一、引言近十年来,由于原子能的应用遍及于物理、化学、医学、生物学、工业、农业、军事等各个方面,因而对辐射在应用方面的计量提出了更多的要求。自1895年伦琴公布了X射线的发现后,在不到数周的时间内,即发现了这种“不可见”的光线对皮肤具有烧伤作用,从而引起了医学家的注意。几个月以后,X射线就被作为一种医 I. INTRODUCTION In the past decade, due to the application of atomic energy in various fields such as physics, chemistry, medicine, biology, industry, agriculture and military, more requirements have been put on the application of radiation in the measurement. Since the discovery of X-rays by Roentgen in 1895, in less than a few weeks, it has been found that this “invisible” light has a burning effect on the skin, thus attracting the attention of medical scientists. A few months later, X-ray was used as a medical treatment