Novel Microscopy Development
Apertureless Nearfield Scanning Optical Microscopy (ANSOM)
As the requirement for viewing images at high spatial resolutions increases, the complexity in the imaging tools also increases. The near-field nanoprobe is one of the nanometrological tools capable of seeing at the nanoscale and is a relatively modern tool compared to the conventional optical and electron microscopes. Chemical etching, electron/focused ion beams, and carefully applied thin-film deposition techniques make it possible to fabricate very high-resolution imaging probes. These systems are capable of detecting fluorescence, Raman, and other nonlinear signals at spatial resolutions previously thought impossible.
Neutral Atom Microscopy (NAM)
Scanning surfaces using a beam of noncharged atoms or molecules allows for especially nondestructive and low-energy surface imaging, with the potential to obtain new information about surfaces that cannot be easily obtained otherwise. We have developed a new approach, operating with the sample at a close working distance from an aperture, the need for optics to focus the beam is obviated. Compared to more complex approaches, the theoretical performance has no other disadvantage than the short working distance. Resolution of 1.5 μm has been achieved, and submicron resolution appears to be practical. Construction of the microscope and results are presented, including first images done in reflection mode, theory for optimization of the design and avenues for future improvement.
Electron and Ion Microscopies
Our group designs a lot of prototype systems utilizing electron and Ion beams, we use these microscopes to teach students how these machines work. In addition, novel emitter sources and attachments have been invented by our group to increase the usefulness of these systems for use as educational tools as well as novel research tools.
Numerical Modeling
Our group utilizes different forms of numerical modeling, from Finite difference time domain (FDTD), monte carlo particle simulations (SIMION), particle in a cell (PIC) and a home made Vlasov solver in order to solve problems in both microscopy development and Fusion research. Utilizing a 3D Finite Difference Time Domain (FDTD) technique for the modeling of tip shapes coupled with the use of a dual-beam Focused Ion Beam (FIB), it has been possible to design tips with high electric field enhancement factors in order to achieve ultra-high resolution spectroscopic images. We use our universities high performance clusters (HPCs) to solve these complex problems.
Fusion Research
While the majority of fusion energy research is focused on magnetic confinement, there have been several alternative confinement methods aimed at the development of smaller and less expensive reactors. A number of these alternative reactors are based on a spherically convergent beam of recirculating ions and include designs such as inertial electrostatic confinement (IEC), multi-grid IEC, and the periodically oscillating plasma sphere (POPS) concept. Our work involves a combination of techniques to improve the level of neutron emission from the fusion reactor in our lab at Portland State University.
Material Development
Our efforts in material started with YBCO single crystal superconductors and have branched out to scintillation crystals, 3D additive machining of alloy materials and PVD of dielectrics as well as alloying metals. We are presently creating a 3D metal powder printer for fabrication of parts for our fusion reactor as well as microscopy development.
Physics Education
Our group creates multiple labs for learning upper-level physics courses. In addition, our group has created a novel microscope design which allows people to learn advanced microscopy though making the microscope from scratch and learning its inner workings and how to correctly operate it. It is an amazing project involving a lot of different ways of thinking about how one can image objects at the submicron level.
High Electric Field Research
Our group often has to create large electric fields in order to test reactor designs. We have developed several Marx generators, Cockcroft Walton Multipliers, HV DC supplies, and RF generators. As of late, we have been looking into novel DC electrostatic generator design.