Matching And Transport Of Beams In A Continuously Twisted Quadrupole Channel

Twisted quadrupole (stellarator) focussing can reduce dis- persion in the bends of a recirculating accelerator, such as the Spiral Line Induction Accelerator(l) (SLIA) under de- velopment at Pulse Sciences. Envelope oscillations caused by guide field/stellarator transitions add free energy to the beam which can couple into the beam emittance. This ef- fect can be reduced by phase space matching of the beam at the transitions. We present experimental results on the coupled 4-D problem of envelope matching into a straight helical quadrupole channel, compare these results against envelope code predictions, and discuss expected benefits from such matching in a few-turn accelerator system.