title: Study of x-ray emission enhancement via a high-contrast femtosecond laser interacting with a solid foil.
abstract: We observed the increase of the conversion efficiency from laser energy to Kalpha x-ray energy (eta(K)) produced by a 60 fs frequency doubled high-contrast laser pulse focused on a Cu foil, compared to the case of the fundamental laser pulse. eta(K) shows a strong dependence on the nonlinearly modified rising edge of the laser pulse. It reaches a maximum for a 100 fs negatively modified pulse. The hot electron efficient heating leads to the enhancement of eta(K). This demonstrates that high-contrast lasers are an effective tool for optimizing eta(K), via increasing the hot electrons by vacuum heating.
authors: Advanced Photon Research Center, Kansai Photon Science Institute, JAEA, Kyoto 619-0215, Japan.
authors: L M
authors: LM
authors: Chen
authors: M
authors: M
authors: Kando
authors: M H
authors: MH
authors: Xu
authors: Y T
authors: YT
authors: Li
authors: J
authors: J
authors: Koga
authors: M
authors: M
authors: Chen
authors: H
authors: H
authors: Xu
authors: X H
authors: XH
authors: Yuan
authors: Q L
authors: QL
authors: Dong
authors: Z M
authors: ZM
authors: Sheng
authors: S V
authors: SV
authors: Bulanov
authors: Y
authors: Y
authors: Kato
authors: J
authors: J
authors: Zhang
authors: T
authors: T
authors: Tajima