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The emission angle and the transverse momentum distributions of projectile fragments produced in the fragmentation of 56Fe on CHs, C and A1 targets at 471 A MeV are measured. It is found that for the same target, the average value and width of the angular distribution decrease with an increase of the projectile fragment charge; for the same projectile fragment, the average value of the distribution increases and the width of the distribution decreases with increasing the target charge number. The transverse momentum distribution of a projectile fragment can be explained by a single Gaussian distribution and the averaged transverse momentum per nucleon decreases with the increase of the charge of projectile fragment. The cumulated squared transverse momentum distribution of a projectile fragment can be explained well by a single Rayleigh distribution. The temperature parameter of the emission source of the projectile fragment, calculated from the cumulated squared transverse momentum distribution, decreases with the increase of the size of the projectile fragment. 相似文献
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The total charge-changing cross sections and partial cross sections for the production of projectile fragments are measured in the interactions of 400 A MeV 20Ne with aluminum, carbon and polyethylene targets sandwiched with CR-39 plastic nuclear track detectors. The measured total charge-changing cross sections are compared with the predictions using the Bradt-Peters semi-empirical formula, and the NUCFRAG2 and PHITS models. It is shown that the measured experimental results are in good agreement with the theoretical model prediction and other experimental results, and it can be clearly seen that the partial cross sections for fragment production show obvious odd-even effects. 相似文献
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D. Sampsonidis M. Debeauvais J. C. Adloff B. A. Kulakov M. I. Krivopustov V. S. Butsev M. Zamani 《Radiation measurements》1995,25(1-4):231-234
We investigate the charge changing collisions for 16O and 32S beams at 3.65 GeV/n on several targets, by using Solid State Nuclear Track Detectors (SSNTD). Track measurements were performed by an automatic measurement system. We determined the total charge changing cross sections and the elemental cross sections for the production of fragments of charge 9 ≤ Z ≤ 14. Comparison with theoretical models as well as with experimental data are given. 相似文献
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Angular distribution measurement for ~(12)C fragmentation via ~(12)C + ~(12)C scattering at 100 MeV/u
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The angular distributions and energy spectra of~(11)B,~(10)B,and~9Be fragments of~(12)C in the angular range from 1.0°~to 7.5°~at 100 Me V/u were obtained via~(12)C+~(12)C scattering.Detailed comparisons are presented between the experimental data and the modified antisymmetrized molecular dynamics(AMD-FM),binary intranuclear cascade model(BIC)and Liege intranuclear cascade model(INCL++).The experimental angular distributions and energy spectra are well reproduced by the AMD-FM calculations but fail to be reproduced by the physical models installed in the Geant4 program,including the BIC and INCL++models. 相似文献
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The total charge-changing cross sections and the partial cross sections of 56Fe fragmentation on polyethylene, carbon and aluminum targets at the highest energy of 496 A MeV are investigated using CR-39 plastic nuclear track detector. The total charge-changing cross-section for hydrogen target is calculated based on the results of polyethylene and carbon targets. It is found that the total charge-changing cross sections for fragmentation of 56Fe on hydrogen, carbon and aluminum targets are independent on the beam energy in our studied energies, and are consistent with the predictions of Bradt–Peter semi-empirical formula, Nilsen parameterized formula, NUCFRG2 and QMSFRG theoretical simulation codes. The partial cross sections for projectile fragment production are independent on beam energy in our studied energies for each targets and do not show a significant even-odd effect. 相似文献
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用统计擦碎模型计算了140AMeV40,48Ca+9Be和58,64Ni+9Be弹核碎裂反应产物的截面.通过对碎片截面计算结果和实验测量结果的比较发现,采用自由空间的核子-核子反应截面计算时,对非中心反应产物的截面拟合很好,而对中心反应产物的截面有较大高估,而采用饱和密度相关的核子-核子反应截面计算时,对非周边反应产物的截面拟合较好,而对周边反应产物的截面有一定程度的低估.在统计擦碎模型中,对核子-核子反应截面进行细致的介质密度关联,可能会改进计算值与实验值的符合程度. 相似文献
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Zeitlin C Heilbronn L Miller J Rademacher SE Borak T Carter TR Frankel KA Schimmerling W Stronach CE 《Physical review C: Nuclear physics》1997,56(1):388-397
We have obtained charge-changing cross sections and partial cross sections for fragmentation of 1.05 GeV/nucleon Fe projectiles incident on H, C, Al, Cu, and Pb nuclei. The energy region covered by this experiment is critical for an understanding of galactic cosmic ray propagation and space radiation biophysics. Surviving primary beam particles and fragments with charges from 12 to 25 produced within a forward cone of half-angle 61 mrad were detected using a silicon detector telescope to identify their charge and the cross sections were calculated after correction of the measured yields for finite target thickness effects. The cross sections are compared to model calculations and to previous measurements. Cross sections for the production of fragments with even-numbered nuclear charges are seen to be enhanced in almost all cases. 相似文献
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The cross sections for ~(59,60)Ca, recently measured in the 345 A MeV ~(70)Zn+~9 Be reaction,were estimated using the FRACS parametrization and an empirical formula,which are in good agreement.The FRACS parametrization and the empirical formula are combined to predict the cross sections for extreme calcium isotopes ~(66,70)Ca in the~(70,80)Zn+~9 Be reactions at the incident energies of ~(60,80),and 345 A MeV.The dependence of emperical formula parameters on the reaction system,as well as the incident energy,are discussed.The results indicate that ~(66,70)Ca can be discovered in reactions of ~(60,80)A MeV ~(80)Zn+~9 Be.The predicted binding energy for extreme neutron-rich isotopes by the spherical relativistic continuum Hartree-Bogoliubov theory was adopted in the calculation.Hence,the planned Beijing Isotope-Separation-On Line Neutron-Rich Beam Facility(BISOL),which is a third generation radioactive ion beam facility,could provide the opportunity to discover ~(66,70) Ca and neighboring neutron-drip line nuclei. 相似文献
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The differential cross sections of elastic and inelastic scattering of 3He ions on 13C and 14C have been studied at an energy of 37.9 MeV with a double folding model based on M3Y-Reid effective nucleon-nucleon interaction. The resulted parameters have been used for the standard Distorted Wave Born Approximation calculations of angular distributions corresponding to different excitations levels of 13C and 14C and deformation parameters have been deduced. 相似文献
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The double-differential neutron emission cross sections for n+56Fe reactions at incident energies of 7-13 MeV at different angles are calculated by the UNF (abbreviation for unified, 2009 Version) code, which is based on the unified Hauser-Feshbach and exciton model. The results indicate that the higher the incident energies, the better the results, although there are some discrepancies between the calculated results and the measured data for natural iron. These discrepancies are analyzed in detail in this paper. In addition, the calculated results are also compared with the evaluated results of ENDFB Ⅶ.0 and JEFF-3.1.1 near the angle of 90° at incident energies of 8.17 and 11.5 MeV, respectively. 相似文献
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Predictions for cross sections of light proton-rich isotopes in the ~(40)Ca + ~9Be reaction
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The cross sections for Z=10–19 with isotopes T_z=-3/2 to-5 in the 140A Me V~(40)Ca+~9Be projectile fragmentation reaction have been predicted.An empirical formula based on the correlation between the cross section and average binding energy of an isotope has been adopted to predict the cross section.The binding energies in the AME16,WS4,and the theoretical prediction by the spherical relativistic continuum Hartree-Bogoliubov theory have been used.Meanwhile,the fracs parametrization and the modified statistical abrasion-ablation model are also used to predict the cross sections for the proton-rich isotopes.The predicted cross sections for the T_z=-3 isotopes are close to 10~(-10)mb,which hopefully can be studied experimentally.In addition,based on the predicted cross sections,Z=14 is suggested to be a new magic number in the light proton-rich nuclei with T_z-3/2,for which the phenomenon is much more evident than it is from the average binding energy per nucleon. 相似文献
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段芳芳 杨彦云 庞丹阳 胡碧涛 王建松 王康 杨过 Valdir Guimar?es 马朋 许世伟 刘星泉 马军兵 白真 胡强 金树亚 孙欣欣 姚佳盛 齐航凯 孙志宇 《中国物理C(英文版)》2020,(2):72-79
Elastic scattering of 10Be on a 208Pb target was measured at ELab=127 MeV,which corresponds to three times the Coulomb barrier.The secondary 10Be beam was produced at the Radioactive Ion Beam Line in Lanzhou of the Heavy-Ion Research Facility in Lanzhou.The angular distribution of elastic scattering in the 10 Be+208Pb system shows a typical Fresnel diffraction peak.Optical model analysis of the angular distribution was performed using the Woods-Saxon,double-folding and global potentials.With the global potential,different density distributions were used.The results indicate that different density distributions for the projectile induce distinct effects in the angular distribution. 相似文献
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在美国Argonne国家实验室连接有IVEM-Tandem National Facility加速器的Hitatch3000电子显微镜上,通过能量600keV及注量率为2.5×1012cm-2·s-1的Ne离子原位辐照,研究了锆-4合金中沉淀相hcp Zr(Cr,Fe)2的重离子辐照效应,结果表明:600keV的Ne离子在350℃原位辐照至0.2dpa时,hcp-Zr(Cr,Fe)2沉淀相的层错条纹开始消失;0.8dpa时沉淀相的电子衍射斑点大部分消失,发生明显的化学无序;2.7dpa时明场像衬度完全消失,非晶环已非常明显,表明沉淀相已经非晶化。600keV的Ne离子在350℃辐照hcp-Zr(Cr,Fe)2相非晶化的临界损伤离位率约为2.7dpa。 相似文献
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J.K. Tripathi 《Applied Surface Science》2007,253(21):8689-8694
Fe film (∼50 nm) have been deposited on pSi substrate by electron beam evaporation technique. The bilayers have been irradiated by 100 MeV Fe7+ ions having fluences of 1 × 1013, 1 × 1014 and 5 × 1014 ions cm−2. SEM study of the unirradiated devices show surface modifications having a annular structures. From XRD study of the bilayer, it is observed that grain size has reduced from 70 to 25 nm after the irradiation for a fluence of 1 × 1014 ions cm−2. Moreover electronic transport data of the bilayer show practically no effect on the current flow for a fluence of 1 × 1013 ions cm−2 irradiation whereas for 1 × 1014 ions cm−2 fluence, there is very significant change in current flow (by two orders in magnitude) across the bilayer. However, for a higher fluence of irradiation 5 × 1014 ions cm−2, the bilayer becomes highly resistive. It has been found from the above observations that the fluence of 1 × 1014 ions cm−2 of swift heavy ion irradiation is a optimum fluence. 相似文献
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TOGANO Y AOI N BABA H HONDA T OKADA K HARA Y IEKI K ISHIBASHI Y ITOU Y IWASA N KANNO S KAWABATA T KIMURA H KONDO Y KURITA K KUROKAWA M MORIGUCHI T MURAKAMI H OISHI H OTA S OZAWA A SAKURAI H SHIMOURA S SHIODA R TAKESHITA E TAKEUCHI S YAMADA K YAMADA Y YASUDA Y YONEDA K MOTOBAYASHI T 《中国科学:物理学 力学 天文学(英文版)》2011,(Z1)
Two-proton relative momentum distributions from the break-up channels 23Al→p+p+21Na and 22Mg→p+p+20Ne at an energy of 60-70 A MeV have been measured together with two-proton opening angles at the projectile fragment separator beamline (RIPS) in the RIKEN Ring Cyclotron Facility. The results demonstrate the existence of diproton emission component from single-step 2He for highly excited 23Al and 22Mg. 相似文献
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