Search

The research work in this paper is based on generation of high voltage pulses using compact power supply sources for abatement of NOX from the diesel engine exhaust. The high voltage source is made up of zero voltage switch cascaded with flyback converter to produce high voltage AC, a Cockroft-Walton voltage multiplier to generate high voltage DC and a rotary spark gap for the production of high voltage pulses of rise time in the range of nano seconds. The rectifier based power supply is validated by a 12 V battery supply. To corroborate the feasibility of proposed methodology in diesel operated vehicles, the experiments are conducted with a 12 V battery. Performance of various shapes of electrodes (cylindrical 5mm diameter, square 5 mm diagonal and hexagonal with vertex to vertex diameter of 5 mm) at different flow rates of 2 l/min, 4 l/min and 6 l/min are also examined. [ABSTRACT FROM PUBLISHER]

Formulae giving the voltage drop of a Cockroft-Walton voltage multiplier are derived using a thorough analysis of the circuit. They differ from standard formulae found in the literature. We show that these new analytical expressions give improved results compared to both numerical simulations and experimental data. [ABSTRACT FROM AUTHOR]

The 350-keV Cockroft-Walton accelerator at Sandia National laboratory's Ion Beam facility is being used to calibrate absolutely a total DT neutron yield diagnostic based on the 63Cu(n,2n)62Cu(β+) reaction. These investigations have led to first-order uncertainties approaching 5% or better. The experiments employ the associated-particle technique. Deuterons at 175 keV impinge a 2.6 μm thick erbium tritide target producing 14.1 MeV neutrons from the T(d,n)4He reaction. The alpha particles emitted are measured at two angles relative to the beam direction and used to infer the neutron flux on a copper sample. The induced 62Cu activity is then measured and related to the neutron flux. This method is known as the F-factor technique. Description of the associated-particle method, copper sample geometries employed, and the present estimates of the uncertainties to the F-factor obtained are given. [ABSTRACT FROM AUTHOR]