在超音速F-F2-IF与NH3气流中产生IF(B3Π0+)的研究

研究了在超音速F-F_2-IF气流与NH_3气流中通过化学反应与碰撞传能产生IF(B~(3Π_0~+))的过程。用光学多通道分析仪在450-750 nm范围内记录到IF(B~(3Π_0~+)→X~(1∑~+))辐射的33条光谱线。提出了产生IF(B~(3Π_0~+))的机制。

STUDIES OF THE PRODUCTION OF IF (B3Π0+) IN THE SUPERSONIC F-F2-IF AND NH3 STREAMS

Iodine monofluoride is a potential visible lasing medium due to its ease of emission on IF(B→X) transition in 450-750 nm with favorable Franck-Condon factors. Nevertheless, the production of IF(B~3Π_0~+)) by a chemically-pumped pro- cess involving energy transfer has scarcely been investigated~1-4]. We have succeeded in producing NF(b~1∑~+)) species directly in the F-F_2-NH_3 system via a supersonic regime. It is of interest to extend our studies to ob- tain IF(B~3Π_0~+) by energy transfer between NF(b~1∑~+) and ground state IF, in the hope of developing a visible chemical laser.As in reference5], the experimental arrangement cosists essentially of a remodeled supersonic c_w HF chemical laser, a 0.3 M polychromator and an optical multichannel analyzer. F_2, D_2 and CF_3I are burned in a combustor to produce F atoms and IF molecules. The supersonic stream of F+F_2_IF flowing out of the nozzle bank is then mixed with a subsonic stream of NH_3 in a 30 cm long reaction zone.The IF(B→X) emission was observed from the OMA recordings in the range of 450 to 750 nm with 33 band heads as shown in Fig.2.Fig.3 shows the distribution of NH_2~*, NH~*, NF(b) and IF(B) emissions along X.The production of IF(B) may include the following steps:F+NH_3→NH_2~*+HF(v≤2) (1)F+NH_2~*→NH~*+HF(v≤4) (2)F_2+NH~*→NF(a)+HF (3)NH(a)+HF(v)→NF(b)+HF (4)NH~++IF(X)→NH(X)+IF(B) (5)NF(b)+IF(X)→NF(X)+IF(B) (6)The initial rise in IF(B), as shown in Fig.3, is consistent with5]. The continued rise in IF(B) is probably due to excitation by NF(b) which rises more steeply than NH~* decays with distance. Unless IF(B) is excited by another species it cannot decrease while NF(b) increases unless IF(X) is being chemically removed.