THE FAR-INFRARED LASER MAGNETIC RESONANCE SPECTRUM OF THE $HBr^{+}$ MOLECULAR ION

Author Institution:Pure rotational transitions in the paramagnetic $\Omega = 3/2$ fine-structure component of the $^{2}\Pi$ ground state of the $HBr^{+}$ molecular ion were observed by the laser magnetic resonance technique. The $J = 3/2 \rightarrow 5/2$ transition was observed with laser lines at 251.1 $\mu m (CH_{3}OH)$ and 253.7 $\mu m (CD_{3}OH)$ and the $J = 5/2 \rightarrow 7/2$ transition was observed at l80.7 $\mu m (CD_{3}OH)$. In addition, the $J = 5/2 \rightarrow 7/2$ transition in the first excited vibrational state was observed at 186.2 $\mu m(CH_{3}OH)$ and the $J= 3/2 \rightarrow 5/2$ transition of the $DBr^{+}$ isotope was detected at 496.1 $\mu m(CH_{3}F)$. $HBr^{+}$ was generated inside the laser cavity in the positive column of a DC glow discharge through a flowing mixture of HBr (1%) in helium at ambient temperature