Monte Carlo simulation of atmospheric neutron transport at high altitudes using MCNP. Technical report

Technical Report · Wed Aug 01 04:00:00 EDT 1990

OSTI ID:5997446

Culp, D R; Monti, D L; Shoemaker, J R; Wesley, D; Mathews, K A

Neutron transport calculations were performed using the Monte Carol code, MCNP. The transport problem considered has a point source at high altitude (40 km). Since atmospheric density decreases with altitude, two-dimensional effects (cylindrical coordinates) can be important. Results were compared to those obtained with the SMAUG-II computer code, which performs mass-integral scaling of approximate fits to one-dimensional spherical discrete ordinates solutions. These comparisons show the importance of two-dimensional computations. The report discusses practical issues of applying MCNP to this problem, without code modifications and includes example input files for MCNP and for SMAUG-II. Computational modelling of neutron transport in the atmosphere is complicated by the variation of air density with altitude.

• Research Organization: Air Force Inst. of Tech., Wright-Patterson AFB, OH (USA). School of Engineering
• OSTI ID: 5997446
• Report Number(s): AD-A-226773/0/XAB; AFIT/EN-TR--90-5
• Country of Publication: United States
• Language: English

Related Subjects

654003* -- Radiation & Shielding Physics-- Neutron Interactions with Matter
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
AIR
ALTITUDE
COMPARATIVE EVALUATIONS
COMPUTER CODES
COMPUTERIZED SIMULATION
DENSITY
DOCUMENT TYPES
EARTH ATMOSPHERE
FLUIDS
GASES
M CODES
MODIFICATIONS
MONTE CARLO METHOD
NEUTRAL-PARTICLE TRANSPORT
NEUTRON TRANSPORT
NEUTRON TRANSPORT THEORY
PHYSICAL PROPERTIES
POINT SOURCES
PROGRESS REPORT
RADIATION SOURCES
RADIATION TRANSPORT
S CODES
SIMULATION
TRANSPORT THEORY
TWO-DIMENSIONAL CALCULATIONS
VARIATIONS