Low-energy H− injector design for SSC RFQ

We present a design for the low‐energy H− injector. It is used in conjunction with a rf‐driven multicusp source and will deliver 30 mA of H− at 35 kV, at a pulse length of less than 1 msec to a RFQ downstream (used in the LINAC booster of the SSC, for example). It has several distinguishing features and meets the goal of having an outgoing beam free of electron contamination, with small radius, large convergent angle and small projectional emittance. The specific example presented meets all the requirements of the injector for SSC RFQ. However, the principle and method used should easily be adapted for the designs of injectors with similar requirements for other purposes.