Bremsstrahlung Cross Section of 60-Mev Electrons in Lead

Abstract

Sixty-Mev electrons from a pulsed betatron passed through lead foils of thicknesses 0.001, 0.005, and 0.015 inch placed in a magnetic cloud chamber. Measurements of approximately 1100 large energy losses gave the differential bremsstrahlung cross section as a function of x-ray energy for the high energy portion of the x-ray spectrum. Corrections were applied for instrumental discrimination and for multiple radiation and ionization energy losses in the foils. While the shape of the top 30 percent of the x-ray spectrum agreed with the theory within experimental uncertainty, the magnitude of the cross section was about 7 percent lower than theory.