mm. The EGUN code is used to simulate the structure and properties of the electron gun. The reference size debugging parameters for replacing the electron gun are given for assembly requirements．