射线II级基础理论试卷 RT Lev el II General Ex amination 姓名： 答卷时间： 地点： Name Time Location 得分： 评卷人： 时间： Marks Ex aminer Date 1. Ｘ射线管中，轰击靶的电子运动速度取决于： ( C ) A) 阴极材料的原子序数 B) 灯丝材料的原子序数 C) 阴极和阳极之间的电位差 D) 整流电路的电流 The velocity of electrons striking the target in an X-ray tube is a function of: A) the atomic number of the cathode material B) the atomic number of the filament material C) the voltage difference between the cathode and anode D) the current flow in the rectifier circuit 2. 哪种源发出的射线其穿透力最大？ ( C ) A) 钴60 B) 220kVpＸ射线管 C) 15MeV回旋加速器 D) 铱192发射的电子 Of the following, the source providing the most penetrating radiation is: A) cobalt-60 B) 220kVp X-ray tube C) 15MeV X-ray betatron D) electrons from iridium-192 3. 铱192源适用的厚度极限约为： ( B ) A) 2英寸钢或当量厚度 B) 4英寸钢或当量厚度 C) 15/2英寸钢或当量厚度 D) 11英寸钢或当量厚度 An iridium-192 gamma-ray source has an approximate practical thickness limit of: A) 2 inches of steel or its equivalent B) 4 inches of steel or its equivalent C) 15/2 inches of steel or its equivalent D) 11 inches of steel or its equivalent 4. 单色Ｘ射线束： ( D ) A) 是用来产生高对比度射线照片的窄射线束 B) 也叫做多频Ｘ射线束 C) 是只含有标识射线的Ｘ射线束 D) 是由单一波长射线组成的Ｘ射线束 A monochromatic X-ray beam: A) is a narrow beam used to produce high contrast radiographs. B) is also referred to as a heterogeneous X-ray beam. C) is a beam containing only characteristic X-radiation. D) is a beam consisting of a single wavelength. 5. 钴60源的半衰期为5.3年。用新钴源曝光一定时间可得到满意的射线照片，两年后用该钴源对同一工件进行照相，为得到同样的射线照片，曝光时间应： ( C ) A) 不变 B) 约延长11% C) 约...
