• M. Mori, S.V. Bulanov, Y. Hayashi, K. Kawase, K. Kondo, A.S. Pirozhkov, A. Sugiyama
  JAEA, Kyoto
• M. Kando
  JAEA APRC, Ibaraki-ken
• H. Kotaki, K. Ogura
  JAEA/Kansai, Kyoto
• H. Nishimura
  ILE Osaka, Suita

The pointing stability and the divergence of a quasi-monoenergetic electron bunch generated in a self-injected laser-plasma acceleration regime were investigated. Gas-jet targets have been irradiated with focused 40 fs laser pulses at the 4-TW peak power. A pointing stability of 2.4 mrad root-mean-square (RMS) and a beam divergence of 10.6 mrad (RMS) were obtained using argon gas-jet target for 50 sequential shots, while these values were about three times smaller than at the optimum condition using helium. In particular, the peak electron energy was 9 MeV using argon, which is almost three times lower than that using helium. This result implies that the formation of the wake-field is different between argon and helium, and it plays an important role in the generation of a electron bunch. This stabilization scheme is available for another gas material such as nitrogen. At nitrogen gas-jet target, the pointing stability is more improved to 1.4 times smaller (1.7 mrad (RMS)) than that in argon gas-jet target and the peak energy is increased to grater than 40 MeV. These results prove that this method not only stabilize the e-beam but also allows controlling the electron energy.

• C. Steier, B.J. Bailey, A. Biocca, A. Madur, H. Nishimura, G.J. Portmann, S. Prestemon, D. Robin, S.L. Rossi, F. Sannibale, T. Scarvie, D. Schlueter, W. Wan, L. Yang
  LBNL, Berkeley, California

The Advanced Light Source is one of the earliest 3rd generation light sources. With an active upgrade program it has remained competitive over the years. The latest in a series of upgrades is a lattice upgrade project that was started in 2009. When it will be completed, the ALS will operate with a horizontal emittance of 2.2 nm and an effective emittance of 2.6 nm. Combined with the high current of 500 mA and the small vertical emittance the ALS already operates at this upgrade will keep it competitive for years to come. The presentation will present the status of the upgrade, including beam dynamics studies and lattice optimizations as well as the magnet design and status.