近玻尔速度氙离子激发钒的K壳层X射线
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摘要
测量了2.4—6.0 MeV Xe~(20+)离子轰击V靶表面过程中辐射的X射线.计算了V的K壳层X射线发射截面,并将实验结果与平面波恩近似、ECPSSR、两体碰撞近似的理论计算进行了对比.讨论了近玻尔速度非对称碰撞过程中,BEA模型估算高电荷态重离子激发内壳层电离的修正因素.结果表明,综合考虑库仑偏转和有效电荷态修正后,BEA理论与实验结果符合较好.
The X-ray emission spectra produced by 2.4–6.0 MeV Xe~(20+)ions impacting on vanadium surface were measured.The V K-shell X-ray production cross sections were extracted from the experimental yield data and compared with the theoretical predictions of the binary encounter approximation(BEA), the plane wave born approximation(PWBA), and the energy-loss coulomb-repulsion perturbed-stationary-state relativist(ECPSSR). In order to predict reasonably the inner-shell ionization induced by highly charged heavy ions during the asymmetric collisions at near the Bohr velocity,the corrections of BEA model are discussed. It is found that the X-ray production cross section induced by highly charged heavy ions moving at near the Bohr velocity is on the magnitude of 1 barn, which is almost four orders of magnitude larger than that induced by proton. The ECPSSR, which is regarded as the best model to simulate the inner-shell ionization by light ions, may underestimate the experimental data at least three orders of magnitude. The PWBA model presents a prediction to the results on an order of magnitude better than the ECPSSR simulation, but gives a worse tendency than the BEA model. The BEA calculations, corrected both by Coulomb repulsion and effective nuclear charge, present the best agreement with the experimental results. It is proposed, that in the energy region near the Bohr velocity, during the asymmetric collisions of Xe~(20+)ions with V atoms, the K-shell electron of V is ionized by direct ionization, and that it can be described by the binary encounter process between the xenon ions and the bound electrons. The X-ray production cross section can be simulated by BEA model, but the corrections of Coulomb repulsion and effective nuclear charge must be considered.
The X-ray emission spectra produced by 2.4–6.0 MeV Xe~(20+)ions impacting on vanadium surface were measured.The V K-shell X-ray production cross sections were extracted from the experimental yield data and compared with the theoretical predictions of the binary encounter approximation(BEA), the plane wave born approximation(PWBA), and the energy-loss coulomb-repulsion perturbed-stationary-state relativist(ECPSSR). In order to predict reasonably the inner-shell ionization induced by highly charged heavy ions during the asymmetric collisions at near the Bohr velocity,the corrections of BEA model are discussed. It is found that the X-ray production cross section induced by highly charged heavy ions moving at near the Bohr velocity is on the magnitude of 1 barn, which is almost four orders of magnitude larger than that induced by proton. The ECPSSR, which is regarded as the best model to simulate the inner-shell ionization by light ions, may underestimate the experimental data at least three orders of magnitude. The PWBA model presents a prediction to the results on an order of magnitude better than the ECPSSR simulation, but gives a worse tendency than the BEA model. The BEA calculations, corrected both by Coulomb repulsion and effective nuclear charge, present the best agreement with the experimental results. It is proposed, that in the energy region near the Bohr velocity, during the asymmetric collisions of Xe~(20+)ions with V atoms, the K-shell electron of V is ionized by direct ionization, and that it can be described by the binary encounter process between the xenon ions and the bound electrons. The X-ray production cross section can be simulated by BEA model, but the corrections of Coulomb repulsion and effective nuclear charge must be considered.
引文
[1]Mei C X,Zhang X A,Zhao Y T,Zhou X M,Ren J R,Wang X,Lei Y,Sun Y B,Cheng R,Wang Y Y,Liang C H,Li Y Z,Xiao G Q 2013 Chin.Phys.B 22 103403
[2]Ghanbari-Adivi E,Eskandari S 2015 Chin.Phys.B 24013401
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[4]Liang C H,Zhang X A,Li Y Z,Zhao Y T,Mei C X,Zhou X M,Xiao G Q 2015 Acta Phys.Sin.64 053201(in Chinese)[梁昌慧,张小安,李耀宗,赵永涛,梅策香,周贤明,肖国青2015物理学报64 053201]
[5]Li Y Z,Zhang X A,Liang C H,Zhao Y T,Zhou X M2014 Acta Phys.Sin.63 163202(in Chinese)[李耀宗,张小安,梁昌慧,赵永涛,周贤明2014物理学报63 163202]
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[24]Slater J C 1930 Phys.Rev.36 57
[2]Ghanbari-Adivi E,Eskandari S 2015 Chin.Phys.B 24013401
[3]Zhou X M,Cheng R,Lei Y,Sun Y B,Ren J R,Liu S D,Deng J C,Zhao Y T,Xiao G Q 2015 Nucl.Instr.Meth.B 342 133
[4]Liang C H,Zhang X A,Li Y Z,Zhao Y T,Mei C X,Zhou X M,Xiao G Q 2015 Acta Phys.Sin.64 053201(in Chinese)[梁昌慧,张小安,李耀宗,赵永涛,梅策香,周贤明,肖国青2015物理学报64 053201]
[5]Li Y Z,Zhang X A,Liang C H,Zhao Y T,Zhou X M2014 Acta Phys.Sin.63 163202(in Chinese)[李耀宗,张小安,梁昌慧,赵永涛,周贤明2014物理学报63 163202]
[6]Briand J P,Billy L de,Charles P,Essabaa S 1990 Phys.Rev.Lett.65 159
[7]Briand J P,de Billy L,Charles P,Essabaa S 1991 Phys.Rev.A 43 565
[8]Briand J P,Thuriez S,Giardino G,Borsoni G,Froment M,Eddrief M,Sébenne C 1996 Phys.Rev.Lett.77 1452
[9]Burgd?rfer J,Lerner P,Meyer F W 1991 Phys.Rev.A44 5674
[10]Garcia J D,Fortner R J,Kavanagh T M 1973 Rev.Mod.Phys.45 111
[11]Johnson D E,Basbas G,Mc Daniel F D 1979 At.Data Nucl.Data Tables 24 1
[12]Brandt W,Lapicki G 1974 Phys.Rev.A 10 474
[13]Halpern A M,Law J 1973 Phys.Rev.Lett.31 4
[14]Kavanagh T M,Der R C,Forter R J,Cunningham M E1973 Phys.Rev.A 8 2322
[15]Zhou X M,Zhao Y T,Cheng R,Wang Y Y,Lei Y,Wang X,Sun Y B 2013 Nucl.Instr.Meth.B 299 61
[16]Basbas G,Brandt W,Laubert R 1973 Rhys.Rev.A 7983
[17]Dabich E,Paul H,Marwick D J,Cuomo G A,Poeter W A http://www.srim.org/SRIM/SRIMLEGL[2015-07-26]
[18]Pajek M,Kobzev A P,Sandrik R,Iikhamov R A,Kusmurodov S H 1989 Nucl.Instr.Meth.B 42 346
[19]Cipolla S J,Verzani C J 1995 Nucl.Instr.Meth.B 9918
[20]Meyerhof W E,Anholt R,Saylor T K,Lazarus S M,Little A 1976 Phys.Rev.A 14 1653
[21]Tawara H,Richard P,Gray T J,Newcomb J,Jamison K A,Schmiedekamp C,Hall J M 1978 Phys.Rev.A 181373
[22]Krause M O 1979 J.Phys.Chem.Ref.8 307
[23]Magon C,Milazzo M,Pizzi C,Porro F,Rota A,Riccobono G 1979 Nuovo Cimento A 54 277
[24]Slater J C 1930 Phys.Rev.36 57