@misc{oai:repo.qst.go.jp:00060025,
 author = {Kitagawa, Yoneyoshi and 北川 米喜},
 month = {Oct},
 note = {Plasma is an attractive source for the future particle accelerators.  However, the plasma size has been a few mm or less, which is too short to accelerate particles to gigaelectronvolts or teraelectronvolts.  Capillary-confined plasmas can be longer and  will make a breakthrough to the advanced accelerator development.  15 J -1.053 $\mu$m pulse in $0.5 $ ps was injected into a glass capillary of 1 cm long and 60 $\mu$m in bore size and accelerated plasma electrons to 100 MeV via the resonant wakefield inside the capillary. The plasma length was longer than any gas jet plasmas. The laser ablated the wall plasma, whose density was estimated to be $\sim2 \times 10^{16}$cm$^{-3}$, containing the wakefield of 10 GV/m. An isolated energy peak (a bump) is observed at 60 MeV, which shows the electron trapping in the excited wakefield. The 2-d PIC supports the trapping effects both at the shoulder at middle energy around 10 MeV in the acceleration phase and at the high energy bump around maximum in the deceleration phase. It also shows the low energy plateau of dephased electrons. As increasing the bore diameter to 120 $\mu$m, the energy gain reduced to 10 MeV. The reason why the PIC simulations so well explained the capillary acceleration will be that the capillary confined the laser pulse as well as the plasma much longer than  $Z_R$.   The plasma length of only few mm has been an obstacle to the laser accelerator progress. The capillary may overcome it.  The results will give us a  promising future to the advanced laser accelerate., Workshop on Laser and Plasma Accelerators},
 title = {超短パルスレーザー照射キャピラリーターゲットを用いた、高品質100 MeV},
 year = {2003}
}