A radiation source is configured to generate radiation. The radiation source includes a first electrode and a second electrode configured to produce an electrical discharge during use to generate radiation-emitting plasma from a plasma fuel. The radiation source also includes a fuel supply configured to supply a plasma fuel to a fuel release area that is associated with the first electrode and the second electrode, and a fuel release configured to induce release of fuel, supplied by the fuel supply, from the fuel release area. The fuel release area is spaced-apart from the first electrode and from the second electrode.