Yamakawa Koichiro, Sasakawa Yuya, Ishibashi Atsuki, Namiyoshi Toshinobu, Arakawa Ichiro, Fukutani Katsuyuki		
		
			Abstract of annual meeting of the Surface Science of Japan, 2018		
		
			Nuclear spin conversion in H2 has attracted much interest for a long time, but the unified view of its mechanism has not been attained yet. The authors trapped H2 in solid CO and CO2 and on H2O ice to observe induced infrared absorption by H2. We determined the conversion rates from the time evolution of absorption peaks originating from ortho- and para-H2. We will discuss the temperature dependence of the rates in the different systems and will compare the results with conversion in H2 adsorbed on the surface of a rare-gas solid measured with the resonance-enhanced multiphoton ionization technique.