Reevaluation of atomic bomb dose 1986 (DS86) -Radiation effect for atomic bomb survivors according to new dosimetry system-

由于DS 86存在遗留问题，因此我们进行了广岛和长崎原子弹剂量再评估的研究。我们已经与一些美国团体进行了合作。1996年，我们在美国小组之间举行了研讨会，并决定开始正式的联合研究。1997年我们在RERF举办了工作坊，讨论了进一步的研究。我们认为，中子感生数据与前人的计算结果存在系统性的差异。我们应该特别注意到，在1公里的距离上的差异是非常大的。2.因此，应在不同群体之间进行比较测量。3.为了直接测量快中子，我们收集了铜样品，测量了铜n，p反应产生的中子感生镍63。4.在长崎的资料中，有两组相互矛盾的资料，一组与广岛有相同的系统性差异，另一组与DS 86有很好的一致性。我们必须 ...更多信息 t收集样本，并在两组之间进行比较。5.我提出了一个假设，即原子弹底部脱落时产生的裂缝中有裸露的裂变中子泄漏。我从美国小组那里得到的答复是不可信的，但他们答应我带回去和专家们一起考虑，因为除了这种方法之外，没有好的可能的方法来解决广岛的中子差异。提出了解决广岛核事故的假设：（1）裂变中子泄漏率为5%，（2）提高爆炸高度90 m，（3）提高当量20%。美国小组从不同的证据中同意（3）。广岛超过1 km的中子数据太大，无法从输运计算中解释，因此，我们需要考虑测量数据的背景问题。我们根据这些讨论进行了研究性的研究，以建立精确的广岛和长崎原子弹爆炸幸存者剂量评估系统。少

There are residual problems concerning DS86, therefore we proceed the study of the reevaluation of atomic bomb dose in Hiroshima and Nagasaki. We have been performed collaboration with some of the US groups. In 1996 we had workshop between US group and decided to begin a formal joint study. In 1997 we had workshop at RERF and discussed further studies.Problems are as follows : 1. We aagreed that there exists the systematic discrepancy between neutron induced data and calculation according to the former studies. We should note especially that the discrepancy over the distance of 1km is very large. 2. Therefore we should make intercomparison measurement among different groups. 3. To measure directly fast neutrons, we collect copper samples and measure neutron-induced nickel 63 as a result of copper n, p reaction. 4. In the case of Nagasaki data there are two contradicting data groups.One has the same systematic discrepancy as Hiroshima and the other has a good agreement with DS86. We mus … More t collect samples and make intercomparison between the two groups. 5. I proposed an assumption of leakage of bare fission neutrons from a crack which was produced when the botoom of the atomic bomb was came off. I had an answer from US group that it is not plausible, however they promised me to bring back and consider among the specialists, because there are not good possible process to solve neutron discrepancy in Hiroshima except this way. I also proposed the assumption to solve everything in Hiroshima.They are (1) there was 5% leakage of bare fission neutrons from the crack, (2) elevate 90m of the height of explosion and (3) increase 20% of the yield. The US group agreed the (3) from the different evidence. The neutron data more than 1km in Hiroshima is too large to explain from the transport calculation, therefore, we need to consider background problem of the measured data. We proceed the research study according to these discussions to have accurate dose evaluating system for atomic bomb survivors in Hiroshima and Nagasaki. Less