Luminescence and characteristics of electron-holeplasma created in wide-band-gap crystals by ion irradiation.

我们感兴趣的是高密度重离子激发，这是目前的方法中最高的激发。在宽带隙绝缘体的激发下，重离子束的激发强度比W激光高3倍。为了探索离子辐照的特征现象，阐明离子径迹初始阶段的动力学过程。我们发展了单离子单光子符合技术。目前，时间分辨率约为，85 ps，这是最快的工具，是。至少在顺序上比通常的离子技术更好。通过SISP的应用，我们发现许多绝缘体晶体普遍存在超快发光。这样的发光现象还没有被观测到，也不能用目前的认识来解释。我们提出了电子空穴等离子体作为快速发光的起源，并给出了证据：无尾快衰减，产额与激发密度的超线性关系，产额与样品的依赖关系，以及温度的影响很小。然而，一定还有许多未知的特征。绝缘体中的电子氢等离子体，认为绝缘体中的电子氢等离子体是第一个发现，也是一个起点。此外，到目前为止，我们的时间分辨光谱容易受到光束起伏的影响。为了克服这个弱点，获得精确的光谱，我们计划建立8个波长同时的SISP和nbw系统，该系统已准备好进行测量。然而，自去年4月以来，离子加速器正在重建中。我们在等待加速器的操作。

We are interested in high-density excitation by heavy ions, which is the highest exclitation in the present methods. In case of excitation of insulators with wide band-gaps, the intensity of excitation density by heavy ibns is three ofders higher thap tera W laser. In order to search phenomena characteristic to ion irradiation and elucidate dynamics of ion-tracks at initial stages. we developed a single ion and single photon (SISP) coincidence techaiques. At present, the time resolution is about, 85 ps, which is the fastest tool and is. better at least by order than usual techniques for ions. By application of SISP, we found ultra-fast luminescence commonly for many insulator crystals. Such lumjnescence has been not oberved and cannot be explained by so-far understanding. We proposed electron-hole plasma as origin of the fast luminescence with showimg evidences : non-tailed fast decay, super-linear excitation-density dependence of yield, sampl e dependence of yield, and little influence of temperaturle. However, there must be yet many unknown chaiacteristics regaiding with. e-h plasma in insulators, considering that e-h plasma in insulators is the frst finding and at starting point. Ih addition, so far our tirne-resolved spectra were apt to be influenced by beam fluctuation In order to overcome this week point and obtain precise spectra, we planed to construct simultaneous 8-wavelengths SISP and nbw this system is ready to measurements. However, the ion accelerator is in reconstruction since the last April. We are waiting the operation ofthe accelerator.