2005 Vol. 22, No. 1
Display Method:
2005, 22(1): 1-2.
doi: 10.11804/NuclPhysRev.22.01.001
Abstract:
Differential cross sections for quasi elastic scattering at forward angles and for 1n and 2n transfer reaction at backward angles induced by 6He at 25 MeV/u from 9Be target were measured. The experimental data were analyzed in the framework of the CRC model. The raise at backward angle of the 1n and 2n transfer cross section can not reproduced by the current calculation.
Differential cross sections for quasi elastic scattering at forward angles and for 1n and 2n transfer reaction at backward angles induced by 6He at 25 MeV/u from 9Be target were measured. The experimental data were analyzed in the framework of the CRC model. The raise at backward angle of the 1n and 2n transfer cross section can not reproduced by the current calculation.
2005, 22(1): 3-5.
doi: 10.11804/NuclPhysRev.22.01.003
Abstract:
Different products of 6He nuclei from 9Be target has been measured with a 6He beam at energy of 25 MeV/u. The energy spectra at different angles for 4He isotope were analyzed and the experiment differential cross sections for the direct breakup reaction were obtained.
Different products of 6He nuclei from 9Be target has been measured with a 6He beam at energy of 25 MeV/u. The energy spectra at different angles for 4He isotope were analyzed and the experiment differential cross sections for the direct breakup reaction were obtained.
2005, 22(1): 6-10.
doi: 10.11804/NuclPhysRev.22.01.006
Abstract:
We analyzed the 6He elasticscattering from 9Be target at 25 MeV/u. A CenterofBeam (CB) method was used to calibrate the particletracking detectors and set the reference system of the detection system. The doublefolding model approach was used to calculate the real part of the optical model potential. The preliminary optical model potential parameters were extracted by fitting the experimental differential elasticscattering crosssections.
We analyzed the 6He elasticscattering from 9Be target at 25 MeV/u. A CenterofBeam (CB) method was used to calibrate the particletracking detectors and set the reference system of the detection system. The doublefolding model approach was used to calculate the real part of the optical model potential. The preliminary optical model potential parameters were extracted by fitting the experimental differential elasticscattering crosssections.
2005, 22(1): 11-16.
doi: 10.11804/NuclPhysRev.22.01.011
Abstract:
Properties of two pairs of mirror nuclei 13N13C and 15N15O are investigated by using the nonlinear relativistic meanfield theory. It is found that all the calculated binding energies with two different parameter sets are very close to the experimental ones for both the ground states and the excited states. The calculations show that the first excited state (2s1/2) and the third excited state (1d5/2) in 13N are both unbound resonances with proton halo structure, whereas the third excited state (1d5/2) in 13C is weakly bound with a neutron skin. It is also predicted that there has a proton halo in the second excited state (2s1/2) of 15N as well as a neutron skin in the first excited state (2s1/2) of 15O.
Properties of two pairs of mirror nuclei 13N13C and 15N15O are investigated by using the nonlinear relativistic meanfield theory. It is found that all the calculated binding energies with two different parameter sets are very close to the experimental ones for both the ground states and the excited states. The calculations show that the first excited state (2s1/2) and the third excited state (1d5/2) in 13N are both unbound resonances with proton halo structure, whereas the third excited state (1d5/2) in 13C is weakly bound with a neutron skin. It is also predicted that there has a proton halo in the second excited state (2s1/2) of 15N as well as a neutron skin in the first excited state (2s1/2) of 15O.
2005, 22(1): 17-19.
doi: 10.11804/NuclPhysRev.22.01.017
Abstract:
We have measured the reaction cross section of 17C on a 12C target at 79 MeV/u using the transmission method. Together with previous data at high energy, we deduced the density distribution of 17C by fitting the experimental data using the finiterange Glauber model.
The analysis shows that a simple harmonicoscillator (HO) density is not adequate to explain consistently the present experimental data and the one at high energy simultaneously. To get a better fit of both the data, the existence of a tail in the density distribution of 17C is proposed. Based on the assumption of a core plus a single neutron, it is found that the valence neutron of 17C is mostly in the dorbital. This is in agreement with the conclusion from the measured momentum distribution.
We have measured the reaction cross section of 17C on a 12C target at 79 MeV/u using the transmission method. Together with previous data at high energy, we deduced the density distribution of 17C by fitting the experimental data using the finiterange Glauber model.
The analysis shows that a simple harmonicoscillator (HO) density is not adequate to explain consistently the present experimental data and the one at high energy simultaneously. To get a better fit of both the data, the existence of a tail in the density distribution of 17C is proposed. Based on the assumption of a core plus a single neutron, it is found that the valence neutron of 17C is mostly in the dorbital. This is in agreement with the conclusion from the measured momentum distribution.
2005, 22(1): 20-22.
doi: 10.11804/NuclPhysRev.22.01.020
Abstract:
We have measured the angular distribution of 2H(8Li,9Li)1H at Ecm= 7.8 MeV and deduced the astrophysical Sfactor of 8Li(d, p)9Li reaction as well as the Asymptotic Normalization Coefficient (ANC) for 9Li → 8Li+n virtual decay.
We have measured the angular distribution of 2H(8Li,9Li)1H at Ecm= 7.8 MeV and deduced the astrophysical Sfactor of 8Li(d, p)9Li reaction as well as the Asymptotic Normalization Coefficient (ANC) for 9Li → 8Li+n virtual decay.
2005, 22(1): 23-26.
doi: 10.11804/NuclPhysRev.22.01.023
Abstract:
Two numerical schemes of rotational neutron star based on general relativity，hartle code and Butterworth and Ipser′s code (BI code), are introduced and discussed. The numerical results of the two codes with different equations of state (EOSs) are compared, and the results indicate that most properties of rotational neutron star with different EOSs and different numerical schemes are in accordance with each other.
Two numerical schemes of rotational neutron star based on general relativity，hartle code and Butterworth and Ipser′s code (BI code), are introduced and discussed. The numerical results of the two codes with different equations of state (EOSs) are compared, and the results indicate that most properties of rotational neutron star with different EOSs and different numerical schemes are in accordance with each other.
2005, 22(1): 27-28.
doi: 10.11804/NuclPhysRev.22.01.027
Abstract:
By adding isospin dependent high order correction ferms to existing relativistic mean field models．tlle thickness of neuron．skin in 208Pb and the radius of 1
.4 solar mass neutron star are studied．The effecfive interaction PK1 would lead the thickness of neutron-skin to a minimum of 0.17 fm which agrees with the analysis from Skyrme‘HF models． The coupling constants of the isospin dependent high order corection terms tend to change，the thickness of neutron-skin and the radius of neutron stars chan ge simultaneously.
By adding isospin dependent high order correction ferms to existing relativistic mean field models．tlle thickness of neuron．skin in 208Pb and the radius of 1
.4 solar mass neutron star are studied．The effecfive interaction PK1 would lead the thickness of neutron-skin to a minimum of 0.17 fm which agrees with the analysis from Skyrme‘HF models． The coupling constants of the isospin dependent high order corection terms tend to change，the thickness of neutron-skin and the radius of neutron stars chan ge simultaneously.
2005, 22(1): 29-31.
doi: 10.11804/NuclPhysRev.22.01.029
Abstract:
The density dependencies of various effective interaction strengths in the relativistic mean field and their influences on the properties of nuclear matter and neutron stars are studied and carefully compared. The differences of saturation properties given by various effective interactions are subtle in symmetric nuclear matter. The OppenheimerVolkoff mass limits of neutron stars calculated from different equations of state are 1.52—2.06 M☉, and the radii are 10.24—11.38 km with hyperons included.
The density dependencies of various effective interaction strengths in the relativistic mean field and their influences on the properties of nuclear matter and neutron stars are studied and carefully compared. The differences of saturation properties given by various effective interactions are subtle in symmetric nuclear matter. The OppenheimerVolkoff mass limits of neutron stars calculated from different equations of state are 1.52—2.06 M☉, and the radii are 10.24—11.38 km with hyperons included.
2005, 22(1): 32-33.
doi: 10.11804/NuclPhysRev.22.01.032
Abstract:
After adding isospin dependent high order correction terms to existing relativistic mean field models (RMF), the density dependence of symmetry energy and the neutron skin thickness S for 208Pb are studied. Using the new effective interaction PK1, together with NL3, S271 and Z271, a range of 29—38 MeV for the symmetry energy for nuclear matter at saturation point and the corresponding neutron skin thickness S = 0.14—0.28 fm for 208Pb are obtained. For all effective interactions, a linear relation between the symmetry energy at saturation point and the neutron skin thickness for 208Pb is observed.
After adding isospin dependent high order correction terms to existing relativistic mean field models (RMF), the density dependence of symmetry energy and the neutron skin thickness S for 208Pb are studied. Using the new effective interaction PK1, together with NL3, S271 and Z271, a range of 29—38 MeV for the symmetry energy for nuclear matter at saturation point and the corresponding neutron skin thickness S = 0.14—0.28 fm for 208Pb are obtained. For all effective interactions, a linear relation between the symmetry energy at saturation point and the neutron skin thickness for 208Pb is observed.
2005, 22(1): 34-35.
doi: 10.11804/NuclPhysRev.22.01.034
Abstract:
The significance of the synthesis and study of heavy neutron-rich nuclides far from β-stability is briefly introduced. The important role of element assignment for studying heavy neutron-rich nuclides far from β-stability is reported.
The significance of the synthesis and study of heavy neutron-rich nuclides far from β-stability is briefly introduced. The important role of element assignment for studying heavy neutron-rich nuclides far from β-stability is reported.
2005, 22(1): 36-38.
doi: 10.11804/NuclPhysRev.22.01.036
Abstract:
New isotope ~(265)Bh(Z=107) was produced in bombardment of an ~(243)Am target with 135 MeV ~(26)Mg ions at HIRFL. Identification was made by observation of correlated α-particle decays between the new isotope ~(265)Bh and its ~(261)Db and ~(257)Lr daughters with four pairs of detectors. The experimental results show that the half-life of ~(265)Bh is 0.94~(+0.70)_(-0.31) s and its α energy is (9.24±0.05) MeV.
New isotope ~(265)Bh(Z=107) was produced in bombardment of an ~(243)Am target with 135 MeV ~(26)Mg ions at HIRFL. Identification was made by observation of correlated α-particle decays between the new isotope ~(265)Bh and its ~(261)Db and ~(257)Lr daughters with four pairs of detectors. The experimental results show that the half-life of ~(265)Bh is 0.94~(+0.70)_(-0.31) s and its α energy is (9.24±0.05) MeV.
2005, 22(1): 39-43.
doi: 10.11804/NuclPhysRev.22.01.039
Abstract:
The current status of tumor therapy with protons and heavy ions from historical perspective is briefly presented. In the world there are 23 centers and 39 612 patients with proton therapy, 3 facilities and 4 511 patients with heavy ion therapy including2 054 patients by Heion.
The current status of tumor therapy with protons and heavy ions from historical perspective is briefly presented. In the world there are 23 centers and 39 612 patients with proton therapy, 3 facilities and 4 511 patients with heavy ion therapy including2 054 patients by Heion.
2005, 22(1): 44-46.
doi: 10.11804/NuclPhysRev.22.01.044
Abstract:
The advance of tumor therapy with heavy ions beam is due to the physics quality of heavy ions.So,the investigation of heavy ions action with biological materials will be a basic task. In the paper, the investigated results show a picture to resolve some problems which attract people＇s attention.
The advance of tumor therapy with heavy ions beam is due to the physics quality of heavy ions.So,the investigation of heavy ions action with biological materials will be a basic task. In the paper, the investigated results show a picture to resolve some problems which attract people＇s attention.
2005, 22(1): 47-79.
doi: 10.11804/NuclPhysRev.22.01.047
Abstract:
We have demonstrated for the first time that a larger amount of junctions were formed by multiwall carbon nanotubes (MWCNTs)converted amorphous carbon nanowires (ACNWs) during carbon ion beam irradiation. This is very suitable for production of novel type junctionlike structiures consisting of amorphous nanowires with uniform diameter of trunk and branches. The present method, ionbeam weld (IBW) of crossed MWCNTs, not only used to provide a powerful way in which to achieve perfect welding to build various junctionlike structures, but also may be helpful for preparing other systems or aligned arrays on substrates by micromanipulator for potential device.
We have demonstrated for the first time that a larger amount of junctions were formed by multiwall carbon nanotubes (MWCNTs)converted amorphous carbon nanowires (ACNWs) during carbon ion beam irradiation. This is very suitable for production of novel type junctionlike structiures consisting of amorphous nanowires with uniform diameter of trunk and branches. The present method, ionbeam weld (IBW) of crossed MWCNTs, not only used to provide a powerful way in which to achieve perfect welding to build various junctionlike structures, but also may be helpful for preparing other systems or aligned arrays on substrates by micromanipulator for potential device.
2005, 22(1): 50-53.
doi: 10.11804/NuclPhysRev.22.01.050
Abstract:
The defects and electronic momenta in graphite and nanocrystalline carbon have been studied by positron annihilation techniques. The results show that the concentration and open volume of defects in nanocrystalline carbon are higher/larger than that in graphite. Two kinds of microdefects were found in the nanocrystalline carbon: free volume (with a size of smaller than that of a monovacancy) and microvoids (with a size of about ten monovacancies). The anisotropic distribution of electronic momentum was found in single crystalline graphite, the momentum of free electron shows a maximum value in \[0001\] direction, and decreases with the increase of the angle deviation from \[0001\] direction and then reaches a minimum value in the direction perpendicular to \[0001\]. However, this phenomenon was not found in nanocrystalline carbon since the distribution of electronic momentum is isotropic.
The defects and electronic momenta in graphite and nanocrystalline carbon have been studied by positron annihilation techniques. The results show that the concentration and open volume of defects in nanocrystalline carbon are higher/larger than that in graphite. Two kinds of microdefects were found in the nanocrystalline carbon: free volume (with a size of smaller than that of a monovacancy) and microvoids (with a size of about ten monovacancies). The anisotropic distribution of electronic momentum was found in single crystalline graphite, the momentum of free electron shows a maximum value in \[0001\] direction, and decreases with the increase of the angle deviation from \[0001\] direction and then reaches a minimum value in the direction perpendicular to \[0001\]. However, this phenomenon was not found in nanocrystalline carbon since the distribution of electronic momentum is isotropic.
2005, 22(1): 54-57.
doi: 10.11804/NuclPhysRev.22.01.054
Abstract:
The quadrupole interactions in the nanoand crystalline LaFeO3 perovskites have been investigated by TDPAC. The TDPAC probing nuclei 14057La14058Ce were produced through the nuclear reaction 139La(n.γ)140La at the CIAE heavy water experimental reactor. One electric quadrupole interaction was detected for each material, which is assigned to the La site. The quadrupole interaction frequencies of 687.4, 698.3 and 742.9 Mrad/s with a distribution coefficient of 0.014, 0.009 and 0.001 were observed at room temperature for the 20 and 40 nm nanoLaFeO3 and crystalline LaFeO3, respectively. The fitting yielded the EFG asymmetry parameter η=0, which indicates that the principal axes of the EFG is aligned with the crystallographic axes. The experimental results show that the structure of crystalline LaFeO3 is rhombohedral, the changing of the structure towards the orthorhombic structure takes place from the crystalline LaFeO3 to the nanoLaFeO3, and the smaller the nanograin size, the larger the change. The frequency distribution is caused by the perturbation of the neighboring atoms, and thus, the distribution coefficient increases with decreasing the nanograin size and the crystalline LaFeO3 arrives at its maximum.
The quadrupole interactions in the nanoand crystalline LaFeO3 perovskites have been investigated by TDPAC. The TDPAC probing nuclei 14057La14058Ce were produced through the nuclear reaction 139La(n.γ)140La at the CIAE heavy water experimental reactor. One electric quadrupole interaction was detected for each material, which is assigned to the La site. The quadrupole interaction frequencies of 687.4, 698.3 and 742.9 Mrad/s with a distribution coefficient of 0.014, 0.009 and 0.001 were observed at room temperature for the 20 and 40 nm nanoLaFeO3 and crystalline LaFeO3, respectively. The fitting yielded the EFG asymmetry parameter η=0, which indicates that the principal axes of the EFG is aligned with the crystallographic axes. The experimental results show that the structure of crystalline LaFeO3 is rhombohedral, the changing of the structure towards the orthorhombic structure takes place from the crystalline LaFeO3 to the nanoLaFeO3, and the smaller the nanograin size, the larger the change. The frequency distribution is caused by the perturbation of the neighboring atoms, and thus, the distribution coefficient increases with decreasing the nanograin size and the crystalline LaFeO3 arrives at its maximum.
2005, 22(1): 58-60.
doi: 10.11804/NuclPhysRev.22.01.058
Abstract:
Using the machanism of beamtarget and heatnuclics, the scaling relationship between the neutron yields of denser plasma focus and the PF plasma current is induced.The results of DPF .The principle is brief discussed with denser plasma focus(DPF) as the neutron generator.We have stated that some factors that influnce the DPF discharging to produce neutron yield and some methodsthat improve stability of neutron yields on the denser plasma focus(DPF).
Using the machanism of beamtarget and heatnuclics, the scaling relationship between the neutron yields of denser plasma focus and the PF plasma current is induced.The results of DPF .The principle is brief discussed with denser plasma focus(DPF) as the neutron generator.We have stated that some factors that influnce the DPF discharging to produce neutron yield and some methodsthat improve stability of neutron yields on the denser plasma focus(DPF).
2005, 22(1): 61-63.
doi: 10.11804/NuclPhysRev.22.01.061
Abstract:
When the sample contains many kinds of energies γrays,their peak’s area not only records the matters of opticalelectronic effect but also the Compton scattering matters with higher energyγrays.So that,theγrays intensity conducted by the peak’s area can’t gain.Using the anti-matrix method,the better results of anlyze on theγSpectrometry may be getten.
When the sample contains many kinds of energies γrays,their peak’s area not only records the matters of opticalelectronic effect but also the Compton scattering matters with higher energyγrays.So that,theγrays intensity conducted by the peak’s area can’t gain.Using the anti-matrix method,the better results of anlyze on theγSpectrometry may be getten.
2005, 22(1): 64-66.
doi: 10.11804/NuclPhysRev.22.01.064
Abstract:
It is difficult to detect low intensity γ radiation by using traditional γ radiation detection technique in a close distance n, γ commix pulse radiation field with very high intensity neutron radiation. PbWO4 and CeF3 which are newly developed inorganic scintillator in our country have been studied. Photoelectricity detector systemes which have high γ sensitivity and relative insensitive to neutron and fast time response were assembled by using CeF3 and photomultiplier tube. The ratio of signaltonoise for γ ray detection can be up to more than 10 times in close distance n, γ commix pulse radiation field by using this detector system.
It is difficult to detect low intensity γ radiation by using traditional γ radiation detection technique in a close distance n, γ commix pulse radiation field with very high intensity neutron radiation. PbWO4 and CeF3 which are newly developed inorganic scintillator in our country have been studied. Photoelectricity detector systemes which have high γ sensitivity and relative insensitive to neutron and fast time response were assembled by using CeF3 and photomultiplier tube. The ratio of signaltonoise for γ ray detection can be up to more than 10 times in close distance n, γ commix pulse radiation field by using this detector system.
2005, 22(1): 67-71.
doi: 10.11804/NuclPhysRev.22.01.067
Abstract:
In this paper, the new analyzing method & software and applications of enelactic spectra from Carbon/oxygen spectrometry log is reported. It were included that enelastic Gammaray spectra(256 channels)of the formations by NaI(Tl) detector were analyzed quantitatively based on standard enelastic spectra, the methods which the ratio of elements yields and new ratio of C to O & of Ca to Si, the ratio of yield of C to O and the ratio of weight percent of C to O and the ratio of atoms C to O were found, and the corresponding ratio of Ca to Si were found simultaneously in new analyzing method. The differencevalue of the ratio of atoms C to O is greater than 0. 33 between 100% oil saturation and 100% water saturation in sandstone formation for porosity is thirtyfife percent. The differencevalue between oil and water increase by a factor of 60%. In addition oil saturations curves changed with the depth were computed.
In this paper, the new analyzing method & software and applications of enelactic spectra from Carbon/oxygen spectrometry log is reported. It were included that enelastic Gammaray spectra(256 channels)of the formations by NaI(Tl) detector were analyzed quantitatively based on standard enelastic spectra, the methods which the ratio of elements yields and new ratio of C to O & of Ca to Si, the ratio of yield of C to O and the ratio of weight percent of C to O and the ratio of atoms C to O were found, and the corresponding ratio of Ca to Si were found simultaneously in new analyzing method. The differencevalue of the ratio of atoms C to O is greater than 0. 33 between 100% oil saturation and 100% water saturation in sandstone formation for porosity is thirtyfife percent. The differencevalue between oil and water increase by a factor of 60%. In addition oil saturations curves changed with the depth were computed.
2005, 22(1): 72-75.
doi: 10.11804/NuclPhysRev.22.01.072
Abstract:
A new analyzing theory and method of C/O spectrometry logging is reported. Fast neutron enelastic scattering γray spectra(256 channels) were acquired in borehole by NaI(Tl) detector. The enelastic scattering γray from major elements C, O, Si, Ca, Fe, etc. have the fractions of mixed enelastic spectrum in formation respectively. Because F factor is the same for identical formation, then the ratio of yield of C to O, the ratio of weight percent of C to O, and the ratio of atoms C to O could be found, and the corresponding ratio of Ca to Si was found.
A new analyzing theory and method of C/O spectrometry logging is reported. Fast neutron enelastic scattering γray spectra(256 channels) were acquired in borehole by NaI(Tl) detector. The enelastic scattering γray from major elements C, O, Si, Ca, Fe, etc. have the fractions of mixed enelastic spectrum in formation respectively. Because F factor is the same for identical formation, then the ratio of yield of C to O, the ratio of weight percent of C to O, and the ratio of atoms C to O could be found, and the corresponding ratio of Ca to Si was found.
2005, 22(1): 76-78.
doi: 10.11804/NuclPhysRev.22.01.076
Abstract:
Because it can on line analyze many elements quickly and precisely without sampling and movement, prompt gamma neutron activation analysis is one of the most effective methods to monitor latent dynamite especially nonmetal. Many researchers studied the neutron detecting latent dynamite technique and get some achievements. This paper mainly discussed each method and technology route of neutron detecting landmine and latent dynamite, studied the AmBe isotope neutron source and 14 MeV pulse neutron tube activation analysis, and analyzed the geometrical layout of movable system.
Because it can on line analyze many elements quickly and precisely without sampling and movement, prompt gamma neutron activation analysis is one of the most effective methods to monitor latent dynamite especially nonmetal. Many researchers studied the neutron detecting latent dynamite technique and get some achievements. This paper mainly discussed each method and technology route of neutron detecting landmine and latent dynamite, studied the AmBe isotope neutron source and 14 MeV pulse neutron tube activation analysis, and analyzed the geometrical layout of movable system.
2005, 22(1): 79-80.
doi: 10.11804/NuclPhysRev.22.01.079
Abstract:
A preliminary experiment is conducted with directfilm method under the condition that fast neutron is generated by the reaction of 9Be (d,n) on the Peking University 4.5 MV Van de Graff, whose energy is lower than 7 MeV.Basic characteristics of direct-film neutron radiography system is researched with the help of samples in different materials, different thickness and holes of different diameter. The fast neutron converter, which is vital for fast neutron imaging, is produced with the materials made in china. The result indicates that fast neutron converter can meet the requirment of fast neutron imaging; what's more, further research of fast neutron imaging can be conducted on the accelerator and neutron-generator in China.
A preliminary experiment is conducted with directfilm method under the condition that fast neutron is generated by the reaction of 9Be (d,n) on the Peking University 4.5 MV Van de Graff, whose energy is lower than 7 MeV.Basic characteristics of direct-film neutron radiography system is researched with the help of samples in different materials, different thickness and holes of different diameter. The fast neutron converter, which is vital for fast neutron imaging, is produced with the materials made in china. The result indicates that fast neutron converter can meet the requirment of fast neutron imaging; what's more, further research of fast neutron imaging can be conducted on the accelerator and neutron-generator in China.
2005, 22(1): 81-83.
doi: 10.11804/NuclPhysRev.22.01.081
Abstract:
The principle of RFQ (Radiofrequency Quadrupole) cooler and buncher is briefly introduced. The characteristics of the being designed RFQ cooler and buncher and the preliminary results simulated by using the SIMION code are discussed.
The principle of RFQ (Radiofrequency Quadrupole) cooler and buncher is briefly introduced. The characteristics of the being designed RFQ cooler and buncher and the preliminary results simulated by using the SIMION code are discussed.
2005, 22(1): 84-87.
doi: 10.11804/NuclPhysRev.22.01.084
Abstract:
The principles and structure characteristics of LASCAR scintillator array detector at RIBLL terminal are described. Special emphases are laid upon the latest progress for the development of LASCAR array detector to meet the requirements of the RIB experiments. The working plan and steps for optimizing configuration of the LASCAR multiunit neutron scintillator array detector are also presented.
The principles and structure characteristics of LASCAR scintillator array detector at RIBLL terminal are described. Special emphases are laid upon the latest progress for the development of LASCAR array detector to meet the requirements of the RIB experiments. The working plan and steps for optimizing configuration of the LASCAR multiunit neutron scintillator array detector are also presented.
2005, 22(1): 88-90.
doi: 10.11804/NuclPhysRev.22.01.088
Abstract:
A nuclear microprobe was set up at the Institute of Modern Physics of Fudan University.The key parts were imported from Oxford Microbeams Ltd.The hardware system of the microprobe,including beam line,target chamber,focusing system and DAQ system is introduced. About several micrometer could be achieved at present beam spot size.
A nuclear microprobe was set up at the Institute of Modern Physics of Fudan University.The key parts were imported from Oxford Microbeams Ltd.The hardware system of the microprobe,including beam line,target chamber,focusing system and DAQ system is introduced. About several micrometer could be achieved at present beam spot size.
2005, 22(1): 91-93.
doi: 10.11804/NuclPhysRev.22.01.091
Abstract:
The characteristics of pulsed electron beam generated by multiplate pseudospark chamber (MPC) on the basis of field escalation effects have been described in this paper. The phenomena such as instability, filament effect, and self-pinch effect of pseudospark electron beam were studied and analyzedby the bombardment of solid evident films and metal targets.
The characteristics of pulsed electron beam generated by multiplate pseudospark chamber (MPC) on the basis of field escalation effects have been described in this paper. The phenomena such as instability, filament effect, and self-pinch effect of pseudospark electron beam were studied and analyzedby the bombardment of solid evident films and metal targets.
2005, 22(1): 94-96.
doi: 10.11804/NuclPhysRev.22.01.094
Abstract:
It’s important for development of PET detector that the interaction effect of γrays and scintillator units are studied. The detection efficiencies and energy resolutions of γrays for BGO, CsI and NaI crystal detector units are measured. Geant4 Monte Carlo simulations are compared with the experimental results. The results of the best detection units for PET detector are presented.
It’s important for development of PET detector that the interaction effect of γrays and scintillator units are studied. The detection efficiencies and energy resolutions of γrays for BGO, CsI and NaI crystal detector units are measured. Geant4 Monte Carlo simulations are compared with the experimental results. The results of the best detection units for PET detector are presented.
2005, 22(1): 97-99.
doi: 10.11804/NuclPhysRev.22.01.097
Abstract:
A thin plastic scintillator film detector with an inner ellipsoidal reflection mirror made of aluminum is introduced. Detection efficiency and light collection efficiency of the detector have been investigated. The time resolution of the detector has been also studied. The testing results show that the detection efficiency of BC498 with the thickness of 1 micron to be used in the coming superheavy synthesis experiments is approximately 100%, and the time resolution is better than 200 ps (σ). The performances of the thin plastic scintillator film detector meet the requirements for the time measurement of the superheavy element synthesis.
A thin plastic scintillator film detector with an inner ellipsoidal reflection mirror made of aluminum is introduced. Detection efficiency and light collection efficiency of the detector have been investigated. The time resolution of the detector has been also studied. The testing results show that the detection efficiency of BC498 with the thickness of 1 micron to be used in the coming superheavy synthesis experiments is approximately 100%, and the time resolution is better than 200 ps (σ). The performances of the thin plastic scintillator film detector meet the requirements for the time measurement of the superheavy element synthesis.
2005, 22(1): 100-102.
doi: 10.11804/NuclPhysRev.22.01.100
Abstract:
Neutron solid bubble detector was considered as a unique one for meeting the need of the personal neutron dosimeter recommended by International Committee of radiation protection,ICRP60.It has the flat response for neutron from low energy to high energy,and insensitive for gamma rays. In this work,superheated liquid drops were dispersed into a kind of soft polymer homogeneously.A personal neutron bubble dosimeter has been made,and the sensitivity reached to about 40bubbles/mrem.The principle and the processing procedure of bubble detector were also introduced in this paper.
Neutron solid bubble detector was considered as a unique one for meeting the need of the personal neutron dosimeter recommended by International Committee of radiation protection,ICRP60.It has the flat response for neutron from low energy to high energy,and insensitive for gamma rays. In this work,superheated liquid drops were dispersed into a kind of soft polymer homogeneously.A personal neutron bubble dosimeter has been made,and the sensitivity reached to about 40bubbles/mrem.The principle and the processing procedure of bubble detector were also introduced in this paper.
2005, 22(1): 103-105.
doi: 10.11804/NuclPhysRev.22.01.103
Abstract:
Neutroninduced promptγ activation analysis(PGNAA),is one of the nuclear analytical method,which is a powerful tool for H,B,etc.undestructive determination.The applications of PGNAA are increased in recent years.In this paper,the basic principle of PGNAA was introduced briefly.The facilities of PGNAA in HWRR of China Institute of Atomic Energy as well as the efficiency calibration for a wide range gamma from 50 keV to 10 MeV were emphasized.A deep sea polymetallic nodule CRM,GSPN3 was analyzed by using PGNAA in this work,the results have agreement with the certified values.
Neutroninduced promptγ activation analysis(PGNAA),is one of the nuclear analytical method,which is a powerful tool for H,B,etc.undestructive determination.The applications of PGNAA are increased in recent years.In this paper,the basic principle of PGNAA was introduced briefly.The facilities of PGNAA in HWRR of China Institute of Atomic Energy as well as the efficiency calibration for a wide range gamma from 50 keV to 10 MeV were emphasized.A deep sea polymetallic nodule CRM,GSPN3 was analyzed by using PGNAA in this work,the results have agreement with the certified values.
2005, 22(1): 106-109.
doi: 10.11804/NuclPhysRev.22.01.106
Abstract:
Monte Carlo simulation with the energetics described by the embedded atom method has been employed to calculate dependence of the grain boundary cohesion on the Zr bulk atom concentration, for the Ni3Alx % Zr (100%Ni\\100%Ni)\[001\]/Σ5(210)/36.87° symmetric tilt grain boundary, at the equilibrium. Calculations show that when x (the Zr bulk atom concentration) increases from 0.1 to 0.5, the Zr enrichment increases, both the Ni enrichment and the Al depletion maximizes at x=0.3. The calculations also show the best cohesion of the grain boundary at x=0.3.
Monte Carlo simulation with the energetics described by the embedded atom method has been employed to calculate dependence of the grain boundary cohesion on the Zr bulk atom concentration, for the Ni3Alx % Zr (100%Ni\\100%Ni)\[001\]/Σ5(210)/36.87° symmetric tilt grain boundary, at the equilibrium. Calculations show that when x (the Zr bulk atom concentration) increases from 0.1 to 0.5, the Zr enrichment increases, both the Ni enrichment and the Al depletion maximizes at x=0.3. The calculations also show the best cohesion of the grain boundary at x=0.3.
2005, 22(1): 110-114.
doi: 10.11804/NuclPhysRev.22.01.110
Abstract:
Dependence of radiation damage in the modified 316L stainless steel has been investigated on irradiation temperature from room temperature to 802 ℃ at 21 and 33 dpa and on irradiation dose up to 100 displacemets/atom(dpa) at room temperature by the heavy ion irradiation simulation and positron annihilation lifetime techniques. A radiation swelling peak was observed at ~580 ℃ where the vacancy cluster contains 14 and 19 vacancies and has an average diameter of 0.68 and 0.82 nm, respectively for the 21 and 33 dpa irradiations. The size of the vacancy clusters increases with the increasing of irradiation dose, and the vacancy cluster produced at 100 dpa consists of 8 vacancies and reaches a size of 0.55 nm in diameter. The experimental results show that the radiation damage in this modified 316L stainless steel is more sensitive to irradiation temperature.
Dependence of radiation damage in the modified 316L stainless steel has been investigated on irradiation temperature from room temperature to 802 ℃ at 21 and 33 dpa and on irradiation dose up to 100 displacemets/atom(dpa) at room temperature by the heavy ion irradiation simulation and positron annihilation lifetime techniques. A radiation swelling peak was observed at ~580 ℃ where the vacancy cluster contains 14 and 19 vacancies and has an average diameter of 0.68 and 0.82 nm, respectively for the 21 and 33 dpa irradiations. The size of the vacancy clusters increases with the increasing of irradiation dose, and the vacancy cluster produced at 100 dpa consists of 8 vacancies and reaches a size of 0.55 nm in diameter. The experimental results show that the radiation damage in this modified 316L stainless steel is more sensitive to irradiation temperature.
2005, 22(1): 115-117.
doi: 10.11804/NuclPhysRev.22.01.115
Abstract:
The metal hydride PdAgHx with a hydrogen concentration x ranging from 0 to 0.35 has been investigated by positron annihilation lifetime method in the temperature region between 77 K and 295 K. The measured lifetime spectra in metal hydride PdAgHx are characterized by two lifetimes τ1 and τ2. The short lifetime τ1 is independent of both hydrogen concentration and temperature, which is ascribed to the annihilation lifetime of free positrons. The long lifetime τ2 and its intensity I2 do not change with temperature, while τ2 increases and I2 decreases with increasing of hydrogen concentration. τ2 is attributed to the lifetime of positrons trapped at the hydrogen bubble. The increase of τ2 indicates the growth of the hydrogen bubble, and the decrease of I2 shows the reduction of the hydrogen bubble concentration. The experimental result shows a microscopic mechanism that the hydrogen bubble produced causes hydrogen embrittlement.
The metal hydride PdAgHx with a hydrogen concentration x ranging from 0 to 0.35 has been investigated by positron annihilation lifetime method in the temperature region between 77 K and 295 K. The measured lifetime spectra in metal hydride PdAgHx are characterized by two lifetimes τ1 and τ2. The short lifetime τ1 is independent of both hydrogen concentration and temperature, which is ascribed to the annihilation lifetime of free positrons. The long lifetime τ2 and its intensity I2 do not change with temperature, while τ2 increases and I2 decreases with increasing of hydrogen concentration. τ2 is attributed to the lifetime of positrons trapped at the hydrogen bubble. The increase of τ2 indicates the growth of the hydrogen bubble, and the decrease of I2 shows the reduction of the hydrogen bubble concentration. The experimental result shows a microscopic mechanism that the hydrogen bubble produced causes hydrogen embrittlement.
2005, 22(1): 118-121.
doi: 10.11804/NuclPhysRev.22.01.118
Abstract:
High power density electron beams generated by multiplate pseudospark discharge chamber, have been used to bombard various kinds of steel targets such as 45#, 65Mn, T8, 9Cr18, GCr15, etc, and studyits applications for modification of metal surface. The microhardness and corrosive resistance property have been measured and the morphology was obtained by using SEM analysis. The results showed that the surface properties and structure of the matevials bom barded have been modified; in the bombarded center area, the microhardness as well as corrosive resistance property was improved obviously. The interactions befween the electron beam and metal materials were theoretically considered and discussed on the basis of simple calculation with one dimensional thermal transfer equation. It showed that the cooling rate of metal surface with 1.2×1012 ℃/s was so high that caused the metal surface instant melted, and abrupt cooled.
High power density electron beams generated by multiplate pseudospark discharge chamber, have been used to bombard various kinds of steel targets such as 45#, 65Mn, T8, 9Cr18, GCr15, etc, and studyits applications for modification of metal surface. The microhardness and corrosive resistance property have been measured and the morphology was obtained by using SEM analysis. The results showed that the surface properties and structure of the matevials bom barded have been modified; in the bombarded center area, the microhardness as well as corrosive resistance property was improved obviously. The interactions befween the electron beam and metal materials were theoretically considered and discussed on the basis of simple calculation with one dimensional thermal transfer equation. It showed that the cooling rate of metal surface with 1.2×1012 ℃/s was so high that caused the metal surface instant melted, and abrupt cooled.
2005, 22(1): 122-124.
doi: 10.11804/NuclPhysRev.22.01.122
Abstract:
Status of the study on the measurement of grease stain thickness in petroleum pipeline by gamma and neutron rays is reported. The basic theory , test experiment system and main results for the γray transmission method are discussed. The study shows the possibility to design a γray transmission device in technique. In addition, the preliminary experiment results for the γray surface scattering method and neutron surface scattering method in the measurement of grease stain thickness in petroleum pipeline are also presented.
Status of the study on the measurement of grease stain thickness in petroleum pipeline by gamma and neutron rays is reported. The basic theory , test experiment system and main results for the γray transmission method are discussed. The study shows the possibility to design a γray transmission device in technique. In addition, the preliminary experiment results for the γray surface scattering method and neutron surface scattering method in the measurement of grease stain thickness in petroleum pipeline are also presented.
2005, 22(1): 125-126.
doi: 10.11804/NuclPhysRev.22.01.125
Abstract:
The photon fluences for 60 CT container inspection system are calculated by using Monet Carlo method. The paper provides that these results of calculation for 60 photon fluences can give a correction method to increase CT image resolution.
The photon fluences for 60 CT container inspection system are calculated by using Monet Carlo method. The paper provides that these results of calculation for 60 photon fluences can give a correction method to increase CT image resolution.
2005, 22(1): 127-130.
doi: 10.11804/NuclPhysRev.22.01.127
Abstract:
Based on the concept of relative detection efficiency, some experiments have been conducted to measure the isotopic abundance and the age of the plutonium material in a sealed container by a high-resolution γ-ray spectrometer. The PC/FRAM software analyzes the spectra. The study shows that the analysis precision of the isotopic abundance and the age will rise as the spectral measurement precision increases, and that If the spectral measurement precision is not enough, the analyzed results by the PC/FRAM software might be lower. Hence, the study suggests that a spectral peak is monitored to show lights on the spectral measurement precision during the process of spectrum acquirement.
Based on the concept of relative detection efficiency, some experiments have been conducted to measure the isotopic abundance and the age of the plutonium material in a sealed container by a high-resolution γ-ray spectrometer. The PC/FRAM software analyzes the spectra. The study shows that the analysis precision of the isotopic abundance and the age will rise as the spectral measurement precision increases, and that If the spectral measurement precision is not enough, the analyzed results by the PC/FRAM software might be lower. Hence, the study suggests that a spectral peak is monitored to show lights on the spectral measurement precision during the process of spectrum acquirement.
2005, 22(1): 131-134.
doi: 10.11804/NuclPhysRev.22.01.131
Abstract:
Ancient ceramic is fired with porcelain clay.It contains various provenance information and age characteristic.That is the scientific foundation to analyze and research the ancient ceramic with modern analysis methods.According to the property of nuclear analysis technique,the function and application of it is discussed.
Ancient ceramic is fired with porcelain clay.It contains various provenance information and age characteristic.That is the scientific foundation to analyze and research the ancient ceramic with modern analysis methods.According to the property of nuclear analysis technique,the function and application of it is discussed.
2005, 22(1): 135-137.
doi: 10.11804/NuclPhysRev.22.01.135
Abstract:
The major, minor and trace elements in the bodies of ancient colored glazes which came from the site of Xiyue Temple and Lidipo kiln in Shangxi province, and were unearthed from the stratums of Song, Yuan, Ming, Early Qing and Late Qing dynasty were analyzed by instrumental neutron activation analysis (INAA). The results of multivariable statistical analyses show that the chemical compositions of the colored glaze bodies are steady from Song to Early Qing dynasty, but distinctly difference with that in Late Qing. Probably, the sources of fired material of ancient colored glaze from Song to Early Qing came from the site of Xiyue Temple. The chemical compositions of three pieces of colored glazes in Ming dynasty and that of Late Qing are similar to that of Lidipo kiln. From this, we could conclude that the sources of the materials of ancient coloured glazes of Xiyue Temple in Late Qing dynasty have been fired in Lidipo kiln.
The major, minor and trace elements in the bodies of ancient colored glazes which came from the site of Xiyue Temple and Lidipo kiln in Shangxi province, and were unearthed from the stratums of Song, Yuan, Ming, Early Qing and Late Qing dynasty were analyzed by instrumental neutron activation analysis (INAA). The results of multivariable statistical analyses show that the chemical compositions of the colored glaze bodies are steady from Song to Early Qing dynasty, but distinctly difference with that in Late Qing. Probably, the sources of fired material of ancient colored glaze from Song to Early Qing came from the site of Xiyue Temple. The chemical compositions of three pieces of colored glazes in Ming dynasty and that of Late Qing are similar to that of Lidipo kiln. From this, we could conclude that the sources of the materials of ancient coloured glazes of Xiyue Temple in Late Qing dynasty have been fired in Lidipo kiln.
2005, 22(1): 138-141.
doi: 10.11804/NuclPhysRev.22.01.138
Abstract:
Provenance characteristic is an important scientific parameter to identify ancient porcelain wares unearthed from sites and graves.The porcelain samples of SiLongKou kiln of Zhejiang Province,HongZhou kiln of Jiangxi Province and Yao Zhou kiln of Shanxi Province have been analyzed with neutron activation analysis(NAA) in this paper.The experimental data were studied with statistic methods.The results show that the chemical compositions of porcelain body samples for three kilns were different. The difference was been able identified. The body materials of both SiLongKou Yue kiln and HongZhou kiln of Jiangxi were similar. The samples of YaoZhou kiln in north of China existed obvious difference.
Provenance characteristic is an important scientific parameter to identify ancient porcelain wares unearthed from sites and graves.The porcelain samples of SiLongKou kiln of Zhejiang Province,HongZhou kiln of Jiangxi Province and Yao Zhou kiln of Shanxi Province have been analyzed with neutron activation analysis(NAA) in this paper.The experimental data were studied with statistic methods.The results show that the chemical compositions of porcelain body samples for three kilns were different. The difference was been able identified. The body materials of both SiLongKou Yue kiln and HongZhou kiln of Jiangxi were similar. The samples of YaoZhou kiln in north of China existed obvious difference.
2005, 22(1): 142-144.
doi: 10.11804/NuclPhysRev.22.01.142
Abstract:
400 sherds were collected from Hongzhou Kiln covering 8 periods from Eastern Han to Late Tang Dynasty/the Five Dynastied and their bodies were analysed by NAA. The results show that the elemental contents in different samples are quite distinct， even for those in the same period. It means no single element can be used as “fingerprint” to distinguish the period. The curves of the contents of Na， Rb， Ba and Fe varying with time are very similar， like “U” shape. As a colorant element， the content of Fe is consistent with the color of the body. The higher content of Fe， the more dark of the body. The outcome of principal component analysis (PCA) indicate that most of the sherds can be classified into 5 groups: (1) Eastern Han & Eastern Wu; (2) Western Jin， Eastern Jin and Southern Dynasties; (3) Sui; (4) Early Tang and Middle Tang; (5) Late Tang & Five Dynasties.
400 sherds were collected from Hongzhou Kiln covering 8 periods from Eastern Han to Late Tang Dynasty/the Five Dynastied and their bodies were analysed by NAA. The results show that the elemental contents in different samples are quite distinct， even for those in the same period. It means no single element can be used as “fingerprint” to distinguish the period. The curves of the contents of Na， Rb， Ba and Fe varying with time are very similar， like “U” shape. As a colorant element， the content of Fe is consistent with the color of the body. The higher content of Fe， the more dark of the body. The outcome of principal component analysis (PCA) indicate that most of the sherds can be classified into 5 groups: (1) Eastern Han & Eastern Wu; (2) Western Jin， Eastern Jin and Southern Dynasties; (3) Sui; (4) Early Tang and Middle Tang; (5) Late Tang & Five Dynasties.
2005, 22(1): 145-147.
doi: 10.11804/NuclPhysRev.22.01.145
Abstract:
Polyester and polycarbonate membranes with different thickness werebombarded by the heavy particle， 32S， induced from the tandem accelerator of China Institute of Atomic Energy. Then the bombarded membranes were etched at different conditions， such as etching time， concentration of sodium hydroxide solution and temperature. The effect of etching for the porous shape， diameter size and membrane surface losing were also investigated at present work. The insulating capability of antimetallic contamination of treated membranes were evaluated by using silver coatings. The results indicated the insulating capability of antimetallic contamination is greatly improved.
Polyester and polycarbonate membranes with different thickness werebombarded by the heavy particle， 32S， induced from the tandem accelerator of China Institute of Atomic Energy. Then the bombarded membranes were etched at different conditions， such as etching time， concentration of sodium hydroxide solution and temperature. The effect of etching for the porous shape， diameter size and membrane surface losing were also investigated at present work. The insulating capability of antimetallic contamination of treated membranes were evaluated by using silver coatings. The results indicated the insulating capability of antimetallic contamination is greatly improved.
2005, 22(1): 148-152.
doi: 10.11804/NuclPhysRev.22.01.148
Abstract:
Helium trapping in the Ti films deposited by DC magnetron sputtering with a He/Ar mixture was studied. He atoms with a surprisingly high concentration (He/Ti atomic ratio is as high as 56%)incorporate evenly in deposited film. The trapped amount of He can be controlled by the helium partial amount. The introduction of the helium with no extra damage(or very low damage) can be realized by choosing suitable deposition conditions. It was also found that because of the formation of nanophase Ti film a relative high He flux for bubble formation is needed and the amount of the retain He in sputtering Ti films is much higher than that in the coarsegrain Ti films. The nanophase Ti film can accommodate larger concentration of trapped sites to He, which results in a high density and small size of the He bubbles. With the increasing He irradiation flux, the grain size of Ti film decreases and the lattice spacing and width of the X ray diffraction peak increase due to the He introduction, and the film tends to amorphous phase.
Helium trapping in the Ti films deposited by DC magnetron sputtering with a He/Ar mixture was studied. He atoms with a surprisingly high concentration (He/Ti atomic ratio is as high as 56%)incorporate evenly in deposited film. The trapped amount of He can be controlled by the helium partial amount. The introduction of the helium with no extra damage(or very low damage) can be realized by choosing suitable deposition conditions. It was also found that because of the formation of nanophase Ti film a relative high He flux for bubble formation is needed and the amount of the retain He in sputtering Ti films is much higher than that in the coarsegrain Ti films. The nanophase Ti film can accommodate larger concentration of trapped sites to He, which results in a high density and small size of the He bubbles. With the increasing He irradiation flux, the grain size of Ti film decreases and the lattice spacing and width of the X ray diffraction peak increase due to the He introduction, and the film tends to amorphous phase.
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