Characterization of Solidified Gas Thin Film Targets via Alpha Particle   Energy Loss
  A method is reported for measuring the thickness and uniformity of thin films of solidified gas targets. The energy of alpha particles traversing the film is measured and the energy loss is converted to thickness using the stopping power. The uniformity is determined by measuring the thickness at different positions with an array of sources. Monte Carlo simulations have been performed to study the film deposition mechanism. Thickness calibrations for a TRIUMF solid hydrogen target system are presented. 
MUH collaboration at TRIUMF: M. C. Fujiwara (1), G. A. Beer (2), J. L.   Beveridge (3), J. L. Douglas (2), T. M. Huber (4), ...