LABORATORY SUBMILLIMETER-WAVE SPECTROSCOPY OF THE CH2 (B-3(1)) RADICAL

We have measured the submillimeter-wave spectrum of the N-KaKc = 2(12)-3(03) and 5(05)-4(14) transitions at 440-445 and 592-594 GHz, respectively, of the ($) over tilde X B-3(1), CH2 radical by laboratory spectroscopy. The CH2 radical was generated by DC glow discharge of CH2CO. The each line is observed to be split into three components due to electron spin-spin and spin-rotation interactions. The observed frequencies are found to be deviated by several MHz from the frequency predicted by laser magnetic resonance spectroscopy. The transition frequency of the F-2 component of the 2(12)-3(03) rotational level can be used for a rest frequency of para-CH2 in astronomical uses.