Tritium consists of about 4.5 kilograms of plutonium-239. Since tritium undergoes radioactive decay, and is also difficult to confine physically, the much larger secondary charge of heavy hydrogen isotopes needed in a true hydrogen bomb uses solid lithium deuteride as its source of deuterium and tritium, producing the tritium "in situ" during secondary ignition. During the detonation of the primary fission bomb stage in a thermonuclear weapon (Teller-Ullam staging), the sparkplug, a cylinder of U-235/Pu-239 at the center of the fusion stage(s), begins to fission in a chain reaction, from excess neutrons channeled from the primary. The neutrons released from the
On-Line Isotope Mass Separator or to the REX accelerator for acceleration to higher energies. The facility is operated by the ISOLDE Collaboration comprising CERN and 9 European countries. One of the major experiments in ISOLDE is the Miniball-setup. An upgrade of the post-acceleration system is currently on-going, ready to produce energetic Radioactive-Ion Beams (RIBs) of up to 10 MeV per nucleon in 2018. On-Line Isotope Mass Separator The On-Line Isotope Mass Separator, also known as the ISOLDE Radioactive Ion Beam Facility, is a facility located at CERN on the PS Booster. It started operating in 1967 and was rebuilt twice with major upgrades in