Boosted acceleration of protons by tailored ultra-thin foil targets

• Published in: Scientific reports Vol. 9; no. 1; pp. 18672 - 10
• Main Authors: Kaymak, Vural, Aktan, Esin, Cerchez, Mirela, Elkin, Bentsian, Papenheim, Marc, Prasad, Rajendra, Pukhov, Alexander, Scheer, Hella-C., Schroer, Anna-Marie, Willi, Oswald, Aurand, Bastian
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10-12-2019; Nature Publishing Group
• Subjects: 639/766/1960/1135; 639/766/1960/1137; Energy; Humanities and Social Sciences; Lasers; multidisciplinary; Protons; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-55011-2

We report on a detailed experimental and numerical study on the boosted acceleration of protons from ultra-thin hemispherical targets utilizing multi-Joule short-pulse laser-systems. For a laser intensity of 1 × 10
20
 W/cm
2
and an on-target energy of only 1.3 J with this setup a proton cut-off energy of 8.5 MeV was achieved, which is a factor of 1.8 higher compared to a flat foil target of the same thickness. While a boost of the acceleration process by additionally injected electrons was observed for sophisticated targets at high-energy laser-systems before, our studies reveal that the process can be utilized over at least two orders of magnitude in intensity and is therefore suitable for a large number of nowadays existing laser-systems. We retrieved a cut-off energy of about 6.5 MeV of proton energy per Joule of incident laser energy, which is a noticeable enhancement with respect to previous results employing this mechanism. The approach presented here has the advantage of using structure-wise simple targets and being sustainable for numerous applications and high repetition rate demands at the same time.