Ion cyclotron absorption by fusion alpha-particlesFunded under: EAEC-FUSION 12C
Calculations of ion cyclotron damping of fast waves by alpha-particles in a tokamak are presented, at frequencies corresponding to alpha-particle cyclotron harmonics. In this frequency range (typically 50 MHz - 200 MHz in JET), the single-pass wave absorption is large compared with that of the thermal ions for conditions typical of present-day DT experiments. Furthermore, for wave propagation at angles almost perpendicular to the field, the damping on the thermal electrons is small. For such waves, a measurement of the fraction of wave power absorbed is proportional to the density of resonant energetic alpha-particles integrated along the path of the wave, a result showing the potential of ion cyclotron absorption (ICA) measurements for alpha-particle diagnosis. ICA measurements may also be used to diagnose other types of energetic ions of a non-fusion origin, for example energetic ICRH minority ions.
Bibliographic Reference: Report: JET-R(94)10 EN (1994) 10 pp.
Availability: Available from the Publications Officer, JET Joint Undertaking, Abingdon, Oxon. OX14 3EA (GB)
Record Number: 199510565 / Last updated on: 1995-04-21
Original language: en
Available languages: en