X射线半值层是指一束X射线的空气比释动能减弱到其初始值一半所需的标准物质的厚度。它直观的反映了X射线束的穿透能力,是医用X射线诊断辐射源的重要性能指标。根据JJG744-2004《医用诊断X射线辐射源检定规程》,半值层对于所有的X射线辐射源的首次和后续检定都是必检项目。但遗憾的是,JJG744-2004中对 X-ray half-value layer refers to a beam of X-ray air kerma can weaken to its initial value of half the thickness of the required standard material. It intuitively reflects the penetrating power of X-ray beams and is an important performance indicator of medical X-ray diagnostic radiation sources. According to JJG744-2004 “Medical diagnostic X-ray radiation source verification procedures”, the half-value layer for all X-ray radiation source of the first and subsequent tests are the items to be seized. But unfortunately, JJG744-2004 right