2009 Vol. 26, No. 3
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2009, 26(3): 177-182.
doi: 10.11804/NuclPhysRev.26.03.177
Abstract:
The αdecay potential barrier of the newly synthesized superheavy nuclei starting from 294118 and 291116 have been determined and their halflives have been studied with the Generalized Liquid Drop Model(GLDM) connected with WKB approximation and Royer’s formulae.The αdecay halflives of the nuclei belonging to the superheavy nuclei starting from 294118 and 291116 have been calculated.The calculated results are in agreement with the experimental data, which show that the α decay halflives of superheavy nuclei with the GLDM and Royer’s formulae can be applied in the studying on superheavy nuclei successfully.Finally, the halflives of Z=118 and 116 isotopes have been predicted, and the results suggest there may be some longlived superheavy nuclei for αdecay in those isotopes.
The αdecay potential barrier of the newly synthesized superheavy nuclei starting from 294118 and 291116 have been determined and their halflives have been studied with the Generalized Liquid Drop Model(GLDM) connected with WKB approximation and Royer’s formulae.The αdecay halflives of the nuclei belonging to the superheavy nuclei starting from 294118 and 291116 have been calculated.The calculated results are in agreement with the experimental data, which show that the α decay halflives of superheavy nuclei with the GLDM and Royer’s formulae can be applied in the studying on superheavy nuclei successfully.Finally, the halflives of Z=118 and 116 isotopes have been predicted, and the results suggest there may be some longlived superheavy nuclei for αdecay in those isotopes.
2009, 26(3): 183-187.
doi: 10.11804/NuclPhysRev.26.03.183
Abstract:
Properties of the ground state and the excited states in N=127 isotones are investigated with relativistic mean field theory with the interactions PK1 and NL3. By analyzing the rms of proton and neutron, the single particle levels of valence nucleon and the density distributions of neutron, proton and the last neutron, it can be found that there exists a neutron halo in the excited states of 3d5/2,4s1/2 and 3d3/2. It is also predicted that there exists a neutron halo in the excited states of 3d5/2,4s1/2 and 3d3/2 in 207Hg,208Tl,210Bi and 211Po.
Properties of the ground state and the excited states in N=127 isotones are investigated with relativistic mean field theory with the interactions PK1 and NL3. By analyzing the rms of proton and neutron, the single particle levels of valence nucleon and the density distributions of neutron, proton and the last neutron, it can be found that there exists a neutron halo in the excited states of 3d5/2,4s1/2 and 3d3/2. It is also predicted that there exists a neutron halo in the excited states of 3d5/2,4s1/2 and 3d3/2 in 207Hg,208Tl,210Bi and 211Po.
2009, 26(3): 188-193.
doi: 10.11804/NuclPhysRev.26.03.188
Abstract:
Radiative decay of mesons is an important aspect in lowenergy hadronic physics,through which structures and properties of mesons can be revealed. In view of effective field theories, the radiative decay of mesons involves mainly interactions between photons and hadrons. In this paper,we investigate the decay of vector mesons by using SU(3) symmetry and the vector meson dominance model respectively. By fitting with experiments, we give the theoretic widths for V→Pγ in both cases and the mixing angle of pseudoscalars θP is -6°.
Radiative decay of mesons is an important aspect in lowenergy hadronic physics,through which structures and properties of mesons can be revealed. In view of effective field theories, the radiative decay of mesons involves mainly interactions between photons and hadrons. In this paper,we investigate the decay of vector mesons by using SU(3) symmetry and the vector meson dominance model respectively. By fitting with experiments, we give the theoretic widths for V→Pγ in both cases and the mixing angle of pseudoscalars θP is -6°.
2009, 26(3): 194-197.
doi: 10.11804/NuclPhysRev.26.03.194
Abstract:
The large n vortices in the dual superconductor model was investigated. An approximate analytical solution was obtained for nfold quantized vortices with n=90—110 by variationally solving the AbelianHiggs model, and the vortex tension was calculated as a function of n. It was found that the vortex tension rises linearly as n grows. It is hoped that our solution shines light on the understanding of the wall behavior of the large n vortices in AbelianHiggs model.
The large n vortices in the dual superconductor model was investigated. An approximate analytical solution was obtained for nfold quantized vortices with n=90—110 by variationally solving the AbelianHiggs model, and the vortex tension was calculated as a function of n. It was found that the vortex tension rises linearly as n grows. It is hoped that our solution shines light on the understanding of the wall behavior of the large n vortices in AbelianHiggs model.
2009, 26(3): 198-202.
doi: 10.11804/NuclPhysRev.26.03.198
Abstract:
The scheme of longitudinal bunch compression cavity for the Cooling Storage Ring(CSR) is an important issue. Plasma physics experiments require high density heavy ion beam and short pulsed bunch, which can be produced by nonadiabatic compression of bunch implemented by a fast compression with 90° rotation in the longitudinal phase space. The phase space rotation in fast compression is initiated by a fast jump of the RFvoltage amplitude. For this purpose, the CSR longitudinal bunch compression cavity, loaded with FINEMETFT1M is studied and simulated with MAFIA code. In this paper, the CSR longitudinal bunch compression cavity is simulated and the initial bunch length of 238U72+ with 250 MeV/u will be compressed from 200 ns to 50 ns. The construction and RF properties of the CSR longitudinal bunch compression cavity are simulated and calculated also with MAFIA code. The operation frequency of the cavity is 1.15 MHz with peak voltage of 80kV, and the cavity can be used to compress heavy ions in the CSR.
The scheme of longitudinal bunch compression cavity for the Cooling Storage Ring(CSR) is an important issue. Plasma physics experiments require high density heavy ion beam and short pulsed bunch, which can be produced by nonadiabatic compression of bunch implemented by a fast compression with 90° rotation in the longitudinal phase space. The phase space rotation in fast compression is initiated by a fast jump of the RFvoltage amplitude. For this purpose, the CSR longitudinal bunch compression cavity, loaded with FINEMETFT1M is studied and simulated with MAFIA code. In this paper, the CSR longitudinal bunch compression cavity is simulated and the initial bunch length of 238U72+ with 250 MeV/u will be compressed from 200 ns to 50 ns. The construction and RF properties of the CSR longitudinal bunch compression cavity are simulated and calculated also with MAFIA code. The operation frequency of the cavity is 1.15 MHz with peak voltage of 80kV, and the cavity can be used to compress heavy ions in the CSR.
2009, 26(3): 203-209.
doi: 10.11804/NuclPhysRev.26.03.203
Abstract:
he transmission of RIBLL has been studied by experimental measurement and Monte Carlo simulation methods. The analysis of influence factors of the simulated transmission has been accomplished, and it was found that the momentum distribution of fragments is one of the most important factors influencing the simulation results. Furthermore, through comparing the measured and simulated results, it is found that the simulated result is larger than the measured transmission for most fragments and the maximal difference between them is about several tens of times. This simulation is a good theory tools for estimating the intensity of the secondary beam and designing the experiment in the future.
he transmission of RIBLL has been studied by experimental measurement and Monte Carlo simulation methods. The analysis of influence factors of the simulated transmission has been accomplished, and it was found that the momentum distribution of fragments is one of the most important factors influencing the simulation results. Furthermore, through comparing the measured and simulated results, it is found that the simulated result is larger than the measured transmission for most fragments and the maximal difference between them is about several tens of times. This simulation is a good theory tools for estimating the intensity of the secondary beam and designing the experiment in the future.
2009, 26(3): 210-214.
doi: 10.11804/NuclPhysRev.26.03.210
Abstract:
he Ripple coefficient is one of the important factor for the stability of industrial high voltage electron accelerator. Accelerator can’t work well when the ripple coefficient is high. The increment of the measured ripple values becomes very large with the increase of the accelerator load current. From the simulation with finite element method of high voltage generator,we found that the leakage magnetic field was the most important reason for the results of ripple measurement. The ripple was measured after changing the frame of the high voltage generator to suppress the leakage magnetic field. It can be concluded that the actual value is acceptable to the accelerator and the measured high ripple coefficient is not the reason of malfunction of this high power electron accelerator.
he Ripple coefficient is one of the important factor for the stability of industrial high voltage electron accelerator. Accelerator can’t work well when the ripple coefficient is high. The increment of the measured ripple values becomes very large with the increase of the accelerator load current. From the simulation with finite element method of high voltage generator,we found that the leakage magnetic field was the most important reason for the results of ripple measurement. The ripple was measured after changing the frame of the high voltage generator to suppress the leakage magnetic field. It can be concluded that the actual value is acceptable to the accelerator and the measured high ripple coefficient is not the reason of malfunction of this high power electron accelerator.
2009, 26(3): 215-221.
doi: 10.11804/NuclPhysRev.26.03.215
Abstract:
Collimated proton microbeam has been used to irradiate the biological living cells since 1850s. Due to its unique characteristic in irradiation, microbeam has been extensively applied to many research fields,such as biology, material science, biomedicine,aeronautics and stronautics, environmental science, geology,micromachining and so on. Based on the much research of predecessors, the microbeam facilities and their corresponding applications are summarized in this paper. At last,prospects on the development trend of microbeam are made, and the intermediate energy and high energy heavy ion microbeam irradiation facility being constructed at the Institute of Modern Physics of Chinese Academy of Sciences is briefly introduced.
Collimated proton microbeam has been used to irradiate the biological living cells since 1850s. Due to its unique characteristic in irradiation, microbeam has been extensively applied to many research fields,such as biology, material science, biomedicine,aeronautics and stronautics, environmental science, geology,micromachining and so on. Based on the much research of predecessors, the microbeam facilities and their corresponding applications are summarized in this paper. At last,prospects on the development trend of microbeam are made, and the intermediate energy and high energy heavy ion microbeam irradiation facility being constructed at the Institute of Modern Physics of Chinese Academy of Sciences is briefly introduced.
2009, 26(3): 222-226.
doi: 10.11804/NuclPhysRev.26.03.222
Abstract:
Chlorinated phenols have been paid great concerns recently because of their extreme toxicity and persistency in the environment. The paper reviews mainly the recent progresses on irradiation degradation of chlorinated phenols in aqueous solution by using high energy electron beam & γrays. Mechanisms dealing with the irradiation degradation of chlorophenols and the different effect on degradation efficiency have been discussed. The results show that synergetic effect of the combination of γ irradiation and O3 on degradation of chlorinated phenols is significant.
Chlorinated phenols have been paid great concerns recently because of their extreme toxicity and persistency in the environment. The paper reviews mainly the recent progresses on irradiation degradation of chlorinated phenols in aqueous solution by using high energy electron beam & γrays. Mechanisms dealing with the irradiation degradation of chlorophenols and the different effect on degradation efficiency have been discussed. The results show that synergetic effect of the combination of γ irradiation and O3 on degradation of chlorinated phenols is significant.
2009, 26(3): 227-230.
doi: 10.11804/NuclPhysRev.26.03.227
Abstract:
A 127° electrostatic coaxial cylindrical energy spectrometer with a radial position sensitive MCP detector is designed for sputtering ions measurement. It has been tested by measuring the energy spectrum of the sputtering ions in the collision of 800 keV Ar8+ bombarding beryllium target. A segment of the energy spectrum (0.85Ec≤E≤1.15Ec) can be obtained at one working voltage (U), which is much efficient than the traditional pointtopoint voltage scanning method.
A 127° electrostatic coaxial cylindrical energy spectrometer with a radial position sensitive MCP detector is designed for sputtering ions measurement. It has been tested by measuring the energy spectrum of the sputtering ions in the collision of 800 keV Ar8+ bombarding beryllium target. A segment of the energy spectrum (0.85Ec≤E≤1.15Ec) can be obtained at one working voltage (U), which is much efficient than the traditional pointtopoint voltage scanning method.
2009, 26(3): 231-237.
doi: 10.11804/NuclPhysRev.26.03.231
Abstract:
An extended equivalent twobody method for threebody systems is introduced in this article. The method is applied to an atomic threebody system. Energies and wave functions of a heliumlike ion are calculated,which are consistent with the experimental data much better,in contrast to the results obtained by a oneparameter calculus of variations approach. Then we use a twoparameter calculus of variations approach to verify the precision of the ground state energy and wave function obtained by the extended equivalent twobody method. These results indicated that the extended equivalent two body method is applicable to an atomic threebody problem.
An extended equivalent twobody method for threebody systems is introduced in this article. The method is applied to an atomic threebody system. Energies and wave functions of a heliumlike ion are calculated,which are consistent with the experimental data much better,in contrast to the results obtained by a oneparameter calculus of variations approach. Then we use a twoparameter calculus of variations approach to verify the precision of the ground state energy and wave function obtained by the extended equivalent twobody method. These results indicated that the extended equivalent two body method is applicable to an atomic threebody problem.
2009, 26(3): 238-241.
doi: 10.11804/NuclPhysRev.26.03.238
Abstract:
In this paper, ion implantation techniques were used to study the photoluminescence(PL) of the Coimplanted crystal ZnO. After Coion implanted, the samples were annealed at 700 ℃ for 10 min in Ar gas flow. It was observed violet emission peak of 406 and 370 nm in the PL spectrum. The PL spectra of the ZnO crystal samples which were implanted by Co ions and Cu ions, respectively, have been compared and observed that the PL spectrum of the Coimplanted ZnO is similar to that of the Cuimplanted ZnO. We studied the influence of implantation dose on the PL of the Coimplanted ZnO and found that the green luminescence centre shifted with increasing of implantation dose. It is concluded that the shift of the green luminescence centre is related to the change of ZnO band gap which was caused by ion implantation.
In this paper, ion implantation techniques were used to study the photoluminescence(PL) of the Coimplanted crystal ZnO. After Coion implanted, the samples were annealed at 700 ℃ for 10 min in Ar gas flow. It was observed violet emission peak of 406 and 370 nm in the PL spectrum. The PL spectra of the ZnO crystal samples which were implanted by Co ions and Cu ions, respectively, have been compared and observed that the PL spectrum of the Coimplanted ZnO is similar to that of the Cuimplanted ZnO. We studied the influence of implantation dose on the PL of the Coimplanted ZnO and found that the green luminescence centre shifted with increasing of implantation dose. It is concluded that the shift of the green luminescence centre is related to the change of ZnO band gap which was caused by ion implantation.
2009, 26(3): 242-247.
doi: 10.11804/NuclPhysRev.26.03.242
Abstract:
An exploration of a new light source by PXR as Laser gived rise to extensive attention. The particle motion must be stable in order to obtain coherent PXR source. But, an instability of system is possible due to the effect of bent crystal, thus the reflection, the diffraction, the focus and the spectral distribution of PXR will be effected.In the classical mechanics frame and dipole approximation the particle motion equation in bent crystal is reduced to the pendulum equation with a constant momentum by the sinesquared potential.The phase planar properties are analysed by means of Jacobian elliptic function and the elliptic integral. It shows that the stability of the system is related to the curvature Q of the bent crystal. When the condition 0≤Q<1 is satisfied, the system is stable。
An exploration of a new light source by PXR as Laser gived rise to extensive attention. The particle motion must be stable in order to obtain coherent PXR source. But, an instability of system is possible due to the effect of bent crystal, thus the reflection, the diffraction, the focus and the spectral distribution of PXR will be effected.In the classical mechanics frame and dipole approximation the particle motion equation in bent crystal is reduced to the pendulum equation with a constant momentum by the sinesquared potential.The phase planar properties are analysed by means of Jacobian elliptic function and the elliptic integral. It shows that the stability of the system is related to the curvature Q of the bent crystal. When the condition 0≤Q<1 is satisfied, the system is stable。
2009, 26(3): 248-252.
doi: 10.11804/NuclPhysRev.26.03.248
Abstract:
Human normal liver cell line HL-7702 cells were irradiated with different doses of Xrays. Micronucleus and apoptosis rates in the irradiated cells were measured with cytokinesisblock micronucleus method and Annexin VFITC apoptosis detection kit, respectively. Experimental data showed that the micronucleus and apoptosis rates increased obviously with increasing irradiation dose. After seven population doublings, the micronucleus and apoptosis rates of the cells surviving exposure to the Xrays reduced to the same levels as nonirradiated control cells; the progenies of the cells were secondly exposed to Xrays at the same dose of 2.5 Gy. We found that the progenies of the cells surviving the first irradiations of the various doses showed markedly differential micronucleus frequencies and apoptotic rates. Although the same dose of 2.5 Gy was applied in the second irradiations, the micronucleus frequencies and apoptotic rates of the progenies of the cells initially exposed at higher doses were significantly higher than the others. These results indicate that Xrays lead to genomic instability in HL7702 cells, which is an important manifestation of radiationinduced delayed effect, and a second radiation stimulus makes the delayed effect in the progeny of the previously irradiated cells be expressed obviously.
Human normal liver cell line HL-7702 cells were irradiated with different doses of Xrays. Micronucleus and apoptosis rates in the irradiated cells were measured with cytokinesisblock micronucleus method and Annexin VFITC apoptosis detection kit, respectively. Experimental data showed that the micronucleus and apoptosis rates increased obviously with increasing irradiation dose. After seven population doublings, the micronucleus and apoptosis rates of the cells surviving exposure to the Xrays reduced to the same levels as nonirradiated control cells; the progenies of the cells were secondly exposed to Xrays at the same dose of 2.5 Gy. We found that the progenies of the cells surviving the first irradiations of the various doses showed markedly differential micronucleus frequencies and apoptotic rates. Although the same dose of 2.5 Gy was applied in the second irradiations, the micronucleus frequencies and apoptotic rates of the progenies of the cells initially exposed at higher doses were significantly higher than the others. These results indicate that Xrays lead to genomic instability in HL7702 cells, which is an important manifestation of radiationinduced delayed effect, and a second radiation stimulus makes the delayed effect in the progeny of the previously irradiated cells be expressed obviously.
2009, 26(3): 253-258.
doi: 10.11804/NuclPhysRev.26.03.253
Abstract:
Accumulating evidence indicates that irradiated cells can release signals which induce a series of biological responses in nonexposed cells. This is known as irradiationinduced bystander effects. Both reactive oxygen species(ROS) and nitric oxide(NO) play important roles in bystander effects. In this study, we determined the relationship of ROS and NO in the signaling pathway of bystander effects. HeLa cells were treated with or without dimethye sulfoxide(DMSO) before Xray irradiation, and micronuclei formation as well as cell proliferation rate was detected in both irradiated and bystander cells. In addition, we also detected inducible nitric oxide synthase(iNOS) expression and NO level in irradiated cells using Western blotting and DAFFM DA fluorescent probe, respectively. Our results showed that micronuclei were induced in irradiated and bystander cells while DMSO treatment significantly suppressed the formation of micronuclei in both of them. We also found that when cells were irradiated their proliferation rate was suppressed while DMSO treatment eliminated this inhibition effect. In contrast, the cells received conditioned medium from irradiated cells proliferated more quickly than the cells received medium from non irradiated cells while DMSO treatment reduced the difference. Finally, we found that irradiated cells had higher level of iNOS and NO compared to nonirradiated controls, whereas DMSO treatment decreased their levels. These results suggest that ROS is the upstream signal of NO in Xray induced bystander effects in HeLa cells.
Accumulating evidence indicates that irradiated cells can release signals which induce a series of biological responses in nonexposed cells. This is known as irradiationinduced bystander effects. Both reactive oxygen species(ROS) and nitric oxide(NO) play important roles in bystander effects. In this study, we determined the relationship of ROS and NO in the signaling pathway of bystander effects. HeLa cells were treated with or without dimethye sulfoxide(DMSO) before Xray irradiation, and micronuclei formation as well as cell proliferation rate was detected in both irradiated and bystander cells. In addition, we also detected inducible nitric oxide synthase(iNOS) expression and NO level in irradiated cells using Western blotting and DAFFM DA fluorescent probe, respectively. Our results showed that micronuclei were induced in irradiated and bystander cells while DMSO treatment significantly suppressed the formation of micronuclei in both of them. We also found that when cells were irradiated their proliferation rate was suppressed while DMSO treatment eliminated this inhibition effect. In contrast, the cells received conditioned medium from irradiated cells proliferated more quickly than the cells received medium from non irradiated cells while DMSO treatment reduced the difference. Finally, we found that irradiated cells had higher level of iNOS and NO compared to nonirradiated controls, whereas DMSO treatment decreased their levels. These results suggest that ROS is the upstream signal of NO in Xray induced bystander effects in HeLa cells.
2009, 26(3): 259-262.
doi: 10.11804/NuclPhysRev.26.03.259
Abstract:
Human hepatoma SMMC7721 and normal liver L02 cells were irradiated with γrays,12C6+ and 36Ar18+ ion beams at the Heavy Ion Research Facility in Lanzhou(HIRFL). We reported the kinetic repair of chromosome breaks of L02 and SMMC7721 cells in 24 h of postirradiation time. The relative biological effectiveness(RBE) for inducing chromatid breaks were 3.6 for L02 and 3.5 for SMMC7721 cell lines at the linear energy transfer(LET) peak of 96.55 keV/μm 12C6+ ions, and 2.9 (both of the two cell lines) at 512 keV/μm 36Ar18+ ions.It suggested that the RBE of isochromatidtype breaks induced by 36Ar18+ was higher than those by 12C6+. We concluded that the high production of isochromatidtype breaks, induced by the densely ionizing track structure, could be regarded as a signature of high LET radiation exposure.
Human hepatoma SMMC7721 and normal liver L02 cells were irradiated with γrays,12C6+ and 36Ar18+ ion beams at the Heavy Ion Research Facility in Lanzhou(HIRFL). We reported the kinetic repair of chromosome breaks of L02 and SMMC7721 cells in 24 h of postirradiation time. The relative biological effectiveness(RBE) for inducing chromatid breaks were 3.6 for L02 and 3.5 for SMMC7721 cell lines at the linear energy transfer(LET) peak of 96.55 keV/μm 12C6+ ions, and 2.9 (both of the two cell lines) at 512 keV/μm 36Ar18+ ions.It suggested that the RBE of isochromatidtype breaks induced by 36Ar18+ was higher than those by 12C6+. We concluded that the high production of isochromatidtype breaks, induced by the densely ionizing track structure, could be regarded as a signature of high LET radiation exposure.
2009, 26(3): 263-268.
doi: 10.11804/NuclPhysRev.26.03.263
Abstract:
The study on the relationship between telomerase and tumor become one of hotspots in biology because of its function in tumorigenesis. We reviewed the changes of telomerase activity of cancer cells irradiated by different radiations, especially heavy ion. Meanwhile, because of contradictory results, we should be cautious to the application of telomerase inhibition to kill tumor cell and thought deeply about evaluating the killing effect of adiotherapy by telomerase activity index.
The study on the relationship between telomerase and tumor become one of hotspots in biology because of its function in tumorigenesis. We reviewed the changes of telomerase activity of cancer cells irradiated by different radiations, especially heavy ion. Meanwhile, because of contradictory results, we should be cautious to the application of telomerase inhibition to kill tumor cell and thought deeply about evaluating the killing effect of adiotherapy by telomerase activity index.
2009, 26(3): 269-273.
doi: 10.11804/NuclPhysRev.26.03.269
Abstract:
Five mutants with high ability of producing alcohol were selected out by using TTC as an indicator after irradiation of the alcohol yeast with 100 MeV/u carbon ions. The fermentation experiment in sweet sorghum juice showed that the alcohol production ability of mutant T4 strain increased 18.6% compared to the control strain. The residual sugar content in the juice was decreased too. After that, the optimum fermentation conditions of the T4 strain in sweet sorghum juice were investigated. The results showed that the optimum temperature and pH value for fermentation were 30 ℃ and 4.5, respectively. The verification experiment was fermented in a 10 l bioreactor and the obtained data indicated that the fermentative rate and the ability of producing alcohol in T4 strain was higher than that in the control strain under the same fermentation condition.
Five mutants with high ability of producing alcohol were selected out by using TTC as an indicator after irradiation of the alcohol yeast with 100 MeV/u carbon ions. The fermentation experiment in sweet sorghum juice showed that the alcohol production ability of mutant T4 strain increased 18.6% compared to the control strain. The residual sugar content in the juice was decreased too. After that, the optimum fermentation conditions of the T4 strain in sweet sorghum juice were investigated. The results showed that the optimum temperature and pH value for fermentation were 30 ℃ and 4.5, respectively. The verification experiment was fermented in a 10 l bioreactor and the obtained data indicated that the fermentative rate and the ability of producing alcohol in T4 strain was higher than that in the control strain under the same fermentation condition.