@misc{oai:repo.qst.go.jp:00067774,
 author = {Adachi, Masahiro and 阿達 正浩},
 month = {Apr},
 note = {There have been some reports on electron acceleration in a plasma produced by an intense laser pulse shorter than 50 fs. Most of experiments were performed with a plasma of which electron density was ~1019 cm-3. We report electron acceleration experiment with higher density (~1020 cm-3) plasma produced by a 50-fs laser pulse. The experiment was performed with a 2-TW Ti:sapphire laser system. The center wavelength was 800 nm. The laser beam was focused on a surface of a nitrogen or helium supersonic gas jet. An intensity at a focal point was 5 1018 W cm-2. The maximum electron energy and the total number of electrons above 1MeV were 30 MeV and 10 pC per shot, respectively. A Hump in the electron energy spectrum was observed at 6 MeV. The maximum electron energy and the total charge become higher, as the electron density become higher and maximized at the density around 1020 cm-3. In a forward scattered light spectrum, a Stokes satellite peak was observed and we could estimate a plasma density where a plasma wave was excited as around 1020 cm-3., 高速点火レーザー相互作用国際会議},
 title = {FIHFP},
 year = {2004}
}