• R.P. Fliller
  BNL, Upton, Long Island, New York

Injection into a ring requires that the injected beam be optimally matched to the storage ring lattice. For on axis injection this requires that the twiss functions of the transfer line match the twiss functions of the lattice. When injection off axis, as is done in light sources for top off injection, the goal is to use the minimum phase space area in the storage ring. A. Streun* has given an analytical method to compute the twiss functions for top off injection into the SLS where injection occurs at a beam waist. We have extended his theory to include cases where there is no beam waist. A simple analytical formula is not possible in this case, however we give an algorithm to compute the twiss parameters of the injected beam given the storage ring lattice. We also compute the twiss functions for a variety of cases for the NSLS-II storage ring.

* A. Streun. "SLS booster-to-ring transfer line optics for optimum injection effciency". Technical Note SLS-TME-TA-2002-0193. May 27, 2005.

• R.P. Fliller, R. Heese, S. Kowalski, J. Rose, T.V. Shaftan, G.M. Wang
  BNL, Upton, Long Island, New York

The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source currently under construction at Brookhaven National Laboratory. The NSLS-II injection system consists of a 200 MeV linac and a 3 GeV booster synchrotron. The injection system needs to deliver 7.5 nC in 80 - 150 bunches to the storage ring every minute to achieve current stability goals in the storage ring. This is a very stringent requirement that has not been demonstrated at an operating light source, though it should be achievable. To alleviate the charge requirement on the linac, we have designed a scheme to stack two bunch trains in the booster. In this paper we discuss this stacking scheme. The performance of the stacking scheme is studied in detail at injection and through a full booster ramp. We show the the ultimate performance of the stacking scheme is similar to a single bunch train in the booster if the linac emittance meets the requirements. Increasing the emittance of the linac beam degrades the performance, but still allows an overall increase of train charge vs. one bunch train.

• R.P. Fliller, W.R. Casey, R. Faussete, H. Fernandes, G. Ganetis, R. Heese, H.-C. Hseuh, P.K. Job, B.N. Kosciuk, R. Meier, D. Padrazo, I. Pinayev, J. Rose, T.V. Shaftan, O. Singh, J. Skaritka, C.J. Spataro, G.M. Wang
  BNL, Upton, Long Island, New York

The NSLS-II injection system consists of a 200 MeV linac and a 3 GeV booster synchrotron and associated transport lines. The transport lines need to transport the beam from the linac to the booster and from the booster to the storage ring in a way that provide high injection efficiency. In this paper we discuss progress on specifying and prototyping the NSLS-II transfer lines including diagnostics, magnet specifications, and safety systems. Commissioning plans are also discussed.

• A. Blednykh, W.X. Cheng, R.P. Fliller, Y. Kawashima, J. Rose, T.V. Shaftan, L.-H. Yu
  BNL, Upton, Long Island, New York

In this paper, we present an overview of the impact of collective effects upon the performance of the NSLS-II booster.

• 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.