## How to Use the New Ray Termination Feature for Geometrical Optics

##### Christopher Boucher May 2, 2017

The release of version 5.3 of the COMSOL Multiphysics® software includes a new Ray Termination feature to simplify the setup and results analysis for optical simulations with the Ray Optics Module. Use the Ray Termination feature to remove rays that are no longer relevant to the solution, either because they have escaped from the geometry or their intensity is negligibly small. In this blog post, we’ll learn how to use this feature and see how it simplifies ray optics simulation.

### Sampling from Phase Space Distributions in 3D Charged Particle Beams

##### Christopher Boucher September 22, 2016

In the previous installment of this series, we explained two concepts needed to model the release and propagation of real-world charged particle beams. We first introduced probability distribution functions in a purely mathematical sense and then discussed a specific type of distribution — the transverse phase space distribution of a charged particle beam in 2D. Now, let’s combine what we’ve learned and find out how to sample the initial positions and velocities of 3D beam particles from this distribution.

### Phase Space Distributions and Emittance in 2D Charged Particle Beams

##### Christopher Boucher September 19, 2016

Previously in our Phase Space Distributions in Beam Physics series, we introduced probability distribution functions (PDFs) and various ways to sample from them in the COMSOL Multiphysics® software. Such knowledge of PDFs is necessary to understand how ion and electron beams propagate within real-world systems. In this installment, we’ll discuss the concepts of phase space and emittance as they apply to the release of ions or electrons in beams.

### Sampling Random Numbers from Probability Distribution Functions

##### Christopher Boucher September 15, 2016

In this blog series, we’ll investigate the simulation of beams of ions or electrons using particle tracking techniques. We’ll begin by providing some background information on probability distribution functions and the different ways in which you can sample random numbers from them in the COMSOL Multiphysics® software. In later installments, we’ll show how this underlying mathematics can be used to accurately simulate the propagation of ion and electron beams in real-world systems.

### How to Model Solar Concentrators with the Ray Optics Module

##### Christopher Boucher June 23, 2016

A paraboloidal solar dish can focus solar radiation onto a small target or cavity receiver. Because solar energy is collected over a large area, the incident heat flux at the receiver is extremely high. This thermal energy can then be converted to electrical energy or used to produce a chemical energy source, such as hydrogen. Today, we discuss strategies for computing the distribution of heat flux in the focal plane of a typical solar dish concentrator/receiver system.

### Using the New Ray Tracing Algorithm in COMSOL Multiphysics® 5.2a

##### Christopher Boucher June 20, 2016

With the release of COMSOL Multiphysics® version 5.2a, it is now possible to trace rays in unmeshed domains and even release and trace rays outside a geometry. The Ray Optics Module provides an entirely new algorithm that offers these capabilities and more, so that you can model your ray optics designs with ease and accuracy. Let’s investigate how this new algorithm affects your workflow when setting up a typical ray optics model.

### Evaluating Static Mixer Performance with a Simulation App

##### Christopher Boucher June 8, 2016

Static mixers are well-established tools in a wide variety of engineering disciplines due to their efficiency, low cost, ease of installation, and minimal maintenance requirements. When evaluating whether a mixer can be used for a certain purpose, it is important to determine whether the resulting mixture is sufficiently uniform. In this blog post, we will discuss the setup of an app designed to quantitatively and qualitatively analyze the performance of a static mixer using the Particle Tracing Module.

### Modeling Thin Dielectric Films in Optics

##### Christopher Boucher May 6, 2015

Thin dielectric films are versatile tools for controlling the propagation of light. They can be used, for example, as anti-reflective coatings to reduce the amount of stray light in a system. They can also be used as low-loss reflectors or as filters to selectively transmit certain frequencies of radiation. Here, we’ll discuss some of the built-in tools that the Ray Optics Module provides for modeling optical systems with dielectric films.

### Ray Tracing in Monochromators and Spectrometers

##### Christopher Boucher December 25, 2014

Optical devices such as monochromators and spectrometers can be used to separate polychromatic, or multi-colored, light into separate colors. These devices have many applications in diverse areas that range from chemistry to astronomy. Using built-in tools in the Ray Optics Module, it is possible to model the separation of electromagnetic rays at different frequencies with a monochromator or spectrometer as well as analyze the resolution of such devices.

### New Accumulators Boost Particle and Ray Tracing Functionality

##### Christopher Boucher November 26, 2014

With the release of COMSOL Multiphysics version 5.0, the Particle Tracing Module now includes a series of features called Accumulators, which can be used to couple the results of a particle tracing simulation to other physics interfaces. The accumulated variables may represent any physical quantity and can be defined either within domains or on boundaries, making them extremely flexible. Here, I will explain the different types of accumulators and their applications in particle tracing and ray optics models.

### Modeling Thermally Induced Focal Shift in High-Powered Laser Systems

##### Christopher Boucher November 18, 2014

Almost all media absorb electromagnetic radiation to some extent. In high-powered laser focusing systems, a medium such as a glass lens may absorb enough energy from the laser to heat up significantly, resulting in thermal deformation and changing the material’s refractive index. These perturbations, in turn, can change the way the laser propagates. With the Ray Optics Module, it is possible to create a fully self-consistent model of laser propagation that includes thermal and structural effects.