Negative hydrogen ion sources for accelerators

Abstract

A variety of H ion sources are in use at accelerator laboratories around the world. A list of these ion sources includes surface plasma sources with magnetron, Penning and surface converter geometries as well as magnetic-multipole volume sources with and without cesium. Just as varied is the means of igniting and maintaining magnetically confined plasmas. Hot and cold cathodes, radio frequency, and microwave power are all in use, as well as electron tandem source ignition. The extraction systems of accelerator H ion sources are highly specialized utilizing magnetic and electric fields in their low energy beam transport systems to produce direct current, as well as pulsed and/or chopped beams with a variety of time structures. Within this paper, specific ion sources utilized at accelerator laboratories shall be reviewed along with the physics of surface and volume H production in regard to source emittance. Current research trends including aperture modeling, thermal modeling, surface conditioning, and laser diagnostics will also be discussed.

Ion Source Choices — An H− Source for the High Intensity Neutrino Source

“…No attempt to normalize or separate out cathode, aperture or LEBT/pre-accelerator types has been made, nor was the measurement apparatus or analysis method investigate or accounted for with the exception of the right most data point which was included twice. In some cases a Gaussian beam approximation was assumed in order to convert fractional emittance to RMS [6]. Fig.…”

“…The straight line is a linear fit to the data and the curve line represents a square root fit to the data. The emittance values in this plot were gleaned from the following references [6,11,12,13,14,15,16,17,18,19].…”

“…[6]. In this paper, long pulse tests of the SNS RF source, the DESY RF source and the BNL style magnetron are presented.…”

An experimental study of waveguide coupled microwave heating with conventional multicusp negative ion sources

“…Therefore, negative ions are extracted with reasonably low amount of co-extracted electrons. A filament driven arc discharge or inductively coupled RF-discharge driven by an internal or external antenna are typically used to sustain the main discharge [2].…”

Cesiation in highly efficient surface plasma sources

“…Reviews of SPS development and their use in accelerators and in neutral beam injectors are presented in Refs. [3,[5][6][7][8].…”