The John D. Fox laboratory operates a two-stage accelerator
comprised of a 9~MV Super-FN tandem van-de-Graaff accelerator and an
8~MV superconducting linear accelerator (LINAC). The Super-FN tandem
is injected by either a NEC SNICS-II cesium sputter ion source, for
most beams created from solid chemicals, or an NEC rf-discharge source
for beams generated from gaseous materials, most
importantly 3He and 4He. Among the beams
available from the sputter source is the radioactive isotope 14C.
A negative beam enters the TANDEM on the Low-Energy (LE) end, and is accelerated towards the High-Energy (HE) end by a voltage potential generated by the van-de-Graff generator consisting of two rotating chains. At the midpoint of the TANDEM, the negative beam strikes a stripper foil which ``strips'' it of electrons, causing the beam to become positive and carry on into the rest of the lab.
|Beam||Tandem||Current||Stage 2||Stage 3||Stage 4|
|3He||8.7 MeV/u||12.2 MeV/u||13.5 MeV/u|
|6Li||5.8 MeV/u||9.1 MeV/u||10.5 MeV/u|
|16O||3.8 MeV/u||7.8 MeV/u||8.8 MeV/u||10.2 MeV/u||10.7 MeV/u|
|24Mg||2.9 MeV/u||6.4 MeV/u||7.4 MeV/u||8.8 MeV/u||9.5 MeV/u|
|32S||2.4 MeV/u||5.6 MeV/u||6.4 MeV/u||7.9 MeV/u||8.8 MeV/u|
|40Ca||2.2 MeV/u||4.7 MeV/u||5.5 MeV/u||6.9 MeV/u||7.9 MeV/u|