TIMEX: a time-dependent explicit discrete ordinates program for the solution of multigroup transport equations with delayed neutrons
TIMEX solves the time-dependent, one-dimensional multigroup transport equation with delayed neutrons in plane, cylindrical, spherical, and two-angle plane geometries. Both regular and adjoint, inhomogeneous and homogeneous problems subject to vacuum, reflective, periodic, white, albedo or inhomogeneous boundary flux conditions are solved. General anisotropic scattering is allowed and anisotropic inhomogeneous sources are permitted. The discrete ordinates approximation for the angular variable is used with the diamond (central) difference approximation for the angular extrapolation in curved geometries. A linear discontinuous finite element representation for the angular flux in each spatial mesh cell is used. The time variable is differenced by an explicit technique that is unconditionally stable so that arbitrarily large time steps can be taken. Because no iteration is performed the method is exceptionally fast in terms of computing time per time step. Two acceleration methods, exponential extrapolation and rebalance, are utilized to improve the accuracy of the time differencing scheme. Variable dimensioning is used so that any combination of problem parameters leading to a container array less than MAXCOR can be accommodated. The running time for TIMEX is highly problem-dependent, but varies almost linearly with the total number of unknowns and time steps. Provision is made for creation of standard interface output files for angular fluxes and angle-integrated fluxes. Five interface units (use of interface units is optional), five output units, and two system input/output units are required. A large bulk memory is desirable, but may be replaced by disk, drum, or tape storage. 13 tables, 9 figures. (auth)
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 7354440
- Report Number(s):
- LA-6201-MS; TRN: 76-014065
- Country of Publication:
- United States
- Language:
- English
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TIMEX. 1-D Time-Dependent Multigroup Discrete Ordinates
TIMEX. 1-D Time-Dependent Multigroup Discrete Ordinates
Related Subjects
COMPUTER CODES
T CODES
NEUTRON TRANSPORT THEORY
MULTIGROUP THEORY
DELAYED NEUTRONS
DISCRETE ORDINATES
NEUTRON FLUX
TIME DEPENDENCE
BARYONS
ELEMENTARY PARTICLES
FERMIONS
FISSION NEUTRONS
HADRONS
NEUTRONS
NUCLEONS
RADIATION FLUX
TRANSPORT THEORY
654003* - Radiation & Shielding Physics- Neutron Interactions with Matter