Characterization of field emitter arrays for compact neutron sources utilizing field ionization

Compact neutron generators with a low power consumption can be used in portable material analysis, active interrogation and oil-well logging application. Important parameters for these generators are size, energy use, neutron yield and lifetime. Today, plasma sources using either hot or cold cathode discharge are in use, many applications also rely on radioactive material for neutron production. We investigate the use of a field ionization source for these applications that can lead to a replacement of these sources.Neutrons are produced by creating deuterium ions and accelerating these ions into a deuterated target where a D/D fusion reaction takes place [1]. Acceleration voltages of the order of 100kV are needed to maximize the yield while keeping the design compact. Field ionization is an alternative way to create ions in a plasma-free environment that has the promise to provide a long lifetime and low power consumption. Ion productions from single tips is routinely achieved in, for example, helium ion microscopes [2] and the challenge is to scale this mechanism from one tip to a large assembly of tips. To minimize shielding effects of close by tips, arrays of field emitters are investigated. We will report on our current progress to achieve uniform field ionization across a 1cm x 1cm array of tips. Experimental data showing neutron production, uniformity measurement using a scintillator screen and data from characterization using electron emission will be presented.deuterium ionsD/D fusion reactionAcceleration voltages