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CyberRay is a particle beam simulator operating in the regime of geometric optics. A CyberRay beam consists of either charged particles or photons. The state of a beam at various times is determined by calculating the path of every particle in the beam through some set of objects in three-dimensional space. The simulation is fully 3D, and is capable of determining any spatial, temporal, or spectral properties of the beam.
Optical Beam Modeling
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Charged Particle Beams
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CyberRay features an excellent graphical user interface complete with 3D rendering of the virtual apparatus and animation of the particle trajectories as they are computed. Exhaustive diagnostic capabilities allow virtually any data regarding the beam to be recorded. CyberRay runs on either Mac OS X or Windows 2000/XP.
The CyberRay user interface is designed such that the process of running a simulation resembles that of performing an experiment. To prepare a virtual experiment, one selects the appropriate items from the equipment window. For instance, to include a source of photons in the virtual apparatus, one would press the "Lamp" button, which would bring up the following dialog box:
The user sets the various dialog fields to the desired values and presses the "OK" button. Then the lamp is part of the apparatus. It will appear in the "Apparatus View" window, shown below:
This particular apparatus consists of a lamp, a converging lens, a diverging lens, a spherical mirror, and a beamsplitter. Also shown are the trajectories of a large number of photons. The picture can be rotated using the sliders, or the observer can move around as in a flight simulator by using the mouse. Multiple apparatus views can be open simultaneously, allowing the user to observe the apparatus from various viewpoints. The user can even fly around with the particles!
After building the virtual apparatus, the user simply selects "Run Simulation..." from the menu bar. This generates the photon trajectories shown above.
While the simulation is running, the motions of the particles will be animated in all apparatus view windows. This is the simplest way to retrieve feedback from the simulation. Quantitative information, however, must be obtained using detectors. Detectors are treated just like another piece of equipment.
Suppose we have an apparatus consisting of a linac and a fluorescer. A fluorescer is a detector that measures the transverse positions of any particles that hit it. After the simulation, the console window would report information regarding the hits on the fluorescer:
The first two lines here were produced by an apparatus with no detectors. The next set of lines contain the results from the fluorescer simulation. The centroid of the hits and the spot size in each direction implied by the hits are computed. In addition, a scatter plot window would be created showing the actual particle hits:
The coordinates of the hits on the scatter plot can be exported for analysis by other software. The plot itself can be saved in PDF format.
Beam monitors can be used to interactively monitor the progress of a beam in any two dimensions of phase space. Here is an example of a beam monitor window:
As the simulation runs, the plot is constantly updated to reflect the current state of the beam. The popup menus can be used to select the phase space axes from a range of values including x,y,z,px,py,pz,r,theta,pr,ptheta,vx,vy,vz,vr,vtheta.
CyberRay models light beams according to a photon kinetic model. This means that a light beam is approximated by a statistical distribution of photons in six-dimensional phase space. Optical systems are modelled by allowing each photon to interact with some set of three dimensional objects in space. The objects are generally composed of reflecting surfaces, absorbing surfaces, or solid pieces of dielectric. Examples include lenses, prisms, apertures, etc. A graded index of refraction can be applied to any object composed of solid dielectric. The gradient profile can be specified to fifth order, and can be applied linearly, radially, or spherically. Four orders of dispersion can also be included. Objects can be placed in contact with one another. Overlapping objects are dealt with in a consistent manner.
Here are some photon trajectories through a plano-plano GRIN lens:
Gaussian beams fit naturally into the photon kinetic model. If one chooses the transverse emittances from the lamp dialog box to be the photon wavelength in microns, the resulting photon distribution function will evolve exactly the same way a diffraction limited Gaussian beam would. One simply replaces the energy density of the wave with photon density. Higher emittances correspond to a less than diffraction limited beam, while lower emittances correspond to the idealized non-physical beams of geometric optics. For more on the theory of photon kinetics, click here.
CyberRay models charged particle beams also using particle kinetics. Charged particles are initialized into some phase space configuration, and are allowed to interact with various three-dimensional objects. The physical models available include
Here is an image of transition radiation. The blue rays are the photons emitted by 2 MeV electrons incident on a metal foil inclined at 45 degrees:
CyberRay's easy integration of photon and particle optics into one package is so beautiful we refuse to separate CyberRay into two packages as many people advise. Instead, we charge a price commensurate with only one of CyberRay's two capabilities so you only pay for what you need despite the fact that you get everything. If you don't need to model particle beams, don't worry. The fact that there are some magnets on the equipment shelf won't get in your way at all. Think of it as having a particle beam lab next door to your optics lab. If you ever decide to go in, it will be there waiting.
If you do happen to be interested in both charged particles and photons, then CyberRay is clearly your solution. Only with CyberRay could you launch an electron beam into a magnetic lens, focus it into a glass lens, allow the electrons to scatter through the glass while emitting Cherenkov photons, allow the Cherenkov photons to refract as they leave the glass, and all the while allow the electrons to exert space charge forces on themesleves. With CyberRay, such a simulation is not only possible, it's easy!
A CyberRay simulation consists of the interaction between beams and various objects. The objects are in general three-dimensional objects which can be placed anywhere in space and in any orientation. The user can often create new objects by joining the predefined objects together.
Here is a table of all the objects available in CyberRay 2.3:
| Particles | Surface Optics | Solid Optics | Fields | Hardware | Detectors |
| Linac | Flat Mirror | Spherical Lens | Solenoid | Tube | Counter |
| Lamp | Ideal Lens | Cylindrical Lens | Quadropole | Aperture | CCD |
| Thermal Electrons | Ideal Cyl. Lens | Axicon | Rectangular Dipole | Rectangular Aperture | Fluorescer |
| Thermal Photons | Spherical Mirror | Prism | Sector Dipole | Thin Foil | Transverse Phase Plane |
| File Electrons | Cylindrical Mirror | Paraboloid | File Magnet | Shutter | Longitudinal Phase Plane |
| File Photons | Parabolic Mirror | Ellipsoid | File Electrode | Filter | Streak Camera |
| Ellipsoidal Mirror | Block | Circular Dipole | Slit Array | Spectrometer | |
| Pellicle Beamsplitter | File Dielectric | Switcher Magnet | R Matrix | ||
| Grating | Axisymmetric File Magnet | Phase Dump | |||
| Retro Reflector | Axisymmetric File Electrode | ||||
| Toroidal Mirror | Wiggler |
Features of CyberRay Objects:
CyberRay offers a data acquisition feature which allows the user to automatically run a sequence of simulations during which two arbitrary sets of parameters are varied. The data from each simulation is recorded in any number of tables. Simple graphing facilities are provided for quickly viewing the data in tables. The tables can also be saved as ASCII files.
Below is an example of a table created for a fluorescer. The tabs allow the user to switch between data sets corresponding to the two axes of the fluorescer.
Below is an example of an intensity plot created from a table of data created by a counter.
Click to here to obtain a free demo version of CyberRay, now available for either Windows 2000/XP, Mac OS X, or classic Mac OS.