The Continuous X-Rays Excited by the Beta-Particles of 15 P 32
The Continuous X-Rays Excited by the Beta-Particles of 15 P 32
复制标题
15 P 32 β粒子激发的连续X射线
DOI：
10.1103/physrev.59.481
复制
发表时间：
1941
期刊：
影响因子：
--
通讯作者：
Chien‐Shiung Wu
中科院分区：
文献类型：
--
作者：
Chien‐Shiung Wu
利用装有氟里昂的电离室和灵敏的直流放大器相连接的方法，研究了由P32 15的β粒子激发的内外X射线(Innere和äussere韧致辐射)。用外推法测得解离电子离开原子核时激发的内部X射线强度约等于完全停止铝中电子激发的外部X射线强度的四分之一。根据实验数据，估算了两种辐射的总能量。对于内X射线，这一估计导致每个崩解电子的能量约为0.0020 mc2，而在铝中激发的外X射线的能量约为0.0082 mc2。另一方面，根据Knipp和Uhlenbeck理论计算的内X射线能量为每个崩解电子0.0020 mc2，由Bethe和Heitler理论预计的外X射线能量为0.0089 mc2，因此实验结果与理论预测相一致。研究了铅、钨、锡、银、钼、铜、铁、铝、碳和铍的完全停止电子激发的外部X射线强度与原子序数的关系。发现它与根据Bloch的非弹性碰撞电子能量损失公式(F·Bloch，Ann)导出的理论曲线相当吻合。D.Physik 16,285(1933)；Zeits。F.Physik 81,363(1933))和Bethe和Heitler理论，即强度与原子序数的平方成正比。从总X射线吸收曲线的形状可以看出，外部X射线的光谱分布与原子序数Z无关，也与内部X射线的光谱分布大致相同。
The internal and external x-rays (innere and äussere bremsstrahlung) excited by the beta-particles of P 32 15 were investigated by means of a Freon-filled ionization chamber connected to a sensitive dc amplifier. The intensity of the internal x-rays excited by the disintegration electrons when leaving the nucleus was found by the extrapolation method to be approximately equal to one-fourth of that of external x-rays excited by completely stopping the electrons in aluminum. From the experimental data the total energies of the two radiations were estimated. For internal x-rays this estimate leads to about 0.0020 m c 2 per disintegration electron, and for the external x-rays excited in aluminum to about 0.0082 m c 2. On the other hand, by making use of Lyman's magnetic beta-spectrum of P 32 15 the energy of internal x-rays calculated from the theory of Knipp and Uhlenbeck was 0.0020 m c 2 per disintegration electron and the energy of the external x-rays expected from the theory of Bethe and Heitler was 0.0089 m c 2. Therefore the experimental results are in good accord with the theoretical predictions. The relation between the intensity of the external x-rays excited by completely stopping electrons in Pb, W, Sn, Ag, Mo, Cu, Fe, Al, C and Be and the atomic number was investigated. It was found to be in fairly good agreement with the theoretical curve derived according to Bloch's formula for energy loss of electrons by inelastic collisions (F. Bloch, Ann. d. Physik 16, 285 (1933); Zeits. f. Physik 81, 363 (1933)) and the theory of Bethe and Heitler, namely that the intensity is proportional to the square of the atomic number. From the shape of the absorption curves of the total x-rays it will be seen that the spectral distribution of the external x-rays is independent of Z (atomic number) and is also approximately the same as that of the internal x-rays.