Personne
Alan Howling
Publications associées (93)
Negative ion characterization in a helicon plasma source for fusion neutral beams by cavity ring-down spectroscopy and Langmuir probe laser photodetachment
Ivo Furno, Alan Howling, Philippe Frédérique Bruno Guittienne, Rémy Jacquier, Riccardo Agnello, Gennady Plyushchev
Negative ions are characterized in the helicon plasma source resonant antenna ion device (RAID) at the Swiss plasma center by means of cavity ring-down spectroscopy (CRDS) and Langmuir probe (LP)-assisted laser photodetachment. A high density and axially h ...
IOP PUBLISHING LTD2020Application of Thomson scattering to helicon plasma sources
Ivo Furno, Patrick Blanchard, Alan Howling, Yanis Andrebe, Rémy Jacquier, Riccardo Agnello, Alban Sublet
The possibility of performing electron density and temperature measurements in a high power helicon plasma is a crucial issue in the framework of the AWAKE (Advanced WAKefield Experiment) project, which demonstrates acceleration of particles using GeV m(-1 ...
2020Slip Ring Test Assembly With Increased Breakdown Voltage Limit for High-Voltage Bus Satellites
Ivo Furno, Alan Howling, Fabio Avino
In this article, a setup including a passive gas breakdown mitigation technique for satellite slip ring assemblies (SRAs) is introduced and tested. The setup features a central conducting ring, separated from two external conducting limiting discs (LDs) by ...
2020Experimental study of wakefields driven by a self-modulating proton bunch in plasma
Yiming Li, Ambrogio Fasoli, Ivo Furno, Patrick Blanchard, Alan Howling, Yanis Andrebe, Rémy Jacquier, Riccardo Agnello, Sun Hee Kim, Ishkhan Gorgisyan, Shuai Liu
We study experimentally the longitudinal and transverse wakefields driven by a highly relativistic proton bunch during self-modulation in plasma. We show that the wakefields' growth and amplitude increase with increasing seed amplitude as well as with the ...
2020Development of a plasma electroacoustic actuator for active noise control applications
Ivo Furno, Alan Howling, Hervé Lissek, Pénélope Leyland, Stanislav Sergeev, Gennady Plyushchev
Conventional loudspeakers generate sound through the vibration of a diaphragm, attached to a rigid frame through elastic suspensions. Although such construction is satisfactory for sound diffusion in steady environments, it is likely to fail in harsh condi ...
2020Multiple dehydrogenation reactions of negative ions in low pressure silane plasma chemistry
Christoph Hollenstein, Alan Howling, Antoine Descoeudres
Micro-particle formation in low pressure silane (SiH4) plasmas has been of technical interest and concern for at least 40 years. Negative ion plasma chemistry is a candidate for the initial nucleation, which has been extensively studied both experimentally ...
2020Magnetic field configurational study on a helicon-based plasma source for future neutral beam systems
Ivo Furno, Alan Howling, Philippe Frédérique Bruno Guittienne, Rémy Jacquier, Riccardo Agnello
A helicon-based plasma source is under development and exploration at CEA-IRFM to produce an efficient and dense magnetized plasma column. The final objective of this development is the extraction and acceleration of a blade-like negative ion beam in view ...
IOP PUBLISHING LTD2019Two-fluid plasma model for radial Langmuir probes as a converging nozzle with sonic choked flow, and sonic passage to supersonic flow
Ivo Furno, Alan Howling, Philippe Frédérique Bruno Guittienne
Using the Lambert function, Guittienne et al. [Phys. Plasmas 25, 093519 (2018)] derived two-fluid solutions for radial Langmuir probes in collisionless and isothermal plasma. In this Brief Communication, we point out the close analogy with classical compre ...
2019First B-dot measurements in the RAID device, an alternative negative ion source for DEMO neutral beams
Ivo Furno, Alan Howling, Philippe Frédérique Bruno Guittienne, Rémy Jacquier, Riccardo Agnello, Gennady Plyushchev, Claudio Marini
As a new concept of Neutral Beam Injectors (NBI) for DEMO-like reactors, SIPHORE (IRFM, CEA, in France) expects to extract negative deuterium ions and photo-neutralize the accelerated D-. The Swiss Plasma Center (SPC) of EPFL is involved in this project by ...
Elsevier B.V.2019Gas breakdown mitigation in satellite slip rings
Ivo Furno, Alan Howling, Fabio Avino, Paul Jeroen Laureis Martens
Direct current (DC) gas breakdown is experimentally investigated for high-voltage circular conductors and insulators that reproduce the main features of a satellite slip ring. Breakdown voltages are measured in the pressure range 10 ...
2019