  A kinetic model for the shock acceleration of ions in laser-produced plasmas
is developed. A fraction of the warm ions are accelerated by the large
amplitude monotonic potential of the double layer created due the plasma
compression and electron heating by the laser. It is found that the amplitude
of the large amplitude double layer is almost uniquely defined by the electron
temperature. Therefore, a balance between electron heating and plasma
compression is needed for optimal ion acceleration by this scheme. Typical Mach
numbers of the monotonic shocks are close to 1.5. The scheme could potentially
produce monoenergetic ions with a relative energy spread of less than 1
percent. The model is compared with recent simulations and experiments, where
efficient shocks acceleration and production of monoenergetic protons have been
observed. Similarities and differences with other shock models are pointed out
and discussed.
