  A laser-induced acoustic desorption source, developed for use at central
facilities, such as free-electron lasers, is presented. It features prolonged
measurement times and a fixed interaction point. A novel sample deposition
method using aerosol spraying provides a uniform sample coverage and hence
stable signal intensity. Utilizing strong-field ionization as a universal
detection scheme, the produced molecular plume is characterized in terms of
number density, spatial extend, fragmentation, temporal distribution,
translational velocity, and translational temperature. The effect of desorption
laser intensity on these plume properties is evaluated. While translational
velocity is invariant for different desorption laser intensities, pointing to a
non-thermal desorption mechanism, the translational temperature increases
significantly and higher fragmentation is observed with increased desorption
laser fluence.
