diff --git a/doc/user-manual/fpakc_UserManual.pdf b/doc/user-manual/fpakc_UserManual.pdf
index da9471c..0f549be 100644
Binary files a/doc/user-manual/fpakc_UserManual.pdf and b/doc/user-manual/fpakc_UserManual.pdf differ
diff --git a/doc/user-manual/fpakc_UserManual.tex b/doc/user-manual/fpakc_UserManual.tex
index a55c7dd..df29f33 100644
--- a/doc/user-manual/fpakc_UserManual.tex
+++ b/doc/user-manual/fpakc_UserManual.tex
@@ -619,6 +619,8 @@ make
                                   Type of distribution function used to obtain injected particle velocity:
                                   \begin{itemize}
                                     \item \textbf{Maxwellian}: Maxwellian distribution of temperature \textbf{T} and mean \textbf{v} times the value of \textbf{n} in the specified direction.
+                                    \item \textbf{Half-Maxwellian}: Half-Maxwellian distribution of temperature \textbf{T} and mean \textbf{v} times the value of \textbf{n} in the specified direction.
+                                                                    Only takes into account the positive part of the half-Maxwellian.
                                     \item \textbf{Delta}: Dirac's delta distribution function. All particles are injected with velocity \textbf{v} times the value of \textbf{n} in the specified direction.
                                   \end{itemize}
           \item \textbf{T}: Real.