“…For absolute methods of determining neutron fluence (Soares et al, ), the efficiency should be constant when counting tracks in unknown age samples. The fast‐growing areas of FTD using the Laser Ablation Inductively Couple Plasma Mass Spectrometer (LA‐ICP‐MS, [Hadler et al, ; Hasebe, Barbarand, Jarvis, Carter, & Hurford, ; Soares et al, ; Soares, Mertz‐Kraus, Guedes, Stockli, & Zack, ]) or the electron microprobe (Dias, Chemale, Soares, & Guedes, ; Gombosi, Garver, & Baldwin, ) have the same efficiency issues, and could also benefit from automatic counting.…”