Enhancement of ion generation in femtosecond ultraintense laser-foil interactions by defocusing

M. H. Xu*, Y. T. Li, D. C. Carroll, P. S. Foster, S. Hawkes, S. Kar, F. Liu, K. Markey, P. McKenna, M. J V Streeter, C. Spindloe, Z. M. Sheng, C. G. Wahlström, M. Zepf, J. Zheng, J. Zhang, D. Neely

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

13 Citations (Scopus)


A simple method to enhance ion generation with femtosecond ultraintense lasers is demonstrated experimentally by defocusing laser beams on target surface. When the laser is optimally defocused, we find that the population of medium and low energy protons from ultra-thin foils is increased significantly while the proton cutoff energy is almost unchanged. In this way, the total proton yield can be enhanced by more than 1 order, even though the peak laser intensity drops. The depression of the amplified spontaneous emission (ASE) effect and the population increase of moderate-energy electrons are believed to be the main reasons for the effective enhancement.

Original languageEnglish
Article number084101
JournalApplied Physics Letters
Issue number8
Publication statusPublished - 20 Feb 2012

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)


Dive into the research topics of 'Enhancement of ion generation in femtosecond ultraintense laser-foil interactions by defocusing'. Together they form a unique fingerprint.

Cite this