Speaker
Giancarlo Maero
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/O4.J503.pdf
Dynamics and stability in RF-generated nonneutral plasmas
G. Maero1,2 , N. Panzeri1,2 , R. Pozzoli1 , M. Romé1,2
1 Dipartimento di Fisica, Università degli Studi di Milano, Italy
2 INFN Sezione di Milano, Italy
Born and used for a long time as a tool to confine a single-species nonneutral plasma,
Penning-Malmberg traps have been exploited in a wider range of applications than originally
imagined [1]. Deviations from ideal conditions, like the presence of several charged-particle
species and the application of radio-frequency (RF) excitations, represent a challenge both in
terms of physical modelling and of accurate control and manipulation. At the same time, they
have led to important results (e.g., antimatter synthesis) and offer new opportunities of physics
investigations in collective systems. We present here several important features arising from
the in-trap generation of a non-neutral plasma by means of low-amplitude RF fields, whose
continuous application plays a dramatic role in the dynamics of the confined sample [2, 3, 4].
An analysis of basic collective properties is performed by means of a series of experiments,
highlighting analogies and differences between ’conventional’ trapped nonneutral plasmas (i.e.,
injected from a source and let to evolve) and their RF-generated and continuously excited coun-
terpart. The observations on RF-excited plasmas produce a wealth of non-trivial features in
terms of: Evolution towards stable configurations (single and multiple vortex structures); Man-
ifestation of nonlinear diocotron modes; Accumulation of positive ions; New opportunities for
plasma manipulation, e.g., by means of multipolar RF fields combined with the generation drive,
which result in the possible use of the RF-drive technique as a valid alternative to conventional
sources for the study of turbulent fluid flows [5].
References
[1] J. R. Danielson, D. H. E. Dubin, R. G. Greaves and C. M. Surko, Rev. Mod. Phys. 87 247 (2016)
[2] B. Paroli, G. Maero, R. Pozzoli and M. Romé, Phys. Plasmas 21, 122102 (2014)
[3] G. Maero, R. Pozzoli, M. Romé, S. Chen and M. Ikram, JINST 11, C09007 (2016)
[4] G. Maero, Il Nuovo Cimento C 40, 90 (2017)
[5] N.C. Hurst, J.R. Danielson and C.M. Surko, AIP Conf. Proc. 1928, 020007 (2018)
