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Manuscript Title: Tools for the analysis of air shower data.
Authors: K. Kasahara
Program title: ANAAS v1.6
Catalogue identifier: ABZJ_v1_0
Distribution format: gz
Journal reference: Comput. Phys. Commun. 64(1991)98
Programming language: Fortran.
Computer: FACOM M780.
Operating system: OS IV F4/MSP.
RAM: 224K words
Word size: 32
Keywords: Particle physics, Elementary, Event reconstruction, Air shower, Lateral distribution, Surface array, Primary energy Determination, Gamma ray point, Sources.
Classification: 11.9.

Nature of problem:
In obtaining the primary energy of air showers, the lateral distribution of particles in air showers is indispensable. The traditional NKG function for electrons has been pointed out to be too wide as compared to the correct electron distribution by a number of authors. However, it is irrelevant to use the correct distribution in the analysis because the transition effect in the detector deforms the distribution considerably. Therefore, appropriate distributions are necessary depending on the structure of detectors.

Solution method:
A number of air showers by gamma rays or protons with energy up to 10**15 eV has been simulated by the full Monte-Carlo method. The particles reaching a given observation depth are input to a given detector and cascading therein is simulated to obtain an effective lateral distribution. A hybrid simulation method is also used to extend the applicability of the package up to 10**20 eV.

Restrictions:
Muons and hadrons are not included since their contribution in normal observation is negligible. The detector structures supported for quantitative discussions are limited to two types: one is 0.1 cm iron +3.5+-0.5 cm plastic scintillator, and the other is 0.5 cm lead + 0.1 cm iron + 3.5+-0.5 cm plastic scintillator.

Unusual features:
There are essentially two machine or system dependent features in the package. However, they are easily changeable to be suited for a particular system by using Editor commands.

Running time:
In normal use of the package, most of the computational time will be spent by the FIXAGE subroutine, which needs 3.6 msec for a call on FACOM M780 (37 MIPS machine). The calculation of a particle density (RHOOB) requires 0.049 msec for a call. See note in section 3.2 for how to reduce the computational time of FIXAGE.