Toolbox Development For Miniature Integrated Particle Actuator
Charged particle beam actuators such as particle accelerators and particle beam optics systems have wide applications in industry and academia, from medical and industrial diagnostics to investigations in fundamental science. This work details the preliminary efforts in the miniaturization of charged particle accelerators and manipulators to be highly compact and portable, by developing a toolbox of beam actuation components, which can be integrated for different applications. The three components that were developed are the electrostatic curved particle beam guide, a co-planar waveguide based RF resonator architecture for linear accelerators, and the Einzel lens for beam focusing. The central thesis is to use micro-fabrication techniques to attain micron precision in structures with 100-500 micron feature sizes, channels in which high electric fields (>106V/m) could be sustained to act upon charged particles. The use of electrostatic fields is feasible in many applications, eliminating the need for permanent magnets required in macro-scale charged particle systems. The micro-fabricated components utilizing electrostatic fields are realized on a planar substrate with the electrodes defined by micro-machined doped silicon or PCB copper, on a substrate such as silicon handle wafer or PCB dielectric. Within the planar implementation, the charged particle beam propagates in the plane of the substrate, with device sizes varying from 1cm2 chips to cell-phone dimensions. Micro-fabrication processes were developed to accommodate electrically isolated actuator patterning, as well as multilayer high aspect-ratio structures. Planar fabrication and assembly would enable integration of the individual components of the toolkit with micron-precision channel-channel alignment within each layer. Ar+ ion guidance of 90° and 127.5° are demonstrated in 10[MICRO SIGN]m channels of radii of 1mm and 2mm. On-chip Ar+ ion acceleration and deceleration of 30eV is also shown with the use of longitudinal electrical fields of a linear accelerator channel (driven at 35MHz). Using an electrostatic lens focusing of a beam of 2keV electrons is achieved in the plane of the substrate, with focal length shifts of up to 167mm for lens actuating voltages up to 300V. The components of the charged particle beam manipulation toolkit pave the way towards miniaturized systems with applications including e-beam and ion beam imaging, lithography, x-ray generation, spectroscopy, biological scanning and ion-beam therapy.
Miniature particle accelerator; charged beam manipulation chip-scale; focusing guiding
Pollock, Clifford Raymond; Rana, Farhan; Muller, David Anthony
Ph. D., Applied Physics
Doctor of Philosophy
dissertation or thesis