Patent ID: 8558166
Filing Date: 2013-10-15
Classification: H01J

Abstract:
1. A method for determining boron isotopic composition by PTIMS-static double collection, including the following steps: (1) Selecting two parallel Faraday cups with a largest deflection angle in a Faraday collector to collect m/e309 and m/e308 boron isotope ions, respectively, and setting a cup distance as a minimum value; (2) Adjusting Focus Quad and Dispersion Quad parameters in Zoom Optics of an ion source till the following conditions are met: (i) After optical focusing and deflection, m/e309 and m/e308 boron isotope ions are fully collected in the two selected Faraday cups; (ii) The peaks of the two ions are flat peaks without tailing peaks and prepeaks; (iii) The peaks of the two ions are fully overlapped; (3) Adjusting the collection mass number of the center cup of the Faraday collector till the following conditions are satisfied: (i) In this mass number, no ion peak appears for the center cup, the mass number is a baseline mass value during data acquisition of the instrument; (ii) After optical focusing and deflection, m/e309 and m/e308 boron isotope ions are fully collected in the two selected Faraday cups, and the center positions of the peaks are not shifted; and (4) Scanning the ion peaks, checking the peak centers, and initiating the data acquisition and processing program to determine the samples.