Study on heavy-ion beam time-resolved absorption spectroscope

研究重离子束诱导辐射化学的初级过程，对于拓宽离子辐射的应用领域具有重要意义。发展了一种新的基于吸收光谱的重离子束脉冲辐解方法，并用于研究重离子束辐射产生的自由基的行为。(1)重离子束脉冲辐解的发展对于重离子束来说，吸收光谱存在着许多困难，如离子束强度低，离子束穿透材料和光源等。为了克服这些困难，我们首先发展了一种基于一种先进的分析方法的重离子脉冲辐解--闪烁体中的离子束辐射产生的光。(2)重离子束辐射化学初级过程的研究利用重离子束脉冲辐射，成功地测量了重离子束辐射产生的自由基或短寿命物质(如220 MeV~(12)C；lt；5~+&gt；离子束)在纳/皮秒时间尺度上的瞬时吸收动力学。研究了重离子束对材料的高线能量传递(LET)效应，并与电子束等低LET辐射进行了比较。

The study of the primary process of heavy-ion beam induced radiation chemistry is very important for opening the wide application field of ion radiation. A new heavy-ion beam pulse radiolysis based on absorption spectroscopy was developed and used to study the behavior of radicals generated by heavy-ion beam radiation.(1)Development of heavy-ion beam pulse radiolysisFor heavy-ion beams, there are many difficulties to the absorption spectroscopy, such as the low intensity in ion beam, the penetration of the ion beam into material, the light source, and so on. To overcome the difficulties, we developed at first a heavy-ion-pulse radiolysis based on an advanced analyzing-light produced by ion beam radiation in a scintillator. The time resolution of the pulse radiolysis was achieved to be nano/picosecond time region by using a single-photon-counting technique.(2)Study of primary process of heavy-ion beam induced radiation chemistryThe transient absorption kinetics of radicals or short-lived species generated by heavy-ion-beam radiation (such as 220MeV 12C^<5+> ion beam) was measured successfully on nano/picosecond time scale by using the heavy-ion beam pulse radiolysis. The high linear-energy-transfer (LET) effects of the heavy-ion beam on materials were studied and compared with the low LET beam radiation, such as the electron beam radiation.