The thickness of lead’s neutron ‘skin’ has been precisely measured
The atom’s nucleus is surrounded by a neutron shell just 0.28 trillionths of a millimeter thick
![a central component of the Lead Radius Experiment](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2021/04/042621_ec_neutronskin_feat.jpg?fit=1030%2C580&ssl=1)
By scattering electrons off of lead, the Lead Radius Experiment, or PREX-II, measures the thickness of a “skin” of neutrons that surrounds the atomic nucleus. The experiment (a central component shown) detects electrons using quartz crystals (transparent diagonal rectangles).
Kent Paschke