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2013 Vol. 30, No. 1

Nuclear Physics
3-Pion Hadron Physics and Experiments
CHEN Xurong, WANG Rong, HE Jun
2013, 30(1): 1-9. doi: 10.11804/NuclPhysRev.30.01.001
Abstract(2432) PDF (818KB)(509)
Abstract:
Three pion productions off nucleon are of significance in the research of hadron physics. Meanwhile it is the subject of many big experimental apparatus in the world. Due to the variety of three pion productions, it can be applied as an effective tool to study QCD in low energy region. Three pion productions is one of the main reactions in searching light exotic meson state. Moreover, it is possible to find out the "missing" baryon resonance and the cascaded decay process between baryon excited states. We introduce present experiments and theories of three pion productions as well as the partial wave analysis technique. The emphasis is on the CLAS (CEBAF Large Acceptance Spectrometer) experiment at JLab (Jefferson Lab). In the end, we point out the significance of studying the three-pion hadron physics at JLab.
Low-lying Seven-quark qqq(q¯q)2 States in Baryon Spectrum
YUAN Si-gang
2013, 30(1): 10-16. doi: 10.11804/NuclPhysRev.30.01.010
Abstract(2467) PDF (613KB)(458)
Abstract:
The low-lying energy spectra of 7-quark systems qqq(q¯q)2 is investigated with the schematic flavor-spin interaction, as an extension of the qqqq¯q five quark model. The lowest qqq(q¯q)2 state with an approximate energy 2.1 GeV and the spin-parity JP =1/2+ or JP =1/2-, has been predicted with the parameters used in the five quark system.Because of the overlap with the corresponding qqq and qqqq¯q states above 2 GeV, it is possible for the high excited baryon-resonances to have substantial qqq(q¯q)2 admixtures.
Investigation of Spindown of Neutron Stars
XIONG Xue-yu, GAO Chun-yuan, XU Ren-xin
2013, 30(1): 17-21. doi: 10.11804/NuclPhysRev.30.01.017
Abstract(2262) PDF (700KB)(551)
Abstract:
The neutron stars’ braking mechanism is a fundamental problem in the study of neutron stars. The braking index exactly equal to 3 in pure magnetodipole radiation model, however, all the observed braking index of rotationpowered pulsars is less than 3. This indicates that the additional energy loss ways must exist besides the magnetodipole radiation. The magnetodipole radiation, the ejection of particle outflow and quantum vacuum friction are considered as the source of the loss of rotational kinetic energy of rotation-powered pulsars. Based on the three mechanism of loss of the energy, the relation between the period of pulsars and the first derivative of the period to time and the pulsars’ energy losing power are given. The relationship of the periods and the first derivative of the periods of six pulsars(J1119−6127,B1509−58, J1846−0258, B0531+21, B0540−69 and B0833−45) is studied. The relation between the surface magnetic field intensity and the magnetic inclination is discussed. Research shows that when the electric potential difference of vacuum gap is a constant the inclination angle is limited in a smaller range and in the other cases the inclination is the continuous value between 0∼90 degrees.
Investigation of Projectile Fragments in 56Fe Induced Nuclear Reactions in Nuclear Emulsion at 500 AMeV
LI Jun-sheng, ZHANG Dong-hai, LI Hui-ling
2013, 30(1): 22-25. doi: 10.11804/NuclPhysRev.30.01.022
Abstract(1918) PDF (581KB)(442)
Abstract:
A stack of domestic N-4 nuclear emulsion was exposed to 56Fe ions at 500 AMeV at the HIMAC of NIRS. Particle production was investigated in 56Fe-Em interactions. The multiplicity distribution of projectile fragments was given in this paper and compared with other experimental results of heavy ion induced nuclear reactions in nuclear emulsion. The results show that the multiplicity of projectile fragments increase with the increasing target mass, and there
is no dependence on the projectile energy.
Revised Landau Hydrodynamic Model and Pseudorapidity Distributions of Final Charged Particles in Cu+Cu Collisions
JIANG Zhi- jin, LI Qing-guang, ZHANG Hai-li
2013, 30(1): 26-31. doi: 10.11804/NuclPhysRev.30.01.026
Abstract(2105) PDF (663KB)(410)
Abstract:
By using the revised Landau hydrodynamic model and taking into account the effect of leading particles, we discussed the pseudorapidity distributions of final charged particles in high energy heavy ion collisions. We argued that the rapidity distributions of leading particles have the Gaussian form with the normalization constant being equal to the number of participants. The investigations show that the results from the hydrodynamic model alone are not consistent with the experimental data carried out by BNL-RHIC-PHOBOS Collaboration in Cu+Cu collisions at (NN)½ = 200 GeV. Only after the contributions from leading particles are included, can the experimental measurements be described well.
Accelerator
Microwave Impedance Matching of A 2.45 GHz ECR Ion Source
QIAN Cheng, CHEN Zhi, WU Qi, ZHANG Wen-hui, WANG Yun, YANG Yao, MA Hong-yi, FANG Xing, SUN Liang-ting, ZHANG Xue-zhen, ZHANG Zi-min, LIU Zhan-wen, ZHAO Hong-wei
2013, 30(1): 32-37. doi: 10.11804/NuclPhysRev.30.01.032
Abstract(2498) PDF (726KB)(655)
Abstract:
Plasma impedance of an ECR ion source is important for microwave transmission and impedance matching design. Plasma impedance was measured indirectly with the 2.45 GHz ECR proton source at the Institute of Modern Physics, Chinese Academy of Sciences. In the test, we got microwave window mpedance by using water absorption load instead of plasma load, and the source plasma impedance was derived from the test data with the 2.45 GHz ECR proton source and microwave window impedance. The experimental results show that ridge waveguide output impedance and the subsequent load does not exactly match, plasma impedance variation is nonlinear with microwave power. The achieved
result is useful in the design of ridged waveguide and microwave window.
Optimized Program of MSC1210 Power Supply Controller
JIANG Zi-yun, ZHANG Wei, GU Ke-wei, WU Jun-qi, CHEN Yun, YANG Feng, AN Shi, LIU Xiao-jun
2013, 30(1): 38-41. doi: 10.11804/NuclPhysRev.30.01.038
Abstract(1898) PDF (681KB)(417)
Abstract:
The MSC1210 control module is one of the most important power supply controllers of Heavy Ion Research Facility in Lanzhou ( HIRFL ), but there are several problems during beam tuning. In order to deal with the problems,
the main chip’s program was redesigned. In this paper we introduced the controller’s fault phenomena, and analyzed the reasons; then scheduled the optimized program in detail. Several methods were employed to improve the system performance, including instruction receiving process which is based on state machine, the communication mode with parity mechanism, and the remote instruction reset method. Both laboratory and commissioning tests indicate that the optimized controller is stable and reliable, and meet the operation requirement of HIRFL.
Nuclear Technology
Digital Readout Method for Position Sensitive Detectors
TIAN Li-chao, SUN Zhi-jia, QI Hui-rong, TANG Bin, LÜ Xinyu, CHEN Yuan-bo, OU Yanqun
2013, 30(1): 42-46. doi: 10.11804/NuclPhysRev.30.01.042
Abstract(2174) PDF (648KB)(443)
Abstract:
Efficient thermal neutron detectors with large area, two-dimensional position sensitive, high counting rate high detection efficiency and low gamma sensitivity are required to satisfy the demands for the China Spallation Neutron Source (CSNS). Compared with the traditional analog readout method, the digital readout method has the advantages of higher counting rate, smaller quantity of data transmission, simpler readout system and higher signal to noise ratio. The theoretical analysis of the digital readout method is reported in this paper.Used the raw data of GEM detector, the relationship between the position resolution and the width of the readout strip was studied. The results indicate that the digital readout method could be a good choice for the large area position sensitive detector where the requirement of position resolution is less than 4 mm, e.g. the detector of Small-Angle Neutron Scattering (SANS) diffractometer of CSNS.
Monte-Carlo Simulation for Shielding of Cold Neutron Triple-axis Spectrometer
SONG Jian-ming, YIN Yan-peng, LI Jian, LIU Li-juan, WANG Hong, SUN Guang-ai
2013, 30(1): 47-51. doi: 10.11804/NuclPhysRev.30.01.047
Abstract(1943) PDF (707KB)(437)
Abstract:
The shielding of Cold neutron Triple-Axis Spectrometer( CTAS ) is important for radiation safety of workers, and reduce the background of scattering hall as well as enhancing the ratio of signal-to-noise. In this study, Monte-Carlo simulation was performed to conduct the calculation on the shielding of CTAS. To increase the calculation efficiency, neutron source was obtained by using Mcstas code. The results indicate that, in the case of heavy concrete ( density 4.6 g/cm3 ) with thickness of 350 mm for the shielding behind the monochromater, and heavy concrete ( density 3.6 g/cm3 ) with thickness of 300 mm for the other monochromater shielding, as well as the heavy concrete ( density 3.6 g/cm3 ) with thickness of 150 mm for biological shielding, the dose rate outside shielding may meet the requirement of national standard of China.
Monte Carlo Simulation of Neutron Detection Efficiency for NE213 Scintillation Detector
XI Yin-yin, SONG Yu-shou, CHEN Zhi-qiang, YANG Kun, ZHANGSU Ya-la-tu, LIU Xing-quan
2013, 30(1): 52-57. doi: 10.11804/NuclPhysRev.30.01.052
Abstract(2219) PDF (749KB)(570)
Abstract:
A NE213 liquid scintillation neutron detector was simulated by using the FLUKA code. The light output of the detector was obtained by transforming the secondary particles energy deposition using Birks formula. According to the measurement threshold, detection efficiencies can be calculated by integrating the light output. The light output, central efficiency and the average efficiency as a function of the front surface radius of the detector, were simulated and
the results agreed well with experimental results.
Study on Crystal Size and Detection Efficiency of HPGe Detector
MU Wan-jun, LI Mei, ZHONG Zheng-kun
2013, 30(1): 58-62. doi: 10.11804/NuclPhysRev.30.01.058
Abstract(1915) PDF (611KB)(514)
Abstract:
The accurate shape of HPGe detector is needed in order to calculate its detection efficiency with Monte Carlo methods. In our calculation, the influence of the HPGe crystal size on efficiency has been investigated; the final crystal sizes were determined by comparison with experiments and were validated by the experimental efficiency obtained at several source-to-detector positions. The results show that when the crystal dimensions determined are used to calculate the detection efficiency in the energy range 122s1 332 keV, the relative deviations between simulated and most experimental results were within 5%. In addition, the relationship between detection efficiency and axial distance to detector was established.
Cross Discipline
Kinetic Energy Threshold of M-X Spectra Emitted by Interaction of 152Eu20+ on Au
LIANG Chang-hui, ZHANG Xiao-an, LI Yao-zong
2013, 30(1): 63-66. doi: 10.11804/NuclPhysRev.30.01.063
Abstract(2204) PDF (642KB)(424)
Abstract:
It is measured that the characteristic X-ray spectra of Mζ,Mα and Mβ of Au and the characteristic X-ray spectra of M of Eu produced by the interaction of highly charged ions of 152Eu20+ with kinetic energy 2.0 MeV on Au surface. The micro-mechanism of X-ray excitation is preliminary analyzed. The kinetic energy threshold of M-X ray of Au and M-X ray of Eu emitted by Eu20+ with Au is estimated by semiclassical approximation theory of binary collision. The threshold has important referenced value in the study on dynamics of the interaction of highly charged ions with solid surface and on how to choose better target and projectile combination in the conversion efficiency of radiation energy.
Modification of Lithium Tantalate Implanted by 250 keV He-ions
PANG Li-long, WANG Zhi-guang, YAO Cun-feng, CUI Ming-huan, SUN Jian-rong, SHEN Tie-long, WEI Kong-fang, ZHU Ya-bin, SHENG Yan-bin, LI Yuan-fei, LI Jin-yu
2013, 30(1): 67-71. doi: 10.11804/NuclPhysRev.30.01.067
Abstract(2041) PDF (741KB)(430)
Abstract:
The effects of 250 keV He + implantation in the fluence from 5.0x1014 to 5.0x1016 He+/cm2 on lithium tantalate at room temperature were investigated by 3D surface profiler, XRD and UV-Vis optical absorption spectroscopies.The experimental results show that a large number of raised stripes appear on the surface of the sample and the significant lattice swelling occurs along the direction [ 001 ] at the fluence of 5.0x1016 He+/cm2. The dependence of changes absorption edge on the fluences was revealed. After the samples had been exposed to the air for 60 days, the raised stripes on the surface have evolved into narrow cracks. Furthermore, the lattice strain and the optical absorption edge has also recovered dramatically. The relationship between surface morphology, lattice strain, optical absorption edge and behavior
of He-ions was discussed.
The Application of Electron Beam Irradiation on Excess Sludge Treatment
SUN Yong-liang, LI Xin, WANG Jie, WANG Ju-fang, LI Wen-jian, WANG Yi-bo
2013, 30(1): 72-78. doi: 10.11804/NuclPhysRev.30.01.072
Abstract(1960) PDF (715KB)(487)
Abstract:
Recently, electron beam irradiation has great potential in dealing with excess sludge . A great deal of studies showed that the electron beam irradiation played an enormous role in promoting the sludge harmless treatment. Most of pathogenicbacteria was dead and lots of organic substances, especially some non-biodegradable ones, were decomposed by the high electron beam irradiation. The irradiated sludge also had low water content, less odour, low hazard and a better application potential in utilization. This paper reviews the application of electron beam irradiation on excess sludge, the advantages and current situation of the irradiation technology. Mechanisms of removing contaminants, effects of treatment and the construction expense are mainly discussed. The future development of this advanced technology are
prospected finally.
Protective Effect of Diallyl Disulfide against the Irradiation Damage in Mice Induced by 12C6+ Ion Beams
XU Shuai, ZHANG Hong, LIU Yang, MA Xiao-fei
2013, 30(1): 79-83. doi: 10.11804/NuclPhysRev.30.01.079
Abstract(1940) PDF (730KB)(480)
Abstract:
The radioprotective effect of Diallyl disulfide (DADS) on 12C6+ ion irradiation was studied. Pretreated with DADS of different concentration, male Kung-Ming mice were exposed to whole body irradiation with dosage of 4 Gy 12C6+ ion. The animals were sacrificed after irradiation. Then the bone marrow cells micronucleus rate, malondialdehyde (MDA) levels, content of protein carbonylation, total antioxidant capacity ( T-AOC) and alanine aminotransferase ( ALT ) activity were measured. As compared with those in irradiated group, the ratio of micronucleus cells in marrow and the hepatic ALT activity in the pretreatment group with low dose DADS decreased significantly ( p < 0.001 ). Similarly,the content of protein carbonylation and the levels of MDA droped dramatically in the group with middle dose DADS treatment ( p < 0.05 ). On the contrary, the hepatic T-AOC increased markedly in the group of pretreatment with low dose DADS ( p < 0.05 ). The results showed that DADS protect lipoid, protein and genetic material from 12C6+ ion irradiation by right of resisting oxidative stress.
Inhibitory Effect of 12C6+ Ion and X-ray on Angiogenesis in HMEC-1
LIU Yuan-yuan, ZHANG Hong, LIU Yang, SUN Chao, WU Zhen-hua, LI Hong-yan
2013, 30(1): 84-88. doi: 10.11804/NuclPhysRev.30.01.084
Abstract(1908) PDF (818KB)(445)
Abstract:
The study aims to explore the effect of 12C6+ ion and X-ray on proliferation, migration, tube formation and MMPS of human microvascular endothelial cells ( HMEC-1 ). Transwell migration experiment showed that the radiation could inhibit the migration of HMEC-1 in sub-lethal dose 24 h after irradiation. Furthermore, the inhibition ability of 12C6+ ion was stronger than that of X-ray. Matrigel experiment indicated that 12C6+ ion suppressed the tube formation of HMEC-1 spontaneously. However, the inhibitory effect of X-ray had no significance. Meanwhile, Gelatin Zymography showed the expression of MMP-2 was inhibited obviously by 12C6+ ion, while X-ray had little effect on the expression of MMP-2. In conclusion, 12C6+ ion is superior to X-ray in adiotherapy of tumor.
Nuclear Energy and Nuclear Data
Introduction of American Laser Inertial Fusion Energy
LIU Chen-anSHI Xue-ming
2013, 30(1): 89-93. doi: 10.11804/NuclPhysRev.30.01.089
Abstract(2506) PDF (717KB)(554)
Abstract:
In this paper the present study situation and prospect of the American laser-based Inertial Confinement Fusion Energy ( LIFE ) are briefly introduced. It is based on recent progress of National Inertial Facility ( NIF ) and related research have begun. On the assumption of using laser energy of 1.4 to 2.0 MJ, the target fusion gain G=25&#8764;30, the repetition rate 10 to 15 Hz, the fusion power of 350 to 500 MW or neutron source power of 1.3×1020 to 1.8×1020
n/s could be achieved. For a sub-critical fission blanket driven by this fusion neutrons power, energy multiplication M of 4&#8764;10 and several GW of thermal power could be obtained. By novel design on fuel pins, burnup more than 90% would be achieved for heavy metals in the blanket. Inertial Confinement Fusion-fission energy is a promising concept, which characterized by inherent safety, richness in nuclear fuel resources, minimization of nuclear waste, non-CO2 emitting ,and it is a sustainable energy source.
An Energetic Ion Irradiation Equipment Based on HIRFL for Materials under High Temperature and Stress
SHEN Tie-long, WANG Zhi-guang, YAO Cun-feng, SUN Jian-rong, SHENG Yan-bin, WEI Kong-fang, LI Bing-sheng, ZHU Ya-bin, PANG Li-Long, CUI Ming-huan, LI Yuan-fei
2013, 30(1): 94-98. doi: 10.11804/NuclPhysRev.30.01.094
Abstract(1737) PDF (728KB)(462)
Abstract:
In order to expedite the evaluation of properties of irradiated materials and the selection of candidate materials for future nuclear energy systems, we developed a specific ion irradiation equipment installed on the Heavy Ion Research Facility of Lanzhou ( HIRFL ) for materials under high temperature and stress. This equipment consists of ion beam scanning and detector system, high temperature load system, stress load system, water cooling system as well as telecommunication and control system. It can supply a wide range of temperature (from room temperature to 1 200 °C ) and stress ( pull / push from 0 to 1 176 N) simultaneously for materials under ion irradiation. The x-y scanning area with high uniformity is larger than 40 mm40 mm. This is the first suit of ion irradiation equipment made in China that can be used to study co-operating effects of high temperature and stress in an irradiated material. It has been successfully used several times for materials irradiations under high temperatures and stress, which proved that the new equipment has very good performances in experiments.