• C. Milardi, D. Alesini, M.E. Biagini, C. Biscari, A. Bocci, R. Boni, M. Boscolo, F. Bossi, B. Buonomo, A. Clozza, G.O. Delle Monache, T. Demma, E. Di Pasquale, G. Di Pirro, A. Drago, A. Gallo, A. Ghigo, S. Guiducci, C. Ligi, F. Marcellini, G. Mazzitelli, F. Murtas, L. Pellegrino, M.A. Preger, L. Quintieri, P. Raimondi, R. Ricci, U. Rotundo, C. Sanelli, M. Serio, F. Sgamma, B. Spataro, A. Stecchi, A. Stella, S. Tomassini, C. Vaccarezza, M. Zobov
  INFN/LNF, Frascati (Roma)
• N. Arnaud, D. Breton, L. Burmistrov, A. Stocchi, A. Variola, B.F. Viaud
  LAL, Orsay
• S. Bettoni
  CERN, Geneva
• P. Branchini
  roma3, Rome
• M. Esposito
  Rome University La Sapienza, Roma
• E.B. Levichev, P.A. Piminov, D.N. Shatilov
  BINP SB RAS, Novosibirsk
• K. Ohmi
  KEK, Ibaraki
• V.V. Smaluk
  BINP, Novosibirsk
• D. Teytelman
  SLAC, Menlo Park, California
• P. Valente
  INFN-Roma, Roma

In 2007 DAΦNE was upgraded to operate in a regime of large Piwinski angle, with a novel IR optics, reduced vertical beta at the interaction point, and additional sextupoles providing for crab waist collisions. The specific luminosity was boosted by more than a factor of four, and the peak luminosity was more than doubled with respect to the maximum value obtained with the original collider configuration. The DAΦNE commissioning as well as the first experience with large Piwinski angle and crab waist collisions scheme will be reported.

Slides

• V. Guidi, S. Baricordi, P. Dalpiaz, M. Fiorini
  UNIFE, Ferrara
• A.G. Afonin, Y.A. Chesnokov, V.A. Maisheev, I.A. Yazynin
  IHEP Protvino, Protvino, Moscow Region
• G. Ambrosi, B. Bertucci, W.J. Burger, P. Zuccon
  INFN-PG, Perugia
• D. Bolognini, S. Hasan, A. Mozzanica, M. Prest
  Università dell'Insubria & INFN Milano Bicocca, Como
• G. Cavoto, R. Santacesaria, P. Valente
  INFN-Roma, Roma
• G. Della Mea, R. Milan, A. Vomiero
  INFN/LNL, Legnaro (PD)
• A.S. Denisov, Yu.A. Gavrikov, Yu.M. Ivanov, L.P. Lapina, L.G. Malyarenko, V. Skorobogatov, V.M. Suvorov, S.A. Vavilov
  PNPI, Gatchina, Leningrad District
• A.D. Kovalenko, A.M. Taratin
  JINR, Dubna, Moscow Region
• C. Luci
  Università di Roma I La Sapienza, Roma
• A. Mazzolari
  INFN-Ferrara, Ferrara
• W. Scandale
  CERN, Geneva
• E. Vallazza
  INFN-Trieste, Trieste

The H8RD22 collaboration has accomplished an extensive study of axial channeling in the external lines of the CERN SPS. For 400 GeV protons, it was recorded deflection by about 90% of the particles by a short crystal, by far exceeding the performance of previous experiments. Axial channeling with 150 GeV negative hadrons was also firmly observed with deflection capability comparable to the case of positive particles. Near-axis effect such as multiple-volume reflections in a single crystal as a result of the superposition of volume reflections by a series of parallel planes sharing the same axis was investigated with 400 GeV protons. Confirmation of theoretical expectation was observed, in particular most of the particles were deflected by about 50 urad, four times the deflection angle imparted by a single volume reflection of most efficient planes. In this case the angular acceptance was sensitively broader than for the case of channeling. In summary, channeling in axial mode and multi-volume reflections were proven to be two mechanisms for manipulation steering of high-energy particle beams, which side most established techniques such as planar channeling and volume reflection.*

*Contribution on behalf of the H8RD22 collaboration.