Answers are grounded in this paper and cite their sources.
The 220 ← 221 transition of H2D+ was detected by using a dc discharge in a mixture of H2 and D2 with a hollow cathode cooled to liquid nitrogen temperature. The assignment was made on the basis of chemistry for production, the observed linewidth, and the lowering of the spectral intensity by the external magnetic field. The transition frequency was determined to be 155 987.185±0.037 MHz.
No takes yet. Share an insight, caveat, or question.
Saito et al. (1985) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: