Trial Manufacturing Study of Charge Spectrometer for Atoms Produced by Alpha-Decay

如果α粒子从原子核抛出对电子云没有影响，子体物质应该有双负电荷。过剩的负电荷是否留在产物中，首先取决于原子核跃迁对周围电子的影响，其次取决于原子的电子亲和力。α粒子的辐射对电子云K壳层的扰动不同于β衰变的影响。虽然β粒子的运动速度远远超过轨道电子的运动速度，但α粒子的运动速度远远低于K壳层中电子的运动速度。因为阿尔法太重了，移动又很慢，所以它对原子电子的微扰只有在比它们运动的周期长得多的时间里才有明显的变化。由于缓慢变化的微扰产生的影响很小，激发或弹射K壳层电子的几率非常小。相反，当α的速度远大于g…时从这些能级激发和射出的电子比外层电子更重，可以用类似于β衰变的方式处理。这些电子的静电环境的突然扰动可能会引起电子的激发或脱落。然而，这种由阿尔法衰变引起的电离还没有用电荷光谱分析来测量。本研究对α衰变电荷能谱仪进行了试制，并对其性能进行了初步检验。该光谱仪由一个连接有电子或X射线辐照组件的源体积和一个与真空系统耦合的四重质谱仪组成。源体积由八级收集导环组成，将源体积中的离子引入四重质谱仪。在对能谱仪的性能进行了初步研究后，作为实际应用，测量了Xe在DBR、HBr、CH_3Br、C_2H_5B_r中的X射线辐照电荷能谱和碎片分布以及溴-80M的异构化跃迁。上述实验结果证实了该光谱仪的特殊性能，有效地实现了本研究的初步目的。然而，在使用氚氢的进一步研究中，光谱仪被氚严重污染，发现很难在短时间内继续目前的实验。因此，目前被迫将其作为普通质谱仪来去污氚。较少

If the ejection of alpha particle from the nucleus has no effect on the electronic cloud, the daughter species should have a double negative charge. Whether or not the excess negative charge remained with the product will depend firstly on the effect of nuclear transition on the surrounding electrons, and secondly on the electron affinity of the atom. The perturbation of K-shell of the electronic cloud by emission of an alpha particle differs from the effect of beta decay. Although beta-particle moves with speed considerably in excess of the orbital electron motions, the velocity of alpha is much less than that of electrons in the K-shell. Because alpha is so heavy and moves so slowly, its perturbation of the atomic electrons varies appreciably only in times much longer than the period of their motions. Since a slowly-varing perturbation produces very small effect, probability of exciting or ejecting K-shell electrons is very small. On the contrary, when the velocity of alpha is much g … More reater than those of the outer-shell electrons, excitation and ejection of electrons from these levels may treat in a similar manner to that of beta-decay. The sudden perturbation of the electrostatic environment of these electrons may cause excitation or shake-off of electrons. However, such a ionization due to alpha-decay has not yet been measured by charge spectrometry. In the present study, the trial manufacturing of charge spectrometer for alpha-decay was carried out, and its ability was examined fundamentally. The spectrometer consists of a source volume attached with either irradiation assembly of electrons or that of X-ray and a quadruple mass spectrometer coupled with an evacuation system. The source volume consists of collecting guide rings of eight stages which leads ions in the souree volume into the quadruple mass spectrometer. After the abilities of spectrometer were investigated fundamentally, the charge spectrum of xenon irradiated with X-rays and fragment distributions produced in DBr, HBr, CH_3Br and C_2H_5Br by X-ray irradiation and isomeric transition of bromine-80m were measured as practical applications. It was confirmed that the specific capabilities of the spectrometer were shown in the typical results by the above experiments, and that the initial purpose of the present study was achieved effectively. In further study using tritiated hydrogen, however, the spectrometer was highly contaminated with tritium, and it was found to be difficult to continue the present experiments in a short period of time. Hence, at present, it is forced to used as an ordinary mass spectrometer to decontaminate the tritium. Less