25 research outputs found
Recommended from our members
RELATIVISTIC CHARGED-PARTICLE BALLISTICS IN CONSTANT, UNIFORM ELECTROSTATIC AND MAGNETIC FIELDS.
Recommended from our members
Marginal densities of radially symmetric densities in two and three dimensions
Necessary and sufficient conditions are given for a function p(x) on 0 < absolute value (x) < R to be the marginal density of a radially symmetric density f(r) in the case of two and three dimensions. The first case relies on an integral transform due to Bell (CERN/MPS/DL 73-3), while for 3-space the theory is considerably simpler. The two cases appear to be quite different, and no generalization to n-space is known
Recommended from our members
Sampling the Fermi-Dirac density
A method is given for sampling the nonrelativistic Fermi-Dirac electron energy density for all values of the degeneracy parameter eta on the range - infinity < eta less than or equal to 50. The efficiency of the various rejection techniques employed is never less than 30%, and drops below 50% only for a short range of eta values around eta = 2. The range can certainly be extended beyond eta = 50, the efficiency there being 71%, and decreasing very slowly. 5 references
Recommended from our members
Status of Monte Carlo at Los Alamos
At Los Alamos the early work of Fermi, von Neumann, and Ulam has been developed and supplemented by many followers, notably Cashwell and Everett, and the main product today is the continuous-energy, general-purpose, generalized-geometry, time-dependent, coupled neutron-photon transport code called MCNP. The Los Alamos Monte Carlo research and development effort is concentrated in Group X-6. MCNP treats an arbitrary three-dimensional configuration of arbitrary materials in geometric cells bounded by first- and second-degree surfaces and some fourth-degree surfaces (elliptical tori). Monte Carlo has evolved into perhaps the main method for radiation transport calculations at Los Alamos. MCNP is used in every technical division at the Laboratory by over 130 users about 600 times a month accounting for nearly 200 hours of CDC-7600 time
Recommended from our members
Flux at a point in MCNP
The current state of the art of calculating flux at a point with MCNP is discussed. Various techniques are touched upon, but the main emphasis is on the fast improved version of the once-more-collided flux estimator, which has been modified to treat neutrons thermalized by the free gas model. The method is tested on several problems on interest and the results are presented