The secondary electron yield due to polonium‐210 alpha particles emerging from a thin gold surface layer was determined to be 9.2 for an average alpha‐particle charge of 1.86. This result is consistent with yield observations with other high energy charged particles. The ratio of the yield due to fission fragments at normal incidence coming from UO2coatings to the yield due to alpha particles at normal incidence coming from gold was found to be about 20, substantiating the assumption that the secondary yield is proportional to the mass stopping power of the target material. A weak dependency of the yield on electric field was observed; an increase of approximately 8% resulted from a field of 3×105V/m. A slightly more pronounced field dependency was observed for the yield from fission fragments.