1991 Vol. 15, No. 1
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In this paper,the stucture and constructive technologies of the BES End Cap Shower Counter are described.The tension of anode wires,dark currents and some check up results of sampling tubes are given.
The formulas of the space charge fields for annulus and disc bunch of charged particles and the methods of the calculation are developed.The use of the calculation results of the fields in computer simulation of the beam dynamics is introduced.
Under different external electromagnetic fields,the electron densities of the electron cloud in a self-sustaining space-charge lens are measured with the radio-frequency method and the energy distributions of the ions produced in ionization are measured with the stopping field method.From them the relations between the focusing power of space-charge lenses and the external electromagnetic fields are determined.The available region of the Lebedev-Morozov formula is discussed.
In this paper,we introduce a square term of the curvature scale R in the strong gravity Lagrange with de-Sitter form,the square term has made the coupling coefficient of strong gravity Gf to decrease,it can get a reasonable strong gravity model and avoid singularity.
We used the variational method in lattice gauge theory to calculate the fermion condensate <ψ,ψ> of the naive fermions in the Schwinger model,and obtained a nice scaling behavior.
We introduce a simple dynamical scheme to supplement the complementarity and Higgs phase analyses of composite model with semi-simple group and determine the order of appearance of the condensates of the simple groups.Together with the Higgs phase analysis,it can help to determine the global symmetry of the fermion composite.The global symmetry group can be gauged to form the low energy dynamical symmetry group of the composite.
The eigenmatrices of dual transformation for gauge field are presented in covariant form.Their properties and application to the energy-momentum tensor of the U(1) gauge field are discussed.
In this paper,the harmonic oscillator approach to the bound states of few-body ststems is developed and the lower-energy states are introduced as basis vectors and mixed with a part of harmonic oscillator vectors to calculate the binding energy.The lower energy levels of 3-α system and 9Be are presented and compared with experiments or other calculations.The results are satisfactory.
The influence of nuclear Fermi motion on the conventional mechanism of pion double charge exchange (DCX) is examined.Concrete calculations of the 0° excitation function over the energy region 0—300MeV are performed for the double isobaric analog DCX transition on 14C.The calculated results coincide very well with the experimental data for the energies above 100MeV,but are about a factor of 2—3 smaller than the experimental data around 50MeV.It indicates that the pure conventional mechanism seems incapable to fully explain the anomalous behavior of the low energy DCX,and some new mechanisms are needed.
Starting from the normal and proton 2p-2h excitation configurations,as well as the effective nucleon-nucleon interactions,a microscopic approach is proposed to investigate the properties of intruder states and configuration mixing in the doubly even nuclei near closed shells.
A computer program HEDEP-1,written by FORTRAN 77 and run on microcomputer,was developed in order to calculate the depth distribution for swift ion-radiated damage energy in the amorphous materials.The approximation method developed by I.Manning et al.was used in the program.The effects of nuclear force as treating incident ions collision with target atoms were considered.The data of electronic stopping powers given by J.F.Ziegler were used.HEDEP-1 can accept complex targets made up of component materials with elements up to four different kinds and all ions inperiodic table of the elements with energy up to 100MeV/amu.
The radiative capture cross sections of natural Mo relative to the 197Au (n,γ) were measured in the 0.7—1.4MeV neutron energy range,using a large liquid scintillator detector and the time-of-flight method.In the 0.01—2.0MeV neutron energy range,the theoretical calculation of (n,γ) reaction cross section for Mo was performed.The result of calculation is compared with the experimental data.
The sideways flow induced by heavy ion collision have been calculated in the framework of BUU equation with and without medium in n-n collision.The medium effect on sideways flow are important,And the addition of medium dependence to n-n collision cross section gives move sideways flow than that of free n-n collision at 1000MeV/A,but less sideways flow at 200 and 400MeV/A due to the energy and density dependences of the elastic and inelastic n-n cross section in the medium.
In this paper,Vector Coherent State (VCS) representations of SU3 in U1 U1 basis are discussed.Orthonormal basis vectors for SU3 U1 U1 are derived and the multiplicity of a weight for SU3 U1 U1 is determined by using K-matrix technique.
The α-transfer rates of ground states in medium and heavy nuclei are obtained analytically in a two-level pairing force model of j-j scheme.It is concluded that,like the pair transfer,there exist blocking effects from the single and nupaired nucleon in α-transfer reactions.This is agreed with the experimental facts.
A new class of non-topological solitons is constructed in constructed in renormalizable scalar field theories with non-linear self-interactions.There exists a critical value gcrit for the coupling g.For g>gcrit there are no stable non-topological solitons.
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