• W. Guo, S. Krinsky, L. Yang
  BNL, Upton, Long Island, New York

Chromaticity is usually set to non-zero value at the third generation light sources to cure the intensity induced instabilities. It is effective in suppressing the beam centroid oscillation; however, it is repeatedly reported that the beam lifetime decreases significantly when chromaticity goes up. This is probably due to the crossing of resonance lines by the enlarged tune footprint. In this paper we optimize the NSLS-II lattice at different positive chromaticity settings. The tune footprint is adjusted to fit in the stable region divided by the strong resonance lines. Tracking results show that we can maintain a lifetime similar to that of the zero-chromaticity lattice solutions.

• W. Guo, S.L. Kramer, S. Krinsky, B. Nash, J. Skarita, F.J. Willeke
  BNL, Upton, Long Island, New York

NSLS-II is a third-generation light source that is being built at the Brookhaven National Laboratory. The storage ring has 30 double-bend-achromatic cells. Six 3.5-m-long damping wigglers (DW) will be installed in three straight section to lower the emittance. The civil construction of the facility started in June 2009 and major accelerator components, such as magnets and vacuum chambers, have entered production phase. This paper will summarize the physics considerations for the NSLS-II magnet specifications. In particular, we discuss the tuning range required by the lattice flexibility, and the issues which lead to the specification for the higher-order multipoles.

• T.V. Shaftan, A. Blednykh, W.R. Casey, L.R. Dalesio, R. Faussete, M.J. Ferreira, R.P. Fliller, G.S. Fries, G. Ganetis, W. Guo, R. Heese, H.-C. Hseuh, Y. Hu, P.K. Job, E.D. Johnson, Y. Kawashima, B.N. Kosciuk, S. Kowalski, S. Krinsky, Y. Li, H. Ma, R. Meier, S. Ozaki, D. Padrazo, B. Parker, I. Pinayev, M. Rehak, J. Rose, S. Sharma, O. Singh, P. Singh, J. Skaritka, C.J. Spataro, G.M. Wang, F.J. Willeke, L.-H. Yu
  BNL, Upton, Long Island, New York

We discuss status and plans of development of the NSLS-II injector. The injector consists of 200 MeV linac, 3-GeV booster, transport lines and injection straight section. The system design is now nearly completed and the injector development is in the procurement phase. The injector commissioning is planned to take place in 2012.

• G.M. Wang, R.P. Fliller, W. Guo, R. Heese, T.V. Shaftan, L.-H. Yu
  BNL, Upton, Long Island, New York
• Y.-C. Chao
  TRIUMF, Vancouver

The low beam emittance requirement in the NSLS-II storage ring imposes a very tight constraint on its acceptance. This requires the injected beam emittance to be very small, for which a reliable scheme of measurement to determine the phase space and momentum characteristics of the beam coming out the booster is necessary. The original scheme based on the booster-to-dump transport line was hampered by the difficulty in decoupling betatron oscillation from dispersion, due to high concentration of dipoles and limited number of quads after the booster. This paper will describe the alternative method being planned to use the booster extraction line to measure the beam emittance and energy spread, as well as the associated errors.

• M.A. Palmer, J.P. Alexander, M.G. Billing, J.R. Calvey, C.J. Conolly, J.A. Crittenden, J. Dobbins, G. Dugan, N. Eggert, E. Fontes, M.J. Forster, R.E. Gallagher, S.W. Gray, S. Greenwald, D.L. Hartill, W.H. Hopkins, D.L. Kreinick, B. Kreis, Z. Leong, Y. Li, X. Liu, J.A. Livezey, A. Lyndaker, J. Makita, M.P. McDonald, V. Medjidzade, R.E. Meller, T.I. O'Connell, S.B. Peck, D.P. Peterson, G. Ramirez, M.C. Rendina, P. Revesz, D.H. Rice, N.T. Rider, D. L. Rubin, D. Sagan, J.J. Savino, R.M. Schwartz, R.D. Seeley, J.W. Sexton, J.P. Shanks, J.P. Sikora, E.N. Smith, C.R. Strohman, H.A. Williams
  CLASSE, Ithaca, New York
• F. Antoniou, S. Calatroni, M. Gasior, O.R. Jones, Y. Papaphilippou, J. Pfingstner, G. Rumolo, H. Schmickler, M. Taborelli
  CERN, Geneva
• D. Asner
  Carleton University, College of Natural Sciences, Ottawa, Ontario
• L. Boon, A.F. Garfinkel
  Purdue University, West Lafayette, Indiana
• J.M. Byrd, C.M. Celata, J.N. Corlett, S. De Santis, M.A. Furman, A. Jackson, R. Kraft, D.V. Munson, G. Penn, D.W. Plate, M. Venturini
  LBNL, Berkeley, California
• B.T. Carlson
  Grove City College, Grove City, Pennsylvania
• T. Demma
  INFN/LNF, Frascati (Roma)
• R.T. Dowd
  ASCo, Clayton, Victoria
• J.W. Flanagan, P. Jain, K. Kanazawa, K. Kubo, K. Ohmi, H. Sakai, K. Shibata, Y. Suetsugu, M. Tobiyama
  KEK, Ibaraki
• D. Gonnella
  Clarkson University, Potsdam, New York
• W. Guo
  BNL, Upton, Long Island, New York
• K.C. Harkay
  ANL, Argonne
• R. Holtzapple
  CalPoly, San Luis Obispo, CA
• J.K. Jones, A. Wolski
  Cockcroft Institute, Warrington, Cheshire
• D. Kharakh, J.S.T. Ng, M.T.F. Pivi, L. Wang
  SLAC, Menlo Park, California
• M.C. Ross, C.-Y. Tan, R.M. Zwaska
  Fermilab, Batavia
• L. Schächter
  Technion, Haifa
• E.L. Wilkinson
  Loyola University, Chicago, Illinois

The Cornell Electron Storage Ring (CESR) has been reconfigured as a test accelerator (CesrTA) for a program of electron cloud (EC) research at ultra low emittance. The instrumentation in the ring has been upgraded with local diagnostics for measurement of cloud density and with improved beam diagnostics for the characterization of both the low emittance performance and the beam dynamics of high intensity bunch trains interacting with the cloud. Finally a range of EC mitigation methods have been deployed and tested. Measurements of cloud density and its impact on the beam under a range of conditions will be presented and compared with simulations. The effectiveness of a range of mitigation techniques will also be discussed.

Slides