Innovative High-Speed Camera System Diagnostics of Plasma Torch Fluctuations

Abstract

Abstract Instabilities in plasma torches can result in poor particle heating and thus a production of low quality coatings. In order to investigate these fluctuations numerous experiments have been performed using high speed cameras taking pictures at a rate of 1000 images/s to create sequences with duration of few seconds total. Individual exposure times are usually in the range of few microseconds. In order to improve upon these parameters a new high speed camera system (HOBAS) was developed, which has been demonstrated to acquire short film sequences at a rate of 106 images/s using exposure times of down to 1ns/image. The camera system is based on a regular CCD camera mated with an MCP, where the MCP is triggered rapidly while the image is moved across the CCD-chip, thus enabling it to record multiple images during the CCD integration interval. Results of investigations will be presented using this instrument to detect plasma jet fluctuations in single electrode and multi electrode plasma torches.