Osaka University Radiation

To collect this volume of data, linear accelerators with nanosecond time resolution were, and still are now, routinely used around the world. Faster, picoseond linac machines were built first in Toronto and then at Argonne National Laboratory. Picosecond accelerators for pulse radiolysis have been in use for nearly three decades at Argonne, at the Osaka University Radiation Laboratory, and the University of Tokyo Nuclear Engineering Research... 

Masahiro Irie received his B.S. and M.S. degrees from Kyoto University and his Ph.D. in radiation chemistry from Osaka University. He joined Hokkaido University as a research associate in 1968 and started his research on photochemistry. In 1973 he moved to Osaka University and developed various types of photoresponsive polymers. In 1988 he was appointed Professor at Kyushu University. In the middle of the 1980 s he invented a new class of photochromic molecules - diaryl-ethenes - which undergo thermally irreversible and fatigue resistant photochromic reactions. He is currently interested in developing singlecrystalline photochromism of the diarylethene derivatives. 

Acknowledgement We are deeply indebted to Mr. Tadao Takada and Mrs. Sachiko Tojo who have contributed to the experiment. We also thank the members of the Radiation Laboratory of SANKEN, Osaka University, for running the linear accelerator. This work has been partly supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sport and Culture of Japan. 

The author is indebted to Dr. N. Ui of Gunma University, to Dr. K. Yano of Tokyo University, to Dr. T. Samejima of Aoyanra Gakuin University, to Dr. H. Watari of Osaka University, and to Dr. J. Tsurugi of Radiation... 

The author wishes to thank Dr. Richard S. Stein and Dr. Shaw Lin Hsu of the Department of Polymer Science and Engineering, University of Massachusetts at Amherst, USA Dr. M. Satkowskii of Procter Gamble Co., USA Dr. Sono Sasaki of Japan Synchrotron Radiation Institute, SPring-8, Japan and Mr. Masaaki Izuchi, Mr. Kouji Imanishi, and Mrs. Gose Naomi of the Graduate School of Science, Osaka University, for their contribution in these smdies. 

The authors wish to thank the Radiation Laboratory, the Institute of the Scientific and Industrial Research, Osaka University, for allowing them to use the Co facilities. 

Kondo S. 1993. Health effects of low-level radiation. Kinki University Press, Osaka, Japan (available from Medical Physics Publishing, Madison, Wisconsin). 

Masahiro Irie received his B.S. and M.S. degrees from Kyoto University and his Ph.D. in radiation chemistry from Osaka 3 3 University. He joined Hokkaido University as a research associate in 1968 and started his research on photochemistry. 

Oka, Osaka Prefecture University, for his kind assistance with the y-radiation experiment. This work was supported by Grants-in-Aid for Scientific Research on Priority Areas (Area No. 432, No. 16072215) and for Scientific Research (No. 16350067) from the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan. 

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