PRAM - Propagate Rays and Aberrations by Matricies

Updated 25 September 2006

  • PRAM is a program used to design quadrupole probe forming systems.
  • The theory used by PRAM is in chapter 3 of the text 'Materials Analysis with a Nuclear Microprobe' published by John Wiley and Sons, NY, 1996 (ISBN 0-471-10608-9).
  • PRAM can calculate first order focusing properties of electrostatic, magnetic or achromatic quadrupole, sextupole or octupole lenses.
  • PRAM can produce plots of the ray trajectories through the system, accurate to third order.
  • With an additional program, OXTRACE, PRAM can be used to display image intensity plots of the focused probe.
  • OXTRACE uses the aberration coefficients from PRAM to simulate grid shadow patterns.

    • Download the PC - DOS version of PRAM and OXTRACE by clicking here (301kB). This version is no longer maintained.

    Download the UNIX -linux versions of PRAM and OXTRACE by clicking here (729kB). Updated 23 March 2004.

    Download the CYGWIN versions of PRAM, OXTRACE and NUFIT clicking here (1.2MB). Updated 25 September 2006 (fixed problems with dipole and collimator elements).
    Cygwn is an excellent and fully featured unix shell for your Windows operating system. This is how I run PRAM these days.

    You can get cygwin for your machine from: http://www.cygwin.com/

    A PRAM raytrace through the MP2 system in Melbourne:

    An OXTRACE image simulation for the MP2 system for a large aperture showing spherical aberration:

    To the home page of Prof. David N. Jamieson