version 4.8.3
April 2006


New release ver. 4.8.3 (April 2006)
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Supported by
EU 6th framework programme
EU 5th framework programme

S I M R E S   version 4.9

SIMRES is a Monte Carlo (MC) ray-tracing program developed from RESTRAX, which provides more flexibility and accuracy needed for designing new instruments or their parts (neutron guides, strain mapping and powder diffractometers, three-axis spectrometers). The original MC code of RESTRAX has been upgraded to simulate neutron transport through the instrument components more realistically and provides more options for flux simulations, mapping neutron beam in phase space, numerical optimisations etc.


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(see INSTALL for details)

The program comes in a single *.tar.gz  package with source files and installation scripts. Unpack the archive,

% gunzip < simres494.tar.gz | tar -xf -

enter the distribution directory,

% cd simres494

and follow instructions in the file


  • UNIX operating system
  • F 77 and F 90 compilers (F77 with extensions is enough for HPUX)
  • PGPLOT graphics library


The program is developed and tested on following systems and compilers:
  • Linux,  Absoft Fortran
  • Digital Unix, DEC Fortran 77/90
  • HP UX, HP Fortran 9000

In these cases, the configuration files are already prepared and tested. The compiling and installation of the program is then as easy as writing single command, e.g.

% Build  DEC  destination_folder

Porting to other UNIX platforms should be relatively simple. It requires editting corresponding configuration file with library paths and compiler options (see INSTALL.txt). Porting to other non-UNIX systems (Windows, Mac) should also be possible, but wasn't yet tested.

How to start

(see help.html for details)

After installation, the simulation can be immediately started from the ./demo subdirectory with example instrument definition files. You can use these files as templates to define your own instrument setup.


  • Environment variables for PGPLOT library
    • PGPLOT_DIR has to point to the folder with PGPLOT library
    • PGPLOT_DEV optional, default device (e.g. /xserv)
    • PGPLOT_ILL_PRINT_CMD optional, print command (e.g.  lpr)
  • Copy following configuration files to the current directory (examples are in the ./demo folder )
    simres00.cfg file with parameters defining your instrument
    crystal.lib crystal library
    file.res any file with instrument settings (RESCAL format, can be modified interactively during the session)
    mirrorn.n optional, lookup tables for mirror reflectivity (e.g. mirror2.0 from  ./demo folder) optional, lookup table with flux distribution at the source (df/dl)

Start program

From a terminal window, type simres494 -help for the list of command line options or

% simres494 [options]

batch file  :
type the name of your job file name and press <enter> or press just <enter> to start interactive session.

If the batch file is specified (and found), you are asked for the output file name and all commands are read from the batch file. Otherwise the initial dialog continues:

Energy In m[eV] Or T[Hz]? (meV)
Select energy units (meV is default)

Path to the spectra files -
Optionally, give the path, where the data files will be searched for (to read parameters from ILL TAS data files)

Name of a parameter or data file -
Type the file name with instrument parameters (RESCAL format)

The session then continues interactively from the command line:

 ResTrax> _

Type help to see the list of available commands with short explanation. Consult the manual for details.