%A 张竹林 %T On the differentiability of depth distribution function of deposited energy, momentum and ion range %0 Journal Article %D 2002 %J 中国物理B %R 10.1088/1009-1963/11/4/314 %P 389-392 %V 11 %N 4 %U {https://cpb.iphy.ac.cn/CN/abstract/article_107034.shtml} %8 2002-04-13 %X Based on the translational invariance of a medium, a new theorem has been proposed and proved rigorously: the depth distributions of the deposited energy, momentum and ion range must be infinitely differentiable functions in amorphous or polycrystalline infinite targets by ion bombardment, if these functions exist. The origin of the "discontinuity", derived by Dr Glazov in 1995 in J. Phys.: Condens. Matter 7 6365, has been analysed in detail. For the power cross section, neglecting electronic stopping, the linear transport equations determining the depth distribution functions of the deposited energy and momentum (by taking the threshold energy into account) have been solved asymptotically. An important formula derived by Dr Glazov has been confirmed and generalized. The results agree with the new theorem.