Apparatus is described for the production of argon atom beams of energies of 500 ev to 3500 ev and for the measurement of the elastic scattering of these beams in argon gas at rest. Differential scattering cross sections are found and from them an interaction potential over a range of 0.6 to 1.2A is determined. This is compared to the exponential repulsive term of the potential suggested by Buckingham for argon. The agreement is within the experimental error.

• Received 29 November 1948

DOI:https://doi.org/10.1103/PhysRev.75.913