CCC-0220 LUIN-II.

1. NAME OR DESIGNATION OF PROGRAM:  LUIN-II.

3. DESCRIPTION OF PROGRAM OR FUNCTION

The code calculates secondary particle fluxes and resulting ionization produced in the earth's atmosphere by galactic cosmic rays as well as spectra which are a function of zenith angle and energy. The code takes into account altitude above the earth's surface, geographical location, atmospheric temperature and solar activity.  Absorption and production cross sections are assumed to be independent of energy, and in solving the Boltzmann equations, the straight-ahead approximation is used. Also, the shape of all secondary hadron spectra are assumed to be identical when resulting from a collision at a given energy.

4. METHODS

Passow and Alsmiller have obtained a solution to the Boltzmann equation in the straight-ahead approximation with constant cross sections and with certain other restrictions on particle emission spectra in-flight decay and charged particle stopping, for an incident flux homogeneous energy and angle - i.e., for a Green's function from which solutions of other kinds can be obtained by numerical integration over space and angle. The resulting Green's functions are integrated over the primary galactic spectra to yield the desired quantities. Muon spectra are obtained from the pion spectra also in the straight-ahead approximation.

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The underlying theory is invalid below about 100 MeV for hadrons. Muons are followed to 10 MeV. The upper limit of validity is not really known, but sea-level hadron spectra at energies of 40 TeV have been shown to be within about 20% of experiment.

6. TYPICAL RUNNING TIME:  RSIC made no check on typical running time
for LUIN.

10. REFERENCES

- C. Passow:
  Phenomenologische Theorie zur Berechnung einer Kaskade aus     schweren Teilchen (Nukleonenkaskade) in der Materie,
DESY Notiz A 2.85 (1962).
- F. S. Alsmiller:
  A General Category of Soluble Nucleon-Meson Cascade Equations, ORNL-3746 (1965).

-  Keran O'Brien
   Luin, A Code for the Calculation of Cosmic Ray Propagation in the Atmosphere
   EML-238 (February 1978)

11. HARDWARE REQUIREMENTS:  LUIN-II is operable on the CDC 6600 computer.

13. SOFTWARE REQUIREMENTS:  A FORTRAN IV compiler is required.

15. NAME AND ESTABLISHMENT OF AUTHORS

Contributed by:
                Radiation Safety Information Computational Center
                Oak Ridge National Laboratory
                Oak Ridge, Tennessee, U. S. A.

Developed by:
                ERDA
                Health and Safety Laboratory
                New York, NY, U.S.A.

MISTP: README.RSI Read Me files
MISTP: C220.ABS Abstract for LUIN-II
SRCTP: F01 LUIN-II FORTRAN-IV source
DATTP: F02 Data
MISTP: F03 Program IR
DATTP: F04 IR data
MISTP: 220C660 LUIN-II program directory
REPPT: EML-338 (February 1978)