In this work, the features of secondary emission phenomena were investigated under cluster bombardment. The emission of ion‐photons, secondary ions, and electrons associated with the thermal peak regime were experimentally carried out. The experiments were conducted using modernized a static magnetic mass spectrometer. The integral yield of secondary ion and electron emission was measured by bombarding Tb and Tm targets with cluster ions Aum− (m = 1–9) and Bim− (m = 1–7) within the energy range of 1–21 keV for the bombarding ions. Additionally, the integral yield of ion‐photon emission was measured by bombarding a Tm target with cluster ions Bim− (m = 1–5) within the same energy range. The experimental results showed that an increase in the yield of ion‐photon emission, secondary ion, and ion‐electron emission was observed with an increase in the number of atoms bombarded by cluster ions. This can be explained the formation of thermal peaks under dense collision cascades.