[en] Geometric effects have been investigated on the cold and dense divertor plasma formation. So far, this problem has been discussed only qualitatively. Here the results of numerical calculations are presented quantitatively, with the throat length and the void width as the parameters. Such data will be useful data base for the FER engineering design. It is concluded that the effectively closed divertor will work better than the open divertor. The closed divertor with no void width forms a cold and dense divertor plasma for a wide range of throat length. (author)