deletions | additions       diff --git a/section_Wet_SEM_From_the__.tex b/section_Wet_SEM_From_the__.tex  index 6659649..6fda65f 100644  --- a/section_Wet_SEM_From_the__.tex  +++ b/section_Wet_SEM_From_the__.tex 
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\begin{equation}  R = \frac{K}{\rho}E_{0}^{\gamma}  \end{equation}  where the $K=0.064$ and $\gamma = 1.68$ with $E_0$ being the energy of the primary beam in $KeV$. And $\rho$ is the density of the gas in $g/cm^3$, approximated by the ideal gas relationship. From eq. (17),  the electron range for $1atm$ nitrogen is found to be $20 \sim 300 \mu m$ for energy $E_0 = 5 \sim 30 KeV$. The electron range is less than the working distance; thus, only a very small fraction of the primary electrons will reach and sample. Both the SE (with range $\approx$ several nanometers) and BSE (with range from nanometer to micrometer) cannot reach the detector with working distance $d = 5\sim 10 mm$ away. Without the possibility of operating ESEM in $1atm$, the sample protection should be introduced to avoid evaporation and drying effects.