INFN/LNF, Frascati (Roma)
SLAC, Menlo Park, California
CERN, Geneva
BINP SB RAS, Novosibirsk
KEK, Ibaraki
University of Pisa and INFN, Pisa
The SuperB project aims at the construction of an asymmetric (4x7 GeV), very high luminosity, B-Factory on the Roma II (Italy) University campus. The luminosity goal of 1036 cm-2 s-1 can be reached with a new collision scheme with large Piwinski angle and the use of “crab” sextupoles. A crab-waist IR has been successfully tested at the DAPHNE Phi-Factory at LNF-Frascati (Italy) in 2008. The crab waist together with very low beta* will allow for operation with relatively low beam currents and reasonable bunch length, comparable to those of PEP-II and KEKB. In the High Energy Ring, two spin rotators permit bringing longitudinally polarized beams into collision at the IP. The lattice has been designed with a very low intrinsic emittance and is quite compact, less than 2 km long. The tight focusing requires a sophisticated Interaction Region with quadrupoles very close to the IP. A Conceptual Design Report was published in March 2007, and beam dynamics and collective effects R&D studies are in progress in order to publish a Technical Design Report by the end of 2010. A status of the design and simulations is presented in this paper.
INFN/LNF, Frascati (Roma)
LAL, Orsay
CERN, Geneva
roma3, Rome
Rome University La Sapienza, Roma
BINP SB RAS, Novosibirsk
KEK, Ibaraki
BINP, Novosibirsk
SLAC, Menlo Park, California
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.
BINP SB RAS, Novosibirsk
INFN/LNF, Frascati (Roma)
KEK, Ibaraki
A novel scheme of crab waist collisions has been successfully tested at the electron-positron collider DAΦNE, Italian Phi-factory. In this paper we compare numerical simulations of the crab waist beam-beam interaction with obtained experimental results. For this purpose we perform weak-strong and quasi strong-strong beam-beam simulations using a realistic DAΦNE lattice model that has proven to reproduce reliably both linear and nonlinear collider optics.
BINP SB RAS, Novosibirsk
INFN/LNF, Frascati (Roma)
A project of the SuperB Factory in Italy with the crab-waist collision scheme and extremely large luminosity addresses new challenges to the nonlinear beam dynamics study. Among these challenges are: low emittance lattice requiring strong sextupoles for chromatic correction, sub-mm vertical betatron function at the IP, crab sextupoles placed at both sides from the IP, etc. In this report we describe the results of the DA limiting sources analysis and optimization of the arrangement of the IR and Crab sextupoles and octupoles for the Low Energy Ring (LER).
INFN/LNF, Frascati (Roma)
KEK, Ibaraki
Funding: Work supported in part by the “Ministero degli Affari Esteri, Direzione Generale per la Promozione e la Cooperazione Culturale”
A strong horizontal instability has been observed in the DAΦNE positron ring since 2003. Experimental observations suggest an electron cloud induced coupled bunch instability as a possible explanation. In this communication we present a simulation study of the electron cloud coupled bunch instability for the DAΦNE positron ring, performed with the code PEI-M, and compare the numerical results with experimental observations.
SLAC, Menlo Park, California
INFN/LNF, Frascati (Roma)
Funding: work supported by the Department of Energy under contract number DE-AC03-76SF00515
We give an overview of wake fields and impedances in a proposed Super B project, which is based on extremely low emittance beams colliding at a large angle with a crab waist transformation. Understanding the effect wake fields have on the beam is critical for a successful machine operation. We use our combined experience from the operation of the SLAC B-factory and DAΦNE Phi-factory to eliminate strong HOM sources and minimize the chamber impedance in the Super B design. Based on a detailed study of the wake fields in this design we have developed a quasi-Green’s function for the entire ring that is used to study bunch lengthening and beam stability. In particular, we check the stability threshold using numerical solutions of the Fokker-Plank equation. We also make a comparison of numerical simulations with the bunch lengthening data in the B- factory.