低能质子引起的金LX射线相对产生截面

对于能量为０．５－１ＭｅＶ的入射质子，在计算中采用ＡｕＬ１次壳层荧光产额的实验值代替相应的Ｄｉｒａｃ－Ｈａｒｔｒｅｅ－Ｓｌａｔｅｒ值时，使用ＲＰＷＢＡ－ＢＣ（经结合能和库仑歪曲修正的相对论平面波玻恩近似）电离截面计算得到的金原子ＬＸ射线相对产生截面与测量值相符。以前报道的对ＲＰＷＢＡ－ＢＣ截面的各种修正都是不需要的     

^11B快中子非弹性散射的理论计算

本文采用直接作用模型和扭曲波玻恩近似理论，计算了＾１１Ｂ的２．１４ＭｅＶ激发态在入射中子能量为７．５４－２０．０ＭｅＶ的非弹性散射的积分截面和角分布，计算结果与评价的实验值进行了比较，符合较好。对实验上所缺乏的数据作出了理论预期值。     

16O＋24Mg反应全熔合激发函数的类共振结构

本工作用位置灵敏的△Ｅ－Ｅ望远镜系统，入射能量长为１．０ＭｅＶ，测量了５５－９０ＭｅＶ１６Ｏ＋２４Ｍｇ反应全熔全激发函数，实验结果表明，这个反应的全熔合激发函数不是平滑的，存在着宽结构。峰位在ＥＣＭ＝３４．２，３７．８，４０．６，４３．８和４６．６ＭｅＶ。当ＥＣＭ＞４８ＭｅＶ时。激发函数的结构消失了。     

用于等离子体电位测量的电容探针和发射探针

本文给出了发射探针和电容探针测量等离子体电位的实验和方法。发射探针采用直流功率加热，并在较强电子发射条件下运行（Ｉ_（ｅ０）／Ｉ_（ｅ０）＞１）。电容探针表面二次电子发射系数δ≥１。本文对发射探针的电子发射性能、工作电流、电容探针的输入、输出电压关系进行了标定实验。得到了电容探针的校准系数分别为３×１０（－３）、５×１０（－４）。实验给出了ＭＭ－４会切中心等离子体电位Ｖ_（ｐ４）＝－８２±９－１２２±１２Ｖ；ＭＭ－４Ｕ东、西会切中心等离子体电位分别为Ｖ_（Ｐ４ｕ１）＝－５２．９±３．２Ｖ，Ｖ_（Ｐ４ｕ２）＝－６２±３．２Ｖ。     

关于l／η（1440）的结构分析

本文通过对Ｊ／ψ辐射衰变到Ｋ＋Ｋ－πＯ和终态中ｉｏｔａ能区的振幅分析，发现ｉｏｔａ峰下有一个０－＋共振态（Ｍ＝１４６７±３ＭｅＶ，＝８９±６ＭｅＶ）和两个１＋＋共振态（Ｍ＝１４３５±３ＭｅＶ，＝５９±５ＭｅＶ；Ｍ＝１４９７±２ＭｅＶ，＝４４±７ＭｅＶ），分别对应于η（１４４０），ｆ１（１４２０）和ｆ１（１５１０）．     

用卢瑟福背散射和弹性背散射分析高T＿c超导薄膜中的元素组份及氧含量

提出了用能量为１．５－２．５ＭｅＶ的质子弹性背散射分析（ｅｌａｓｔｉｃｂａｃｋｓｃａｔｔｅｒｉｎｇ，缩写为ＥＢＳ）来测定薄膜中的氧含量，这个方法对于厚度为几十纳米到几个微米的样品，测量精度约５％。采用ＲＢＳ分析并结合ＥＢＳ分析，可全面测得薄膜中各元素的含量。     

慢电子被氧原子弹性散射的截面计算

采用Ｈａｒａ ｆｒｅｅ－ｅｌｅｃｔｒｏｎ－ｇａｓ ｅｘｃｈａｎｇｅ ａｐｐｒｏｘｉｍａｔｉｏｎ（ＨＦＥＧＥ）交换势和本文作者提出的极化势，用等效势模型计算了能量在０．１３６－１２ｅＶ内的ｅ－Ｏ弹性散射总截面和动量转移截面，结果与Ｔｈｏｍａｓ和Ｎｅｓｂｅｔ的理论计算结果以及实验结果作了比较。     

入射能量为5．1MeV中子~（58）Ni（n，α）~（55）Fe反应截面和出射

用屏栅电离室测量了入射中子能量为５．１ＭｅＶ的５８Ｎｉ（ｎ，α）５５Ｆｅ核反应的α粒子角分布，２３８Ｕ裂变电离室作中子注量率的测量，测得该能点５８Ｎｉ（ｎ，α）５５Ｆｅ的总截面为（４７．４±５．０）ｍｂ．用中国核数据中心推荐的理论计算程序ＵＮＦ计算了在１—８ＭｅＶ能区５８Ｎｉ（ｎ，ｐ）５８Ｃｏ，５８Ｎｉ（ｎ，α）５５Ｆｅ的反应截面和入射中子能量为５．１ＭｅＶ的５８Ｎｉ（ｎ，α）反应角分布．理论和测量数据的比较说明，用复合核模型来描写该能点的角分布是可行的．     

用卢瑟福背散射和弹性背散射分析高Tc超导薄膜中的元素组份及氧含量

提出了用能量为１．５－２．５ＭｅＶ的质子弹性背散射分析（ｅｌａｓｔｉｃ ｂａｃｋｓｃａｔｔｅｒｉｎｇ，缩写为ＥＢＳ）来测定薄膜中的氧含量，这个方法对于厚度为几十纳米到几个微米的样品，测量精度约５％。采用ＲＢＳ分析并结合ＥＢＳ分析，可全面测得薄膜中各元素的含量。 关键词：     

~（56，57）Fe，~（59）Co（α，d）核反应及拉长态性质的实验研究

利用△Ｅ—Ｅ望远镜及Ｑ３Ｄ磁谱仪，在ＨＩ－１３串列加速器提供的３５ＭｅＶα离子束轰击下，测量５６，５７Ｆｅ，５９Ｃｏ（α，ｄ）５８、５９Ｃｏ，６１Ｎｉ核反应的精细能谱和微分截面角分布，微观ＤＷＢＡ近似用来分析实验数据．在５６Ｆｅ（α，ｄ）５８Ｃｏ核反应观测的９个强激发能级中，重点分析和讨论了６．７９ＭｅＶ和６．４ＭｅＶ能级的性质，观测到迄今所能看到的最高拉长组态（１ｇ９／２，１ｇ９／２）９和首次确认了６．４ＭｅＶ能级Ｊπ＝１＋．在５７Ｆｅ，５９Ｃｏ（α，ｄ）核反应测量中，未看到孤立强激发能级，它意味着强度分散在许多能级上，以致看不到孤立拉长态存在的实验证据．     

Optical model and DWBA analysis of the7Li(d,d)- and7Li(d,p 0)-reactions in the energy region 1.0 to 2.6 MeV

Absolute differential cross sections for the elastic scattering of deuterons by⁷Li have been determined in the energy range of 1.0 to 2.6 MeV. Two excitation curves measured at laboratory angles of 90° and 160° vary smoothly with energy. At higher energies an extremely strong enhancement of the cross section relative to the Rutherford value was observed at large angles. It was, however, possible to find realistic optical potentials that describe these distributions fairly well over the whole energy region. For two of these potentials good fits could be obtained with DWBA calculations on the⁷Li (d, p ₀)-reaction, one of them yielding a spectroscopic factor in close agreement with shell model predictions.     

Neutron total and scattering cross sections of 6Li in the low-MeV range

Neutron total cross sections of ⁶Li are measured at intervals of ? 10 keV from ≈ 0.1 to 4.8 MeV with precisions of ≈ 1 to 3 %. Differential elastic scattering cross sections are measured at intervals of ? 100 keV from 1.5 to 4.0 MeV at 10 or more scattering angles distributed between ≈ 20 and 160 deg. Differential inelastic scattering cross sections are measured at selected angles in the energy range 3.5 to 4.0 MeV. The experimental results are analyzed in terms of R-matrix theory and the model parameters used to deduce the ${}^6\text{Li(n}\text{,α)}$ cross sections. The implications of the measurements and their interpretation on the level structure of ⁷Li and the reaction mechanisms are discussed.     

Scattering of negative pions on helium

Differential cross sections for negative pion scattering on ⁴He have been measured at five pion kinetic energies between 110 and 260 MeV in the angular range from 5° to 180°. Total cross sections have also been measured at eleven energies between 67 and 285 MeV. The differential cross sections have been fitted with a phenomenological expression for the nuclear scattering amplitude. Conventional phase shifts have been reconstructed starting from the parameters of the fits.     

Differential cross sections of proton compton scattering at photon laboratory energies between 700 and 1000 MeV

Differential cross sections of proton Compton scattering have been measured at the Bonn 2.5 GeV synchrotron. 78 data points are presented as angular distributions at photon lab energies of 700, 750, 800, 850, 900, and 950MeV. The c.m. scattering angle ranges from 40°–130°, corresponding to a variation of the four momentum transfer squared betweent=?0.10 tot=?0.96 GeV² at 700 and 950 MeV, respectively. Two additional differential cross sections have been measured at 1000MeV, 35.6° and 47.4°. The angular distributions show forward peaks whose extrapolations to 0° are consistent with calculated forward cross sections taken from literature. The small angle data (|t| ?0.2 GeV²) together with the calculated cross sections at 0° are also consistent with the assumption of a slope parameterB of 5 GeV^?2. For the first time a rerise of the angular distributions towards backward angles has been observed. It becomes less steep with increasing energy. The most interesting feature of the angular distributions is a sharp structure which appears betweent=?0.55 GeV² at 700MeV andt=?0.72 GeV² at 950 MeV. Such a rapid varation of the differential cross section witht has never been ovserved in elastic hadron-hadron scattering or photoproduction processes. It indicates the existence of a dynamical mechanism which could be a peculiarity of Compton scattering.     

Low-energy proton reactions on 45Sc of interest in stellar nucleosynthesis

Differential cross sections on ⁴⁵Sc have been measured for inelastic scattering (p, p_i; i = 2–13) at lab angles of 70° and 110° in the proton energy range 2.5 to 3.5 MeV and for the (p, α_{0, 1}) reactions at 125° between 2.8 and 3.8 MeV. Angular distributions were obtained at incident energies of 2.90, 3.15 and 3.40 MeV. These data were compared with calculations performed with a Hauser-Feshbach statistical model and average parameters which have been used to calculate reaction rates during stellar nucleosynthesis. The general agreement between the calculations and the trend of the data supports the use of these calculations for reaction rates involving nuclei in excited states, a situation important during stellar silicon burning.     

Fluctuations in inelastic proton scattering from58Ni in the energy range 17.1 to 20.6 MeV

Excitation functions of proton elastic and inelastic scattering on⁵⁸Ni have been measured for proton energies in the range 17.1 to 20.6 MeV, at laboratory angles of 90°, 120° and 155°. All show cross section fluctuations. Excitation functions are presented for the elastic and for five inelastic groups in the energy range 18.1 to 18.59 MeV. These were analyzed by the Fourier analysis method, and the average level width found to be about 13 keV. The observation of strong fluctuations in the higher inelastic yields has implications for several microscopic analyses reported in the literature of⁵⁸Ni(p, p′) data obtained at 17.7 MeV incident proton energy.     

Richtungskorrelation für Kernresonanzfluoreszenz und Lebensdauer des 412 keV-Niveaus von198Hg

Using the method of thermal Doppler-broadening of the emission line, the effective differential cross sections for nuclear resonance scattering for 412 keV photons by¹⁹⁸Hg has been measured for well defined scattering angles of 120° and 160°. The results indicate a partial mean lifetime for this energy level of τ_γ=(5·12±0·23)·10^?11 sec. This result differs appreciably from the values reported by other workers. Possible reasons for these discrepancies are discussed. The ratio of the differential cross sections for resonance scattering at angles of 120° and 160° is consistent with a 0-2-0 transition.     

Observation of the nuclear rainbow scattering for12C+12C atE Lab =300 MeV

The elastic and inelastic scattering of¹²C on¹²C has been measured in the angular range between 2.8° and 70.4° in the c.m. system atE _Lab =300 MeV. Optical model calculations have been performed with Woods-Saxon and folded potentials, the ground state and the first 2⁺-state were coupled in the calculations. The large cross sections of the elastic scattering at large angles is related to the nuclear rainbow scattering, which is centered at about 56°. This requires a potential depth of 100 MeV at a distance of 3 fm, the fit to the data is sensitive down to this region. The calculations with the folded potential show a better agreement with the data than those with the Woods-Saxon shape. The total reaction cross section of 1,420 mb, obtained from the optical model analysis, corresponds to the geometrical value; no transparency is observed.     

Elastic scattering of 3He nuclei on 13C nuclei at 50 and 60 MeV and V-W ambiguity in choosing optical potentials

At energies of 50 and 60 MeV, the elastic scattering of ³He nuclei on ¹³C nuclei is investigated at laboratory angles in the range 10°–170°. The measured differential cross sections are analyzed on the basis of the optical model of the nucleus by using Woods-Saxon potentials, including both volume and surface absorption. The potential parameters are determined by fitting the computed cross sections to experimental data. It is found that, even in the region of sensitivity, the values of the real and imaginary parts of the potentials (V and W, respectively) show considerable scatter, with extreme values differing by a factor greater than two. This scatter is explained by the existence of a V-W ambiguity in choosing optical potentials.     

Coherent π0-photoproduction on deuterium in the first resonance region

Differential cross sections for coherent π⁰-photoproduction from deuterium have been measured in the photon energy range from 240 to 400 MeV and for pion c.m. angles between 70 ° and 160 °. The recoil deuterons were analysed in angle and momentum by a magnetic spectrometer. The cross sections obtained were higher by a factor of about 2 compared with the results from Stanford [7], the only data available up to now in the first resonance region. Below the resonance the measured cross sections give a smooth extension to the low energy data from Glasgow [5] and Orsay [6].