AN OVERVIEW OF THE ION-BEAM LABORATORY AT BEIJING-INSTITUTE-OF-PHYSICS

A multi-user MeV ion beam system has been installed and has been operating since 1983. It was used for research projects in various areas such as solid state physics, materials science and atomic physics. The operational characteristics and experiences, modifications, and end-station developments are discussed. The system is based on a small 2 x 1.7 MV Tandetron accelerator (General Ionex Corporation, USA) with a negative sputtering ion source and a home-made cold cathode Penning ion source with a charge-exchanger. Ions of almost all elements can be extracted with a large switching magnet to form three small angle beam lines. There are five beam lines installed. A summary of the beam lines that are being constructed for the activities of the laboratory will also be given. These include: Rutherford backscattering spectrometry (RBS), channeling analysis, particle-induced X-ray emission (PIXE), nuclear reaction analysis (NRA), elastic recoil detection analysis (ERDA), high-energy ion implantation (HEII). A proton microprobe, an atomic collision system for various optical measurements, and a cross-beam RBS-implantation end-station coupled with a 200 keV implanter are also installed in the laboratory.