⁹⁰ Y 核药制备中⁹⁰ Sr 活度测量装置的模拟研究

To quantify ⁹⁰Sr content and radioactivity in the preparation of ⁹⁰Y nuclear propellant, this paper presents a method of using charged particle deflection in a magnetic field and discusses the influence of various parameters on the detection result. The Geant4 toolkit based on the Monte Carlo method was used to simulate the detection of emitted electrons. Two kinds of launch models, i. e., point-source and volume-source, were constructed for the simulation. The number of emitted β particles deflected by the magnetic field was detected by two detectors, and the contents of the two nuclides were deduced according to the characteristics of electron energy spectra of ⁹⁰Y and ⁹⁰Sr nuclides. The result verifies that the content of ⁹⁰Sr in ⁹⁰Y microspheres can be theoretically determined by this method; however, the method accuracy significantly depends on the type of detector used. Moreover, the accuracy can be improved by optimizing several parameters, including the type of material, size, and placement of the detector.