Because there is a very steep gradient in Fig. 4, the metal tungsten has good thermal conductivity, the energy the tungsten electrons obtain will be rapidly diffused to the low temperature region by the electrons and phonons, and taking into account the watercooled temperature of approximately 18 ± 5C, so the actual temperature is much lower than the temperature of Table 2, except for the short distance between surface and internal highest temperature, we also know that differentiation between surface and internal highest temperatures cannot be strictly distinct between surface and internal, but Table 2 can reflects the temperature damages increase with fluences during irradiation