复旦大学单粒子微束研制进展

Development of Single-ion Microbeam at Fudan University

建设了一基于复旦大学2×3MV串列加速器的单粒子微束装置。离子束经分析磁铁30°水平偏转传输后再经90°偏转磁铁竖直上行至辐照终端,以内径1.5μm的毛细玻璃管微准直器获取离子微束。采用薄膜闪烁体结合光电倍增管的探测结构对微束离子进行精确探测和计数,并以高压静电偏转开关快速关断束流以实现对离子数目的精确控制。目前实验已获得在质子能量为3 MeV时,能散(能量分布曲线中半高宽FWHM)<60keV、束分辨<2.2μm、定量照射精度>95%的质子微束。本文对复旦大学单粒子微束的束流管道设计、微束获取、束开关及单粒子探测等核心环节的研制进展进行介绍。

New beam line was constructed on the 2 × 3 MV tandem accelerator in the Institute of Modern Physics , Fudan University , for the development of a biological single-ion microbeam .Accelerated ion beam will first be deflected by 30° by an analyzing magnet and bended vertically up by 90° to the end of the beam line .Borosilicate glass capillary ,with the inner diameter of 1.5 μm ,was installed at the end of the beamline to extract an ion microbeam .A special structure of scintillator film and photomultiplier installed at the endstation of the microbeam exit was used for precise detection and counting of the microbeam ions .A high voltage beam deflector was installed on the beam line for a fast beam cutting action when pre-defined number of microbeam ions had arrived to target cells .Based on the overall design ,low energy proton microbeam ,with the energy of 3 MeV ,FWHM〈60 keV and a spatial resolution within 2.2 μm has been acquired in current experiment .Quantitative irradiation by the collimated microbeam has shown a precision above 95% .In this paper , the basic design and development progress of the microbeam facility was introduced , including the relevant parts of beamline design , microbeam generation , high voltage beam deflector and single-ion detection .