How did Patrick Blackett use a cloud chamber to study nuclear disintegrations?

Patrick Blackett utilized the Wilson cloud chamber—a device that visualizes the paths of ionizing particles—to study nuclear disintegrations by modifying the apparatus to function as an automatic instrument.12

In 1924, Blackett used this modified cloud chamber to photograph approximately 400,000 collisions involving alpha particles. By analyzing these photographs, he observed that while the majority of interactions were ordinary elastic encounters, eight instances clearly showed nuclear disintegration. These images revealed that the alpha particle was absorbed into the target nucleus, which subsequently ruptured into two fragments. This work provided the first visual evidence explaining the mechanism of such disintegrations, a significant contribution to the field of nuclear physics for which Blackett was awarded the 1948 Nobel Prize for Physics.21