The Mg atomic frequency standard

Recent advances towards the realization of an absolute frequency standard in the submillimeter region are reported. The
³
p
1
-
³
P_{0} \Delta m_{j} = 0
fine structure transition in the metastable triplet of
²⁴
Mg has been observed in an atomic beam with both Rabi and Ramsey interrogation techniques. Experimental results and theoretical predictions are compared and discussed in view of an Mg frequency standard.