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Full-Text Articles in Physics
Improving Low Order, Linear, Positive Spatial Quadratures For The Partial Current Neutron Transport Method, John M. Snyder
Improving Low Order, Linear, Positive Spatial Quadratures For The Partial Current Neutron Transport Method, John M. Snyder
Theses and Dissertations
AFIT researchers have developed a new approach to solving Discrete Ordinates equations, which approximate the linear Boltzmann Transport Equation (BTE). The usual approach is von Neumann iteration on the scattering source, which requires repeated sweeps through the spatial-angular grid. Acceptable convergence requires complicated and expensive acceleration schemes. The new approach, Partial-Current Transport (PCT) with Adaptive Distribution Iteration, eliminates scattering source iteration through matrix inversions and a reduced-size global linear algebra problem. It creates the needed matrices directly from the standard spatial quadratures used in the sweeping. Positivity, linearity, and (higher-than-first-order) accuracy are the key desirable qualities with all Discrete Ordinates …
Rubidium Recycling In A High Intensity Short Duration Pulsed Alkali Laser, Wooddy S. Miller
Rubidium Recycling In A High Intensity Short Duration Pulsed Alkali Laser, Wooddy S. Miller
Theses and Dissertations
Laser induced fluorescence was used to study how pump pulse duration and alkali recycle time effects maximum power output in a Diode Pumped Alkali Laser (DPAL) system. A high intensity short pulsed pump source was used to excited rubidium atoms inside a DPAL-type laser. The maximum output power of the laser showed a strong dependence upon the temporal width of the pump pulse in addition to the input pump intensity. A linear relationship was observed between the maximum output power and the pulse width due to the effective lifetime of the excited state, defined as the time it takes for …