Development of Beam Monitoring Materials for 2-dimensional Beam-lntensity Monitoring of High lntensity Beams.

本项目的目的是开发用于二维束流监测的束流监测材料，该材料使用离子束辐照诱导的氧化物材料的光子发射。在用于常规束监测的单片陶瓷如氧化铝和二氧化硅板中，不能观察到高强度束的光子发射饱和和束轮廓，并且板由于束加热的热应力而制动。本项目研制的束流监测材料克服了陶瓷类监测材料的这些缺点。本课题的特点是将氧化物陶瓷粉末弥散金属应用于束流监测材料。在这种监测材料中，铜、铝等基体金属起到冷却和热应力机械强度的作用，弥散陶瓷粉末起到光束监测的作用。本文介绍了这些监测材料的制备方法，高强度离子束辐照过程中的光电发射行为和耐热性的估计。报告摘要如下：氧化物弥散金属束流监测是由粉末冶金方法制造的。使用东北大学的dynamitron加速器，通过氦离子束估算了离子束辐照响应。研究了氧化物种类、氧化物粉末含量、粉末粒度及基体金属对光子发射行为、耐热性及加工性能的影响。基于这些结果表明，含2%至5%氧化铝的Cu合金最适合于高强度束流的二维束流监测。将合金固定在水冷平台上，即使在13 MW/m2的束流载荷下，也没有观察到束流加热引起的温度升高，并且可以观察到2D束流轮廓。在此基础上，提出了束流监测材料的设计思路和制备的基本条件。

The purpose of this project is to develop beam-monitoring materials for 2-dimensional beam monitoring using ion-beam irradiation induced photon emission from oxide materials. In the monolithic ceramics such as alumina and silica plates which are used for conventional beam monitoring, photon emission by high intensity beam saturates and beam profiles can not be observed and the plates brakes by thermal stress by the beam heating. Beam monitoring materials which were developed by this project overcome these weak points of these ceramics types of monitoring materials. Characteristic point of this research project is applying oxide-ceramic powder dispersion metals to beam monitoring materials. In this monitoring materials, base metal such as copper and aluminum takes parts of cooling and mechanical strength for thermal stress, dispersion ceramic powder take a part of beam-monitoring. This report describes fabrication methods of these monitoring materials, estimation of photo-emission behavior during high-intensity ion-beam irradiation and heat resistance. The summaries of the report are as follows ;Oxide dispersion metals for beam monitoring were fabricated by powder metallurgy method. Ion beam-irradiation response was estimated by helium-ion beam using a dynamitron accelerator at Tohoku University. Effects of oxide types, the contents of oxide powders, the size of powders and base metals on photon emission behavior, heat resistance and workability were studied. Based on these results showed that Cu containing 2 to 5% alumina alloys were the most appropriate to 2-dimensional beam-monitoring for high-intensity beams. Fixing the alloy on a water cooling stage, temperature increase by beam-heating were not observed and 2D beam profile could be observed even under beam-loading of 13MW/m2. Based on these results and discussion, the material design concepts and basic conditions for fabrication of beam-monitoring materials were obtained.