Cavendish Laboratory : Diagram of C.T.R. Wilson's expansion chamber

Cavendish Laboratory

<p style='text-align: justify;'>C.T.R. Wilson used this type of expansion chamber in the 1890s in his research on water vapour condensation. He showed that water droplets can condense on ions and not just on dust particles, as was previously believed. He calculated the critical expansion ratios required to cause condensation on ions and neutral nuclei respectively. These were later crucial for his subsequent cloud chamber experiments. Reference: https://doi.org/10.1098/rsta.1897.0011</p>