Abstract
The yield of photodeuterons has been investigated by using an improved method of grain counting developed by the present author. Grain density distributions of photodeuterons and photoprotons were clearly separated by density ratios 1.25–1.30 being in good accord with the value predicted for deuterons and protons by a former work.
In the case of antimony, ratio of the yield of photodeuterons to that of photoprotons were determined to be as high as 0.13±0.05 measured at the maximum bremsstrahlung energy of 24.0 MeV, which is in agreement with a value reported by Medicus. An energy spectrum of photodeuterons from antimony exhibited a peak in an energy region 8–9 MeV. The ratio for copper at an X-ray energy of 25.5 MeV were 0.06±0.04 and 0.04±0.02 measured at 90° and 126° to the X-ray beam, respectively. These values are the same order of magnitude as a value determined recently by Hamburger using a method of magnetic field and plates, but are inconsistent with values hitherto reported by all the other investigators. For nickel and tin, values of approximately 0.02 for 25.5 MeV X-rays and 0.04 for 24.0 MeV X-rays, respectively, were obtained for the ratio.
