• W. Meng, Y. Hao, A.K. Jain, V. Litvinenko, G.J. Mahler, J.E. Tuozzolo
  BNL, Upton, Long Island, New York

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

eRHIC, a future high luminosity electron-ion collider at BNL, will add polarized electrons to the list of colliding species in RHIC. A 10-to-30 GeV electron energy recovery linac will require up to six passes around the RHIC 3.8 km circumference. We are developing and testing small (3-to-5 mm gap) dipole and quadrupole magnets and vacuum chambers for cost-effective eRHIC passes. We are also studying the sensitivity of eRHIC pass optics to magnet and alignment errors in such a small-magnet structure. We present the magnetic and mechanical designs of the small gap eRHIC components and prototyping test results.

• J. Skaritka, J. Bengtsson, G. Danby, G. Ganetis, W. Guo, R.C. Gupta, J.W. Jackson, A.K. Jain, S.L. Kramer, S. Krinsky, Y. Li, W. Meng, B. Nash, S. Ozaki, M. Rehak, S. Sharma, C.J. Spataro, F.J. Willeke
  BNL, Upton, Long Island, New York

Funding: US DOE Office of Basic Energy Sciences

NSLS-II is a new state-of-the-art medium energy synchrotron light source designed to deliver world leading brightness and flux with top-off operation for constant output. Design and engineering of NSLS-II began in 2005 and the beginning of construction and operations are expected to start in 2009 and 2015, respectively. The energy of the machine is 3Gev and the circumference 792 m. The chosen lattice requires tight on magnetic field tolerances for the ring magnets. These magnets have been designed with 3D Opera software. The required multipole field quality and alignment preclude the use of multifunctional sextupoles, leading to discrete corrector magnets in the storage ring. The corrector magnets are multifunctional and will provide horizontal and vertical steering as well as skew quadrupole. This paper describes the dipoles, quadrupoles, sextupoles, and corrector magnets design and prototyping status of the NSLS-II.

• J.W. Glenn, H. Huang, A.K. Jain, C.J. Liaw, I. Marneris, W. Meng, J.-L. Mi, S.P. Pontieri, P.J. Rosas, J. Sandberg, J.E. Tuozzolo, W. Zhang
  BNL, Upton, Long Island, New York

Funding: Work supported by Brookhaven Science Associates, LLC underContract No. DE-AC02-98CH10886 with the U.S. Department of Energy.

In order to cross more rapidly the 82 weak resonances caused by the horizontal tune and the partial snakes, we plan to jump the horizontal tune 82 times during the acceleration cycle, 41 up and 41 down*. To achieve this, the magnets creating this tune jump will pulse on in 100 micro-seconds, hold the current flat for about four milli-seconds and zero the current in another 100 micro-seconds. The magnets are old laminated beam transport magnets with longitudinal shims closing the aperture to reduce inductance and power supply current. The power supply uses a high voltage capacitor discharge to raise the magnet current, which is then switched to a low voltage supply, and then the current is switched back to the high voltage capacitor to zero the current. The current in each of the magnet pulses must match the order of magnitude change in proton momentum during the acceleration cycle. The magnet, power supply and cabling will be described with coast saving features and operational experience.

*Overcome Horizontal Depolarizing Resonances in the AGS with Tune Jump