Projectile-energy dependence of intensity ratio ofLαtoLlx rays produced by proton andHe3impacts on Ho and Sm

The $L$ x rays of Ho and Sm produced by proton and ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ impacts were measured with a Si(Li) detector over the incident energy ranges $E_p=0.75-4.75\mathrm{}$ MeV and $E_{{}_{}{}^3{}_{}{}^{}\mathrm{He}}=1.5-9.3\mathrm{}$ MeV in the direction of 90° to the projectile. Ratios of x-ray-production cross sections for the $L\alpha$ and $L_l$ lines depend markedly on projectile energy but are independent of the projectile charge. It is shown that these experimental results are in good agreement with the plane-wave-Born-approximation calculation taking into account the effect of inner-shell alignment.