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Author's experiments |
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The author's experiments
Contents
2 - The air flow in the corona discharge gap
3 - Mobile coronas investigations
4 - Point to plane coronas data
5 - Interactions between coronas
6 - Headphone and speakers data
The basic idea was to use the ion flow in the same manner than the electrons beam of a vacuum triode. The goal was to control the whole ionic current with an intermediate electrode at a smaller voltage than the full gap voltage. Unfortunately the existence of a strong diffusion of the ion beam due to the dispersive effect of neutral particles induced unexpected losses and problems on the control electrodes. We tried several forms of control electrodes (grids, rings) and also electrodes covered with insulating materials, with a poor success. The losses in conductive electrodes and the repulsive effect of charge deposition on insulating materials were respectively so important and so hard to manage that the project was abandoned. More details here
2 - The neutral flow in the corona discharge gap
The neutral flow is generated by the interaction between ions and neutrals. The interaction's force is proportional on one side to the charge density and on the other side to the local value of the electric field. Both parameters take their highest values very close from the emitter. As a consequence it is very interesting to have an idea of the the neutral flow in the region between emitter and collector and the closest as possible to the emitter. Because of diffusion effects (see The air triode failure). It was impossible to introduce any type of solid sensor without modifying strongly the discharge behaviour. So we decided to use a non invasive technique: the laser anemometry. More details here
3 - Mobile corona investigations
The momentum transfer from the ions to the neutrals generates a neutral flow always directed from the emitter towards the collector. If the ions in the usual configuration are all absorbed by the collector to maintain the global electrical neutrality of the electrodes assembly, the neutral flow on its side can move very far from the device. As a result of the global momentum conservation law (first principal of dynamics), a recoiling force is observed on the electrode assembly. The whole process is very similar to usual rocket propulsion, neutral gas is expulsed in one direction and the device is propelled in the opposite one. If the electrodes are free to move and well profiled, they can reach speeds well above the speeds measured in the neutral flow created by fixed electrodes. Moreover the measurement of the acceleration of the mobile part gives a value of the force applied to it. We were able to measure the electric force up to 50 m/s and to prove that it remains constant. As a consequence the efficiency rises linearly as the speed increases to reach values well above 10%. More details soon.
4 - Point to plane coronas investigations
5 - Interactions between coronas
6 - Headphone and speakers data