2012 Vol. 29, No. 1
Display Method:
2012, 29(1): 1-13.
doi: 10.11804/NuclPhysRev.29.01.001
Abstract:
Heavy quarkonium is a sensitive signature of the new state of matter-quarkgluon plasma produced in high energy nuclear collisions. We describe the spacetime evolution of the quarkgluon plasma by relativistic hydrodynamic equations and the quarkonium motion by transport equation. We found that the competition between the gluon dissociation and regeneration can explain naturally the J/ψ puzzles at RHIC energy. We predict the increase of the nuclear modification factor in semicentral and central collisions and the related transverse momentum suppression at LHC energy.
Heavy quarkonium is a sensitive signature of the new state of matter-quarkgluon plasma produced in high energy nuclear collisions. We describe the spacetime evolution of the quarkgluon plasma by relativistic hydrodynamic equations and the quarkonium motion by transport equation. We found that the competition between the gluon dissociation and regeneration can explain naturally the J/ψ puzzles at RHIC energy. We predict the increase of the nuclear modification factor in semicentral and central collisions and the related transverse momentum suppression at LHC energy.
2012, 29(1): 14-20.
doi: 10.11804/NuclPhysRev.29.01.014
Abstract:
We calculate the momentum distribution of nucleons in asymmetric nuclear matter within the framework of the extended BruecknerHartreeFock approximation at zero temperature, use Argonne V18 potential as two nucleons potential. The isospinasymmetry dependence of the nucleon momentum distribution predicted and discussed. It is shown that as the asymmetry increases, the proton momentum distribution become smaller while the neutron one gets higher below their respective Fermi surfaces with respect to their common values in symmetric nuclear matter. The quasiparticle strength at the Fermi momentum also calculated and discussed, we got an improved fulfillment of the Migdal Luttinger theorem and nucleon number conservation.
We calculate the momentum distribution of nucleons in asymmetric nuclear matter within the framework of the extended BruecknerHartreeFock approximation at zero temperature, use Argonne V18 potential as two nucleons potential. The isospinasymmetry dependence of the nucleon momentum distribution predicted and discussed. It is shown that as the asymmetry increases, the proton momentum distribution become smaller while the neutron one gets higher below their respective Fermi surfaces with respect to their common values in symmetric nuclear matter. The quasiparticle strength at the Fermi momentum also calculated and discussed, we got an improved fulfillment of the Migdal Luttinger theorem and nucleon number conservation.
2012, 29(1): 21-24.
doi: 10.11804/NuclPhysRev.29.01.021
Abstract:
Influence of densitydistributionwhichisgivenbyRMFandSkyrme－Hartrere－Fork etalnuclearstructuremodelonnuclearstoppinginheavy－ioncollisionsatintermediateenergiesarestudiedbyusingisospin－dependentquantummoleculardynamics(IQMD)model.ResearchshowsthatrangeformtheFermienergytothelargerenergyof 100 Mev/u, for bothsmallandlargemasssystem,nuclearstoppingisfoundtobestronglydependentonthenucleon－nucleoncrosssections,andweaklyondifferentdensitydistribution.ThisshowsthatnuclearstoppingcanbeusedasaprobetoextracttheinformationontheisospindependenceN－Ncrosssectionsandhasnorelationshipwithnuclearstructuremodels.
Influence of densitydistributionwhichisgivenbyRMFandSkyrme－Hartrere－Fork etalnuclearstructuremodelonnuclearstoppinginheavy－ioncollisionsatintermediateenergiesarestudiedbyusingisospin－dependentquantummoleculardynamics(IQMD)model.ResearchshowsthatrangeformtheFermienergytothelargerenergyof 100 Mev/u, for bothsmallandlargemasssystem,nuclearstoppingisfoundtobestronglydependentonthenucleon－nucleoncrosssections,andweaklyondifferentdensitydistribution.ThisshowsthatnuclearstoppingcanbeusedasaprobetoextracttheinformationontheisospindependenceN－Ncrosssectionsandhasnorelationshipwithnuclearstructuremodels.
2012, 29(1): 25-35.
doi: 10.11804/NuclPhysRev.29.01.025
Abstract:
Using a unified description on multiplicity distributions of finalstate particles, the energy spectra of light charged particles and evaporation residues in heavy ion induced reactions at low energy are studied in the framework of a multisource ideal gas model. Each source in an excited composite contributes energy spectra of light charged particles and evaporation residues to be an exponential law. The calculated results are compared and found to be in agreement with the expe rimental data of inclusive and exclusive energy distributions for light charged particles and evaporation residues measured in the 20Ne (158, 170, 180, and 200 MeV) +12C reactions.
Using a unified description on multiplicity distributions of finalstate particles, the energy spectra of light charged particles and evaporation residues in heavy ion induced reactions at low energy are studied in the framework of a multisource ideal gas model. Each source in an excited composite contributes energy spectra of light charged particles and evaporation residues to be an exponential law. The calculated results are compared and found to be in agreement with the expe rimental data of inclusive and exclusive energy distributions for light charged particles and evaporation residues measured in the 20Ne (158, 170, 180, and 200 MeV) +12C reactions.
2012, 29(1): 36-44.
doi: 10.11804/NuclPhysRev.29.01.036
Abstract:
Based on the multisource ideal gas model, which do not consider the dynamic mechanism of particles, two formulae are given to describe the transverse mass distributions of protons, kaons and pions produced in central heavy ion collisions at high energies. In the case of neglecting the relativistic effect, our calculated results approximately describe the experimental data, except for pions. By considering the subsamples of the sources, it is found that our calculated results are in good agreement with the experimental data in the central AuAu and PbPb collisions at high energies.
Based on the multisource ideal gas model, which do not consider the dynamic mechanism of particles, two formulae are given to describe the transverse mass distributions of protons, kaons and pions produced in central heavy ion collisions at high energies. In the case of neglecting the relativistic effect, our calculated results approximately describe the experimental data, except for pions. By considering the subsamples of the sources, it is found that our calculated results are in good agreement with the experimental data in the central AuAu and PbPb collisions at high energies.
2012, 29(1): 52-56.
doi: 10.11804/NuclPhysRev.29.01.052
Abstract:
We divide the particle generating sources in nucleon-nucleon collisions into two parts： binary collisions and leading particles， and present the analytical relation between chargedparticle pseudorapidity distributions and incident energy. On the basis of this work， we classify the particle generating sources in nucleus-nucleus collisions into three parts：binary collisions，leading particles and spectators，and formulate the chargedparticle pseudorapidity distributions as the function of incident energy and impact parameter. We then analyze with the model the experimental measurements in d+Au collisions at sNN=200 GeV. The theoretical results are well consistent with experimental data.
We divide the particle generating sources in nucleon-nucleon collisions into two parts： binary collisions and leading particles， and present the analytical relation between chargedparticle pseudorapidity distributions and incident energy. On the basis of this work， we classify the particle generating sources in nucleus-nucleus collisions into three parts：binary collisions，leading particles and spectators，and formulate the chargedparticle pseudorapidity distributions as the function of incident energy and impact parameter. We then analyze with the model the experimental measurements in d+Au collisions at sNN=200 GeV. The theoretical results are well consistent with experimental data.
2012, 29(1): 57-61.
doi: 10.11804/NuclPhysRev.29.01.057
Abstract:
This paper considers the extended Skyrme model with the anticommutator of the chiral current. By deducing the equations of motion of extended Skyrme model， the spherically symmetric Skyrmion was numerically simulated. After the Zero-mode quantization of the model， the static properties of nucleons were calculated and the connection of the anticommutator of the chiral current with QCD was discussed.
This paper considers the extended Skyrme model with the anticommutator of the chiral current. By deducing the equations of motion of extended Skyrme model， the spherically symmetric Skyrmion was numerically simulated. After the Zero-mode quantization of the model， the static properties of nucleons were calculated and the connection of the anticommutator of the chiral current with QCD was discussed.
2012, 29(1): 62-66.
doi: 10.11804/NuclPhysRev.29.01.062
Abstract:
Based on the parameters of the Middle Energy Beam Transport (MEBT) of the Heavy Ion Therapy Facility in Lanzhou (HITFiL)， which is now under design and construction at the Institute of Modern Physics， Chinese Academy of Sciences (IMPCAS)， a debuncher will be used to reduce the momentum spread for the injection requirement of the synchrotron according to the injection demand of the synchorotron. Both analytical model and tracking simulation with MathCAD are used for the choice of debuncher’s parameters. The conclusion shows that the effective cavity voltage of the debuncher is 102 kV and the minimum finial momentum spread is 2.764×10-4.
Based on the parameters of the Middle Energy Beam Transport (MEBT) of the Heavy Ion Therapy Facility in Lanzhou (HITFiL)， which is now under design and construction at the Institute of Modern Physics， Chinese Academy of Sciences (IMPCAS)， a debuncher will be used to reduce the momentum spread for the injection requirement of the synchrotron according to the injection demand of the synchorotron. Both analytical model and tracking simulation with MathCAD are used for the choice of debuncher’s parameters. The conclusion shows that the effective cavity voltage of the debuncher is 102 kV and the minimum finial momentum spread is 2.764×10-4.
2012, 29(1): 67-71.
doi: 10.11804/NuclPhysRev.29.01.067
Abstract:
A 5T actively shielded superconducting magnet was designed for Lanzhou Penning Trap project. In order to achieve homogeneity of physical requirements， superconducting magnet was made up of six coils， which were wound on framework of three layers. Meanwhile， three framework structure can ensure the precision of coil winding and the mechanical stability under intense magnetic field. The results of simulation show that the insulation and fixed structure of the coil can satisfy the electrical and mechanical requirements under intense magnetic field. At last， properties of the used materials and coil fabrication have been presented.
A 5T actively shielded superconducting magnet was designed for Lanzhou Penning Trap project. In order to achieve homogeneity of physical requirements， superconducting magnet was made up of six coils， which were wound on framework of three layers. Meanwhile， three framework structure can ensure the precision of coil winding and the mechanical stability under intense magnetic field. The results of simulation show that the insulation and fixed structure of the coil can satisfy the electrical and mechanical requirements under intense magnetic field. At last， properties of the used materials and coil fabrication have been presented.
2012, 29(1): 72-76.
doi: 10.11804/NuclPhysRev.29.01.072
Abstract:
A longitudinal field MUltiple Sampling Ionization Chamber (MUSIC)， which makes multiple measurements of energy loss for very high energy heavy ions at RIBLL2， has been constructed and tested with 3 constituent α source （239Pu: 3.435 MeV， 241Am: 3.913 MeV， 244Cm: 4.356 MeV）. The voltage plateau curve has been plotted and －500 V is determined as a proper work voltage. The energy resolution is 271.4 keV FWHM for the sampling unit when 3.435 MeV energy deposited. A Geant4 Monte Carlo simulation is made and it indicates the detector can provide unique particle identification for ions Z≥4.
A longitudinal field MUltiple Sampling Ionization Chamber (MUSIC)， which makes multiple measurements of energy loss for very high energy heavy ions at RIBLL2， has been constructed and tested with 3 constituent α source （239Pu: 3.435 MeV， 241Am: 3.913 MeV， 244Cm: 4.356 MeV）. The voltage plateau curve has been plotted and －500 V is determined as a proper work voltage. The energy resolution is 271.4 keV FWHM for the sampling unit when 3.435 MeV energy deposited. A Geant4 Monte Carlo simulation is made and it indicates the detector can provide unique particle identification for ions Z≥4.
2012, 29(1): 77-80.
doi: 10.11804/NuclPhysRev.29.01.077
Abstract:
The HEU sample was measured by HPGe- γ spectrometry. By analyzing the detected γspectrum， the N(214Bi)/N(234U) of the HEU sample was acquired, and the age of HEU samples was determined， which was coincided with the reference value. At last， the other potential methods of determining the age of HEU were analyzed systematically. N(214Bi)/N(234U) is more feasible，and algorithm of spectrumdecomposition in N(231Pa)/N(235U) should be studied further.
The HEU sample was measured by HPGe- γ spectrometry. By analyzing the detected γspectrum， the N(214Bi)/N(234U) of the HEU sample was acquired, and the age of HEU samples was determined， which was coincided with the reference value. At last， the other potential methods of determining the age of HEU were analyzed systematically. N(214Bi)/N(234U) is more feasible，and algorithm of spectrumdecomposition in N(231Pa)/N(235U) should be studied further.
2012, 29(1): 81-84.
doi: 10.11804/NuclPhysRev.29.01.081
Abstract:
A small neutron generator has been developed for meeting the need of well logging in oil fields. The miniature cold cathode Penning ion source and single electrode ion optics system are used in neutron generator. The good performance of the generator has been proved in the laboratory test and well logging in oil field. The generator has good characteristics， such as small diameter， high temperature resistant，high neutron output and good stability. At present， the neutron generator is the smallest logging generator in China， which has been used in oil field generally for conforming the geological data.
A small neutron generator has been developed for meeting the need of well logging in oil fields. The miniature cold cathode Penning ion source and single electrode ion optics system are used in neutron generator. The good performance of the generator has been proved in the laboratory test and well logging in oil field. The generator has good characteristics， such as small diameter， high temperature resistant，high neutron output and good stability. At present， the neutron generator is the smallest logging generator in China， which has been used in oil field generally for conforming the geological data.
2012, 29(1): 85-91.
doi: 10.11804/NuclPhysRev.29.01.085
Abstract:
The evolution of helium bubbles in materials has been simulated by Monte Carlo methods based on the migrationcoalescence mechanism. The influences of simulation parameters on the results are studied. It is found that the initial depth distribution must be considered when assessing the parameters influence， and the frequency of updating neighbor list should also be taken into account when selecting the cutoff range for neighbors.
The evolution of helium bubbles in materials has been simulated by Monte Carlo methods based on the migrationcoalescence mechanism. The influences of simulation parameters on the results are studied. It is found that the initial depth distribution must be considered when assessing the parameters influence， and the frequency of updating neighbor list should also be taken into account when selecting the cutoff range for neighbors.
2012, 29(1): 92-96.
doi: 10.11804/NuclPhysRev.29.01.092
Abstract:
In this paper， the biological effects，such as germination percentage， germination index and the length of seedlings and roots were investigated by using lowenergy N+， 60Co- γ rays and ultraviolet UVC to irradiate the embryos of wheat seeds （Xiaoyan81）. The anti oxidative enzyme system (CAT，POD， SOD) and GSH content were studied as well. The results show that the vitality of seed increased and then reduced with increasing the dosage of N+ ion implantation. The length of roots and seedlings were significantly higher than control. The seed vigor was significant effected after irradiated by 60Co-γrays and ultraviolet UV-C, but the length of roots and seedlings were significantly lower than control. After N+ implantation， the changing pattern of CAT was not obviously. The enzymatic activity of POD and SOD were increased at low dosage and reduced at high dosage. The content of GSH was reduced and then raised. The results proved that the damage induced by γray and UVC to the radicle of wheat was severe that result in a large number of seedling died. However the damage induced by N+ implantation was lower than that by rays and UVC irradiation. Certain dosage of ion implantation can promote the growth of wheat.
In this paper， the biological effects，such as germination percentage， germination index and the length of seedlings and roots were investigated by using lowenergy N+， 60Co- γ rays and ultraviolet UVC to irradiate the embryos of wheat seeds （Xiaoyan81）. The anti oxidative enzyme system (CAT，POD， SOD) and GSH content were studied as well. The results show that the vitality of seed increased and then reduced with increasing the dosage of N+ ion implantation. The length of roots and seedlings were significantly higher than control. The seed vigor was significant effected after irradiated by 60Co-γrays and ultraviolet UV-C, but the length of roots and seedlings were significantly lower than control. After N+ implantation， the changing pattern of CAT was not obviously. The enzymatic activity of POD and SOD were increased at low dosage and reduced at high dosage. The content of GSH was reduced and then raised. The results proved that the damage induced by γray and UVC to the radicle of wheat was severe that result in a large number of seedling died. However the damage induced by N+ implantation was lower than that by rays and UVC irradiation. Certain dosage of ion implantation can promote the growth of wheat.
2012, 29(1): 97-102.
doi: 10.11804/NuclPhysRev.29.01.097
Abstract:
Compared with the cultured monolayer (2D) cells， threedimensional (3D) tissue could be more similar to the environment in vivo including the physical support， chemical factors， cellcell and cellmatrix interaction and so on. With the development of threedimensional cell culture techniques (TDCC)， 3D tissue is widely used in the areas of bystander effect research. This review focuses on introducing the TDCC method and its application in bystandereffect research. First， the development process of 3D tissue culture method was introduced. Secondly， the induction of radiation induced bystander effects both in 2D cell and 3D tissue and its mechanisms were reviewed. Finally， because heavy ion (carbon ion beam) has been developed as a useful tool to cure solid cancer ，and the 3D tissue model is an ideal material to study the damages on body after being irradiated and to understand the underlying mechanisms， future study about heavy ion radiation inducing bystander effect in 3D tissue was discussed.
Compared with the cultured monolayer (2D) cells， threedimensional (3D) tissue could be more similar to the environment in vivo including the physical support， chemical factors， cellcell and cellmatrix interaction and so on. With the development of threedimensional cell culture techniques (TDCC)， 3D tissue is widely used in the areas of bystander effect research. This review focuses on introducing the TDCC method and its application in bystandereffect research. First， the development process of 3D tissue culture method was introduced. Secondly， the induction of radiation induced bystander effects both in 2D cell and 3D tissue and its mechanisms were reviewed. Finally， because heavy ion (carbon ion beam) has been developed as a useful tool to cure solid cancer ，and the 3D tissue model is an ideal material to study the damages on body after being irradiated and to understand the underlying mechanisms， future study about heavy ion radiation inducing bystander effect in 3D tissue was discussed.
2012, 29(1): 103-108.
doi: 10.11804/NuclPhysRev.29.01.103
Abstract:
p73 was the first identified homologue of the tumor suppressor gene, p53. p73 has two groups of protein isoforms: TAp73 and DNp73. TAp73 can induce cell cycle arrest, resulting in the ability of apoptosis, however DNp73 has antagonistic property of a tumor promoting effect. In this paper, the dual roles of p73 gene and its research progress was reviewed. Finally, combined with heavy ion treatment of tumor, we explored some new ideas of p73heavy ion joint therapy.
p73 was the first identified homologue of the tumor suppressor gene, p53. p73 has two groups of protein isoforms: TAp73 and DNp73. TAp73 can induce cell cycle arrest, resulting in the ability of apoptosis, however DNp73 has antagonistic property of a tumor promoting effect. In this paper, the dual roles of p73 gene and its research progress was reviewed. Finally, combined with heavy ion treatment of tumor, we explored some new ideas of p73heavy ion joint therapy.
2012, 29(1): 109-113.
doi: 10.11804/NuclPhysRev.29.01.109
Abstract:
After three days of medicine administrated, Kunming mice were exposured to 8 Gy of 100 kVp Xrays. Hemogram, viscere, survival, MDA yields and SOD activity were examined. Results showes that, (1) Survival of medicineadministrated mice were similar to the control group. After irradiation, survival dropped significantly. It took 20 days for the control group to reach to 50% survival, while 9 days for DMSO group 29 days for 1# drug group, and 24 days for 5# drug group. (2) The medicine per se had no obvious impacts on visceral indexes. Liver index and spleen index of the control group and DMSO group were elevated after irradiated, while those of medicineadministrated group did not change much. (3) The groups treated by DMSO and 1# drug had high yield of MDA, but low activity of SOD. Compared with DMSO group, 5# drug had high SOD activity while low MDA level. Irradiation increased MDA level but decreased SOD activity of every group, However, 5# drug still showed higher SOD activity and lower MDA level than DMSO group. (4) The medicine did not show distinctive contributions to variation of hemogram. In summary, our results demonstrated that GANRAlike 1# and 5# medicine had radioprotective effects and their mechanisms might be related to the scavenging ability of free radicals.
After three days of medicine administrated, Kunming mice were exposured to 8 Gy of 100 kVp Xrays. Hemogram, viscere, survival, MDA yields and SOD activity were examined. Results showes that, (1) Survival of medicineadministrated mice were similar to the control group. After irradiation, survival dropped significantly. It took 20 days for the control group to reach to 50% survival, while 9 days for DMSO group 29 days for 1# drug group, and 24 days for 5# drug group. (2) The medicine per se had no obvious impacts on visceral indexes. Liver index and spleen index of the control group and DMSO group were elevated after irradiated, while those of medicineadministrated group did not change much. (3) The groups treated by DMSO and 1# drug had high yield of MDA, but low activity of SOD. Compared with DMSO group, 5# drug had high SOD activity while low MDA level. Irradiation increased MDA level but decreased SOD activity of every group, However, 5# drug still showed higher SOD activity and lower MDA level than DMSO group. (4) The medicine did not show distinctive contributions to variation of hemogram. In summary, our results demonstrated that GANRAlike 1# and 5# medicine had radioprotective effects and their mechanisms might be related to the scavenging ability of free radicals.
2012, 29(1): 114-116.
doi: 10.11804/NuclPhysRev.29.01.114
Abstract:
Reactivity temperature coefficient is one of important parameters of burst reactor. The methods of measuring the coefficient were introduced and analyzed. The whole process of burst is split into “peak” process and “tail” process. Reactivity reduction is twice as large as initial excess reactivity in “peak” process from FuchsHansen model. Increment of temperature induced by “peak” process was got through removing “tail”. So we deduced reactivity temperature coefficient of CFBR-Ⅱ αT=-0.00202 $/K.
Reactivity temperature coefficient is one of important parameters of burst reactor. The methods of measuring the coefficient were introduced and analyzed. The whole process of burst is split into “peak” process and “tail” process. Reactivity reduction is twice as large as initial excess reactivity in “peak” process from FuchsHansen model. Increment of temperature induced by “peak” process was got through removing “tail”. So we deduced reactivity temperature coefficient of CFBR-Ⅱ αT=-0.00202 $/K.
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