Portal de Periódicos da CAPES

Radiochemical study of the combined ( p , π 0 ) and ( p , γ ) reactions on bismuth with protons from 62 to 480 MeV

1981; American Institute of Physics; Volume: 24; Issue: 2 Linguagem: Inglês

10.1103/physrevc.24.588

1538-4497

Τ. E. Ward, Pushpendra P. Singh, D.L. Friesel, A. I. Yavin, A. Doron, J.M. D’Auria, Gabriel Sheffer, M. Dillig,

Quantum Chromodynamics and Particle Interactions

The excitation function for the combined $^{209}\mathrm{Bi}(p,\ensuremath{\gamma})^{210}\mathrm{Po}$ and $^{209}\mathrm{Bi}(p,{\ensuremath{\pi}}^{0})^{210}\mathrm{Po}$ reactions was measured for proton energies from 62 to 480 MeV. The measurements were made using standard radiochemical and residual $\ensuremath{\alpha}$-counting techniques. Below pion-production threshold the radiative proton-capture cross section was observed to decrease with increasing proton energy. Above threshold the combined cross section increases to about 10 \ensuremath{\mu}b at 170 MeV. From a smooth extrapolation of the ($p,\ensuremath{\gamma}$) cross section to energies above pion-production threshold, an estimate of a cross section for the ($p,{\ensuremath{\pi}}^{0}$) process is obtained. A theoretical fit of the summed total cross section into all particle bound states was made using a density of states factor, a two nucleon $t$ matrix, and by taking into account the initial state (proton) and final state (pion) distortions using optical potentials.[NUCLEAR REACTIONS $^{209}\mathrm{Bi}(p,\ensuremath{\gamma})^{210}\mathrm{Po}+^{209}\mathrm{Bi}(p,{\ensuremath{\pi}}^{0})^{210}\mathrm{Po}$, $^{209}\mathrm{Bi}(p,2n)^{208}\mathrm{Po}$, $^{209}\mathrm{Bi}(p,4n)^{206}\mathrm{Po}$, ${E}_{p}=62\ensuremath{-}480$ MeV, measured polonium-production cross section, thin targets, radiochemical method, $\ensuremath{\alpha}$ counting, theoretical fit to the ($p,{\ensuremath{\pi}}^{0}$) data using two-nucleon model.]