EPJ D Highlight - Optimising laser-driven electron acceleration

The net energy gain of electrons as a function of time with corresponding electron momentum (centre). E. Molnár, D. Stutman, C. Ticos (2020)

A new paper examines how tuning aspects of a powerful laser beam can affect the acceleration of electrons, attempting to find the recipe for maximum net energy gain.

The interaction between lasers and matter is at the forefront of new investigations into fundamental physics as well as forming a potential bedrock for new technological innovations. One of the initiatives spearheading this investigation is the Extreme Light Infrastructure Nuclear Physics (ELI-NP) project. Here the project’s High-Power Laser System (HPLS) — the world’s most powerful laser—is just one of the tools driving electron acceleration with lasers, Direct Laser Acceleration (DLA). In a new paper published in EPJ D, Etele Molnár, ELI-NP, Bucharest, and co-authors study and review the characteristics of electron acceleration in a vacuum caused by the highest-power laser pulses achievable today looking for the key to maximum net energy gain.

In particular, the authors calculate the optimal values of the laser beam required to achieve maximum electron energy for different laser power levels. They observe that tuning certain aspects of a laser such as its beam waist—the point at which a laser beam has its minimum radius—can favourably increase the maximum acceleration of electrons in a vacuum for both linearly and circularly polarised lasers.

As may be expected, Molnár and colleagues find that the net energy of the electrons, and thus their acceleration, is raised with increased laser power for beams with optimal beam waists. The paper describes an average energy gain in electrons of a few MeV in full pulse interactions, in which the highest energy electrons possess is roughly 160 MeV. In other cases such as half-pulse interactions, however, the authors say that these energy gains are almost an order of magnitude greater— reaching up to 1 GeV.

In terms of future research, the paper puts forward other potential directions. For example, the researchers suggest a study with a focus on direct laser acceleration with higher Laguerre Gaussian modes — circularly symmetric beam profiles or lasers with cavities that are cylindrically symmetric —should follow the current paper.

This was our first experience of publishing with EPJ Web of Conferences. We contacted the publisher in the middle of September, just one month prior to the Conference, but everything went through smoothly. We have had published MNPS Proceedings with different publishers in the past, and would like to tell that the EPJ Web of Conferences team was probably the best, very quick, helpful and interactive. Typically, we were getting responses from EPJ Web of Conferences team within less than an hour and have had help at every production stage.
We are very thankful to Solange Guenot, Web of Conferences Publishing Editor, and Isabelle Houlbert, Web of Conferences Production Editor, for their support. These ladies are top-level professionals, who made a great contribution to the success of this issue. We are fully satisfied with the publication of the Conference Proceedings and are looking forward to further cooperation. The publication was very fast, easy and of high quality. My colleagues and I strongly recommend EPJ Web of Conferences to anyone, who is interested in quick high-quality publication of conference proceedings.

On behalf of the Organizing and Program Committees and Editorial Team of MNPS-2019, Dr. Alexey B. Nadykto, Moscow State Technological University “STANKIN”, Moscow, Russia. EPJ Web of Conferences vol. 224 (2019)

ISSN: 2100-014X (Electronic Edition)

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