Diode-laser absorption measurements of hydrazine and monomethylhydrazine

Abstract

Absorption measurements of pure hydrazine, N 2H 4, and monomethylhydrazine, CH 3N 2H 3 (MMH), were recorded in an optical absorption cell (3 passes, 50 cm/pass) at low pressure (0–35 Torr) using a tunable external-cavity diode laser (ECDL), operating in the range from 6350 to 6650 cm -1 (1.49 to 1.58 μm). Peak absorption cross-section measurements of hydrazine and MMH, as determined from fixed wave-length absorption measurements, were found to be α e( ν)=0.163±0.008 cm -1atm -1 at 6495 cm -1 ( λ=1539.6 nm) and α e( ν)=0.152±0.003 cm -1atm -1 at 6560 cm -1 ( λ=1524.4 nm), respectively.