TANAKA Kenichiro National. Lab. High Energy Phys., Photon Factory, Associate professor, 放射光実験施設, 助教授 (90106162)
UKAI Masatoshi Tokyo Inst. Tech., Dept. Chem., Res. Associate, 理学部, 助手 (80192508)
KOUCHI Noriyuki Tokyo Inst. Tech., Dept. Chem., Associate Professor, 理学部, 助教授 (50161873)
KAMETA Kosei Tokyo Inst. Tech., Dept. Chem., Res. Associate, 理学部, 教務職員 (90214551)
|Budget Amount *help
¥17,400,000 (Direct Cost : ¥17,400,000)
Fiscal Year 1990 : ¥3,000,000 (Direct Cost : ¥3,000,000)
Fiscal Year 1989 : ¥14,400,000 (Direct Cost : ¥14,400,000)
On the existence and nature of superexcited molecules, the present investigator demonstrated experimentally for the first time through some studies of radiation chemistry, and continued the research using electron impact studies on simple molecules. In the recent few years, studies on the superexcited molecules by means of synchrotron radiation has become, internationally, an important scientific research subject. From the above mentioned background, the present investigation aimed a detailed experimental study on the creation and destruction processes of superexcited molecules by using various advantageous properties of synchrotron radiation, which would provide various hot information to the worldーwide scientific and technological communities.
In order to realize the purpose, the present investigators have built and standardized some experimental instruments based on the previous setーup to obtain experimental information about photoabsorption, photoionization, and photodissociation of
superexcited molecules. Practically, they have built
(A) VUV (vacuumーultraviolet) -monochromator equipped with a ultraーhigh vacuum pumping system,
(B) advanced coincidence detection system for optical emissions with high timeーresolution, and
(C) photoelectron detection system.
Among the above systems, system (A) has been employed for detection of VUV-optical emissions from neutral fragments produced via neutral dissociation of superexcited molecules, system (B) for measurements of lifetimes of optical emissions from dissociation fragments or superexcited molecules themseles, and system (C) for detection and energy analysis of photoelectrons emitted via autoionization of superexcited molecules.
By using the systems the present investigators have obtained detailed information about the creation and destruction processes of simple superexcited molecules, which has been revealed in the correct, absolute, and comprehensive measurements of the cross sections for
(i) photoabsorption, photoionization, and photodissociation of C_2H_2, SiH_4, and Si_2H_6,
(ii) partial photoionization and dissociative excitation of O_2, CO, N_2, and CO_2, and
(iii) angularーmomentum dependent dissociation of H_2->H(31)+H(ls).
As shown above, the present investigation has been carried out according to schedule without any severe delay and difficulty. Less