Progress in submicron width ion beam system using double acceleration lenses

Production of a microbeam of slow highly charged ions with a tapered glass capillary

“…Using such lenses, submicron ion beam of a few tens of keV region was reported, 15 where lenses with small aberration and an ion source with good emittance were employed. Our method presented here is not so sensitive to the initial beam with broad energy spread and divergence, and was realized just by a tiny tapered glass tube of ϳ50 mm in length.…”

Generalization of the Langmuir–Blodgett laws for a nonzero potential gradient

“…In light of these observations, the authors of this paper were not able to find any generalizations of the planar, cylindrical, or spherical cases applicable to plasmas in the literature, and, as many papers on the extraction of ions from plasmas employ the Langmuir-Blodgett relations either directly 10,9 or indirectly by using elements of the Pierce electrode design method, 18,21,17 it is of some interest to develop an expression for the flow of particles in diodes based on the boundary conditions implied by extraction from a plasma.…”

“…The most recent work in the literature on the extraction of ions from plasmas still seems to be based on the Pierce method and therefore relies on the Child-Langmuir and Langmuir-Blodgett laws. 17,18 Two important assumptions underpinning these relations are that both the electric field and the initial velocity of the particles at the emission surface are zero. Although these may hold for thermionic emission from a hot filament ͑as was Child, Langmuir, and Blodgett's initial intention͒, the assumption that the electric field at the emission surface is zero, central to the Langmuir-Blodgett derivations, is incorrect in the case of particle extraction from a plasma because the field across the meniscus is commonly several hundred kilovolts per meter.…”

Note: Proton microbeam formation with continuously variable kinetic energy using a compact system for three-dimensional proton beam writing

“…To use the proton microbeam widely for 3D PBW applications, a compact system in keV range, namely, a focused gaseous ion beam (gas-FIB), has been developed at Japan Atomic Energy Agency (JAEA). 9,10 The gas-FIB system has a plasma ion source using hydrogen gas to generate a proton beam and is composed of a series of two electrostatic lenses, called the "acceleration lens system," each of which is a pair of disk-shaped electrodes with a small center hole (hereinafter referred to as acceleration lens). 10 The acceleration lens system has an extraction stage and a few acceleration stages.…”

“…In fact, a beam diameter of 160 nm has been obtained with a 46 keV proton beam focused by a previous acceleration lens system of 300 mm length which consisted of two acceleration stages, and the demagnification reached more than 1000. 9 However, this previous gas-FIB system is not sufficient for application in 3D PBW because of the short penetration depth in the sample due to the low kinetic energy. A higher energy gas-FIB to form a proton microbeam of at least several hundreds of keV, which corresponds to a penetration depth of micrometer range, is necessary for application to 3D PBW microfabrication.…”