用光声方法观测乙烯酮分子的激光诱导离解以及研究离解碎片ＣＨ２（Ｘ３Ｂ１）的动力学。实验结果说明在３５５ｎｍ强激光辐射下，乙烯酮的非线性吸收只能诱导乙烯酮母体分子和（或）离解碎片的多光子离子化，这是造成光声信号随激光能量升高而降低的原因，再化合过程ＣＨ２（Ｘ３Ｂ１）＋ＣＨ２（Ｘ３Ｂ１）—→Ｃ２Ｈ２＋２Ｈ的速率常数是２．３９×１０－１１ｃｍ３ｍｏｌｅｃｕｌｅ－１Ｓ－１ＣＨ２（Ｘ３Ｂ１）＋ＣＨ２ＣＯ—→ＣＨ３＋ＣＨＣＯ的反应速度常数估计是１０－１２ｃｍ３ｍｏｌｅｃｕｌｅ－１Ｓ－１． The photo-acoustic method was used to observe the laser-induced dissociation of ketene molecules and to study the kinetics of the dissociated fragment CH2 (X3B1). The experimental results show that the non-linear absorption of ketene can only induce the multiphoton ionization of ketene and / or dissociated fragments under the strong laser irradiation of 355 nm, which is the reason for the decrease of photoacoustic signal with the increase of laser energy , The rate constant of the re-compounding process CH2 (X3B1) + CH2 (X3B1) - → C2H2 + 2H is 2.39 × 10-11 cm3molecule-1S-1CH2 (X3B1) + CH2CO- → CH3 + CHCO The rate constant of reaction is estimated to be 10-12cm3molecule-1S-1 .