Results of the study of X-ray characteristic spectra of free atoms of a num
ber of rare-earth metals from Ce to Ho are reported. L-alpha1 and L-beta1 l
ines were studied, and the shifts of the peaks of emission lines of free at
oms relative to their positions in the case of emission by the solid aggreg
ate state were measured. The data obtained enable one to use the correspond
ing X-ray characteristic lines as references with the accuracy Delta lambda
/lambda approximate to 10(-5). The Z-dependences of shifts are plotted. (C)
2001 MAIK "Nauka/Interperiodica".