Velocity distribution measurements in atomic beams generated using laser   induced back-ablation
  We present measurements of the velocity distribution of calcium atoms in an atomic beam generated using a dual-stage laser back-ablation apparatus. Distributions are measured using a velocity selective Doppler time-of-flight technique. They are Boltzmann-like with rms velocities corresponding to temperatures above the melting point for calcium. Contrary to a recent report in the literature, this method does not generate a sub-thermal atomic beam. 
A. Denning, A. Booth, S. Lee, M. Ammonson, and S. D. Bergeson