The ornaments represent the majority of the constituents of the plasma in the ion source, which sits at the beginning of Fermilab’s chain of accelerators. The ornament marked “H” represents hydrogen; its red color represents hydrogen’s emission spectrum. The blue ornament marked “Cs” represents cesium and its blue emission spectrum. The “e” stands for electrons, and “H-” stands for negative hydrogen ions. Members of the Accelerator Division extract H- ions from the source, inject them into the radio-frequency quadrupole and accelerate them down the Linac. See part 1. Photo: Dan Bollinger, AD