1983 Vol. 7, No. 3
Display Method: |
Abstract:
In this paper the influence of various proportion of Ne-He gases and the time delay on the quality of streamer tracks has been studied. The diameterand density of streamers under these mixed-gas conditions have been measured.
The time resolution of this streamer chamber was determined to be 2.1μs in 69% Ne+31% He+8×10－8 SF6, and as 177μs in pure neon by using the exponentially decreasing relation of streamer desity with delay time. The spatial resolution was determined to be 0.32mm in Ne+3×10－8 SF6 by measuring the streamer diameters, and the method of track standard deviation was also used.
Some results show that the diameter and brightness increase with increasing high voltage, but become rather even when high voltage continues increasing.
Photographs were taken with domestically produced special film (32 DIN, 60 lines/mm), being similar to Kodak SO-143.
A special designed central electrode of the streamer chamber with its wires inlaid in lucite plate is successful for preventing gas from breakdown near wires. Besides, delay time has been reduced to 1.3μs, mainly by the Marx generator and its trigger system the parameters of which have been chosen by a series of experiments.
In this paper the influence of various proportion of Ne-He gases and the time delay on the quality of streamer tracks has been studied. The diameterand density of streamers under these mixed-gas conditions have been measured.
The time resolution of this streamer chamber was determined to be 2.1μs in 69% Ne+31% He+8×10－8 SF6, and as 177μs in pure neon by using the exponentially decreasing relation of streamer desity with delay time. The spatial resolution was determined to be 0.32mm in Ne+3×10－8 SF6 by measuring the streamer diameters, and the method of track standard deviation was also used.
Some results show that the diameter and brightness increase with increasing high voltage, but become rather even when high voltage continues increasing.
Photographs were taken with domestically produced special film (32 DIN, 60 lines/mm), being similar to Kodak SO-143.
A special designed central electrode of the streamer chamber with its wires inlaid in lucite plate is successful for preventing gas from breakdown near wires. Besides, delay time has been reduced to 1.3μs, mainly by the Marx generator and its trigger system the parameters of which have been chosen by a series of experiments.
Abstract:
This is the first try to use PPAC as sampling calorimeter. The article is discussing the possible fluctuations in this type of calorimeter, presenting the results of simulating measurements performed on single gap PPAC and actual measurements for multiplate PPAC calorimeter. It is prospected that the energy resolution could be 17%/√E, if using 2 mm Pb plates as absorbers.
This is the first try to use PPAC as sampling calorimeter. The article is discussing the possible fluctuations in this type of calorimeter, presenting the results of simulating measurements performed on single gap PPAC and actual measurements for multiplate PPAC calorimeter. It is prospected that the energy resolution could be 17%/√E, if using 2 mm Pb plates as absorbers.
Abstract:
In this paper, a multi-strip scintillation counter hodoscope and a small on-line system are described. The hodoscope is a 4×4 array of scin tillation strip counter, each of which consists of a plastic scintillation strip of type NE104 with the dimension of 50×4×1cm3 and a Photomultiplier of type GDB-50L. An on-line program for hodoscope property test has been compiled. The hodoscope read-out system is linked with PDP-11/03 computer and with them some on-line experiments have been done.
The experimental results are as follows. The efficiency of each cell of the hodoscope is between 96.5% and 99.5%. The counting distribution caused by a radiative source Ru106 put at various locations can be displayed as a histogram directly and promptly on a printer. The intensity of cosmic ray fluxes and its distribution versus azimuthal angle has been measured. All these results are reasonable. The performances of this system are well and stable and it can be used in some experiments of high energy physics.
In this paper, a multi-strip scintillation counter hodoscope and a small on-line system are described. The hodoscope is a 4×4 array of scin tillation strip counter, each of which consists of a plastic scintillation strip of type NE104 with the dimension of 50×4×1cm3 and a Photomultiplier of type GDB-50L. An on-line program for hodoscope property test has been compiled. The hodoscope read-out system is linked with PDP-11/03 computer and with them some on-line experiments have been done.
The experimental results are as follows. The efficiency of each cell of the hodoscope is between 96.5% and 99.5%. The counting distribution caused by a radiative source Ru106 put at various locations can be displayed as a histogram directly and promptly on a printer. The intensity of cosmic ray fluxes and its distribution versus azimuthal angle has been measured. All these results are reasonable. The performances of this system are well and stable and it can be used in some experiments of high energy physics.
Abstract:
The scale-breaking parameter 
F2ep(x, Q2) of non-singlet component F2ep-F2en and some other quantities in the electro-production process are discussed by usinb the analytic expression for the distribution function of valence quarks in ha.drons up to leading log approximation given by a, previous paper[1]. Comparisons with data are also given.
Abstract:
The QCD behaviours of the structure functions xF3 in the neutrino deep-inelastic processes are discussed by using the analytic expression for the distribution function of valence quarks in hadrons up to the leading log approximation given by a previous paper[9]. The theoretical predictions are in good agreement with experimental data. The error arising from an approximation in solving the A-p equation is discussed. The calculation shows that relative error remains smaller than 1% even in the case of Q2=200 GeV and x=0.1
The QCD behaviours of the structure functions xF3 in the neutrino deep-inelastic processes are discussed by using the analytic expression for the distribution function of valence quarks in hadrons up to the leading log approximation given by a previous paper[9]. The theoretical predictions are in good agreement with experimental data. The error arising from an approximation in solving the A-p equation is discussed. The calculation shows that relative error remains smaller than 1% even in the case of Q2=200 GeV and x=0.1
Abstract:
In this paper the forms of the gluon distribution function at different Q2 are discussed with the aid of the three-quarks model associated with dynamical calculations of QCD (the LLA approximation). The Buras-Gaemers parametrization is improved and the gluon distribution functions are obtained. It can be described by a simple parameter form: xG(x, Q2)=xG1(x, Q2)+xG2(x, Q2)=[1+B(s)]1(Q2)>2(1-x)[B(s)]+[1+D(s)]2)>(1-x)D(s), The form satisfies the QCD evolution equations and does not contradict evidently with existing experimental data. Then the properties of the constituent gluons in a nucleon are analyzed on these basis and it is indicated that the gluon distribution function could be considered as to be made of two different parts-soft and hard parts.
In this paper the forms of the gluon distribution function at different Q2 are discussed with the aid of the three-quarks model associated with dynamical calculations of QCD (the LLA approximation). The Buras-Gaemers parametrization is improved and the gluon distribution functions are obtained. It can be described by a simple parameter form: xG(x, Q2)=xG1(x, Q2)+xG2(x, Q2)=[1+B(s)]
Abstract:
Assuming that leptons are composed of a heavy fermion and a heavy scalar boson and using Bethe-Salpeter equation, we conclude that in the non-relativistic limit the radius and , in particular, the anomalous magnetic moment of leptons can be sufficiently small provided that the interaction of the constituents is of vector type and that the fermion is much beavier than the scalar boson. Whereas the scalar type interaction can only give wavefunctions with large radius and anomalous magnetic moment.
Assuming that leptons are composed of a heavy fermion and a heavy scalar boson and using Bethe-Salpeter equation, we conclude that in the non-relativistic limit the radius and , in particular, the anomalous magnetic moment of leptons can be sufficiently small provided that the interaction of the constituents is of vector type and that the fermion is much beavier than the scalar boson. Whereas the scalar type interaction can only give wavefunctions with large radius and anomalous magnetic moment.
Abstract:
In a renormalizable gauge theory of spontaneously broken symmetry, using the path integral method, we derive a formula for calculating the one loop corrections of the effective potentials in the general case and the expressions for the one loop corrections of the fermion masses. Using this results, we calculate the contributions of the one loop corrections of the fermion masses to the QCD CP-violation, and have obtained a more general results than V. Goffins'. We discuss also the weak CP-violation in this paper.
In a renormalizable gauge theory of spontaneously broken symmetry, using the path integral method, we derive a formula for calculating the one loop corrections of the effective potentials in the general case and the expressions for the one loop corrections of the fermion masses. Using this results, we calculate the contributions of the one loop corrections of the fermion masses to the QCD CP-violation, and have obtained a more general results than V. Goffins'. We discuss also the weak CP-violation in this paper.
Abstract:
Using the method proposed in the paper (Ⅰ)[1], we investigate the potential between two neutral scalar nucleons by exchanging neutral scalar mesons. The results show that the contribution of mesonic folded diagrams to this potential is not negligible.
Using the method proposed in the paper (Ⅰ)[1], we investigate the potential between two neutral scalar nucleons by exchanging neutral scalar mesons. The results show that the contribution of mesonic folded diagrams to this potential is not negligible.
Abstract:
A state space model is described, the time response of ferrite loaded cavity is proposed and a new digital measuring method devised.
Results of actual measurement on model cavity are given. On these bases the stability of stationary state of bias autotuning system to fast external perturbation is discussed.
A state space model is described, the time response of ferrite loaded cavity is proposed and a new digital measuring method devised.
Results of actual measurement on model cavity are given. On these bases the stability of stationary state of bias autotuning system to fast external perturbation is discussed.
Abstract:
In this paper, the radiative capture in the inelastic channel of the compound nucleus is discussed.
Starting from the S-matrix theory, the calculation formular for this situation is derived. Then connected with the optical model and Hauser-Feshbach's statistical theory with the width fluctuation correction, a formular convenient for calculations is given.
Making use of the formular obtained above, the numerical calculations are made for the average cross-section of 51V and other nuclei, and the comparison with the statistical (n, γ) and (n, n′) cross sections is made.
The results show that if the incident energies of the neutron are large enough to open the inelastic channel, the cross sections of this process will have the same order of magnitude as the statistical cross sections. Hence it is an important mechanism in the (n, γ) reactions.
In this paper, the radiative capture in the inelastic channel of the compound nucleus is discussed.
Starting from the S-matrix theory, the calculation formular for this situation is derived. Then connected with the optical model and Hauser-Feshbach's statistical theory with the width fluctuation correction, a formular convenient for calculations is given.
Making use of the formular obtained above, the numerical calculations are made for the average cross-section of 51V and other nuclei, and the comparison with the statistical (n, γ) and (n, n′) cross sections is made.
The results show that if the incident energies of the neutron are large enough to open the inelastic channel, the cross sections of this process will have the same order of magnitude as the statistical cross sections. Hence it is an important mechanism in the (n, γ) reactions.
Abstract:
A method of data analysis of the magnetic spectrometer with heavy ion is discussed. The determination of the charge state, the atomic number, the atomic mass and the energy of reaction products are described. The paper also deals with the soft ware correction of Bρ non-linear dispersion, kinematic and the difference of flight path.
A method of data analysis of the magnetic spectrometer with heavy ion is discussed. The determination of the charge state, the atomic number, the atomic mass and the energy of reaction products are described. The paper also deals with the soft ware correction of Bρ non-linear dispersion, kinematic and the difference of flight path.
Abstract:
In this paper, the electromagnetic shower processes occured in the lead glass detector are simulated by the Monte Carlo method, the light collection effects being taken into account. The primary energy of gamma ray is from 8 to 30 MeV. The detected efficiency function, the energy resolution curve and photoelectron number distribution (the pulse-height spectra) are presented for the lead glass detector. The calculated results are satisfactory.
In this paper, the electromagnetic shower processes occured in the lead glass detector are simulated by the Monte Carlo method, the light collection effects being taken into account. The primary energy of gamma ray is from 8 to 30 MeV. The detected efficiency function, the energy resolution curve and photoelectron number distribution (the pulse-height spectra) are presented for the lead glass detector. The calculated results are satisfactory.
Abstract:
A kinematically complete study of the symmetric systems 154Sm+154Sm and 144Sm+144Sm has been performed at energies 30% in excess of the interaction barrier. They have been chosen because of their different internal structure: 144Sm has a closed N=82 neutron shell and hence a spherical ground state confighration; 154Sm with ten neutrons outside this shell is strongly deformed. Over the whole range of kinetic energy loss the variances of the measured mass distributions were found to be similar in both reactions, whereas the variances of the element distributions are considerably larger at small energy losses in the 144Sm system. Based on the shell-corrected potential energy surface these observations are attributed to the closed N=82 neutron shell which, for 144Sm, hinders the neutron exchange and leads to a preferential transfer of protons.
A kinematically complete study of the symmetric systems 154Sm+154Sm and 144Sm+144Sm has been performed at energies 30% in excess of the interaction barrier. They have been chosen because of their different internal structure: 144Sm has a closed N=82 neutron shell and hence a spherical ground state confighration; 154Sm with ten neutrons outside this shell is strongly deformed. Over the whole range of kinetic energy loss the variances of the measured mass distributions were found to be similar in both reactions, whereas the variances of the element distributions are considerably larger at small energy losses in the 144Sm system. Based on the shell-corrected potential energy surface these observations are attributed to the closed N=82 neutron shell which, for 144Sm, hinders the neutron exchange and leads to a preferential transfer of protons.
Abstract:
The data processor of the magnetic field in the bending magnet with curvature is described using a normal measurement devies, moving along straight line. A formula for data trasformation is introduced. The results show that it would be approximately no influence to the fitting coefficients in longitudinal direction.
The data processor of the magnetic field in the bending magnet with curvature is described using a normal measurement devies, moving along straight line. A formula for data trasformation is introduced. The results show that it would be approximately no influence to the fitting coefficients in longitudinal direction.
IF: 3.6
Monthly founded in 1977
Sponsored by:
ISSN 1674-1137 CN 11-5641/O4
Original research articles, Ietters and reviews Covering theory and experiments in the fieids of
- Particle physics
- Nuclear physics
- Particle and nuclear astrophysics
- Cosmology
Author benefits
- A SCOAP3 participating journal - free Open Access publication for qualifying articles
- Average 24 days to first decision
- Fast-track publication for selected articles
- Subscriptions at over 3000 institutions worldwide
- Free English editing on all accepted articles
News
- Chinese Physics C Outstanding Reviewer Award 2023
- Impact factor of Chinese Physics C is 3.6 in 2022
- 2022 CPC Outstanding Reviewer Awards
- The 2023 Chinese New Year-Office closure
- ãChinese Physics CãBEST PAPER AWARDS 2022
Cover Story
- Cover Story (Issue 12, 2024) | Doubly heavy meson puzzle: precise prediction of the mass spectra and hadronic decay with coupled channel effects to hunt for beauty-charm family
- Cover Story (Issue 9, 2024) Measurement of solar pp neutrino flux using electron recoil data from PandaX-4T commissioning run
- Cover Story (Issue 11, 2024) ï½ Form factor for Dalitz decays from J/Ï to light pseudoscalars
- Cover Story (Issue 3, 2024) | First measurement of the ground-state mass of 22Al helps to evaluate the ab-initio theory
- Cover Story (Issue 2, 2024) | Quark/gluon taggers light the way to new physics
Advertising
