0000000001299119
AUTHOR
P.a. Wallace
(γ,2N) reaction inC12
The $^{12}$C(\ensuremath{\gamma},pn) and $^{12}$C(\ensuremath{\gamma},pp) reactions have been measured for photon energies between 80 and 157 MeV using a photon tagging spectrometer and plastic scintillator detectors. The overall energy resolution was \ensuremath{\sim}7 MeV, sufficient to determine the initial shells of the emitted nucleons. Corrections were made for solid angle and threshold effects by means of Monte Carlo simulations. For the (\ensuremath{\gamma},pn) reaction both the missing energy and recoil momentum distributions are largely consistent with a two-nucleon absorption process on p-shell an sp nucleon pairs. For the much smaller $^{12}$C(\ensuremath{\gamma},pp) cross secti…
The 16O(γ, 2N) reaction measured with tagged photons
The results of tagged-photon measurements of the 4He(γ, pn)d, 4He(γ, pn)pn and 4He(γ, pp)nn reactions, carried out with photons of energies 80–131 MeV, are presented. The (γ, pn)d three-body-breakup cross section dominates the four-body-breakup cross section. The three-body-breakup cross section and the corresponding deuteron recoil-momentum spectrum are reasonably accounted for by a mechanism of photon absorption on correlated proton-neutron pairs. In contrast the four-body-breakup mechanism appears to have two components: absorption on correlated proton-neutron pairs and a more complex additional component which has a distribution similar to phase space. The data rule out substantial phot…
Total photoabsorption cross sections forH1,H2, andHe3from 200 to 800 MeV
The total photoabsorption cross sections for $^{1}\mathrm{H}$, $^{2}\mathrm{H}$, and $^{3}\mathrm{He}$ have been measured for incident photon energies ranging from 200 to 800 MeV. The $^{3}\mathrm{He}$ data are the first for this nucleus. By using the large acceptance detector DAPHNE in conjunction with the tagged photon beam facility of the MAMI accelerator in Mainz, cross sections of high precision have been obtained. The results show clearly the changes in the nucleon resonances in going from $^{1}\mathrm{H}$ to $^{3}\mathrm{He}$. In particular, for the ${\mathit{D}}_{13}$ region the behavior for $^{3}\mathrm{He}$ is intermediate between that for $^{1}\mathrm{H}$, $^{2}\mathrm{H}$, and h…
Two-body photodisintegration of the deuteron from 100 to 800 MeV
Abstract The total and the differential cross sections for the D(γ,p)n reaction have been measured over the photon energy range 100-800 MeV at the 855 MeV MAMI Microtron in Mainz. Using the large acceptance detector DAPHNE in conjunction with the Glasgow tagging spectrometer, high precision results with small systematic errors were obtained. The data are presented in the form of thirty-five angular distributions at c.m. proton angles between 30°–160° in 10° intervals and at photon energies in steps of 20 MeV. Previous experimental work is reassessed in the light of the present results and comparison with some recent theoretical calculations.
Differential cross section for the reaction 2H(γ, p)n from 133 to 158 MeV
The cross section for the reaction 2H(γ, p)n has been measured at laboratory photon energies Eγ = 133−158 MeV and c.m. angles between 30° and 150°. The reaction was induced by a tagged bremsstrahlung photon beam incident on a liquid deuterium target. The uncertainty in the absolute cross sections is ⩽ 5%. There is now reasonable agreement between recent measurements in this energy region and the overall data set now defines the cross section sufficiently well to provide a test of current models of the reaction.
"Table 1" of "Differential cross section for the reaction $^2$H(��,p)n from 133 to 158 MeV"
No description provided.
"Table 2" of "The 16O(��, 2N) reaction measured with tagged photons"
PROPOSED THAT THE REACTION IS DUE TO A QUASI DEUTERON MECHANISM AND P N PAIRS E]ECT FROM THE 1P SHELL.
"Table 2" of "Differential cross section for the reaction $^2$H(��,p)n from 133 to 158 MeV"
No description provided.
"Table 1" of "The 16O(��, 2N) reaction measured with tagged photons"
PROPOSED THAT THE REACTION IS DUE TO A QUASI DEUTERON MECHANISM AND P N PAIRS E]ECT FROM THE 1P SHELL.