1983 Vol. 7, No. 2
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Abstract:
Under the condition of primary nucleus incidence, the ultrahigh energy interactions in the atmosphere are simulated using quark-quark scattering and CKP model of ordinary hadronic interactions. The results show that nuclei can produce more two-cluster events than proton and the distance between the two clusters to nucleus incidence is also wider. Because the energy regions of producing two-cluster events for different primary particles are different the main contribution to two-cluster events is still due to protons and heliums. There is no important effect in forming duster structure from geomagnetic field. Comparing with experimental data it is expected that there might exist some new production process with larger PT.
Under the condition of primary nucleus incidence, the ultrahigh energy interactions in the atmosphere are simulated using quark-quark scattering and CKP model of ordinary hadronic interactions. The results show that nuclei can produce more two-cluster events than proton and the distance between the two clusters to nucleus incidence is also wider. Because the energy regions of producing two-cluster events for different primary particles are different the main contribution to two-cluster events is still due to protons and heliums. There is no important effect in forming duster structure from geomagnetic field. Comparing with experimental data it is expected that there might exist some new production process with larger PT.
Abstract:
Preliminary results of the measurement of cosmic ray muon zenith angle distribution are measured using scintillation counter hodoscopes. This method combines the advantage of better angular resolution and the ability of making many sets of data. simultaneously.
The telescope array consists of two 4×4 scintillation counter hodoscopes forming 256 telescope units. Data for ten angles are obtained. Data acquisition and processing are performed with an on-line microcomputer.
Preliminary results of the measurement of cosmic ray muon zenith angle distribution are measured using scintillation counter hodoscopes. This method combines the advantage of better angular resolution and the ability of making many sets of data. simultaneously.
The telescope array consists of two 4×4 scintillation counter hodoscopes forming 256 telescope units. Data for ten angles are obtained. Data acquisition and processing are performed with an on-line microcomputer.
Abstract:
In this paper the principle of self-quenching streamer (SQS) discharge and construction of SQS detectors are described. The main performances of our SQS detectors are: Pulses with a rise time of 3 to 5 ns reach 100 mV into 50Ω with a decay time of 30 ns. The plateau in counting rate vs voltage is about 700 V. The efficiency for registing charged particles is 100%. The rate capability of SQS tubes is better than 103 per second per millimeter along the wire. The localized dead time is obout 10 μs/2 mm which equals a dead zone of 2 μs.cm.
Some examples of using our SQS detectors in areas of low-energy nuclear technology, health physics and environment protection are given.
In this paper the principle of self-quenching streamer (SQS) discharge and construction of SQS detectors are described. The main performances of our SQS detectors are: Pulses with a rise time of 3 to 5 ns reach 100 mV into 50Ω with a decay time of 30 ns. The plateau in counting rate vs voltage is about 700 V. The efficiency for registing charged particles is 100%. The rate capability of SQS tubes is better than 103 per second per millimeter along the wire. The localized dead time is obout 10 μs/2 mm which equals a dead zone of 2 μs.cm.
Some examples of using our SQS detectors in areas of low-energy nuclear technology, health physics and environment protection are given.
Abstract:
The selfdual and non-selfdual solutions for the CP(n) Chiral fields are obtained by means of various methods of embeding the subgroup SU(m)(m≤n) into the SU(n+1) group space. We discuss the origin, the property and corresponding gauge fields as well as topological charges of non-selfdual solutions in detail. The non-selfdual solutions are induced from the present theoretical frames inevitably.
The selfdual and non-selfdual solutions for the CP(n) Chiral fields are obtained by means of various methods of embeding the subgroup SU(m)(m≤n) into the SU(n+1) group space. We discuss the origin, the property and corresponding gauge fields as well as topological charges of non-selfdual solutions in detail. The non-selfdual solutions are induced from the present theoretical frames inevitably.
Abstract:
In this paper the meson structure functions are calculated by use of the method given in ref.[1]. It is obtained that Wπ1(x)~(1-x) for π-meson in the leading-order. Then an approximate expression of Resonance-Regge correction is introduced, and thus obtained nucleon and π-meson valence quark distribution functions are in good agreement with the data in the whole range of 0≤x≤1. Also, the possible influence of scaling violation to the number of passive quarks and to the effective bag-radius is suggested. Finally, it is pointed out that the sea-quark distribution functions can be estimated by using a similar Pomeron correction.
In this paper the meson structure functions are calculated by use of the method given in ref.[1]. It is obtained that Wπ1(x)~(1-x) for π-meson in the leading-order. Then an approximate expression of Resonance-Regge correction is introduced, and thus obtained nucleon and π-meson valence quark distribution functions are in good agreement with the data in the whole range of 0≤x≤1. Also, the possible influence of scaling violation to the number of passive quarks and to the effective bag-radius is suggested. Finally, it is pointed out that the sea-quark distribution functions can be estimated by using a similar Pomeron correction.
Abstract:
We obtain analytic expression for valence quark distribution function from Altarelli-Parisi equation in a reasonable approximation. It is used to discuss the behaviours of structure function in e-p deep inelastic scattering. The fit between theoretical prediction and experimental data are also given.
We obtain analytic expression for valence quark distribution function from Altarelli-Parisi equation in a reasonable approximation. It is used to discuss the behaviours of structure function in e-p deep inelastic scattering. The fit between theoretical prediction and experimental data are also given.
Abstract:
In this paper, the envelope of numatched beam in the periodic focusing system is analyzed and the expression of beam cross section is given. We find that, by using the commonly used methods, we can't get the real emittance of the beam in the ring accelerators, but can only get the acceptance of the accelerator corresponding to the maximum aperature filled by the beam.
In this paper, we propose to measure the beam envelope by a thin plastic scintillation filament. And from the measured data we can get the real emittance of the beam. At the same time, we can get the tune values, the coherent oscillation amplitude and its frequency and the closed orbit distortion.
In this paper, the envelope of numatched beam in the periodic focusing system is analyzed and the expression of beam cross section is given. We find that, by using the commonly used methods, we can't get the real emittance of the beam in the ring accelerators, but can only get the acceptance of the accelerator corresponding to the maximum aperature filled by the beam.
In this paper, we propose to measure the beam envelope by a thin plastic scintillation filament. And from the measured data we can get the real emittance of the beam. At the same time, we can get the tune values, the coherent oscillation amplitude and its frequency and the closed orbit distortion.
Abstract:
Under the quasi-Δ33 doorway state model, The Tmatrix for π-12C elastic scattering at the (3.3) resonance region is calculated. The emphasis is put on that how the variety of the parameters in the model, which reflect many body correction in π-nucleus interaction and the properties of Δ(1232)-hole interaction, influences the angular distribution and total cross section. Acomparison between between theory and experiment is performed, and the agreement is satisfactory. It is interesting that in order to fit existed data, especially the angular distribution, the spin-orbit coupling interaction strength has to be positive which differs from the case for nucleon where it is negative.
Under the quasi-Δ33 doorway state model, The Tmatrix for π-12C elastic scattering at the (3.3) resonance region is calculated. The emphasis is put on that how the variety of the parameters in the model, which reflect many body correction in π-nucleus interaction and the properties of Δ(1232)-hole interaction, influences the angular distribution and total cross section. Acomparison between between theory and experiment is performed, and the agreement is satisfactory. It is interesting that in order to fit existed data, especially the angular distribution, the spin-orbit coupling interaction strength has to be positive which differs from the case for nucleon where it is negative.
Abstract:
Using nuclear coherent structure model and Glauber's multiple scattering theory, the double charge exchange reaction (DCE) of 18O(π+, π－) 18Ne(2+1, 1.89MeV) is studied. The calculated results shows that nuclear structure has important influence on pion-nucleus double charge exchange quadrupole transition, and the mechanism of multiple scattering can explain the experimental data.
Using nuclear coherent structure model and Glauber's multiple scattering theory, the double charge exchange reaction (DCE) of 18O(π+, π－) 18Ne(2+1, 1.89MeV) is studied. The calculated results shows that nuclear structure has important influence on pion-nucleus double charge exchange quadrupole transition, and the mechanism of multiple scattering can explain the experimental data.
Abstract:
Based on the variational method and using two classes (exponential and square) nuclear charge distributions and two classes (Gaussian and exponential) trial wave functions the 1s and 2p energy levels of muonic atoms are calculated and compared with the accurate calculation[1]. Then we use the LCAO (Linear Combination of Atomic Orbitals) to calculate the foure energy levels of Muon in the two centre nuclear extended coulombian potential, and use the PSS (Purterbation of Stationary States) to solve the time-dependent Schrödinger equation and obtain the final Muon probabilities for these four states. We find that after the prompt fission of Muonic atom. Muon is mainly attached on the 1s state of the heavy fragment, only 3.8—5.1% of the probabilities are attached on 1s state of the light fragment, and 0.7—0.9% and ~0.1% on the 2p states of the heavy fragment and the light fragment respectively. These results are in agreement with those of references [2], [3], and also in accordance with the experimental results within the experimental errors.
Based on the variational method and using two classes (exponential and square) nuclear charge distributions and two classes (Gaussian and exponential) trial wave functions the 1s and 2p energy levels of muonic atoms are calculated and compared with the accurate calculation[1]. Then we use the LCAO (Linear Combination of Atomic Orbitals) to calculate the foure energy levels of Muon in the two centre nuclear extended coulombian potential, and use the PSS (Purterbation of Stationary States) to solve the time-dependent Schrödinger equation and obtain the final Muon probabilities for these four states. We find that after the prompt fission of Muonic atom. Muon is mainly attached on the 1s state of the heavy fragment, only 3.8—5.1% of the probabilities are attached on 1s state of the light fragment, and 0.7—0.9% and ~0.1% on the 2p states of the heavy fragment and the light fragment respectively. These results are in agreement with those of references [2], [3], and also in accordance with the experimental results within the experimental errors.
Abstract:
It is assumed that 8Be consists of two α-particles which are close to each other in configration space. A spectroscopic density of 8Be-cluster in the residue nuclei is them obtained which is proportional to the square of the preformation probability of α-particle at nuclear surface. Using the improved method of parametrization of EFRDWBA overlap integral[1], We calculate the double diffirential energy spectra and angular distributions of α-particles for the reactions 209Bi(12C, α) 217Fr and extracte the preformation probability of α-particle at the surface of 217Fr nuclei from fitting the experimental data. The agreement within the range of calculation error between the preformation probabilities extracted from transfer reactions and α-decay suggests that the reaction 209Bi(12C, α) 217Fr may be explained as a diuble α direct transfer process.
Abstract:
The One-Boson-Exchange-Potential (OBEP) is used to perform the Hartree-Fock calculation of the binding energy, the mean-square-root radius and the particle wave functions for nuclei 16O, 12C and 8Be. In the present calculation the spinorbit coupling term and the tenser term in the OBEP are neglected. The calculated results are tather encouraging and satisfactory.
The One-Boson-Exchange-Potential (OBEP) is used to perform the Hartree-Fock calculation of the binding energy, the mean-square-root radius and the particle wave functions for nuclei 16O, 12C and 8Be. In the present calculation the spinorbit coupling term and the tenser term in the OBEP are neglected. The calculated results are tather encouraging and satisfactory.
Abstract:
Yields have been measured with good Z and A resolution for Xe-like fragments produced in quasielastic and partial damped reactions of 5.9 MeV/N 129Xe ion bombarding 56Fe, 124Sn, 116Sn targets and 5.8 MeV/N 136Xe ion bombarding 56Fe target. The relationship between the variance of the mass and charge distributions are found to depend on the degree of energy damping and the system. The relationship of the correlation coefficients ρ with the energy damping are also obtained. It is found that the correlation coefficients ρ is bether quantity to express the degree of correlation between neutron and proton exchange than σ2A/σ2Z.
Yields have been measured with good Z and A resolution for Xe-like fragments produced in quasielastic and partial damped reactions of 5.9 MeV/N 129Xe ion bombarding 56Fe, 124Sn, 116Sn targets and 5.8 MeV/N 136Xe ion bombarding 56Fe target. The relationship between the variance of the mass and charge distributions are found to depend on the degree of energy damping and the system. The relationship of the correlation coefficients ρ with the energy damping are also obtained. It is found that the correlation coefficients ρ is bether quantity to express the degree of correlation between neutron and proton exchange than σ2A/σ2Z.
Abstract:
The quadrupole-octupole two-phonon excitations in inelastic scattering (α, α′) at energies of 31 and 43 MeV are studied with DWBA method. Both nuclear potential and Coulomb potential are considerd. The zeroth-order nuclear potential is taken tobe Woods-Saxon potential. The non-spherical symmetric part V1 of the nuclear potential induced by the vibration of the target nucleus is considered as a perturbation. In this calculation we onlykeep second-order term of the collective variable αλν of nuclear surface for V1 and first-order of V1 for the total initial wave function Ψ(+)i In distorted wave Green function, the absorptive channels as intermediate states are neglected. Furthermore, in the two-phonon excitation mechanism, it is assumed that the contribution of direct two-phonon excitation is important and the contribution of multiple two-phonon excitation is of less importance. The agreement between the theoretical and experimental angular distributions is reasonably well. It follows from this agreement that the 3.72 and 4.19 MeV levels in 64Zn may be quadrupole-octupole two-phonon exciation levels abd the Jπ of these levels may be 3－ and 5－ respectively.
The quadrupole-octupole two-phonon excitations in inelastic scattering (α, α′) at energies of 31 and 43 MeV are studied with DWBA method. Both nuclear potential and Coulomb potential are considerd. The zeroth-order nuclear potential is taken tobe Woods-Saxon potential. The non-spherical symmetric part V1 of the nuclear potential induced by the vibration of the target nucleus is considered as a perturbation. In this calculation we onlykeep second-order term of the collective variable αλν of nuclear surface for V1 and first-order of V1 for the total initial wave function Ψ(+)i In distorted wave Green function, the absorptive channels as intermediate states are neglected. Furthermore, in the two-phonon excitation mechanism, it is assumed that the contribution of direct two-phonon excitation is important and the contribution of multiple two-phonon excitation is of less importance. The agreement between the theoretical and experimental angular distributions is reasonably well. It follows from this agreement that the 3.72 and 4.19 MeV levels in 64Zn may be quadrupole-octupole two-phonon exciation levels abd the Jπ of these levels may be 3－ and 5－ respectively.
Abstract:
For obtaining a satisfactory solution to the problem of expressing explicity the SU2×SU2—representation wave functions of the existing physical bases a new methed is introduced. The two kinds of the physical bases constructed by Chacon et al., are treated in the text. The method is compared with that of paper (Ⅰ) in the concluding section.
For obtaining a satisfactory solution to the problem of expressing explicity the SU2×SU2—representation wave functions of the existing physical bases a new methed is introduced. The two kinds of the physical bases constructed by Chacon et al., are treated in the text. The method is compared with that of paper (Ⅰ) in the concluding section.
Abstract:
Using recent experimental results, we calculate the antiproton flux which is produced by the collisions of cosmic rays with the interstellar matter. This calculated result is compared with the experimental result of Golden et al. It is shown that it is quite possible that primary antiproton exists in cosmic space.
Using recent experimental results, we calculate the antiproton flux which is produced by the collisions of cosmic rays with the interstellar matter. This calculated result is compared with the experimental result of Golden et al. It is shown that it is quite possible that primary antiproton exists in cosmic space.
Abstract:
Vlasov equation and generalized Poisson equation are used here to obtain the energies of oscillations in nuclei. They vary slightly with different nuclei. Comparison of our calculated results and the experimental energies of the giant quadruple resonances is quite good.
Vlasov equation and generalized Poisson equation are used here to obtain the energies of oscillations in nuclei. They vary slightly with different nuclei. Comparison of our calculated results and the experimental energies of the giant quadruple resonances is quite good.
Abstract:
A S-band high-power pulsed klystron is described in this paper. This klystron operates at 2856 MHz, 250 kV and 200 A. Its measured pulsed power exceeds 15 MW with efficiency higher than 40% and gain greater than 40 db. This tube has been used routinely on a 30 MeV Electron Linear Accelerator with reliable performance.
In this paper, the design requirements, the design considerations, the measured results and the problems encountered are discussed.
A S-band high-power pulsed klystron is described in this paper. This klystron operates at 2856 MHz, 250 kV and 200 A. Its measured pulsed power exceeds 15 MW with efficiency higher than 40% and gain greater than 40 db. This tube has been used routinely on a 30 MeV Electron Linear Accelerator with reliable performance.
In this paper, the design requirements, the design considerations, the measured results and the problems encountered are discussed.
Abstract:
The structure and technology and some concerning performance, the characteristic of leakage current ranging with high voltage, the counting plateau, the amplitude characteristic of each wire of the anode plane and efficiency plateau are presented and discussed.
The structure and technology and some concerning performance, the characteristic of leakage current ranging with high voltage, the counting plateau, the amplitude characteristic of each wire of the anode plane and efficiency plateau are presented and discussed.
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