Ion Optical Study on the $He^{++}$ Beam Transport System of the SNU 1.5-MV Tandem Van do Graaff Accelerator

SNU 1.5-MV 직렬형 반데그라프 가속기의 $He^{++}$ 빔 소송계에 대한 이온광학적 고찰

  • Hyen-Cheol JO (Department of Nuclear Engineering, Seoul National University) ;
  • Young-Dug BAE (Department of Nuclear Engineering, Seoul National University) ;
  • Hae-iLL BAK (Department of Nuclear Engineering, Seoul National University)
  • Published : 1991.12.01

Abstract

The $He^{++}$ beam transport system of the SNU 1.5-MV Tandem Van de Graaff accelerator is analysed by ion optical approach. The program OPTRANS is developed to determine the optimum operating conditions of each ion optical component and to simulate ion beam transport. First order matrix formalism is used and the space charge effect is neglected. Optimum operating conditions for the transport of 0.5~3.0 MeV $He^{++}$ beam are determined by the use of the program OPTRANS. Initial ion beam omittance is assumed to be 0.5$\times$80.0 mm.mrad from the structure of the extraction electrode and the experiment of ion beam extraction. ion beam transport characteristics of each ion optical component according to the variation of the operating conditions are investigated, and operating conditions to minimize the beam size at each slit, stripping foil, and target are calculated. Optimum operating conditions obtained from the experiment of ion beam transport show a discrepancy of less than 15% compared with the calculated ones. From the simulation and experiment of ion beam trans-port, the validity of the calculated optimum operating conditions and the usefulness of the program OPTRANS are verified.

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