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Photodisintegration of 89Y and physical criteria of data reliabilityтезисы доклада
- Авторы: Varlamov V.V., Davydov A.I., Orlin V.N., Peskov N.N.
- Сборник: 66-я международная конференция по проблемам ядерной спектроскопии и структуре атомного ядра «Ядро 2016». 10 – 14 октября 2016 г., Саров, Россия. Сборник тезисов
- Тезисы
- Год издания: 2016
- Место издания: ФГУП «РФЯЦ-ВНИИЭФ» г. Саров
- Первая страница: 145
- Последняя страница: 145
- Аннотация: On the base of analysis of experimental partial photonuclear reaction cross sections obtained on the beams of quasimonoenergetic annihilation photons and bremsstrahlung using objective physical criteria of data reliability it was found out that for many medium and heavy nuclei those data are not reliable because do not satisfy to the proposed objective physical criteria. For many energy ranges there are clear correlations between physically forbidden negative values of (g, 1n) reaction cross section and (g, 2n) reaction cross section values for which the ratios F2 = SIGMA(g, 2n)/SIGMA(g, xn), where SIGMA(g, xn) = SIGMA[(g, 1n) + 2(g, 2n) + …], are larger than physically reliable top limit 0.50. Using experimental–theoretical method for partial photoneutron reaction cross sections evaluation new data satisfied to data reliability criteria were obtained. It was shown that evaluated cross sections differ noticeably from experimental once and that the reasons are complicated dependence of neutron multiplicity on its measured kinetic energy and absence of taking into account the contributions of proton GDR decay channels, first of all the reaction (g, 1n1p). The nucleus 89Y is of special interest concern the problems of data reliability because there are results of two experiments carried out using quasimonoenergetic annihilation photons at Livermore (USA) and Saclay (France), one experiment using bremsstrahlung at MSU SINP and one experiment using tagged photons at Illinois (USA) noticeably differ each other. Cross sections of the reaction (g, 2n) are close to each other but those for (g, xn) and (g, 1n) reactions significantly (~ 22%) disagree. At the same time (g, xn) reaction cross section obtained using bremsstrahlung is significantly (~ 47 and 21%) larger in comparison with data obtained using quasimonoenergetic annihilation photons. In addition the (g, 1n) reaction cross section obtained using tagged photons has intermediate value. Using experimental–theoretical method ((SIGMA-eval(g, in) = Fi-theor(g, in) SIGMA-exp(g, xn)) partial photoneutron reaction cross sections satisfied to the data reliability criteria were evaluated. It was shown that evaluated 89Y(g, 1n)88Y reaction cross section has intermediate value between other data. This is real evidence of the presence of noticeable systematic disagreements in the results obtained using neutron multiplicity sorting and confirmation of the reliability of evaluations carried out. The research is carried out in the MSU SINP Department of electromagnetic processes of atomic nuclei and is supported by the Coordinated Research Project (F41032, Research Contract 20501) of the International Atomic Energy Agency.
- Добавил в систему: Варламов Владимир Васильевич