use subscript in mu_n

Doc/DevRef/Scattering.tex

@@ -259,7 +259,7 @@ the propagation of free neutrons becomes spin dependent.
 Therefore the scalar wavefunction of \cref{SnScalar}
 must be replaced by spinor $\v\Psi$.
 \index{Spinor}%
-The magnetic moment~$\mu_n$ of the neutron
+The magnetic moment~$\mu_\text{n}$ of the neutron
 \nomenclature[1μ024 2n000]{$\mu_\text{n}$}{Magnetic moment of the neutron}
 \index{Neutron!magnetic moment}%
 \index{Magnetic moment!neutron}%
@@ -271,7 +271,7 @@ With the coupling term, the Schrödinger equation~\cref{ESchrodi1}
 becomes
 \begin{equation}\label{EHSchrodi}
   \left\{-\frac{\hbar^2}{2m}\Nabla^2+V(\r)
-         +\mu_n\v{B}(\r)\bm{\hat\sigma}-\hbar\omega\right\}
+         +\mu_\text{n}\v{B}(\r)\bm{\hat\sigma}-\hbar\omega\right\}
       \v\Psi(\r) = 0,
 \end{equation}
 \nomenclature[1ψ150 2r040]{$\v\Psi(\r)$}{Stationary coherent spinor wavefunction}%