The ENEA CARM source for nuclear fusion: Project status and perspectives

Abstract

A Cyclotron Auto-Resonance Maser (CARM) is under study at the ENEA Research Laboratories in Frascati as a electron cyclotron heating (ECH) source in plasma magnetic confinement devices like Tokamaks. The aim of the project is the realization of a test source at 250 GHz to verify heating mechanisms in high magnetic field Tokamaks and at the second harmonics ECH frequencies for which a higher energy exchange efficiency has been predicted.

Prospects for a dominantly microwave-diagnosed magnetically confined fusion reactor

“…A CTS source must satisfy additional requirements of narrow spectrum, high power (as a consequence of the small scattering cross-section) and long pulses or continuous operation [101,102]. The typical source of choice is the gyrotron, although the Cyclotron Autoresonance Maser recently regained attention [32]. Table 2: Measurements needed in ITER and, with good approximation, in a reactor, adapted from Refs.…”

“…Transmission lines will be longer than in present devices and will require high mode purity and low losses and reflections [30,31]. Finally the magnetic field will be higher, thus Electron Cyclotron Emission (ECE), Collective Thomson Scattering and other diagnostics will require sources [32] and receivers [33] to operate at higher frequencies.…”

“…A CTS source must satisfy additional requirements of narrow spectrum, high power (as a consequence of the small scattering cross-section) and long pulses or continuous operation [101,102]. The typical source of choice is the gyrotron, although the Cyclotron Autoresonance Maser recently regained attention [32]. The CTS spectrum mimics the ion distribution function [103], or a convolution of ion distribution functions if multiple species are present, due to impurities, to two fuel ions (D and T) and due to fusion α's.…”