This paper describes the observed position dependent emission spectrum and vacuum ultraviolet (VUV) to clarify the optical structure of argon atmospheric pressure plasma jets (APJs). Visible emission spectra of argon, nitrogen and OH molecules were measured as a function of position from the nozzle of plasma jet generator to gas flow direction. From the results, we realized that a certain electric field is required for producing high energy excited atoms of argon in the jet from the high voltage electrode in the device to the ground positioned at downstream side. Moreover, VUV was detected along the plasma jet through the downstream direction. Thus, we could picture that the light pattern of plasma jet of which intensity weaken depend to the distance from the nozzle is sustained by the above two factors with the present steady state experiments.

We have performed measurement of core losses in metal composite toroidal cores over 10 MHz region using a measurement system where capacitors are connected in series with coils wound around sample cores and the measurement is conducted at LC resonant frequencies. In this paper, we introduce this “Resonant Method” and show the core loss measurement of metal composite toroidal cores up to 40 MHz. Furthermore, we examine the accuracy of the Resonant Method by comparing the equivalent resistance evaluated from the energy loss and the real part of the impedance measured by network analyzer.