We report in this article the development of a tool to design and evaluate aerodynamic lens systems: the Aerodynamic Lens Calculator. This Calculator enables quick and convenient design of aerodynamic lens systems based on the parameterized knowledge gained from our detailed numerical simulations of flow and particle transport through aerodynamic lens systems. It designs the key dimensions of a...

In this paper airflow, nano-and micro-particle motions in an aerodynamic particle beam focusing system consisting of several lenses, a nozzle and the downstream chamber, was studied. A three-dimensional numerical simulation for the system was presented and the compressible airflow and thermal conditions in the aerodynamic lens system were evaluated. Dilute particle concentration was assumed so ...

We have designed and characterized a new inlet and aerodynamic lens for the Aerodyne aerosol mass spectrometer (AMS) that transmits particles between 80 nm and more than 3 μm in vacuum aerodynamic diameter. The design of the inlet and lens was optimized with computational fluid dynamics (CFD) modeling of particle trajectories. Major changes include a redesigned critical orifice holder and valve...

in this research between 3-dimensional and axisymmetric modeling for movement of nano-particles in passing through a aerodynamic lens, and also between these models and famous model of wang & liu was compared. for this purpose, output of nano-particles penetration, divergence angel, and nano-particle velocity with wang & liu model was compared. geometrical model used for aerodynamic lens compar...

This is an instruction manual for the aerodynamic lens design tool: the “Aerodynamic Lens Calculator”. We explain how to install and use this software. Examples are provided to use this tool to design or test a lens system. The structures of the source code programming are also provided in this manual. The design tool and its manual mentioned in this article are available in the publisher’s onl...

We have developed a numerical simulation methodology that is able to accurately characterize the focusing performance of aerodynamic lens systems. The commercial computational fluid dynamics (CFD) software FLUENT was used to simulate the gas flow field. Particle trajectories were tracked using the Lagrangian approach. Brownian motion of nanoparticles was successfully incorporated in our numeric...

Flight Mass Spectrometers (ATOFMS) in the 3800 series of instruments with built-in Aerodynamic Focusing Lens technology. Without a focusing lens, the ATOFMS samples particles from a variety of sources through a nozzle. Typically, particles from about 100 to 3000 nanometers are sampled with sharply decreasing efficiency for smaller sizes. To overcome this size bias, to sample smaller particles e...

Particle beams have traditionally been produced by supersonic expansion of aparticle-ladengas through a single nozzle to vacuum. However, it has been shown that, by passing the particle-laden gas through a series of axi-symmetric subsonic contractions and expansions (an aerodynamic lens system) prior to the supersonic expansion to vacuum through a single nozzle, beam divergence can be signiŽ ca...

This article describes the challenges in focusing nanoparticles (<30 nm) into tightly collimated beams, and provide guidelines for designing aerodynamic lens systems for nanoparticles. The major difficulties of focusing nanoparticles arise from their low inertia and high diffusivity. Because of their low inertia, nanoparticles tend to closely follow gas streamlines; their high diffusivities lea...