Angular Distribution and Ranges ofN13Particles Resulting from 27.5-MevN14Ions onMg24

Abstract

The angular distribution and ranges are reported for ${\mathrm{N}}^{13}$ nuclei resulting from the transfer reaction ${\mathrm{Mg}}^{24}$(${\mathrm{N}}^{14}$,${\mathrm{N}}^{13}$)${\mathrm{Mg}}^{25}$ ($Q=-3.22\mathrm{}$ Mev) at an incident ${\mathrm{N}}^{14}$ energy of 27.5 Mev. The data are compared to those reported previously for the reaction ${\mathrm{Mg}}^{25}$(${\mathrm{N}}^{14}$,${\mathrm{N}}^{13}$)${\mathrm{Mg}}^{26}$ ($Q=0.57\mathrm{}$ Mev) to study the effect of $Q$. It is found that while the angular distributions are similar in shape, ${\mathrm{Mg}}^{26}$ states up to 7-Mev excitation contribute significantly to the reaction ${\mathrm{Mg}}^{25}$(${\mathrm{N}}^{14}$,${\mathrm{N}}^{13}$)${\mathrm{Mg}}^{26}$ in contrast to the presented ${\mathrm{Mg}}^{24}$ data which show no ${\mathrm{Mg}}^{25}$ states above ∼5 Mev contributing to the transfer process. The ${\mathrm{N}}^{13}$ ranges when expressed as a function of $Q$ indicate the bulk of ${\mathrm{N}}^{13}$ particles lying between similar $Q$ values for both reactions. Excited-state transfers predominate in the two magnesium reactions in contrast to results reported at the same ${\mathrm{N}}^{14}$ incident energy for ${\mathrm{B}}^{10}$ and ${\mathrm{N}}^{14}$ targets in which ground-state transfers accounted for approximately half of the total cross sections. The angular distributions are replotted as $\frac{d\sigma }{d{R}_{min}}$ vs $R_{min}$ and $r_0\text{'}\mathrm{s}$ calculated for the peak values of $R_{min}$; the $r_0\text{'}\mathrm{s}$ are 1.6 f and 1.55 f for ${\mathrm{Mg}}^{24}$ and ${\mathrm{Mg}}^{25}$ targets, respectively. The magnesium data are compared to the tunneling theory for transfer reactions and fair agreement is found.