Experiments on the effect of fast heat loads on the surface of tungsten were carried out on the BETA facility at the Budker Institute. Tungsten samples were uniformly heated by an electron beam with a heat flux factor below the melting threshold. During and shortly after exposure, the 2D surface temperature distribution was measured, as well as the temperature history on selected surface areas. Active diagnostics using the scattering of CW laser light on a surface exposed by the electron beam allowed us to monitor the damage dynamics. At the heating stage, an increase in the surface roughness occurred, caused by inhomogeneous elastic and plastic deformations of the heated layer. As the cooling progressed, the residual plastic deformations remained. Simultaneously with the modification of the surface, bending of samples with a thickness of 3-4 mm occurred. The bending dynamics of the sample was measured by the intensity of a converging laser beam reflected from the back surface of the sample, polished to a mirror state. The residual sag due to bending increases with the heat load similarly as residual roughness of the front surface of the sample. These data, together with simultaneously measured temperature dynamics and the spatial heating profile, can provide an experimental basis for the numerical calculation of the residual stresses in the sample. The data obtained in situ were compared with those measured outside the vacuum chamber with X-ray diffraction, optical profiler, and optical interferometer. At the stage of cooling, after a sufficient intensity of heating, the second stage of damage took place — the cracking of the surface layer. The time before the start of this relatively fast process usually exceeded the time to achieve a DBTT by 1–4 orders of magnitude.

快速的热负荷对钨表面的影响的实验是在Budker Institute的BETA设施上进行的。钨样品被电子束均匀加热，其热通量因子低于熔化阈值。在曝光期间和之后不久，测量了2D表面温度分布以及选定表面积上的温度历史记录。使用连续波激光在电子束暴露的表面上的散射进行的主动诊断使我们能够监视损坏动态。在加热阶段，由于被加热层的弹性和塑性变形不均匀而导致表面粗糙度增加。随着冷却的进行，残留的塑性变形得以保留。同时进行表面修饰，厚度为3-4 mm的样品发生弯曲。样品的弯曲动力学是通过从样品的背面反射并抛光成镜面状态的会聚激光束的强度来测量的。弯曲引起的残留下垂随着热负荷的增加而增加，与样品前表面的残留粗糙度相似。这些数据，以及同时测量的温度动态和空间加热曲线，可以为样品中残余应力的数值计算提供实验基础。将原位获得的数据与在真空室内使用X射线衍射，光学轮廓仪和光学干涉仪测得的数据进行比较。在冷却阶段，在足够的加热强度之后，发生了第二阶段的损坏-表面层开裂。