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研究了正偏离Bragg定律,即计算Se(E)值高于实测Se(E)的二元系化合物靶的离子射程特性。文中应用“regular”观点引入了“双原子模型”,在二元化合物靶的射程计算中,不仅考虑相同“原子对”对离子的阻止本领S11(E),S22(E),而且考虑不同“原子对”对离子的阻止本领S12(E),S21(E)。文中还应用Berthelot关系,使S12(E)=S21(E)=(S11(E)·S22(E))1/2,则二元系靶的阻止本领及总的射程为NS(E)=1/2[(N1S11(E))1/2+(N2S22(E)1/2)]2, R=4/a[x-A1(arctg(2x+f)/△1/2-arctg(f/△1/2))-B1(ln(x+g)2/g2·e/(x2+fx+e)) -b/2 ln(x2+fx+e/e)。这里X=E1/2,E为离子注入能量,所有其它常数是与离子和靶的质量、原子序数有关的常数。结合文献[1]提出的R与Rp,Rp与△Rp的关系式,可计算得正偏离系统的投影射程Rp及其偏差量△Rp。并对各关系式的物理意义作了阐明。In this work, we investigated the ion range parameters for binary compounds having positive deviation from Bragg rule, that is the calculated Se(E) value is higher than experimental Se(E) value, By introducing a "biatomic model" with the idea of "regular", the implanted range in binary compounds was considered not only as the stopping power of ions by two alike cofposed atoms S11(E) and S22(E), but also as the stopping power of ions by two unlike composed atoms S12(E) and S21 (E). Based on Berthelot relation, let S12(E)=S21(E)=(S11(E)·S22(E))1/2, the stopping power and total range in binary compounds were derived as follows: NS(E)=1/2[(N1S11(E))1/2+(N2S22(E)1/2)]2, R=4/a[x-A1(arctg(2x+f)/△1/2-arctg(f/△1/2))-B1(ln(x+g)2/g2·e/(x2+fx+e)) -b/2 ln(x2+fx+e/e) where X=E1/2 ,E is the ion implanted energy, all the others are constants depend upon the mass and the atomic number of the ions and targets. Combined with the relationships between R and Rp, Rp and △Rp in ref. [1], we calculated the Rp and △ Rp values in systems with positive deviation. The significances of formulas given in this paper were discussed.
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