Electron cyclotron emission with a helical wavefront in millimeter-wave regime from an electron accelerated by a circularly polarized wave

In this study, we calculated an Electron Cyclotron Emission (ECE) with a helical wavefront in the millimeter-wave regime from an electron accelerated by a Circularly Polarized (CP) wave. Recently, it has been shown that radiation from a charged particle with spiral motion has a helical wavefront. Since an electron cyclotron motion is also a type of spiral motion, the ECE should also have a helical wavefront. In particular, we attempt to generate the high power coherent ECE with a helical wavefront from a multi-electron system. Because the radiation with helical wavefront from a single electron is low power, the superposition of the electric field is necessary to detect the radiation. For this reason, the CP wave plays an important role to control the electron’ rotation motion. We have confirmed in the calculation that the rotation phase of the electrons is controlled by an externally applied CP electric field. It was also confirmed by calculation where the radiation from such the electron has a helical wavefront. We will show the details of the calculation results at the meeting.