36Cl and41Ca depth profiles in a Hiroshima granite stone and the Dosimetry System 1986

Rühm, W.; Kato, Kazúo; Korschinek, G.; Morinaga, H.; Nolte, E.

doi:10.1007/bf01298486

Cited by 15 publications

(1 citation statement)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The U.S. group took the lead role in the theoretical (calculations) approach, and the Japanese group took the lead in the experimental (measurements) approach. Besides critical examinations of past 152 Eu data, Accelerator Mass Spectrometry (AMS) of 36 Cl (half-life ϭ 3.0 ϫ 10 5 y) of atomic bomb-exposed samples had already been performed in the U.S. (Straume et al 1992) and Germany (Kato et al 1990;Rühm et al 1992). The 63 Ni induced in copper samples by the fast neutron reaction 63 Cu(n,p) 63 Ni was also discussed in workshops (Shibata et al 1994;Straume et al 1994;McAninch et al 1997;Rühm et al 2000).…”

Section: Introductionmentioning

confidence: 96%

ATOMIC BOMB INDUCED 152Eu: RECONCILIATION OF DISCREPANCY BETWEEN MEASUREMENTS AND CALCULATION

Komura

Hoshi²,

Endo³

et al. 2007

Health Physics

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 96%

ATOMIC BOMB INDUCED 152Eu: RECONCILIATION OF DISCREPANCY BETWEEN MEASUREMENTS AND CALCULATION

Komura

Hoshi²,

Endo³

et al. 2007

Health Physics

View full text Add to dashboard Cite

show abstract

36Cl measurements in hiroshima granite samples as part of an international intercomparison study

Huber

Rühm²,

Hoshi

et al. 2003

Radiat Environ Biophys

Self Cite

View full text Add to dashboard Cite

Within the effort to resolve the so-called Hiroshima neutron discrepancy, an international intercomparison study has been carried out on granite samples from Hiroshima, with participating institutions from Japan, the US, and Germany. (36)Cl and (152)Eu produced in these samples by thermal neutrons from the A-bomb explosion were assessed independently by means of different techniques. At the Maier-Leibnitz-Laboratory near Munich, Germany, (36)Cl concentrations were measured by accelerator mass spectrometry. Measured (36)Cl/Cl ratios ranged from 1,670 x 10(-13) (at a distance of 146 m from the hypocenter) to 2.2 x 10(-13) (at a distance of 1,163 m from the hypocenter). One granite sample not exposed to A-bomb neutrons was measured as a control, and a (36)Cl/Cl ratio of 2.6 x 10(-13) was obtained. On average, our experimental results are 20-30% lower than those provided by model calculations based on the dosimetry system DS86. The results presented here do not support previous assessments of (36)Cl, (60)Co, and (152)Eu which had suggested much larger thermal neutron fluences than those calculated on the basis of DS86 for distances from the hypocenter of more than 1,000 m.

show abstract

The Hiroshima thermal-neutron discrepancy for 36Cl at large distances. Part I: New 36Cl measurements in granite samples exposed to A-bomb neutrons

Huber

Rühm

Kato

et al. 2005

Radiat Environ Biophys

View full text Add to dashboard Cite

The long-lived radioisotope (36)Cl (half-life: 301,000 years) was measured in granite samples exposed to A-bomb neutrons at distances from 94 to 1,591 m from the hypocenter in Hiroshima, by means of accelerator mass spectrometry (AMS). Measured (36)Cl/Cl ratios decrease from 1.6 x 10(-10) close to the hypocenter to about 1-2 x 10(-13), at a distance of 1,300 m from the hypocenter. At this distance and beyond the measured (36)Cl/Cl ratios do not change significantly and scatter around values of 1-2 x 10(-13). These findings suggest that the (36)Cl had been predominantly produced by thermalized neutrons from the A-bomb via neutron capture on stable (35)Cl, at distances from the hypocenter smaller than about 1,200 m. At larger distances, however, confounding processes induced by cosmic rays or neutrons from the decay of uranium and thorium become important. This hypothesis is theoretically and experimentally supported in a consecutive paper. The results are compared to calculations that are based on the most recent dosimetry system DS02. Close to the hypocenter, measured (36)Cl/Cl ratios are lower than those calculated, while they are significantly higher at large distances from the hypocenter. If the contribution of the cosmic rays and of the neutrons from the decay of uranium and thorium in the sample was subtracted, however, no significant deviation from the DS02 calculations was observed, at those distances. Thus, the Hiroshima neutron discrepancy reported in the literature for (36)Cl for samples from large distances from the hypocenter, i.e., higher measured (36)Cl/Cl ratios than predicted by the previous dosimetry system DS86, was not confirmed.

show abstract

36Cl and41Ca depth profiles in a Hiroshima granite stone and the Dosimetry System 1986

Cited by 15 publications

References 9 publications

ATOMIC BOMB INDUCED 152Eu: RECONCILIATION OF DISCREPANCY BETWEEN MEASUREMENTS AND CALCULATION

ATOMIC BOMB INDUCED 152Eu: RECONCILIATION OF DISCREPANCY BETWEEN MEASUREMENTS AND CALCULATION

36Cl measurements in hiroshima granite samples as part of an international intercomparison study

The Hiroshima thermal-neutron discrepancy for 36Cl at large distances. Part I: New 36Cl measurements in granite samples exposed to A-bomb neutrons

Contact Info

Product

Resources

About