@article{685928669c5144d3a8d491623cd5e9fd,
title = "Effect of Small Focus on Electron Heating and Proton Acceleration in Ultrarelativistic Laser-Solid Interactions",
abstract = "Acceleration of particles from the interaction of ultraintense laser pulses up to 5×1021 W cm-2 with thin foils is investigated experimentally. The electron beam parameters varied with decreasing spot size, not just laser intensity, resulting in reduced temperatures and divergence. In particular, the temperature saturated due to insufficient acceleration length in the tightly focused spot. These dependencies affected the sheath-accelerated protons, which showed poorer spot-size scaling than widely used scaling laws. It is therefore shown that maximizing laser intensity by using very small foci has reducing returns for some applications.",
author = "Dover, {N. P.} and M. Nishiuchi and H. Sakaki and Ko Kondo and Alkhimova, {M. A.} and Faenov, {A. Ya} and M. Hata and N. Iwata and H. Kiriyama and Koga, {J. K.} and T. Miyahara and Pikuz, {T. A.} and Pirozhkov, {A. S.} and A. Sagisaka and Y. Sentoku and Y. Watanabe and M. Kando and K. Kondo",
note = "Funding Information: We are grateful to the J-KAREN-P operations team for their support. This work was supported by a JSPS Postdoctoral Fellowship and Kakenhi Project No. 15F15772, JST-MIRAI R&D Program No. JPMJ17A1 and partially supported by JST PRESTO Grant No. JPMJPR16P9 and Kakenhi 10K05506. The EPOCH code was in part funded by the UK EPSRC Grants No. EP/G054950/1, No. EP/G056803/1, No. EP/G055165/1, and No. EP/M022463/1. FLASH was developed by the DOE NNSA ASC and NSF-supported FCCS at the University of Chicago. Publisher Copyright: {\textcopyright} 2020 authors. Published by the American Physical Society.",
year = "2020",
month = feb,
day = "26",
doi = "10.1103/PhysRevLett.124.084802",
language = "English",
volume = "124",
journal = "Physical Review Letters",
issn = "0031-9007",
publisher = "American Physical Society",
number = "8",
}