Issue No 2, 2007 |
ITERATION ACCELERATION RDSA METHOD FOR SOLVING ONE-DIMENSIONAL NEUTRON TRANSPORT EQUATION
A. D. Gadzhiev, I. A. Kondakov, A. A. Shestakov
VANT. Ser.: Mat. Mod. Fiz. Proc. 2007. No 2. P. 3-19.
Diffusive-synthetic method for iteration acceleration based on ROMB scheme (RDSA method) is suggested. It conforms to difference method of transport equation solution. Multi-stage Larsen procedure is used for conformance. It includes:1) P1-design of difference equations for transport equation;2) P1-design of link ratio for transport equation;3) P1-design of boundary conditions;4) transition to Pi-equations in regard to corrections;5) transformation of obtained equations to the form with central differences and solution of obtained equations. Multi-stage Larsen procedure can be formally used for transport equations with all geometries and schemes. But for multidimensional curvilinear geometries the obtained averaged set of P1 equations turns out to be very complicated and execution of stage 5 becomes problematical. In particular, P1-equations can’t be re-arranged to the form with central differences for their subsequent solving. Larsen procedure is simplified with use of ROMB scheme. Transition to three-point form is not required on the stage 5 because the obtained set of Larsen procedure is simplified with use of ROMB scheme. Transition to three-point form is not required on the stage 5 because the obtained set of P1-equations is directly solved. Method is generalized to many-dimensional curvilinear geometries that may be an important advantage of new approach.
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| INCORPORATION TECHNIQUE OF STARK EFFECT ON CALCULATING SPECTRAL CHARACTERISTICS OF HIGH-TEMPERATURE PLASMA | , V. G. Novikov, N. N. Fimin |
VANT. Ser.: Mat. Mod. Fiz. Proc. 2007. No 2. P. 20-33.
Widening of spectral lines under the influence of ion microfield (Stark effect) may be important while calculating photon absorption coefficients in high-temperature dense plasma. Incorporation technique of Stark effect in quasi-static approximation based on diago- nalization of ion Hamiltonian disturbed by ion microfield is considered. Ion field distribution is obtained using disturbing independent particles. Technique can be used both for light elements and for elements with high atomic number. Calculations are based on relativistic Hartry—Fock—Sleter model and are conducted using THERMOS code developed in IPM.
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ON ONE ALGORITHM OF  -SCHEME MONOTONICITY FOR ONE GROUP STEADY-STATE TRANSPORT EQUATION FOR SPHEREE. V. Groshev
VANT. Ser.: Mat. Mod. Fiz. Proc. 2007. No 2. P. 34-49.
The paper considers algorithm of  -scheme monotonicity that in case of need touches up values of difference function on the basis of solution behavior analysis calculated according to first order scheme in a counting cell as well as in cells adjacent by space and angle. Conducted-calculations show that algorithm action results in noticeable improvement of solution monotonicity both for spatial and angle variables.
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| ON PHENOMENOLOGICAL MODEL OF KINETIC DECOMPOSITION OF HETEROGENEOUS HMX-BASED HE S. S. Sokolov
VANT. Ser.: Mat. Mod. Fiz. Proc. 2007. No 2. P. 50-61.
The paper considers one phenomenological model meant for numerical simulation of decomposition processes of heterogeneous HE made on the basis of retarded HMX. Development of such model is connected with solution of applied problems on prediction of detonation excitation and propagation in solid HE under various external impulse mechanical actions.
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| TECHNIQUE FOR DETERMINING SOME PARAMETERS OF INTEGRAL PHOTOSENSITIVE CELL OF PHOTODETECTOR IN OPTOELECTRONIC DEVICE B. P. Mukhachev, S. V. Artamonov
VANT. Ser.: Mat. Mod. Fiz. Proc. 2007. No 2. P. 62-67.
The paper describes technique that allows determining parameters (electrod width and signal storage time) of integral photosensitive cell of matric photodetector in optoelectronic device starting from maximization of ultimate detectability of the given photosensitive cell against a background of its noise. Calculation results for integral photosensitive cell on the basis of InSb are given.
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