Beam Line Design and Simulation for Mass Separation of Beryllium Isotopes at the AMs Facility in Korea

Abstract

Accelerator Mass Spectrometry (AMS) is a powerful technique for measuring long-lived radionuclides that occur naturally in our environment. AMS measurements are used for a wide variety of dating and tracing applications in the geological and planetary sciences, archaeology, and biomedicine and so on. The AMS facility of Seoul National University in Korea has a project to install a new beam line for beryllium measurement. The new beam line mainly consists of two 30-degree deflection and 100- degree deflection dipole magnets which were previously used as a gas-filled recoil mass separator and as a beam analyzer, respectively, at the SF cyclotron facility of CNS, University of Tokyo in Japan. In order to detect 10Be and 9Be simultaneously and to eliminate 10B, a thorough investigation into performance of two dipole magnets were carried out. A transfer matrix of the beam line was determined by the TRANSPORT code. Further simulation for separation between beryllium and boron isotopes was also performed by a ray tracing method using the TURTLE code. 10-MeV isotopes of a 3+ charge state from the 3-MV Tandetron accelerator were allowed to be analyzed by the combination of two dipole magnets. The beam line elements between the existing beam line and the new beam line, such as the length of drift space, positions of two dipole magnets, were carefully determined. We will also report on the future plan to measure cosmogenic nuclides such as triton, aluminum, chlorine, calcium, and iodine.