Cao, T.L., Nguyen , T.H., Tran, Q.D. and Huynh, D.P. 2017. Some initial results of simulating a positron beam system by using SIMION. Nuclear Science and Technology. 7, 3 (Sep. 2017), 17-24. DOI:https://doi.org/10.53747/jnst.v7i3.100.