By applying VORPAL to classical problems in computational physics, you gain confidence that your simulations are based on accurate physical models. Some examples of classical problem solutions achieved with VORPAL include:
Electromagnetics
Photonic Crystal
A photonic crystal is capable of confining electromagnetic fields in waveguides and cavities using a periodic geometry. In this study we will examine coupling of electromagnetic fields around a sudden bend in a photonic crystal slab waveguide. Read more...
Pillbox Cavity Modes
The most basic example of a resonant cavity is that of a pillbox design. This example of Pillbox Cavity Modes consists of a cylindrical cavity 7.65 cm in radius and 10 cm long. Read more...
Metal Waveguide
A waveguide is a key component of microwave devices. This example of a Metal Waveguide shows a standard WG-340 microwave waveguide operating at ν=2.5 GHz (lambda0 = 12 cm). Read more...
Wave Scattering
An electromagnetic wave, at oblique angle, impinges on an object, and detailed knowledge of the strength and pattern of the reflected wave is desired. VORPAL is capable of utilizing the full-field/scattered-field technique, which removes the incident wave pattern, outside a certain radius of the simulation, leaving just the scattered wave. Read more...
Mode Analysis of an A6 Magnetron
The A6 magnetron geometry was developed for high-powered microwaves. It is approximately 3 cm long and 9 cm radially. In VORPAL, we can extract the frequencies and modes of this cavity to help in the cavity design and tuning. Read more...
S-Matrix Simulation
A common measurement made on a 2-port rf device is reflection and transmission of an rf signals. This measurement results in the Scattering-Matrix, or S-Matrix. VORPAL provides the capability to simulate S-Matrix parameters for arbitrarily complex devices connected to waveguides propagating TE, TM, and TEM modes. Read more...
Electromagnetic Particle-in-Cell
Laser Plasma Acceleration
In this example of Laser Plasma Acceleration we look at the full PIC model with a 1 mm long plasma with uniform density of 1.e25 m-3. The laser wavelength is 800 nm with a waist of 9 μm. Read more...
Multipacting
Multipacting, which is the resonant build up of secondary electrons, is often a concern in radio frequency structures. Anytime a there is an oscillating electromagnetic field across a gap between two surfaces there exists the possibility that for the right field amplitude across the gap a resonance condition will exist allowing the exponential build up of secondary electrons. A coaxial waveguide is such structure where these conditions can exist. Read more...
Particles
Two-Stream Instability
The two-stream instability is a rapidly growing collision-less plasma instability arising from small charge imbalances. A local imbalance leads to the acceleration or deceleration of particles in its vicinity, which in turn leads to an even stronger imbalance. One setup that allows to easily observe the instability is two counterstreaming beams of identical charge in a periodic system. The advantage of this configuration is that the generated plasma wave becomes a standing wave, thus allowing to easily observe the formation of the phase space vortices. Read more...
Gas-Stopping Cyclotron
Gas-stopping cyclotrons have been used to decelerate high- or medium-energy particles to low energy for use in low-energy experiments such as those used to study material surface properties. These devices have been used to decelerate muons, pions, and antiprotons. A new device is being designed for ions. Read more...
Statics
Electrostatic Dipole
One basic physics concept is that of electric fields. Specifically, the fields of a point charge or point charge configurations. In this example of Electrostatic Dipole, we look at the electric field and the electric potential for two static point charges. The point charges are given equal values for the electric potential on their surfaces. VORPAL then uses an electrostatic solver to compute the static electric field and potential of the dipole system. Read more...