Single-Proton Pickup Reaction of the Halo Nucleus ^6He on a ^9Be Target at 25 MeV/nucleon

The inclusive differential cross sections of the ^7 Li nucleus in a reaction induced by ^6He on a ^9Be target are measured at an incident energy of 25 MeV/nucleon. Finite-range distorted-wave Born approximation calculations suggest that these ^7 Li particles are formed in a direct single-proton pickup reaction ^9Be（^6He,^7 Li）^8Li. The experimental data can be well reproduced by taking into account of the contributions of both the ground states and the first excited states of ^7Li and ^8Li.     

SINGLE PROTON TRANSFER REACTION INDUCED BY HEAVY ION 40Ar(11B, 10Be)41K

The angular distribution has been measured for elastic scattering on ⁴⁰Ar with ¹¹B and for the single proton transfer reaction ⁴⁰Ar(¹¹B, ¹⁰Be)⁴¹K at the incident beam energy of 50 MeV. The elastic scattering cross section has been fitted in terms of the optical model. The EFR-DWBA aproach with recoil effect has been used to analyze the differential cross section. The spectroscopic factor was extracted.     

Optical Potential Parameters for Halo Nucleus System ^6He＋^12C from Transfer Reaction ^11B（^7Li, ^6He）^12C

The optical potential parameters for the halo nucleus system ^6He＋^12C are extracted from fits to the measured angular distributions of ^11B（^7Li, ^6He）12C reaction at energies of 18.3 and 28.3MeV with distorted-wave Born approximation analysis. The characters of the obtained optical potentiM parameters are basically consistent with the results extracted from the fits to the elastic-scattering angular distributions in the literature.     

Angular Distribution of the 12C(6He, 7Li)11B Reaction

Angular distribution of the ¹²C(⁶He,⁷Li)¹¹B transfer reaction is measured with a secondary ⁶He beam of 36.4MeV for the first time. The experimental angular distribution is well reproduced by the distorted-wave Born approximation (DWBA) calculation. The success of the present experiment shows that it is feasible to measure one-nucleon transfer reaction on a light nucleus target with the secondary beam facility of the HI-13 tandem accelerator at China Institute of Atomic Energy (CIAE), Beijing.     

THE MASSIVE TRANSFER IN 12C+197Au REACTION

In this paper, we present energy spectra and angular distributions for the α-par-ticles emitted in the reaction of ¹²C+¹⁹⁷Au at 64 and 67 MeV and for α, Be and B emittedin the reaction at 71.5 MeV. The most-probable energles of the variousproducts emittedin this reaction decrease.with decreasing incident energy. The angular distributions peak near grazing angle.The peak position of the angular distributions shift from--80°to--120°while the projec-tile energy decreases from 71.5 MeV to 64 MeV. These all show the features of the transferreaction. The ⁶Li product also has been measured and the ⁸Be particle emitted from thisreaction was detected at 90°to the beam direction using α-α coincident technique at 71.5MeV. The coross section of the ³Be is only few percent at the same angle.     

Computation of 7Be Electron-Capture Rate in the Solar Interior

Under conditions near the center of the Sun, it shows that ⁷Be atoms are completely ionized between R=0 to R=0.1217R_⊙. The newly calculated ⁷Be and ⁸B solar neutrino fluxes are about 4.00×10⁹cm^－2·s^－1 and 6.18×10⁶cm^－2·s^－1, while the corresponding predicted values of the standard solar model are 4.80×10⁹cm^－2·s^－1 and 5.15×10⁶cm^－2·s^－1,respectively. It will further increase the discrepancy between the observed and the predicted neutrino fluxes in Super Kamiokande neutrino experiment.     

Further Studies on Halo Nuclei 11Li,14Be and 17B

Based on the three-body model with Yukawa interactions,the halo nuclei ¹¹Li,¹⁴Be and ¹⁷B are further studied by the variation calculation.An analytical expression for the density distribution of the halo neutron is given.The theoretical resultsagree with the recent experimental data.     

A Three-Body Model of 11Li,14Be and 17B

The nuclei ¹¹Li,¹⁴Be and ¹⁷B are considered as three-body systems composed of the N=2Z core and two outside neutrons.The core-neutron and neutronneutron interactions are assumed to be the attractive exponential potentials.It has been shown that the three-body system can have a bound state although any two constituents of the system cannot have a bound state. The experimental data of the binding energy and extraordinarily large matter root-mean-square radius can be explained in the frame of the three-body model.     

Three-body Dynamics of the Hypernucleus 9Be

We have calculated the energy spectra of the hypernucleus ⁹Be up to about 15MeV excitation energy by using an α+α+Λ three-cluster model and using the hamonicoscillator product states as basis function.By analyzing the shape densities in detail,we have determined the most probable shapes in three low-lying ststes of L^π=0⁺,2⁺ and 1^－     

Origins of the Neutrons Emission in the Reaction of 33.4MeV/u 17N on 9Be

In the reaction of 33.4MeV/u ¹⁷N on a target ⁹Be,the measured neutron spectra at different angles exhibit a complex pattern and vary regularly as a function of the detected angle. The detected neutrons probably come from the three origins:nucleon-nucleon collisions between the projectile and target,break-up of ¹⁷N and statistical evaporations from the hot nuclei. By analyzing the measured neutron angular distribution and calculating with QMD and GEMINI for the reaction concerned, 4.49,0.44 and 5.5barns were obtained for neutron emission cross sections due to the three origins mentioned above,respectively.     

Configuration-Dependent Bands in 169Re

High-spin states in ¹⁶⁹Re were studied and resulted in the identification of a strongly coupled band based on the 9/2^－[514] Nilsson state and a decoupled band built on the h_9/2 intruder proton orbital (nominally 1/2^－[541]). The cranked shell nodel calculations present configuration-dependent deformations that can explain the different band crossing frecpiencies. The experimental 9/2^－[514] band in Re shows the largest signature splitting at low spin among the known odd mass Re isotopes. After the alignment of a pair of the i_13/2 neutrons, the phase of the splitting is inverted with a significantly reduced amplitude. Additionally, a three-quasipariticle band was observed and assigned to be built likely on the π9/2^－[514]⊙AE configuration.     

25MeV/u 6He在9Be靶上的弹性转移反应研究

报告了25MeV/u ⁶He在⁹Be靶上的弹性散射和弹性转移的实验结果. 用光学模型和一阶DWBA的方法计算了弹性散射和³He集团转移的截面, 计算结果和实验测量基本一致. 计算表明³He在⁹Be中的谱幅度应该明显大于壳模型的理论计算值0.70.     

INFLUENCE OF THE NEUTRON NUMBER OF TARGET NUCLEUS ON CROSS SECTIONS OF PARTICLES EMISSION IN 12C+112,124Sn

The energy spectra and angular distributions of Li, Be, B particles emitted from the ¹²C+¹¹²Sn and ¹²C+¹²⁴Sn reactions at E_L=70.0MeV are measured. The angular distributions of the Li, Be, and B particles are found to be peaked around the grazing angle, without any forward peaked component.
The experimental results also showed that the cross section for emission is larger in ¹²C+¹¹²Sn reaction than that in ¹²C+¹²⁴Sn reaction, in contrast with the cross sections for Li, Be and B emissions. The indicates the effect of the neutron number of the target nucleus on the emission probability.     

Effects of Yb^3＋ in Er^3＋/Yb^3＋ Codoped Fluorophosphate Glasses

For the Er^3＋ /Yb^3＋ codoped fluorophosphate glasses, Judd-Ofelt theory is used to analyse the influence of YbF3 as not a sensitizer but an average component on the spectroscopic properties around 1530nm emission. The double roles of Yb^3＋, as a sensitizer and as an average component, are discussed. It is found that Yb^3＋ as an average component contributes to the increase of fluorescence lifetime, and Yb^3＋ as a sensitizer has the best sensitization when its concentration is 2.4 mol%.     

Angular distribution of 6He+p elastic scattering

The angular distribution of ¹H(⁶He,p)⁶He elastic scattering has been measured at E_c.m.=4.3 MeV by using a thick-target inverse kinematic method. The experimental differential cross sections are reproduced by the distorted-wave Born approximation calculation utilizing the CH89 global optical potential parameter set. The real part of CH89 is reduced comparing with other potentials, which may be attributed to the couplings necessary for the weakly bound nuclei.     

Study of the Reaction Mechanisms Induced by 16O on 64Ni at 96MeV

The angular distributions and Wilczynski plots of emitted fragments from He to O in reaction of ¹⁶O+⁶⁴Ni at 96MeV have been measured.The DIC cross section and intereaction time were obtained.DIC character of the reaction was discussed.The trace which shows that the emitted fragments of He and Li mainly come from the evaporation process of compound nuclei emerged.     

Isotope Ratios of Light Charged Particles and Temperature in the Reactions 30MeV/u40Ar+112,124Sn

Coincidence measurements between residues and light charged particles (LCPs) have been made for the reactions 30MeV/u 40Ar+^112,124Sn. The LCPs were measured by 11 semi-conduct telescopes from very forward angle to backward angle. The times of flight of the residues were measured by PPACs installed concentrically around the beam at forward angle. The excitation energy of the primary hot nuclei was obtained from the velocity of residues in the frame of incomplete fusion model. The single isotope ratios, as function of observing angle and excitation energy have been studied. The ratio of ³He/⁴He and ⁶Li/⁷Li increases with angle while that of ⁶He/⁴He and ⁸Li/⁷Li decreases. The calculation of statistical theory can not reproduce the curve quantitatively, implying the existence of dynamic effect. Isospin effect of the primary hot nuclei on the single isotopic ratios is demonstrated. However, the temperature extracted from double isotope ratios is target independent.     

STUDY OF THE DEEP INELASTIC SCATTERING OF 12C ON 27AI

The deep inelastic scattering of 71.5 ¹²C ions on a ²⁷Al target was measured.ΔE-E telescope was used to identify the reaction products.The contour plots in the E-θ plane for the measured cross sections in the C.M.S.for B and Be show the generalfeatures of quasi-elastic scattering at grazing angles and the deep inelastic scatteringridge extending from smaller angles and flattening at larger ones.Two special featuresmay be worthwhile to mention.First,there are some fine structures near the Q.E.peak.Secondly,the average C.M.kinetic energy of the completely damped part is notequal to the Coulomb energy of the final state.     

Experimental Study of High-Spin Band Structures of 183Au

High-spin states in ¹⁸³Au have been studied experimentally using heavy-ion-induced fusion-evaporation reaction and standard in-beam γ-ray spectroscopic techniques. The level scheme of ¹⁸³Au was revised and extended. A rotational band proposed as the unfavored signature branch of the πi_13/2 band has been observed for the first time. Interaction properties between the two negative-signature bands of the πh_9/2-πf^7/2 system have been discussed for the light odd-A Au nuclei.