Fragment energy spectra from the 2.1- and 4.9-GeV proton irradiation of C, Al, Ag, and U targets were measured at several angles to the beam for products ranging from He up to Ar for the heavier targets. The fragments were detected in a telescope consisting of a gas $\Delta E$ counter and a silicon $E$ counter. The carbon target measurements are compared with previous data from projectile fragmentation studies. A Maxwellian type functional form which fits the energy spectra from all the targets is presented. The spectra were integrated to obtain values of the cross section as a function of atomic number.

NUCLEAR REACTIONS $\mathrm{C}(p,X)$, $E=2.1, 4.9$ GeV; measured $\sigma (E,\theta )$, $X=\mathrm{He} \mathrm{to} \mathrm{C}$. $\mathrm{Al}(p,X)$, $E=2.1, 4.9$ GeV; measured $\sigma (E,\theta )$, $X=\mathrm{He} \mathrm{to} \mathrm{Na}$. $\mathrm{Ag}(p,X)$, $E=4.9\mathrm{}$ GeV; measured $\sigma (E,90\mathrm{}°)$, $X=\mathrm{N} \mathrm{to} \mathrm{Ar}$. $\mathrm{U}(p,X)$, $E=4.9\mathrm{}$ GeV; measured $\sigma (E,\theta )$, $\sigma \mathrm{}\left(X\right)\mathrm{}$, $X=\mathrm{F} \mathrm{to} \mathrm{Ar}$. Spallation, fragmentation.

• Received 19 December 1977

DOI:https://doi.org/10.1103/PhysRevC.17.1368