Publications by Alan Howling | EPFL Graph Search

Implementing water recirculation in a novel portable plasma-activated water reactor enhances antimicrobial effect against Escherichia coli

Alan Howling, Ivo Furno, Fabio Avino, Lorenzo Ibba, Rita Agus, Leonardo Zampieri, Brayden Graham Myers

The need for sustainable and reliable decontamination methods is driven by concerns regarding antibiotic resistance, as well as environmental and cost -efficiency challenges associated with traditional methods. Plasmaactivated water (PAW) holds significant ...

Elsevier Science Sa2024

A birdcage resonant antenna for helicon wave generation in TORPEX

Philippe Frédérique Bruno Guittienne, Alan Howling, Ivo Furno, Robert Bertizzolo, Rémy Jacquier, Marcelo Baquero Ruiz

A birdcage resonant helicon antenna is designed, mounted, and tested in the toroidal device TORPEX. The birdcage resonant antenna is an alternative to the usual Boswell or half-helical antenna designs commonly used for ∼ 10 cm diameter helicon sources in l ...

2024

Resonant network antennas for radio-frequency plasma sources: Theory, technology and applications

Philippe Frédérique Bruno Guittienne, Alan Howling, Ivo Furno

Resonant antennas are increasingly employed by the plasma industry, and the theory has now developed alongside the technological applications to the extent that it is timely to document the progress in this field to aid antenna design for future novel RF p ...

Institute of Physics Publishing2024

A double-ended helicon source to symmetrize RAID plasma

Philippe Frédérique Bruno Guittienne, Alan Howling, Ivo Furno, Rémy Jacquier, Marcelo Baquero Ruiz, Riccardo Agnello, Christine Stollberg

Neutral Beam Injectors (NBI) for post-DEMO-like reactors must achieve a neutralization efficiency (fraction neutrals/ions) above 70%. To reach this, NBIs based on negative ions are necessary and an innovative concept of this type of injector is based on ph ...

2023

Surface DBD degradation in humid air, and a hybrid surface-volume DBD for robust plasma operation at high humidity

Alan Howling, Ivo Furno, Fabio Avino, Lorenzo Ibba, Alexandra Waskow

Surface dielectric barrier discharge performance deteriorates in humid air, with permanent and/or reversible degradation of its components. Plasma operation in a humid environment is unavoidable when humid air or water-containing materials are treated. Exp ...

IOP Publishing Ltd2023

Catabolism of Glucosinolates into Nitriles Revealed by RNA Sequencing of Arabidopsis thaliana Seedlings after Non-Thermal Plasma-Seed Treatment

Alan Howling, Ivo Furno, Alexandra Waskow

2022

A 1.5D fluid-Monte Carlo model of a hydrogen helicon plasma

Philippe Frédérique Bruno Guittienne, Alan Howling, Ivo Furno, Rémy Jacquier, Riccardo Agnello

Helicon plasma sources operating with hydrogen or deuterium might be attractive for fusion applications due to their higher power efficiency compared to inductive radiofrequency plasma sources. In recent years, the resonant antenna ion device (RAID) has be ...

2022

RNA Sequencing of Arabidopsis thaliana Seedlings after Non-Thermal Plasma-Seed Treatment Reveals Upregulation in Plant Stress and Defense Pathways

Alan Howling, Ivo Furno, Alexandra Waskow

Not all agricultural practices are sustainable; however, non-thermal plasma treatment of seeds may be an eco-friendly alternative to improve macroscopic plant growth parameters. Despite the numerous successful results of plasma-seed treatments reported in ...

2022

Entering the plasma agriculture field: An attempt to standardize protocols for plasma treatment of seeds

Alan Howling, Ivo Furno, Fabio Avino, Alexandra Waskow

Plasma treatments are currently being assessed as a seed processing technology for agricultural purposes. There is sufficient information as a proof-of-concept, but a lack of standardization in the methodology prevents a convincing evaluation of plasma tre ...

2022

Mechanisms of Plasma-Seed Treatments as a Potential Seed Processing Technology

Alan Howling, Ivo Furno, Alexandra Waskow

Plasma treatments are currently being assessed as a seed processing technology for agricultural purposes where seeds are typically subjected to pre-sowing treatments to improve the likelihood of timely and uniform germination. The aim of this review is to ...

2021

Advantages and Limitations of Surface Analysis Techniques on Plasma-Treated Arabidopsis thaliana Seeds

Alan Howling, Ivo Furno, Alexandra Waskow

Surface characterization of plasma-treated seeds has made significant progress over the last decade. Most papers in the literature use scanning electron microscopy (SEM) and contact angle goniometry to investigate surface modifications. However, very few p ...

2021

Experimental study of extended timescale dynamics of a plasma wakefield driven by a self-modulated proton bunch

Patrick Blanchard, Ambrogio Fasoli, Alan Howling, Ivo Furno, Yanis Andrebe, Rémy Jacquier, Riccardo Agnello

Plasma wakefield dynamics over timescales up to 800 ps, approximately 100 plasma periods, are studied experimentally at the Advanced Wakefield Experiment (AWAKE). The development of the longitudinal wakefield amplitude driven by a self-modulated proton bun ...

2021

An In Situ FTIR Study of DBD Plasma Parameters for Accelerated Germination of Arabidopsis thaliana Seeds

Alan Howling, Ivo Furno, Lorenzo Ibba, Alexandra Waskow

Current agricultural practices are not sustainable; however, the non-thermal plasma treatment of seeds may be an eco-friendly alternative to alter macroscopic plant growth parameters. Despite numerous successful results of plasma-seed treatments reported i ...

2021

Latest experimental and theoretical advances in the production of negative ions in caesium-free plasmas

Philippe Frédérique Bruno Guittienne, Alan Howling, Ivo Furno, Rémy Jacquier, Samir Suweis, Riccardo Agnello

This topical review gathers the last updates concerning caesium-free negative ion sources presented during the 63rd Course of the International school of Quantum Electronics of the Ettore Majorana Foundation and European collaborative works related to thes ...

2021

Negative hydrogen ion dynamics inside the plasma volume of a linear device: Estimates from particle-in-cell calculations

Philippe Frédérique Bruno Guittienne, Alan Howling, Ivo Furno, Rémy Jacquier, Riccardo Agnello

Negative hydrogen or deuterium ions are the precursor particles used to generate a high power beam of neutrals in order to heat the tokamak plasma core of magnetic fusion devices, inject current, and to some extent control instabilities. In the case of ITE ...

2021

Helicon wave plasma generated by a resonant birdcage antenna: magnetic field measurements and analysis in the RAID linear device

Philippe Frédérique Bruno Guittienne, Alan Howling, Ivo Furno, Rémy Jacquier, Riccardo Agnello

This paper describes a helicon-wave-sustained plasma generated by a novel birdcage antenna with cosine azimuthal current distribution. The resonant birdcage source maintains a stable intense plasma column from low (300 W) to high (10 kW) steady-state RF po ...

2021

Development of a plasma electroacoustic actuator for active noise control applications

Alan Howling, Pénélope Leyland, Ivo Furno, Hervé Lissek, Gennady Plyushchev, Stanislav Sergeev

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 ...

2020

Cold Atmospheric Plasma Inactivation of Microbial Spores Compared on Reference Surfaces and Powder Particles

Alan Howling, David Martinet

Heat-resistant spores on a dry, heat- and water-sensitive food matrix are difficult to inactivate. Radioactive or X-ray exposure is allowed and accepted only for some selected commodities. Non-thermal atmospheric pressure plasma treatments could offer an e ...

SPRINGER2020

Experimental study of wakefields driven by a self-modulating proton bunch in plasma

Patrick Blanchard, Ambrogio Fasoli, Alan Howling, Ivo Furno, Yanis Andrebe, Sun Hee Kim, Rémy Jacquier, Ishkhan Gorgisyan, Riccardo Agnello, Yiming Li, 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 ...

2020

Proton Bunch Self-Modulation in Plasma with Density Gradient

Patrick Blanchard, Ambrogio Fasoli, Alan Howling, Ivo Furno, Samuel Rey-Mermet, Yanis Andrebe, Ishkhan Gorgisyan, Amarasinghage Tharindu Dasun Perera

We study experimentally the effect of linear plasma density gradients on the self-modulation of a 400 GeV proton bunch. Results show that a positive or negative gradient increases or decreases the number of microbunches and the relative charge per microbun ...

2020