L x-ray production in ionization of 60Nd by 100-250 keV protons

L x rays of Nd have been measured for the bombardment of protons with the energies of 100-250 keV. It is found that L gamma 2 (abbreviation of L gamma'(2,3,4,4)) x-ray emission is largely enhanced by proton impact, compared to the case of photon radiation. It is proposed that is caused by the multiple-ionization of outer-shell electrons. To verify this explanation, the enhancement for relative intensity ratio of L iota and L beta(2) to L alpha x ray and the energy shift of various L-subshell x rays are discussed. In addition, the production cross sections of L iota, L alpha, L beta and L gamma x ray are obtained and compared with theoretical calculations of PWBA, ECPSSR and ECUSAR, along with various atomic parameter databases. (C) 2017 Elsevier B.V. All rights reserved.