Modeling and optimization of the multichannel spark discharge

This paper reports a novel analytic model of this multichannel spark discharge, considering the delay time in the breakdown process, the electric transforming of the discharge channel from a capacitor to a resistor induced by the air breakdown, and the varying plasma resistance in the discharge process. The good agreement between the experimental and the simulated results validated the accuracy of this model. Based on this model, the influence of the circuit parameters on the maximum discharge channel number（MDCN） is investigated. Both the input voltage amplitude and the breakdown voltage threshold of each discharge channel play a critical role. With the increase of the input voltage and the decrease of the breakdown voltage, the MCDN increases almost linearly. With the increase of the discharge capacitance, the MDCN first rises and then remains almost constant. With the increase of the circuit inductance, the MDCN increases slowly but decreases quickly when the inductance increases over a certain value. There is an optimal value of the capacitor connected to the discharge channel corresponding to the MDCN. Finally, based on these results, to shorten the discharge time, a modified multichannel discharge circuit is developed and validated by the experiment. With only 6-kV input voltage, 31-channels discharge is achieved. The breakdown voltage of each electrode gap is larger than 3 kV. The modified discharge circuit is certain to be widely used in the PSJA flow control field.

Optimization of reluctance accelerator efficiency by an improved discharging circuit

In this paper,an improved discharging circuit was proposed to quicken the decay of the current in the drive coil in a reluctance accelerator when the armature reaches the center of the coil.The aim of this is to prevent the suck-back effect caused by the residual current in drive coil.The method is adding a reverse charging branch with a small capacitor in the traditional pulsed discharging circuit.The results under the traditional circuit and the improved circuit were compared in a simulation.The experiment then verified the simulations and they had good agreement.Simulation and experiment both demonstrated the improved circuit can effectively prevent the suck-back effect and increase the efficiency.At the voltage of 800 V,an efficiency increase of 36.34% was obtained.

Local neuronal circuits that may shape the discharge patterns of inferior collicular neurons

The discharge patterns of neurons in auditory centers encode information about sounds.However,few studies have focused on the synaptic mechanisms underlying the shaping of discharge patterns using intracellular recording techniques.Here,we investigated the discharge patterns of inferior collicular（IC）neurons using intracellular recordings to further elucidate the mechanisms underlying the shaping of discharge patterns.Under in vivo intracellular recording conditions,recordings were obtained from 66 IC neurons in 18 healthy adult mice（Mus musculus,Km）under free field-stimulation.Fiftyeight of these neurons fired bursts of action potentials（APs）to auditory stimuli and the remaining eight just generated local responses such as excitatory（n=4）or inhibitory（n=4）postsynaptic potentials.Based on the APs and subthreshold responses,the discharge patterns were classified into seven types：phasic（24/58,41.4%）,phasic burst（8/58,13.8%）,pauser（4/58,6.9%）,phasic-pauser（1/58,1.7%）,chopper（2/58,3.4%）,primary-like tonic（14/58,24.1%）and sound-induced inhibitory（5/58,8.6%）.We concluded that（1）IC neurons exhibit at least seven distinct discharge patterns;（2）inhibition participates in shaping the discharge pattern of most IC neurons and plays a role in sculpting the pattern,except for the primary-like tonic pattern which was not shapedby inhibition;and（3）local neural circuits are the likely structural basis that shapes the discharge patterns of IC neurons and can be formed either in the IC or in lower-level auditory structures.