Study on heavy-ion beam time-resolved absorption spectroscope

重离子束诱导辐射化学初级过程的研究对于打开离子辐射的广阔应用领域具有重要意义。提出了一种新的基于吸收光谱的重离子束脉冲辐射分解方法，并将其用于研究重离子束辐射产生的自由基的行为。(1)重离子束脉冲辐射分解技术的发展对于重离子束的吸收光谱学存在许多困难，如离子束强度低、离子束穿透材料、光源等问题。为了克服这些困难，我们首先开发了一种基于先进分析光的重离子脉冲辐射，这种分析光是由离子束辐射在闪烁体中产生的。采用单光子计数技术，实现了脉冲辐射分解的时间分辨率为纳/皮秒级。(2)重离子束诱导辐射化学主要过程的研究利用重离子束脉冲辐射解，在纳米/皮秒时间尺度上成功测量了重离子束辐射（如220MeV 12C^<5+ b>离子束）产生的自由基或短寿命物质的瞬态吸收动力学。研究了重离子束对材料的高线性能量传递效应，并与电子束等低线性能量传递效应进行了比较。

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.