Interaction of 3- and 29-GeV Protons with Vanadium

Yields for 40 nuclides have been determined in the interaction of 3- and 29-GeV protons with V. Most of the radionuclides were measured by direct $\gamma$-ray spectroscopy of the irradiated targets; stable Ne and Ar isotopes were measured by mass spectrometry; radicargon isotopes were determined both mass spectrometrically and by radioactivity measurements. Charge dispersion curves were derived from independent and cumulative yield measurements for the mass regions 22-29, 36-41, and 42-48. The curves for 29 GeV are almost identical with the corresponding ones for 3 GeV. Total isobaric cross sections were determined at many mass numbers by estimating the unmeasured cross sections, from the charge dispersion curves, and adding them to the directly measured ones. Thus mass-yield distributions were obtained. At 3 GeV the total isobaric cross section is 30 mb at mass 47 and it decreases to a minimum of 8 mb around mass 24. At 29 GeV the cross sections are slightly lower than at 3 GeV for the heavier products, down to about mass 30, and somewhat higher for the lighter products, below mass 30. The mass-yield distributions from V are similar to those determined from Cu and Ag. It is shown that the experimental results (including those from Cu) do not agree as well with the Monte Carlo cascade calculations of Metropolis et al., as has been generally supposed.