Dosimetry calculations characterizing the spatial variation of the energy deposited by the slowing and stopping of energetic electrons are reported and compared with experimental measurements from an electron microbeam facility. The computations involve event-by-event, detailed-histories Monte Carlo simulations of low-energy electrons interacting in water vapor. Simulations of electron tracks w...

The Radiological Research Accelerator Facility at Columbia University has recently added a UV microspot irradiator to a microbeam irradiation platform. This UV microspot irradiator applies multiphoton excitation at the focal point of an incident laser as the source for cell damage, and with this approach, a single cell within a 3D sample can be targeted and exposed to damaging UV. The UV micros...

This article concerns replicability of past results and consistency in data collection using X-ray microbeam and magnetometry, two prominent instruments for speech movement tracking. The same speaker was recorded on both instruments reading identical stimuli and using parallel experimental procedures and the same physician for transducer placement. Data from two X-ray microbeam (XRMB) runs were...

To perform high-throughput studies on the biological effects of ionizing radiation in vivo, we have implemented a microfluidic tool for microbeam irradiation of Caenorhabditis elegans. The device allows the immobilization of worms with minimal stress for a rapid and controlled microbeam irradiation of multiple samples in parallel. Adapted from an established design, our microfluidic clamp consi...

Free vibration of an axially loaded silicon microbeam in MEMS under electrostatic actuation is studied on the basis a sinusoidal shear deformation theory. Based modified couple stress theory (MCST) and von Kármán geometric nonlinearity, nonlinear finite element formulation derived employed to construct discrete governing equations for microbeam. The deflection at given DC voltage firstly calcul...

Some idea of the possibilities of microbeam techniques can be illustrated by examining the following example of a run of mine gold ore sample. Milling and bulk chemical analysis of the ore will provide major and minor element analysis as well as the gold grade. More detailed chemistlY can also reveal the presence of trace elements that may be advantageous or deleterious to downstream processing...

Comparative Dosimetric Estimates of a 25 keV Electron Microbeam with Three Monte Carlo Codes

A single-cell/single-particle microbeam has been designed in which the radiation source is a high specific-activity alpha-particle emitting radioisotope, rather than a particle accelerator. The source is imaged at the focal point of a compound magnetic lens array. A novel precision microscope stage with an extremely compact design is included with the endstation s locating, targeting and imagin...

Our goal was the visualizing the vascular damage and acute inflammatory response to micro- and minibeam irradiation in vivo. Microbeam (MRT) and minibeam radiation therapies (MBRT) are tumor treatment approaches of potential clinical relevance, both consisting of parallel X-ray beams and allowing the delivery of thousands of Grays within tumors. We compared the effects of microbeams (25-100 μm ...

Electrostatically actuated microbeams have been studied by many researchers in the last few years. The aim of this study is to present an improved numerical analysis of the dynamic instability of a cantilever microbeam immersed in an incompressible viscous fluid. The finite element method is used for solving the vibrational equation of the microbeam and the potential functions of the fluids in ...