Elsevier Science Home
Computer Physics Communications Program Library
Full text online from Science Direct
Programs in Physics & Physical Chemistry
CPC Home

[Licence| Download | New Version Template] adnc_v1_0.tar.gz(137 Kbytes)
Manuscript Title: optics: general-purpose scintillator light response simulation code.
Authors: E. Frlez, B.K. Wright, D. Pocanic
Program title: optics
Catalogue identifier: ADNC_v1_0
Distribution format: tar.gz
Journal reference: Comput. Phys. Commun. 134(2001)110
Programming language: Fortran, Tk/Tcl.
Computer: MicroVAX 3100, DECstation 5000/200.
Operating system: DEC VMS V5.5, DEC OSF/1 V1.3A UNIX.
RAM: 1M words
Word size: 32
Peripherals: disc.
Keywords: Elementary particle physics, Detector design, Computer modeling and simulation, Monte Carlo simulation of scintillator response, Scintillation detectors, Computed tomography.
Classification: 11.7.

Nature of problem:
Simulation of the volume and temporal light collection probability distributions given the geometrical shape plus bulk and surface optical properties of a scintillation detector.

Solution method:
The code recognizes cylindrical, spherical, and parabolical as well as arbitrary polygonal scintillator shapes (and optional wrapping reflectors) that could couple via lightguides or wave-length shifters to photosensitive surfaces. The light-generating volume can be subdivided into the elementary cells. The photons generated within each cell are tracked through the scintillating volume taking into account specular, diffuse and rough surface reflections from lateral detector surfaces and wrapping reflectors, and the bulk attenuation and scattering effects from detector defects [1,2].
The code consists of 65 individual files containing the subroutines, data files and command files. A user can modify or expand the photon transport code as well as database files specifying default optical properties of the detector surfaces and the bulk media.
The program uses the CERNLIB programs in packlib library and kernlib Fortran callable libraries (optional).

The statistical uncertainties of the simulated light collection probability distribution are limited by the practically tolerable running time (see below).

Running time:
The running time depends on the number of elementary volume cells chosen and the number of scintillating photons generated per cell and is therefore problem-dependent. For example, assuming a small-step volume subdivision into a 15x15x30 matrix with 6750 elements and aiming for better than 2 per cent average uncertainty in the three-dimensional light nonuniformity function typically requires 10**7 photon statistics per cell and running time of ~24 hours on a 200 MHz computer.

[1] B.K. Wright, Program optics (University of Virginia, Charlottesville, 1992).
[2] B.K. Wright, Program tkoptics (University of Virginia, Charlottesville, 1994).