Ion-beam radiation chemistry

Abstract

One of the new aspects of radiation chemistry at present and that will be in the near future is the use of new radiation sources. The character and potential advantages of ion beam compared to conventional radiation would be large and localized energy deposition in materials with high spatial resolution; the materiality of the beam that can implant atoms into the target and can endow the product with novel function; wide variety of secondarily produced radiation that enables sophisticated analysis of material bulk and surface; and transmutability of material including nuclear reaction. The peculiarity related to large and localized energy deposition is sometimes called linear energy transfer (LET) effects. The chapter focuses on LET, research activities, and technical aspects of ion beam radiation chemistry. An ion beam loses energy through interaction with target material. The energy deposition or energy loss in depth direction per unit thickness -dE/dx, where E is energy and x is depth, is defined as the stopping power. LET is different from stopping power. LET excludes contribution of energetic secondary electrons, whereas stopping power considers every contribution. However, they are very close to each other in most cases of radiation chemistry. The chapter describes two aspects of ion beam radiation chemistry in polymers—namely, fundamental-oriented and application-oriented.