JP2854235B

PURPOSE:To increase the light quantity of irradiation by superimposing the light emitted in the axial direction of the plasma on the light emitted outward in the radial direction with each other, and radiating the superimposed light to a material to be irradiated with plasma. CONSTITUTION:The light 3A emitted from the pinch plasma 3 in the axial direction is reflected by a first light converging device formed of a spherical recessed surface reflecting mirror 6, and a material 7 is irradiated with this reflected light. Furthermore, the light 3B emitted from the plasma 3 outward in the radial direction is transmitted through a second light converging device formed of a projecting lens 5, and the material 7 is irradiated with this transmitted light. The first and the second converged light 3A, 3B are radiated to the same light receiving position of the material 7 so as to be superimposed on each other to improve the quantity of irradiation of the material 7. Furthermore, since the reduction of the transmitted light is not generated in the recessed surface reflecting mirror 6 in comparison with the projecting lens 5, quantity of the irradiation is improved more.