Miniature induction oven for ion sources optimisation

The space and power limitation frequently arising when inserting ovens into ion sources lead us to explore alternatives to the direct current ohmic heating. An induction oven has the following advantages over a resistance one: a) the current in the induction coil is lower; b) heating may be concentrated on the sample surface by choosing the right value of the frequency and the total power is limited; c) there is no contact between the heating coil and the heated sample; in fact a boron nitride crucible separates the sample from the coil. A tantalum enclosure minimizes EMI and coupling to the plasma. The technological and optimisation problems due to the limited size are discussed. In perspective, these devices may heat a broad range of elements up to 2000 K extending application of any ion volume sources.