Alfredo A. Correa edited The_recent_measurement_by_cite__.tex  over 8 years ago

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The recent measurement measurements  by \cite{Cantero_2009} and by \cite{Markin_2009}  of slow ($0.1 \leq v \leq 0.6~\mathrm{a.u.}$) $\mathrm{H^+}$ in $\mathrm{Cu}$ reveals $\mathrm{Cu}$, although disagreeing in absolute scale by 50\%, reveal  the stopping due to conduction band electronic excitation at lower velocity. velocity, evidenced as a change in slope.  The combined effects of both the free electrons and the loosely bound $\mathrm{d}$ electrons causes a change of the slope \cite{Goebl_2013}.   This study supports this even down to $v = 0.02 ~\mathrm{a.u.}$ (see Figure \ref{fig:log_stopping_power}).   The %The  experimental results of Nomura and Kiyota \cite{Nomura_1975} on $\mathrm{H^+ + Cu}$ film show the dependence of $S_\text{e}$ on incident velocity agrees with the calculation of Lindhard \emph{et al.} \cite{Lindhard_Scharff_Schiott}. In the low energy region the energy loss in metal is due to the excitation of a portion of electrons around the Fermi level to empty states in the conducting band. But at higher energies, a minimum momentum transfer of the projectile is possible due to its short duration close to the target.   In this region the electronic curve has a maximum due to the limited response time of target electrons to the projectile ions.  In this paper we concentrate in the intermediate regime.