MOLECULAR-BEAM MASER FOR SHORTER-MILLIMETER-WAVE REGION . SPECTRAL CONSTANTS OF HCN AND DCN

A millimeter-wave molecular-beam maser has been made to operate as both an amplifier and an oscillator on the J=1→0 and the J=2→1 transitions of HCN at 88.6 and at 177.2 kMc/sec, respectively, thus doubling the previously operational frequency range of such masers. With this maser, hyperfine components of these transitions have been measured for H12C14N and D12C14N to nine significant figures. The spectral constants (in kc/sec) that are derived from these frequencies are, for HCN, B0=44 315 975.7±0.4, DJ=87.24±0.06, (eQq)N=-4709.1±1.3, and CN=10.4±0.3; for D12C14N, B0=36 207 462.7±0.2, DJ=57.83±0.04, (eQq)N=-4703.0±1.2, CN=8.4±0.3, (eQq)D=194.4±2.2, and CD=-0.6±0.3. © 1969 The American Physical Society.