Oxygen isotope separation utilizing two-frequency infrared multiphoton dissociation of 2,3-dihydropyran

2,3-ジヒドロピランの二波長赤外多光子解離による酸素同位体分離

橋本 雅史; 大場 弘則  ; 横山 淳

Hashimoto, Masashi; Oba, Hironori; Yokoyama, Atsushi

2,5-ジヒドロピラン(DHP)の赤外多光子解離(IRMPD)を利用したO同位体分離法に対し励起光及び分解光の2波長照射を導入することで、同位体分離効率の向上を試みた。励起光1052.2cm, 0.45J/cmと分解光1031.5cm, 1.06J/cmの照射において、Oを含むDHPの分解確率(D(O))1.610/Pulseと同位体分離係数(S)316を得た。これは単波長照射(1033.5cm, 2.2J/cm, D(O)=2.210/Pusle, S=391)と比較して、より低いフルエンスで同程度の分解確率と分離係数を得たことに相当する。この結果、Oの分離速度を単波長の4倍以上に高めることができ、酸素同位体の大量分離手法としての可能性が示された。

Oxygen isotope separation has been examined by utilizing the two-frequency infrared multiphoton dissociation (IRMPD) of 2,3-dihydropyran (DHP). The two-frequency IRMPD reduces remarkably the required laser fluence. For example, dissociation probability of DHP containing O (D(O)) and enrichment factor (S) were obtained to be 1.610 /pulse and 316 respectively by the simultaneous irradiation with 1052.2 cm photons at 0.45 J/cm and 1031.5 cm photons at 1.06 J/cm. These are comparable with D(O) = 2.210 /pulse and S = 391 obtained by the single-frequency irradiation of 1033.5 cm photons at 2.2 J/cm. Therefore, the production rate of an O enriched dissociation product has been increased to four times or more, compared with the single-frequency IRMPD, and this two-frequency method would promise a practical large scale separation.