Measurement of the J = 0-1 rotational transitions of three isotopes of ArD(+)

The rotational transitions of all three isotopic species of ArD(+) in samples containing the Ar isotopes in their natural abundances have been measured by means of millimeter and submillimeter techniques that employ a magnetically enhanced abnormal glow discharge. All three transition frequency measurements were made from digitally averaged signals detected through a lock-in amplifier with a 10-msec time constant. The Ar-4OD(+) transition was easily visible in real time on an oscilloscope with SNR of about 15. It is noted that the observed transition of Ar-38D(+) is more than five orders of magnitude weaker than that due to HCO(+).