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Shigeo Tanaka

Bio: Shigeo Tanaka is an academic researcher from University of Tokyo. The author has contributed to research in topics: Proton & Alpha particle. The author has an hindex of 14, co-authored 24 publications receiving 544 citations.

Papers
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Journal ArticleDOI
TL;DR: In this article, the absolute (p, n ) cross sections on Ti 47, Ti 48, V 51, Cr 52, Fe 56, Fe 57, Ni 61 and Ni 64 were measured by the activation method at proton energies up to 14 MeV.
Abstract: The absolute ( p , n ) cross sections on Ti 47 , Ti 48 , V 51 , Cr 52 , Fe 56 , Fe 57 , Ni 61 and Ni 64 were measured by the activation method at proton energies up to 14 MeV. The experimental results were compared with the predictions based on statistical model in terms of σ( p , n )/σ total , and it was shown that the predictions based on this simple model are not necessarily in disagreement with the experiments.

93 citations

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TL;DR: Exitation functions have been measured for a number of nuclear reactions of nickel isotopes with 5–56 MeV protons with peak cross-sections determined for 60 Co formation from natural nickel.

76 citations

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TL;DR: In this paper, the authors applied the 10Be method of marine sediment cores to five North Pacific cores, assuming a constant 10Be precipitation rate and varying sedimentation rates with time during the past 2.5 m.y.

55 citations

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TL;DR: In this article, the alpha-particle reactions on Ni/sup 58/ and Ni/Sup 60/ were compared with the proton reactions on Cu/sup 63/, the compound nucleus Zn/sup 64/ being the same for two cases.
Abstract: Excitation functions for the alpha -particle reactions on Ni/sup 58/, Ni/sup 60/, Ni/sup 61/, Ni/sup 62/, and Ni/sup 64/ were measured at inci dent energies up to 40 Mev. The sum of the measured cross sections for Ni/sup 58/ appears to agree with the total reaction cross section calculated from the continuum theory for /sub 0/ = 1.7 x 10-/sup 13/ cm. The sum almost agrees with the optical-model analysis of the reaction cross section for alpha -particles by Igo, whose prediction seems to give a little higher value. In the excitation function, for the ( alpha , alpha n) reaction on Ni/sup 58/ there is a small "knee" immediately after the effective threshold (around 23 Mev). The alpha - particle reactions on Ni/sup 60/ were compared with the proton reactions on Cu/ sup 63/, the compound nucleus Zn/sup 64/ being the same for two cases. The prediction from the compound nucleus theory seems to hold roughly, and it seems inadequate to discuss strictly whether the discrepancy in energy is significant. The same is observed in the comparison between the alpha -particle reactions on Ni/sup 62/ and the proton reactions on Cu/sup 65/. (auth)

48 citations

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TL;DR: In this paper, a simultaneous study of 10Be activity, magnetic reversal, mineralogy and trace elements in a 7 m long core from∼20°S, 170°W in the Pacific Ocean has been made.

28 citations


Cited by
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Journal ArticleDOI
20 Apr 1990-Science
TL;DR: The location and conse-quences of fluid production in subduction zones can be constrained by consideration of phase diagrams for relevant bulk compositions in conjunction with fluid and rock pressure-temperature-time paths predicted by numerical heat-transfer models.
Abstract: Fluids play a critical role in subduction zones and arc magmatism. At shallow levels in subduction zones (<40 kilometers depth), expulsion of large volumes of pore waters and CH(4)-H(2)O fluids produced by diagenetic and low-grade metamorphic reactions affect the thermal and rheological evolution of the accretionary prism and provide nutrients for deep-sea biological communities. At greater depths, H(2)O and CO(2) released by metamorphic reactions in the subducting oceanic crust may alter the bulk composition in the overlying mantle wedge and trigger partial melting reactions. The location and conse-quences of fluid production in subduction zones can be constrained by consideration of phase diagrams for relevant bulk compositions in conjunction with fluid and rock pressure-temperature-time paths predicted by numerical heat-transfer models. Partial melting of subducting, amphibole-bearing oceanic crust is predicted only within several tens of million years of the initiation of subduction in young oceanic lithosphere. In cooler subduction zones, partial melting appears to occur primarily in the overlying mantle wedge as a result of fluid infiltration.

921 citations

Journal ArticleDOI
26 Sep 1980-Science
TL;DR: The concentration of airborne soil dust at Enewetak Atoll in April 1979 was 2.3 micrograms per cubic meter but decreased steadily to 0.02 microgramper cubic meter over the next 5 months, suggesting that the spring dust is probably derived from China.
Abstract: The concentration of airborne soil dust at Enewetak Atoll(11°N, 162°E) in April 1979 was 2.3 micrograms per cubic meter but decreased steadily to 0.02 microgram per cubic meter over the next 5 months. The spring dust is probably derived from China; its deposition rate (∼0.3 millimeter per 1000 years) suggests that it may be a significant contributor to the deep-sea sediments of the North Pacific.

805 citations

Journal ArticleDOI
TL;DR: In this paper, a compilation of experimentally determined properties of energy levels of Z = 11−21 nuclei with special emphasis on nuclear spectroscopy is presented. But this compilation is limited to the case of nuclear spectrograms.

607 citations

Journal ArticleDOI
TL;DR: In this paper, the energy levels of A = 11 and 12 nuclei with emphasis on material leading to information about the structure of the A =11 and 12 systems were analyzed.

571 citations

Journal ArticleDOI
TL;DR: The chemistry, radiochemistry, radiobiology, and radiopharmacology of radiopharmaceuticals containing copper radionuclides are reviewed and are likely to be applied more fully in the future.

367 citations