Diode-laser absorption measurements of hydrazine and monomethylhydrazine

Absorption measurements of pure hydrazine, N2H4, and monomethylhydrazine, C H3N2H3 (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 las er (ECDL), operating in the range from 6350 to 6650 cm(-1) (1.49 to 1.58 mu m). Peak absorption cross-section measurements of hydrazine and MMH, as de termined from fixed wavelength absorption measurements, were found to be al pha(e)(v) = 0.163 +/- 0.008 cm(-1) atm(-1) at 6495 cm-l (lambda = 1539.6 nm ) and alpha(e)(v) = 0.152 +/- 0.003 cm(-1) atm(-1) at 6560 cm(-1) (lambda = 1524.4 nm), respectively. (C) 1999 Elsevier Science Ltd. All rights reserv ed.