Higher moments of the energy loss spectrum of swift charged particles penetrating a thin layer of material

摘要: Higher moments n(≥ 3) over the electronic energy loss spectrum of swift charged particles penetrating a thin layer random matter have been evaluated. The calculations based on dielectric as well kinetic theory particle stopping. aim has to determine leading terms in an expansion inverse powers velocity any moment order n ≥ 3. term this is identical with familiar result for free Coulomb scattering target electrons at rest. correction all 5 kinematic relative 〈v22〉v2, v2 being velocit = 3 and 4, corrections turn out be αv−4 may therefore often by ignored. Just straggling (n 2), they split into resonant comparable magnitude. Interference gives rise higher v−2. Our results compared numerical Bichsel who employed hydrogenic wave functions. agreement very good ≤ 6 For 7 ≤n 10, pronounced differences occur low projectile velocities. This difference consistent increasing importance atomic distribution, v22α, α 2, therefore, considerable caution advised toward use functions evaluation shell moments. Remarks concerning validity Blunck-Leisegang theoretically evaluated profiles conclude paper.