Additivity Rule for Electron--Molecule Total Cross Section Calculations at 50--5000eV: A Geometrical Approach
SHI De-Heng1, SUN Jin-Feng1, MA Heng1, ZHU Zun-Lue1, YANG Xiang-Dong2
1College of Physics and Information Engineering, Henan Normal University, Xinxiang 4530072Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065
Additivity Rule for Electron--Molecule Total Cross Section Calculations at 50--5000eV: A Geometrical Approach
SHI De-Heng1;SUN Jin-Feng1;MA Heng1; ZHU Zun-Lue1;YANG Xiang-Dong2
1College of Physics and Information Engineering, Henan Normal University, Xinxiang 4530072Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065
摘要To quantify the changes of the geometric shielding effect in a molecule as the incident electron energy varies, we present an empirical fraction, which represents the total cross section (TCS) contributions of shielded atoms in a molecule at different energies. Using this empirical fraction, a new formulation of the additivity rule is proposed. Using this new additivity rule, the TCSs for electron scattering by CO2, C2H2, C6H12 (cyclo-hexane) and C8H16 (cyclo-octane) are calculated in the range 50--5000eV. Here the atomic cross sections are derived from the experimental TCS results of simple molecules (H2, O2, CO). The quantitative TCSs are compared with those obtained by experiments and other theories, and good agreement is attained over a wide energy range.
Abstract：To quantify the changes of the geometric shielding effect in a molecule as the incident electron energy varies, we present an empirical fraction, which represents the total cross section (TCS) contributions of shielded atoms in a molecule at different energies. Using this empirical fraction, a new formulation of the additivity rule is proposed. Using this new additivity rule, the TCSs for electron scattering by CO2, C2H2, C6H12 (cyclo-hexane) and C8H16 (cyclo-octane) are calculated in the range 50--5000eV. Here the atomic cross sections are derived from the experimental TCS results of simple molecules (H2, O2, CO). The quantitative TCSs are compared with those obtained by experiments and other theories, and good agreement is attained over a wide energy range.
SHI De-Heng;SUN Jin-Feng;MA Heng; ZHU Zun-Lue;YANG Xiang-Dong. Additivity Rule for Electron--Molecule Total Cross Section Calculations at 50--5000eV: A Geometrical Approach[J]. 中国物理快报, 2007, 24(10): 2819-2822.
SHI De-Heng, SUN Jin-Feng, MA Heng, ZHU Zun-Lue, YANG Xiang-Dong. Additivity Rule for Electron--Molecule Total Cross Section Calculations at 50--5000eV: A Geometrical Approach. Chin. Phys. Lett., 2007, 24(10): 2819-2822.
[1] Raj D 1991 Phys. Lett. A 160 571 [2] Liu Y F, Shi D H, Sun J F, Zhu Z L and Yang X D 2005 Commun. Theor. Phys. 43 309 [3] Shi D H, Zhu Z L, Sun J F, Yang X D, Liu Y F and Zhao Y 2004 Chin. Phys. Lett. 21 474 [4] Bobeldijk M, van der Zande W J and Kistemaker P G 1994 Chem. Phys. 179 125 [5] Deutsch H, Becker K and Mark T D 1997 Int. J. Mass Spectrom. Ion Processes 167/168 503 [6] Joshipura K N and Patel P M 1996 J. Phys. B 29 3925 [7] Zecca A, Melissa R, Brusa R S and Karwasz G P 1999 Phys.Lett. A 257 75 [8] Antony B K, Joshipura K N and Mason N J 2005 J. Phys. B 38 189 [9] Jiang Y H, Sun J F, Wan L D 2000 Phys. Rev. A 62 062712 [10] Lide D R 1994 CRC Handbook of Chemistry and Physics, 74th edn(Boca Raton, FL: Chemical Rubber Company) [11] Karwasz G P, Brusa S A, Gasparoli A and Zecca A 1993 Chem. Phys. Lett. 211 529 [12] Zecca A, Karwasz G P and Brusa S A 1996 Rivista delNuovo Cimento 19 1 [13] Zecca A, Karwasz G P and Brusa S A 1996 28th European Group Atomic Spectr. Conf. (Graz, Austria, Europhys.Conf. Abstracts) D 20 302 [14] Szmytkowski C, Zecca A, Karwasz G, Oss S, Maciag K,Marinkovic B, Brusa R S and Grisenti R 1987 J. Phys. B 20 5817 [15] Kwan Ch K, Hsieh Y -F, Kauppila W E, Smith S J, Stein T S andUddin M N 1983 Phys. Rev. A 27 1328 [16] Xing S L, Yu C Q, Shi Q C, Zhang F, Yao L Q, Ma T Q and Xu K Z1997 J. At. Mol. Phys. 14 294 [17] Garc\'{\ia G and Manero F 1996 Phys. Rev. A 53 250 [18] Jain A and Baluja K L 1992 Phys. Rev. A 45 202 [19] Blanco F and Garc\'{\ia G 2003 Phys. Lett. A 317 458 [20] Garc\'{\ia G and Manero F 1997 Chem. Phys. Lett. 280 419 [21] Jiang Y H, Sun J F and Wan L D 1997 Phys. Lett. A 237 53 [22] Joshipura N and Patel P M 1994 Z. Phys. D 29 269 [23] Ariyasinghe W M and Powers D 2002 Phys. Rev. A 66052716 [24] Xing S L, Shi Q C, Chen X J, Xu K Z, Yang B X, Wu S L andFeng R F 1995 Phys. Rev. A 51 414 [25] Sueoka O and Mori S 1989 J. Phys. B 22 963 [26] Vinodkumar M, Joshipura K N, Limbachiya C G and Antony B K 2006 Eur. Phys. J. D 37 67 [27] Jiang Y H, Sun J F and Wan L D 1997 J. Phys. B 30 5025 [28] Joshipura K N and Vinodkumar M 1999 Eur. Phys. J. D 5 229 [29] Sueoka O, Makochekanwa C, Tanino H and Kimura M 2005 Phys. Rev. A 72 042705 [30] Sueoka O, Makochekanwa C and Kimura M 2006 Eur. Phys.J. D 37 377
2007, Vol. 24 
