Cross sections for muodisintegration reactions ((${\mu }^{\pm }$,${\mu }^{\pm }\mathrm{xN}$)) at $T_{\mu }=60\mathrm{}$ MeV on eight nuclei from ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ to ${}_{}{}^{203}{}_{}{}^{}\mathrm{Tl}$ have been measured by activation techniques. The cross sections, like those for comparable electron reactions, increase with target mass number. An additional measurement with 30-MeV ${\mu }^{+}$ on ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ shows a positive energy dependence. The observation that $\sigma ({\mu }^{+},{\mu }^{+}xn)<\mathrm{}\sigma ({\mu }^{-},{\mu }^{-}xn)$ for heavy nuclei implies the presence of Coulomb distortion of the muon trajectories. Calculations employing the virtual photon method in the plane-wave Born approximation, together with reported photonuclear cross sections, give good agreement with the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$($\mu$,${\mu }^{\prime }n$)${}_{}{}^{11}{}_{}{}^{}\mathrm{C}$ results, but not with those for higher-$Z$ nuclei.

NUCLEAR REACTIONS Muon scattering, 60-MeV (${\mu }^{+}$,${\mu }^{+\prime }\mathrm{xN}$) cross sections in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{46,48}{}_{}{}^{}\mathrm{Ti}$, ${}_{}{}^{58}{}_{}{}^{}\mathrm{Ni}$, ${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$, ${}_{}{}^{174}{}_{}{}^{}\mathrm{Yb}$, ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$, ${}_{}{}^{203}{}_{}{}^{}\mathrm{Tl}$; 30-MeV ${\mu }^{+}$ on ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$; 60-MeV ${\mu }^{-}$ on ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$, ${}_{}{}^{63}{}_{}{}^{}\mathrm{Cu}$, ${}_{}{}^{197}{}_{}{}^{}\mathrm{Au}$, and ${}_{}{}^{203}{}_{}{}^{}\mathrm{Tl}$. Activation method, natural targets, enriched ${}_{}{}^{203}{}_{}{}^{}\mathrm{Tl}$. Comparison with plane-wave Born approximation (PWBA) virtual photon calculations.

• Received 24 October 1979

DOI:https://doi.org/10.1103/PhysRevC.21.1967