Measurement of photon showers in lead produced by electrons of 150 MeV

Abstract The photon energy spectra induced by 150 MeV electrons in lead were measured in the energy range from 40 MeV up to the primary electron energy. The target thickness was varied between 0.1 and 2.5 radiation lengths X 0 . The photons were analyzed by use of a technique based on deuteron photodisintegration. Differential and integral shower spectra are presented and compared with Monte Carlo calculations of Nagel and Messel et al., both interpolated to our primary energy of 150 MeV. The measured spectra show good agreement with these Monte Carlo calculations for the thickest target of 2.5 X 0 and with calculated bremsstrahlung spectra for the thinnest target of 0.1 X 0 . Considerable …

Cross sections for the reactionO16(γ, p0)N15at forward angles forEγ=80MeV

The (γ, n) reaction on 16O between giant resonance and pion threshold

Abstract A new TOF facility has been built for measurements of differential (γ, n) cross sections to discrete final states of light nuclei in the photon energy range between giant resonance and pion threshold. The observed neutron angle θn can continuously be varied between 0° and 150°, and additionally measurements at 175° and 180° are possible. Differential cross sections for the reaction 16O(γ, n0)15O are presented for Eγ = 60 MeV (40° ⩽ θn ⩽ 149°) and for θn = 90° (60 MeV ⩽ Eγ ⩽ 160 MeV). The results, combined with the corresponding (γ, p0) cross sections, indicate an absorption mechanism of high energy photons by neutron-proton pairs.