Meqalac Results - Multichannel Rf Acceleration of Nitrogen-Ions to 1 Mev

In the MEQALAC (Multiple Electrostatic Quadrupole Linear Accelerator) multiple N+ ion beams are accelerated in 32 rf gaps, which are part of a modified interdigital-H-resonator operating at 25 MHz. The transverse focusing of the intense ion beams is achieved by means of sets of miniaturized electrostatic quadrupoles. Results are presented which show that the ion beams are accelerated to 1 MeV. The energy spread is less than 8%. The bunches are shorter than a quarter of the rf period, the peak current is 0.90 mA. The maximum time-averaged beam current measured is 0.20 mA in a single channel, in four channels it is 0.56 mA. This is less than the theoretically predicted current. It is shown that the smaller transmission is due mainly to misalignment of the quadrupole lenses. The rf power coupled into the resonator is around 30 kW, with a possible duty cycle above 90%.