Photo-dissociation on Irradiation with a High Power VUV Laser
Grant-in-Aid for General Scientific Research (C)
|Allocation Type||Single-year Grants|
|Research Institution||Osaka University|
NAKASHIMA Nobuaki INST.OF LASER ENG.ASSOCIATE PROFESSOR, レーザー核融合研究センター, 助教授 (00106163)
|Project Period (FY)
1994 – 1995
Completed(Fiscal Year 1995)
|Budget Amount *help
¥2,000,000 (Direct Cost : ¥2,000,000)
Fiscal Year 1995 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1994 : ¥1,500,000 (Direct Cost : ¥1,500,000)
|Keywords||VUV laser / carbon dioxide / formaldehyde / laser breakdown / hydrofluorocarbon / ablation / F_2レーザー / 一酸化炭素 / フッ化炭化水素|
Photo-dissociation and related chemistry of systems of carbon dioxide and saturated hydrocarbons were studied using an F_2 laser. New findings were obtained for the systems of CO_2. Laser dissociation was applied for surface processing of optical elements.
1. Photo-reduction of CO_2 in the presence of H_2 or hydrocarbons
Plasma chemistry may be useful to reprocess CO_2, because a high yield of reduction takes place. Plasma can be generated by surplus energy from a fusion reactor, and/or focusing sun light. Another point is a possibility of a chain reaction. In the system of CO,CH_2O is suggested to from with a quantum yield higher than 1.0. Therefore, VUV laser chemistry as well as laser break down chemistry were studied in this project.
Major products were formaldehyde and methane, and a small amount of alcohol was detected. The yield was 1.5% under 40.5MPa of H_2 and 26.6kPa of CO_2 and 20% for a system of H_2 and CO under the same pressures. A chain reaction mechanism was suggested.
(2) Laser breakdown
Similar photo-products were obtained from a gas mixture of H_2, and CO_2 or CO by laser induced plasma.
(3) Photo-reduction of CO_2 and oxidation of hydrofluorocarbons
The corresponding alcohols weredetected. The reaction mechanisms were discussed based on the formation of hot alcohols and its collisional relaxation.
2.Surface processing of optical elements
VUV and UV laser ablation has been applied for processing of optical flat elements ; PMMA,glass, etc.
Research Output (10results)