I. Hunyadi

ADDITIONAL MEASUREMENTS OF THE RADIATIVE CAPTURE CROSS SECTIONS FOR 3-MeV NEUTRONS.

The cross-sections for63Cu,74Ge,75As,80Se,81Br,130Te,141Pr,186W,209Bi(n, γ) reactions have been measured at 3 MeV. The results are in agreement with earlier measurements and follow the general trend observed in the radiative capture cross-sections for fast neutrons. In the case of Ge, Se and Pr the isomeric cross-section ratios were also calculated on the basis of theHuizenga-Vandenbosh method. From a comparison of the calculated and measured isomeric ratios the probable value of the spin cut-off parameter and the inertia moment of the nucleus have been deduced.РезюмеПоперечные сечения для реакций63Cu,74Ge,75As,80Se,81Br,130Te,141Pr,186W,209Bi(n, γ) были измерены при 3 Мэв. Результаты находятся в согласии с предыдущими измерениями и следуют общему направлению, наблюдённому для сечений радиационного захвата быстрых нейтронов. Отношения изомерного сечения для Ge, Se и Pr тоже были рассчитаны на основе метода Хуизенга-Ванденбоша. Сравнивая рассчитанные и измеренные изомерные сечения вероятные значения параметра спинового отреза и момент инерции были определены.

Dal{cyrillic small soft sign}nyei{cyrillic, short}shiye izmyeryeniya syechyenii{cyrillic, short} radiatsionnogo zakhvata dlya nyei{cyrillic, short}tronov s enyergiyei{cyrillic, short} 3 Mev

The cross-sections for63Cu,74Ge,75As,80Se,81Br,130Te,141Pr,186W,209Bi(n, γ) reactions have been measured at 3 MeV. The results are in agreement with earlier measurements and follow the general trend observed in the radiative capture cross-sections for fast neutrons. In the case of Ge, Se and Pr the isomeric cross-section ratios were also calculated on the basis of theHuizenga-Vandenbosh method. From a comparison of the calculated and measured isomeric ratios the probable value of the spin cut-off parameter and the inertia moment of the nucleus have been deduced.РезюмеПоперечные сечения для реакций63Cu,74Ge,75As,80Se,81Br,130Te,141Pr,186W,209Bi(n, γ) были измерены при 3 Мэв. Результаты находятся в согласии с предыдущими измерениями и следуют общему направлению, наблюдённому для сечений радиационного захвата быстрых нейтронов. Отношения изомерного сечения для Ge, Se и Pr тоже были рассчитаны на основе метода Хуизенга-Ванденбоша. Сравнивая рассчитанные и измеренные изомерные сечения вероятные значения параметра спинового отреза и момент инерции были определены.

Total neutron cross sections of Be, C, and F near 14 MeV

Abstract Total neutron cross sections of Be, C and F have been measured by the transmission method in the energy range E n = 13.70 to14.60 MeV in steps of 50 keV. The accuracy of the relative total cross section data better than 1%, The cross section curves suggest fluctuations for Be and F and a smooth variation for C.

Activation cross-sections for Na23 and Al27 with 14 MeV neutrons

Abstract The activation cross-section of the reactions (n,α), (n,p), (n,γ) and (n,2n) were determined for Al27 at 14.6 MeV neutron energy. The values obtained were 118 mb, > 2 mb, 0.56 mb and δ nα δ np =3.9±0.3 was obtained. The data are compared with calculations based on the statistical model.

A study of the 14N(d, p)15N reaction at low bombarding energies

Abstract Absolute differential cross sections of the proton groups p 0 , p 1 + p 2 , p 3 , p 4 and p 5 from the 14 N(d, p) 15 N reaction have been determined at bombarding energies between 0.309 and 0.638 MeV. The shape of the measured angular distributions are generally well reproduced by the incoherent sum of the contributions of direct and compound nucleus processes calculated with the distorted wave Born approximation and the Hauser-Feshbach formula respectively. However, a reliable value for the spectroscopic factor can be extracted only for the p 5 transition whose mechanism even at this energy is almost entirely direct.

Correlation between nuclear radii and binding energies for light nuclei

Deviations of measured total neutron cross sections from the “black-nucleus” formula were investigated for light nuclei, Similar trends in electrical charge radii suggest that the deviations are caused by variations in the nuclear radius parameter.,r 0. It was found that a definite correlation exists betweenr 0 and the binding energy per nucleon, e, namelyr 0. e≈11 MeV fm.

Investigation of27Al(d, α)25Mg nuclear reaction in the energy rangeE d=650−540keV using a plastics track detector@@@Исследование ядерной реакции27Al(d, α)25Mg в интервале энергииE d=650−540 кэв посредством пластикового трекового детектора

The angular distributions of the α0 and α1 groups from the27Al(d, α)25Mg nuclear reaction have been measured at deuteron energiesEd=650, 585 and 540 keV using plastics track detector techniques. The angular distributions which are nearly isotropic have been analysed in terms of the Legendre polynomials. Assuming statistical compound reaction mechanism the relative intensity ratio of the two measured alpha groups could be reproduced by a simple calculation giving the statistical weight factors for the alpha transitions concerned.РезюмеИзмеряются угловые распределения групп α1 и α2 в ядерной реакции27Al (d, α)25Mg при энергиях дейтерияEd=650, 585 и 540 КЭВ с помощью пластикового трекового детектора. Угловые распределения, которые почти изотропны, разлагаются в ряд при помощи полиномов Лежандра. Предполагая статистический составной механизм реакции, соотношение относительной интенсивности двух измеренных альфа — групп можно воспроизводить простым вычислением, задавая статистические веса для рассмотренных альфа-переходов.

CORRELATION BETWEEN NUCLEAR RADII AND BINDING ENERGIES FOR LIGHT NUCLEI.

Deviations of measured total neutron cross sections from the “black-nucleus” formula were investigated for light nuclei, Similar trends in electrical charge radii suggest that the deviations are caused by variations in the nuclear radius parameter.,r0. It was found that a definite correlation exists betweenr0 and the binding energy per nucleon, ε, namelyr0. ε≈11 MeV fm.РезюмеИсследованы отклонения измеренного полного сечения нейтронов от формулы «чёрного ядра» для легких ядер. Подобные тенденции радиуса электрического заряда подсказывают, что отклонение причинен изменением параметра ядерного радиуса,r0. Найдена определенная корреляция междуr0 и энергии связи на нуклонε, именноr0ε≈11 Мэв fm.

Korryelyatsiya myezhdu radiusom yadra i enyergiyei{cyrillic, short} svyazi dlya liogkikh yadyer

Deviations of measured total neutron cross sections from the “black-nucleus” formula were investigated for light nuclei, Similar trends in electrical charge radii suggest that the deviations are caused by variations in the nuclear radius parameter.,r0. It was found that a definite correlation exists betweenr0 and the binding energy per nucleon, ε, namelyr0. ε≈11 MeV fm.РезюмеИсследованы отклонения измеренного полного сечения нейтронов от формулы «чёрного ядра» для легких ядер. Подобные тенденции радиуса электрического заряда подсказывают, что отклонение причинен изменением параметра ядерного радиуса,r0. Найдена определенная корреляция междуr0 и энергии связи на нуклонε, именноr0ε≈11 Мэв fm.

The forward-backward asymmetry of recoil nuclei in the reaction AL27 (n, α) Na24

The forward-backward asymmetry of recoil nuclei from the reaction Al/sup 27/(n, alpha )Na/sup 24/ was investigated by the recoil technique. On polyethylene foils placed in forward (F) and backward (B) directions, the recoil nuclei emitted into intervals O/sub BETA / - rature of the d /2 and rature of the d /2- rature of the d , respectively, were captured. The BETA -activity ratio of the Na/sup 24/ upon the forward and backward foils (A/sub F//A/sub B/) was measured as a function of the thickness of the aluminum foil and extrapolated to 0-thickness. The value 5.1 ction in DDT-C/ 0.3 was obtained. (C.E.S.)