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Gamma Ray Instruments Simulation Utility

the Grinnell-Utah simulation and analysis package

HeLp PaGe
version 6.0.0

Version Change Log

documention incomplete for versions > 4.1.5
see version 6.0.0 pilot files and configuration file for up-to-date documentation
also see the file GrISU/README_VERSIONHISTORY for additional details

The vbf writer is now reasonably well tested and works fine with vegas. We added two new features that require a change in detector.pilot and in the array configuration file. You may now by specifying the latitude of the observatory, specify source offset directions on the sky rather than the camera. Thus, the new SOURC record in detector.pilot as described by the following lines from the new detector.pilot file:

Source characteristics(SOURC): x and y coordinates of the source in the field
of view followed by the source extention radius (all in degrees). The fourth
parameter is the latitude of the observatory in degrees. If the latitude is
set to 90degrees the source position is given in camera corrdinates. If the
latitude is less than 90 degrees, the source position in x corresponds to an
offset in the east west direction while the y position corresponds to north
wobble North: SOURC 0.0 0.5 0.0 31.675
wobble East : SOURC 0.5 0.0 0.0 31.675
*SOURC 0.5 0.0 0.0 31.675
 SOURC 0.5 0.0 0.0 90.0

We urge you to read the complete documentation of the wobble coordinate system before you attempt to interpret the wobble North and wobble East values; follow the grisudet and the grisudet input pilot file links.  In brief, wobble North moves the telescope in the direction (y) tangent to the direction of the Source-to-Polaris great circle; Wobble East moves the telescope in a perpendicular direction (x) such that  the x-y-z coordinate system is right handed with the z axis pointing away from the celestial sphere.  If you wish to produce grisudet output for showers from the zenith, we recommend that you use latitude values less than 90 degrees. 

You'll note in the vbf output  that the  wobble angles change the azimuth and zenith angle of the source while the azimuth and zenith angles of the telescopes remain constant. Clearly, the source can't move and we'll fix this in our next release.  Since the wobble angles are small, we don't expect a noticable effect; that is, simulated showers differing by e.g. 0.5 degrees on the sky should show little differencies, except possibly at large zenith angles. 

You may now also choose to rotate the camera (if it isn't properly aligned) and may specify a camera global relative gain through two new parameters in the configuration file CAMRA record. The new CAMRA record in the configuration file is as follows:

Camera design (CAMRA).
   -telescope identification number
   -the number of phototubes.
   -the angle (counter clockwise on the display) by which the camera is
    rotated. The given pixel corredinates will be rotated by minus that angle.
   -the relative gain/throughput for that camera. In the simulation, all the
    PMT signals from that camera will be multipled by that number. In analysis,
    all the PMT signals from that camera will be divided by that number
* CAMRA 1 499 0.0 1.0
* CAMRA 2 499 0.0 1.0
* CAMRA 3 499 0.0 1.0
* CAMRA 4 499 0.0 1.0

And, you may choose to enter the primary zenith angle and azimuth using a new kascade.pilot record. Here are comments and a sample record from kascade.pilot.

or, set the direction using azimuth and zenith angle in the DAZEL record,
all in degrees. The third field sets the range of randomly selected zenith
angles (the range is the cosines of the two zenith angles) and may be
omitted. If omitted, the zenith angle is fixed; or if the third parameter
is 0.0, the zenith angle is fixed.

* DAZZN 0.0 30.0 0.0

Finally, you can now bypass kascade.pilot by using up to three command line arguments for kascade.  Here's the help message produced by "kascade -help":

possible command line arguments:
    -p <pilot filename>
    -s <integer seed>
    -e <azimuth> <zenith angle1> <zenith angle2>
       for constant zenith angle, set zenith angle2 = 0.0
parameters can be in any order on the command line


After opening the grisu* tarball , you will find the /GrISU main directory and a series of subdirectories. You can run all simulations from the GrISU directory, either by typing instructions, running scripts, or by using a cool, click-button interface.

For an easy start-up, you should:

Review the directory structure

Compile the code using the make_them_all script. The only command-line argument is your choice of kascade version: kascade, kascade3, or kascade7. For example,
"make_them_all kascade".

Execute the gui_interface script to open the click-button interface. Review the documentation for each program to understand the use of pilot files and the location and format of output files. The default version of kascade when using the "make_them_all" option within this interface is kascade7!

Set the variables in the pilot files from the interface. Execute your simulations from the interface.

Or, you may type instructions at the command line for production runs.

In a multi-machine environment, either a Beowulf cluster or a standard Linux network, we provide a perl script for running GrISU on each machine without downloading any GrISU files. The script requires that the GrISU directory disk be NSF mounted on each machine. You will find the documentation under the Utilities link.

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In case you still have problems despite the striking  clarity of these help pages or if you would like to point at some spelling mistakes, please do not hesitate to contact  Charlie Duke  or  Stephan LeBohec. e-mail to
dukeATgrinnell.edu and LeBohecATphysics.utah.edu


  Thank you and good luck!