Abstract
In this article, we describe the electron cyclotron emission (ECE) imaging system applied to the Large Helical Device (LHD) at the National Institute for Fusion Science. The imaging system consists of focusing optics installed inside the vacuum chamber of LHD and planer-type detectors fabricated by monolithic microwave integrated circuit technology. The detector consists of the integration of a bowtie antenna, a down-converting mixer using a Schottky barrier diode, and heterojunction bipolar transistors (HBTs) on a GaAs substrate. The HBTs work as an intermediate frequency (IF) amplifier with a 10 GHz bandwidth and a 10 dB voltage gain. The ECE signal and local oscillator beam are irradiated from both sides of the detector. The ECE signals are down-converted at the mixers and the IF signal is fed to a filter bank with center frequencies of 1–8 GHz. The time evolution and the intensity of the ECE signals agree with those obtained by a conventional ECE heterodyne receiver. The cross-correlation spectra of the signals obtained with different IF frequencies (radial correlation) and different detectors (poloidal correlation) are obtained.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
