Stable neodymium isotopic composition of nuclear debris samples

Fission reactions result in Nd isotope decay products which alter Nd isotopic compositions measured in nuclear debris. Trinitite samples measured by MC-ICP-MS show perturbations of Nd isotopes relative to 142 Nd, the only isotope of Nd which is blocked from fission product decay. By measuring 144 Nd/ 142 Nd and the total number of atoms of 142 Nd in the sample, it is possible to quantify the total number of fissions in nuclear debris, an important signature in post-detonation nuclear forensics.