Self-generated surface magnetic fields inhibit laser-driven sheath acceleration of high-energy protons

Journal Article · Thu Jan 18 00:00:00 EST 2018 · Nature Communications

DOI:https://doi.org/10.1038/s41467-017-02436-w· OSTI ID:1441466

Nakatsutsumi, M. ^[1]; Sentoku, Y. ^[2]; Korzhimanov, A. ^[3]; Chen, S. N. ^[4]; Buffechoux, S. ^[5]; Kon, A. ^[6]; Atherton, B. ^[7]; Audebert, P. ^[5]; Geissel, M. ^[7]; Hurd, L. ^[5]; Kimmel, M. ^[7]; Rambo, P. ^[7]; Schollmeier, M. ^[7]; Schwarz, J. ^[7]; Starodubtsev, M. ^[3]; Gremillet, L. ^[8]; Kodama, R. ^[9]; Fuchs, J. ^[4]

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1. UPMC Univ Paris 06: Sorbonne Universités, Palaiseau cedex (France). LULI—CNRS, École Polytechnique, CEA: Université Paris-Saclay; European XFEL, GmbH, Schenefeld (Germany); Osaka University, Suita, Osaka (Japan). Open and Transdisciplinary Research Initiatives
2. Osaka University, Suita, Osaka (Japan). Institute of Laser Engineering; Univ. of Nevada, Reno, NV (United States). Department of Physics
3. Institute of Applied Physics, Nizhny Novgorod (Russia)
4. UPMC Univ Paris 06: Sorbonne Universités, Palaiseau cedex (France). LULI—CNRS, École Polytechnique, CEA: Université Paris-Saclay; Institute of Applied Physics, Nizhny Novgorod (Russia)
5. UPMC Univ Paris 06: Sorbonne Universités, Palaiseau cedex (France). LULI—CNRS, École Polytechnique, CEA: Université Paris-Saclay
6. Osaka University, Suita, Osaka (Japan). Institute of Laser Engineering and Graduate School of Engineering
7. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
8. CEA, DAM, DIF, Arpajon (France)
9. Osaka University, Suita, Osaka (Japan). Institute of Laser Engineering, Open and Transdisciplinary Research Initiatives and Graduate School of Engineering

High-intensity lasers interacting with solid foils produce copious numbers of relativistic electrons, which in turn create strong sheath electric fields around the target. The proton beams accelerated in such fields have remarkable properties, enabling ultrafast radiography of plasma phenomena or isochoric heating of dense materials. In view of longer-term multidisciplinary purposes (e.g., spallation neutron sources or cancer therapy), the current challenge is to achieve proton energies well in excess of 100 MeV, which is commonly thought to be possible by raising the on-target laser intensity. Here we present experimental and numerical results demonstrating that magnetostatic fields self-generated on the target surface may pose a fundamental limit to sheath-driven ion acceleration for high enough laser intensities. Those fields can be strong enough (~10⁵ T at laser intensities ~10²¹ W cm^–2) to magnetize the sheath electrons and deflect protons off the accelerating region, hence degrading the maximum energy the latter can acquire.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Fusion Energy Sciences (FES) (SC-24)
• Grant/Contract Number: AC04-94AL85000; NA0003525; SC0008827
• OSTI ID: 1441466
• Report Number(s): SAND--2018-4540J; 662597
• Journal Information: Nature Communications, Journal Name: Nature Communications Journal Issue: 1 Vol. 9; ISSN 2041-1723
• Publisher: Nature Publishing Group
• Country of Publication: United States
• Language: English

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