Scintillation spectrometry of continuous γ-ray

A response matrix which converts scintillation pulse height spectra to incident photon spectra is presented here. It is applicable for broad parallel γ-rays up to 1.5 MeV incident to a 2 in. long by 2 in. diameter sodium-iodide crystal. Its energy channel is wide as 0.1 MeV. Reliability of the matrix is estimated by experimental pulse height spectra from a ¹³⁷Cs source. The resultant error in a energy channel is estimated as large as 5 % of number of incident photons which have energies higher than the energy of the channel. A correction to incident γ-rays of uniform angular distribution is also discussed. (author)