Poggi C, Sartori E, Zuin M, Brombin M, Cervaro V, Fadone M, Fassina A, Fincato M, Segalini B, Serianni G
Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete S.p.A.), C. Stati Uniti 4, 35127 Padova, Italy.
Università degli Studi di Padova, Via 8 Febbraio 1848, 2, 35122 Padova PD, Italy.
Rev Sci Instrum. 2020 Mar 1;91(3):033314. doi: 10.1063/1.5129641.
A movable Allison type emittance scanner is being developed to characterize the phase-space distribution of the beamlets of spectral phase interferometry for direct electric-field reconstruction, the prototype RF negative ion source of the ITER heating neutral beam injector. To test the electronics and verify the capability of the device to resolve nearby beamlets, a compact RF ion source prototype has been set up, capable of accelerating 1 mA of helium ions up to a voltage of 2 kV. A commercial 100 W RF generator creates a plasma inside a Pyrex tube, with a density between 10 and 10 m and an electron temperature up to 15 eV. Three multi-aperture grids in accel-decel configuration extract and accelerate the ions, which are measured with a Faraday cup. We present in this paper the characterization of the ion source and its first operation, showing that it is suitable for the commissioning of the Allison scanner.
