Getting Started
Screen Shots
Version History

SPring-8 Home

Welcome to the SPECTRA home page!

2012/01/27: Version 9.0.2 has been released

What is SPECTRA?

SPECTRA is an applicaltion software to calculate optical properties of synchrtron radiation emitted from bending magnets, wigglers (conventional and elliptical) and undulators (conventional, helical, elliptical and figure-8). Calculations of radiation from an arbitrary magnetic field distribution is also available. Parameters on the electron beam and the source can be editted completely on graphica user interfaces (GUIs) and it is possible to show the calculation result graphically. The energy spectrum and radiation power after transmitting various filters and convolution of detector's resolution are also available.

Supported Operating Systems

The graphical part of SPECTRA is writtend in the C++ language with wxWidgets GUI tool kit and OpenGL graphic library. Thanks to portability of these libraries, SPECTRA will run on most available operating systems such as Microsoft Windows, Mac OS X, Linux, and most unix-like operating systems.

Important Notes on Brilliance Calculation

From version 7.0, the definitions of the natural divergence and source size of undulator radiation, which are necessary to calculate the brilliance, have been change as summarized in the below table. Because of this, the brilliance of undulator radiation calculated with 7.0 or later may be lower than that with 6.1 or earlier by about factor of 0.3 to 0.4 (dependent on the undulator and accelerator parameters).

Version 6.1 or earlier
Ver7.0 or later
Natural divergence
Natural size

In addition, the brilliance of wiggler radiation is calculated with the depth of the field taken into account, from version 7.1. This may result in a lower value of the brilliance calculated with the version 7.1 or later, e.g., 1 or 2 orders of magnitude, than that with the earlier versions.

Functions supported

At present, the main functions supported in SPECTRA are as follows:
  • Energy spectra of the brilliance, flux density, partial flux after passing through a slit, and total flux
  • Spatial dependence of the flux and power densities
  • Beam size, angular divergence, coherent flux as a function of the gap and K value
  • The peak brilliance, flux, and radiatino power as a function of the gap and K value
  • Radiation power after passing through a filter composed of varisou material
  • Far-field approximation for fast evaluation of radiation
  • More precise estimation of radiation in the near-field zone

GUI for Pre and Postprocessor

SPECTRA is equipped with a full graphical user interface to help the user to input and edit parameters necessary for SR calculation, and to visualize the results of calculation. Examples of the preprocessors are shown below.
GUI windows to accept user input.

Contact Information


Takashi Tanaka, RIKEN SPring-8 Center


Koto 1-1-1, Sayo, Hyogo 679-5148, Japan
Tel: +81-791-58-2809, Fax: +81-791-58-2810