SIGNIFICANT EFFECT ON THE BINDING ENERGY OF 5He BY THE CHANGE OF THE INTERNAL ENERGY OF THE α PARTICLE

The change of the internal energy of the α-particle is usually neglected in the previous calculations of the binding energy of ⁵He.The present work shows explicitly that the change of the internal energy of the α-particle can influence significantly the theoretical value of the binding energy of ⁵He.     

DEPENDENCE OF THE MECHANISM AND CROSS SECTION OF THE α PARTICLES EMITTED FROM 12C+64Ni REACTION ON INCIDENT ENERGY

Energy spectra and angular distributions of the particles emitted from ¹²C+⁶⁴Ni reaction at eight energies in the region of 36.5MeV—69.4MeV are measured. The angular distributions of α particles change from forward peaked one to that peaked near by the grazing angle with decreasing incident energy. This result show that the emission mechanism of non-evaporation α particle is different in different energy regions.     

232Th裂变的电荷分布

在14MeV中子引起²³²Th裂变中,用放射化学方法测定了⁸²Br、⁹⁶Nb、¹¹²Ag、¹³⁰I、¹³²I、¹³⁴I、^134mCs、^135mCs和¹³⁶Cs等9个屏蔽核或准屏蔽核的独立产额以及¹⁴⁰La的独立产额上限。使用各种电荷分布假设和质量公式,高斯电荷分布函数f_i=（πC）^-1/2exp[-（Z—Z_p）²/C],与实验测定的分独立产额进行了关联研究。结果指出,Green质量公式的最小位能假设可以得到最佳拟合,电荷分布宽度参数C=0.80.主要以对称裂变方式产生的¹¹²Ag的分独立产额和以非常不对称裂变产生的⁸²Br的分独立产额偏离拟合的高斯曲线。这似乎表明,对称裂变有较宽的电荷分布宽度;而非常不对称裂变的电荷分布较窄。这个趋势能用液滴模型定性地解释。本工作没有发现40个质子的亚壳层对裂变产额影响的证据。     

A NEW METHOD FOR THE DETERMINATION OF THE SPIN OF ξ(2230)

In this paper we have got the angular distributions of the photon for the moments of process e⁺e^－→J/ψ→γB(J^η),B(J^η)→P₁P₂. It provides a new way to determine the spin of ξ(2230).     

THE STUDY OF SOME NON-SOLATED RESONANCES FOR THE 23Na （p,α）20Ne REACTION

The excitation functions of the ²³Na（p,α₀）²⁰Ne_g·s.and the ²³Na（p,α₁）²⁰Ne_lst reae-tion have been measured from E_p=1 to 2.5 MeV at θ_L=30°,150° and 30°,respectively.Around the resonance at 2.171 MeV,the excitation functions of the（p,α₀）reactionhave been measured at 12 angles,then,some angular distributions have been obtained from these excitation functions.In addition,the angular distribution of the（p,α₀）reaction for the resonance at 2.171 MeV has also been measured directly at energy ofthe resonance peak of the excitation function at 150°.For the resonance at 2.117MeV,the angular distribution have been measured at two energies,one at the energyof the resonance peak of the excitation function at 150°,another at the energy of thehalf maximum point of the resonance peak on the higher energy side.Around the re-sonance at 2.075 MeV,the excitation functions have been measured at 16 angles,andthe angular distribution has been obtained from three excitation functions.The an-gular distributions of the three resonances are not symmetric about 90°,and the posi-tions of the resonance peaks of these resonances varies with the angle of measurement.By means of the compound nucleus theory,discussions have been made for these non-solated resonances.     

THE MACQM CALCULATION OF THE TOTAL ENERGY CURVE FOR THE ICOSAHEDRAL CENTRAL STRUCTURE OF THE CLUSTER H_13~-

ＴＨＥＭＡＣＱＭＣＡＬＣＵＬＡＴＩＯＮＯＦＴＨＥＴＯＴＡＬＥＮＥＲＧＹＣＵＲＶＥＦＯＲＴＨＥＩＣＯＳＡＨＥＤＲＡＬＣＥＮＴＲＡＬＳＴＲＵＣＴＵＲＥＯＦＴＨＥＣＬＵＳＴＥＲＨ－１３ＺｈａｎｇＪｉａｎｐｉｎｇ＊ＬｉＰｉｎｇＧｏｕＱｉｎｇｑｕａｎＩｎｓｔ...     

THE STUDY OF α-EMISSION INDUCED BY 16O ON 27Al

The α-particles induced by 84.5MeV and 62 MeV ¹⁶O on ²⁷Al are measured using ΔE-E semiconductor telescope. The energy spectra, the angular distributions, the contour plot of d²σ/dE﹒dΩ in the E-θ plane of the emitted α particles and the variation of the nuclear temperature with the emission angles are obtained. The mechanism of the direct α particles is discussed.     

A MEASUREMENT OF THE ELASTIC SCATTERING FOR REACTION 12C+28Si AT ENERGIES 56MeV—69MeV

The angular distributions of the elastic scattering for reaction ¹²C+²⁸Si have been measured at the energies 69.5MeV, 66MeV, 59MeV, 56MeV using the large area position sensitive ionization chamber. The experimental data are fitted by use of the optical model. The probable reasons of the enhancement and oscillation of the elastic scattering angular distribution are discussed.     

α PARTICLES EMITTED IN THE REACTION OF 12C ON 209Bi

The energy spectra and angular distributions of alpha particles emitted in the reaction of 12C on 209Bi in the energy range 61.1—73.0 MeV were observed.The △E— E detector system was used to separate alpha particles and other particles emitted in this reaction.The results can be interpreted in terms of the reaction mechanism,in which a 8Be cluster is transfered from the projectile to the target.Good agreement has been obtained between the cross section for the production of the direct alpha particles and that of the heavy residue 217*Fr which,left in the ground state after evaporation of 2 neutron's,decays into 211At by alpha emission.The experimental energy spectra and angular distributions have been fitted by a semi-classical formula for the differential cross section per unit solid angle and energy interval.     

STUDY OF ANGULAR DISTRIBUTION OF THE SCATTERING OF 31.2 MeV α PARTICLE BY THE NUCLEUS 10.11B

Angular distribution of the scattering of 31.2 MeV-α-particle by the nucleus ^10,11B is measured. Our results show that there is anomalous phenomenon in the case of ¹⁰B but there is not in ¹¹B. Calculations and analysis are made with the optical model adding the Regge-Pole model. The results show that for the nucleus of 1p-shell, such as α+¹⁶O, the result of the calculation agrees very well with the experimental measurements but it fails in α+¹⁰B. As to the analysis with the double v-power optieal model for α+¹⁶O, the agreement is somewhat a little worse than the former's and the result for α+¹⁰B agrees only qualitatively with the experimental measurement. It is well known that the analysis with these models for α+⁴⁰Ca agrees very well with the experimental data. Thus we may come to the conclusion that the mechanism of ALAS of the nucleus of 2s-1d shell is different from that of 1p-shell, and the mechanisms of ALAS of the nuclei of 1p-shell are also different.     

CROSS SECTION MEASUREMENT FOR THE REACTION 56Fe（n,p）56Mn

The cross section measurement for the reaction ⁵⁶Fe（n, p）⁵⁶Mn was made using the activation method from 12 MeV to 18 MeV. The absolute cross section was determined at 14.61±0.20 MeV, the value obtained was 108.0±2.7mb. The associated particle method was used to determine the absolute neutron flux and compared with the recoil proton telescope. The agreement between both methods appeared to be within 1—2%. The resulting ⁵⁶Mn activity was measured by using a φ10×7.6cm NaI （Tl） scintillation counter. The counting efficiency of the counter was achieved by means of a standard ⁵⁶Mn source calibrated by the 4πβ-γ coincidence method. The result measured was compared with existing data.     

STUDY OF THE MECHANISM OF 12C（d,d）12C AND 12C（d,p）13C* REACTIONS

A formalism for studying the interference between the direct reaction and the compound resonance processes is presented by the S-matrix theory; The mechanism of ¹²C（d, d） ¹²C, ¹²C（d, p₁） ¹³C* and ¹²C（d, p₂） ¹³C* reactions in the energy range E_d=1.63 MeV to 2.05 MeV is analysed.Te results show that: the interference between these two processes exists; and the quantitative relation between them is given. While the parameters of direct reactions and compound resonance processes, particularly for four resonance states with E_d=1.726, 1.767, 1.792 and 1.86 MeV are determined.     

THE MECHANISM OF THE REACTION 141pr(n,α)138La AT En=14 MeV

The energy spectra of the alpha particles from the reaction ¹⁴¹Pr (n, α) ¹³⁸La at 0°, 30°, 60°, 120°, 150° and 180° are measured and the angular distributions of the alpha particles are given. It shows that the predominant mechanism of the reaction at En=14 MeV is precompound emission.     

THE MACQM CALCULATION OF THE TOTAL ENERGY CURVE OF THE BODY-CENTERED CUBIC STRUCTURE OF THE H_9~- CLUSTER

ＴＨＥＭＡＣＱＭＣＡＬＣＵＬＡＴＩＯＮＯＦＴＨＥＴＯＴＡＬＥＮＥＲＧＹＣＵＲＶＥＯＦＴＨＥＢＯＤＹ－ＣＥＮＴＥＲＥＤＣＵＢＩＣＳＴＲＵＣＴＵＲＥＯＦＴＨＥＨ－９ＣＬＵＳＴＥＲＧｏｕＱｉｎｇｑｕａｎＺｈａｎｇＪｉａｎｐｉｎｇＬｉＰｉｎｇＩｎｓｔｉｔｕ...     

ASYMPTOTIC FREEDOM AND THE WAVE FUNCTIONS AT THE ORIGIN AND THE ENERGY LEVELS OF THE J/ψ AND THEY

On the basis of phenomenological quantum chromodynamics (QCD), a nonre-lativistic linear and Coulomb-like potential describtion of the strong interaction be-tween quarks is assumed and it is considered that the effective quark-gluon coup-ling constant approaches the asymptotically free limit of QCD. The cloice of thepotential parameters is so made as to fit the experimental values of the wave func-tions at the origin as well as the masses of the J/ψ and the γ Following the calcu-lation referring to the ψ′and the γ′, we acquire a consistent explanation for boththe relative values of the wave functions at the origin and the experimental mass asdifferences of these particles.     

WHAT ARE REALLY THE PROPERTIES OF THE TRIPLE BAND FORKING IN 68Ge?

An analysis and discussion has been made for the properties of the triple bandforking in Ge. We also give some supports and questions for the existing explana-tions.     

THE STUDY FOR 8Be(g﹒s) DETECTION EFFICIENCY

The energy reponse in the effective solid angles and the spatial distribution of the detection efficiency for the four frequently used ⁸Be detection systems are obtained by two methods: Monte Carlo simulation and integration of the distribution function. The agreement of the results by the two methods is good. The resultes are tested are tested by some measurements with different geometry and compared with the published data.     

THE RIGHT-HANDED CURRENTS OF NEUTRINOLESS DOUBLE β DECAY IN 48Ca

Right-handed Currents in 0νββ decay with lepton-number nonconservation is discussed by using two nucleons mechanism and the effective operator approach of nuclear matrix elements in this paper. The relation between the mixing parameter η of right-handed currents and the Majorana neutrino mass m_ν is calculated from the experimental decay lifetime of 0νββ decay in ⁴⁰Ca. Our results show that i) m_ν≤(18~23)eV, if |η|=0;ii) |η|≤(1.6~2)×10^－5, if m_ν=0     

THE CROSS-SECTION MEASUREMENTS FOR 59Co(n,p)59Fe,59Co(n,α)56Mn AND 59Co(n,2n)58Co REACTIONS

The cross sections of ⁵⁹Co(n,p)⁵⁹Fe,⁵⁹Co(n,α)⁵⁶Mn AND ⁵⁹Co(n,2n)⁵⁸Co reactions have been measured at neutron energy region of 12.8MeV—17.8MeV by activation method.The coveriance matrix of measured errors was calculated,and the comparison between the values of measured and calculated using theory model was made.The evaluated excitation functions for the three reactions are given.