A Method to Solve the Fokker-Planck Equation With Coordinate-dependent Mass,Friction and Temperature

An analytical expression of the propagator is obtained by using Lie algebramethod.The fission rates at the saddle point in both constant and coordinate-dependentmass,friction and temperature cases are calculated based on the expression of thepropagator and local approximation.The numerical calculation for 240pu shows thatthe fission rates from our method are reasonable.

Measurement of the Mass Excess of ^(158)Sm

A Q-value of —4.076±0.151 MeV has been determined for the two-proton transfer reaction160Gd(18O,20Ne)158Sm,which yields a first experimental measured value of —65.764±0.151 MeV forthe mass excess of 158Sm,the nucleus far from stability.The result is compared with current theoreticalpredictions.

Chinese Nuclear Physics Society

Members of CouncilPresidentSun Zuxun(孙祖训),China Institute of Atomic Energy,P.O.Box 275,Bcijing 102413Vice-PresidentsYang Zesen(杨泽森),Peking University,Beijing 100871Luo Yixiao(罗亦孝),Institute of Modern Physics,Academia Sinica,Lanzhou 730000Xia Yuanfu(夏元复),Nanjing University,Nanjing

Chemical Selectivity of Laser Ion Source for on-Line Mass Separator

Thulium(Tm)atoms are resonantly ionized in a hot tube by stepwise excitations us-ing three dye lasers pumped by a series of copper vapor pulsed at a 10 kHz rate.The chemicalselectivity of the laser ion source is measured as a function of temperature of the tubes made ofTa,Nb-Zr and TaC.The chemical selectivity rises from 50 to 10000 with decreasing tube temp-erature and strongly depends on the tube material.A chemical selectivity of about 10000 withhigh efficiencies is obtained with the Nb-Zr and TaC tubes.Such a laser ion source can be usedin on-line mass separator to obtain isobarically pure ion beams.

Probing the Non-equilibration Component of Tilting Spin Mode

-The probabilities PNCNE of non-equilibration component of tilting spinmode have been extracted from the experimental fragment anisotropies for thesystems of 16O+232Th,19F+232Th,and 16O+238U.It is found that as a function ofBf（〈L〉）/Tsad,the values of PNCNF observed experimentally and expected on the ba-sis of fission before equilibration model have opposite trends.

Semi-Empirical Formulas for Nuclear Charge Radii

Considering the relationship between the nuclear radius and the average bindingenergy of nucleons,a simple semi-empirical formula for the nuclear rms charge radii is suggest-ed together with the formula for light neutron-rich nuclear rms neutron radii.These formulascan well fit the new experimental values.

Self-Consistent Calculation With Density-Dependent Pairing Forces for O Isotopes

The ground state properties of 0 isotopes are investigated by the Skyrme-Hartree-Fock(SHF)approach plus density-dependent pairing correlations.In comparison with the results of SHF calculationsusing the constant-gap approach,our calculations using the density-dependent pairing correlations providea good description of the O isotopes.Detailed comparison and analysis are given.

Synchronizing Hyperchaos by Variable Feedback Control

The synchronization of chaotic nonlinear systems has attracted much attention in recent years.Practical applications are being realized in the area of secure communications.However,a few syn-chronization hyperchaos have been reported.We have extended the drive-response relationship scheme(DRRS)of chaotic synchronizationproposed by Pecora and Carroll to hyperchaos in the complex Lorenz-Haken system.But some-

Cold Nuclear Fusion in the Unitary Quantum Theory

The interaction of the charged particles in the new Unitary Quantum theory isconsidered. It is shown that the distance of approachment of deuterons to each other verystrongly depends on the phase of the wave function and not only upon the energy. This thesis isnot discussed in the conventional quantum theory. It can easily explain the experiments on thecold nuclear fusion.

Final-State Energy Spectrum in Nuclear Electromagnetic Dissociation Process

The final-state energy spectrum in the electromagnetic dissociation is calculated by asimple method.The final-state energy curves obtained from the calculation are in agreementwith the experimental data of 28Si into p+27Al at an energy of 14.6 GeV/u.

Analyses of d-^(6,7)Li and d-^(7,9)Be Reactions

Aiming at the production of 6He,8Li and 7Be radioactive beams,various nuclear dataof d+6,7Li and d+9Be reactions at incident energies spanning 0,1～30.0 MeV are obtained bycalculation with the distorted wave Born approximation,preequilibrium nuclear reaction andHauser-Feshbach（HF）theory.The cross sections of d+7Be reaction are also predicted.Theresults show that the experimental measurement for d+7Be reaction is feasible at HI-13 tandemaccelerator.

Collision Dynamics and Multifragmentation Process in Heavy Ion Collisions

-By using the improved quantum molecular dynamics(IQMD),we have stu-died the influences of items such as the nucleon-nucleon(N-N)collision cross sectionwith or without the medium effect,the momentum dependent interactions(MDI),theequation of state(EOS)and the aggregating method for fragments on the multifrag-mentation process of heavy ion collisions with different beam energies.It is found thatmultifragmentation distribution patterns,the collective flows of fragments and singleparticles,the collision number,and the nuclear matter density all depend strongly on theN-N cross section,the momentum dependent interactions and the nuclear equation ofstate;especially,these dependences are associated with beam energies.However,thefragment multiplicity distribution patterns depend very weakly on the equation of state.

Study on the Coulomb Instability of Hot Nuclei

The modified coexistence equations are solved.The limiting temperature of someimportant nuclei are obtained.The dependence of the limiting temperature on the excessneutron coefficient is identified.

Calculation of Radial Dose Distribution Around the Path of a Heavy Ion in Liquid Water

ＣａｌｃｕｌａｔｉｏｎｏｆＲａｄｉａｌＤｏｓｅＤｉｓｔｒｉｂｕｔｉｏｎＡｒｏｕｎｄｔｈｅＰａｔｈｏｆａＨｅａｖｙＩｏｎｉｎＬｉｑｕｉｄＷａｔｅｒ①ＬｉＱｉａｎｇ，ＷｅｉＺｅｎｇｑｕａｎａｎｄＣｈｅｎＷｅｉｑｉａｎｇＩｎｓｔｉｔｕｔｅｏｆＭｏｄｅｒｎＰ...

Negative Drive of γ Deformation in Rapidly Rotating N=88,90 Nuclei

In the N=88,90 region,a strong negative drive of γ deformation is generatedby the second lowest positive signature vi13/2 quasiparticle orbital.In contrast,thelowest positive-parity and negative-parity orbitals in this region exhibit positive drivesin the γ deformation toward oblate shapes.Replacing one of these with the negativedrive orbital strengthens the collectivity for the side band configurations at very highspins.

TMF-IMPAD Spectrometer

A transient magnetic field-ion implanted perturbed angular distribution spectrometer has beenset up at CIAE HI-13 tandem accelerator.This spectrometer is used to measure y-factors of high spinstates with lifetime of pico-or subpico-seconds.The 9-factors of the high spin states in 83y,84Zr and87Nbhave been successfully determined with it.

Influence of the In-medium Nucleon Swelling on Pion-Nucleus Scattering at High Energy

We investigated the influence of the in-medium nucleon swelling on pion-nu-cleus scattering at energy above the Δ33 resonance.An increased theoretical π+-12Cdifferential cross section at 800 MeV/c was found as a result of the nucleon swellingeffect.

Analysis of Identical.Superdeformed Bands

Identical superdeformed bands in 191Au and 191Hg have been investigated byusing particle-rotor model within the framework of the BCS （Bardeen-Cooper-Schrieffer） pairing correlation.The identity in the γ-transition energies in these bandsshows that the properties of specific individual orbitals may be important to understandidentical bands.

The Role of the Neutron-proton Interaction in Anomalous Band Crossing of Rare Earth Nuclei

Experimental estimate values of the n-p interaction between the odd protonand the aligning neutron pairs for odd proton nuclei in the first band crossing region areextracted based on the experimental quasi-particle routhians.The reliability of thismethod and the relation between the anomalous band crossing and the neutron-protoninteraction are discussed.

Excitation Function of ^(27)AI(d,pα)^(24)Na

The cross sections of 27Al（d,pα）24Na reaction have been measured as a func-tion of deuteron energy from the threshould to 22 MeV by the stacked foil technique.The influence of 27Al（n,α）24Na has been considered in the present measurement.Acomparison is made between our data and other available results.