An ion source with a crucible is disclosed. In some embodiments, the crucible is disposed in one of the ends of the ions source, opposite the cathode. In other embodiments, the crucible is disposed in one of the side walls. A feed material, which may be in solid form is disposed in the crucible. In certain embodiments, the feed material is sputtered by ions and electrons in the plasma. In other embodiments, the feed material is heated so that it vaporizes. The ion source may be oriented so that the crucible is disposed in the lowest wall so that gravity retains the feed material in the crucible.