BNL, Upton, Long Island, New York, USA
RHIC operation as the polarized proton collider presents unique challenges since both luminosity and spin polarization are important. With longitudinally polarized beams at the experiments, the figure of merit is LP4. A lot of upgrades and modifications have been made since last polarized proton operation. A 9 MHz rf system has been installed to improve longitudinal match at injection and to increase luminosity. The beam dumps were upgraded to allow for increased bunch intensities. A vertical survey of RHIC was performed before the run to get better magnet alignment. The orbit control has also been improved this year. Additional efforts were put in to improve source polarization and AGS polarization transfer efficiency. To preserve polarization on the ramp, a new working point was chosen such that the vertical tune is near a third order resonance. The overview of the changes and the operation results are presented in this paper.
BNL, Upton, Long Island, New York, USA
The commissioning of the RHIC spin flipper in the RHIC Blue ring during the RHIC polarized proton run in 2009 showed the detrimental effects of global vertical coherent betatron oscillation induced by the 2-AC dipole plus 4-DC dipole configuration *. Additional three AC dipoles were added to the RHIC spin flipper in the RHIC Blue ring during the summer of 2010 to eliminate the vertical coherent betatron oscillations outside the spin flipper [2]. This new design is scheduled to be commissioned during the RHIC polarized proton run in 2011. This paper presents the status of the system as well as latest simulation results.
* M. Bai , T. Roser, C. Dawson, Y. Makdisi, W. Meng, F. Meot, P. Oddo, C. Pai, P. Pile, RHIC Spin Flipper New Design and Commissioning Plan, IPAC10 proceedings, IPAC 2010, Kyoto, Japan, 2010
Tech-X, Boulder, Colorado, USA
BNL, Upton, Long Island, New York, USA
We have benchmarked UAL-SPINK against Zgoubi and a list of well understood spin physics results. Along the way we addressed issues relating to longitudinal dynamics and orbit bump and distortion handling as well as appropriate slicing necessary for the TEAPOT-SPINK spin orbit integrator. We have also ported this TEAPOT-SPINK algorithm to the GPU’s. We present the challenges associated with this work.
BNL, Upton, Long Island, New York, USA
A number of recent machine designs, including ‘‘nano-beams'', sub-millimeter ‘‘low-beta'' IRs, etc., require high accuracy on beam orbit and beam size, reliable evaluation of machine parameters, dynamic apertures, etc. This can only be achieved using high precision simulation tools. Stepwise ray-tracing methods are in this category of tools, stochastic synchrotron radiation and its effects on an electron beam in a storage ring are simulated here in that manner. Benchmarking of the method against analytical model expectations, using a Chasman-Green cell, is presented.
BNL, Upton, Long Island, New York, USA
A model of the Alternating Gradient Synchrotron is being developed based on stepwise ray-tracing numerical tools. It provides a realistic representation of the lattice, and accounts for the two helical partial Siberian snake insertions. The aim is to make this stepwise ray-tracing based model an aid for the understanding of the AGS, in matter of both beam dynamics and polarization transmission.
BNL, Upton, Long Island, New York, USA
As the worlds’s first high energy polarized proton col- lider, RHIC has made significant progresses in measuring the proton spin structure in the past decade. In order to have better understanding of the contribution of u quark and d quark to the proton spin structure, collisions of high energy polarized neutron beams are required. In this paper, we discuss the perspectives of accelerating polarized light ions, like deuteron, Helium-3 and tritium. We also repre- sent simulation studies of accelerating polarized Helium-3 in RHIC.
Brookhaven National Lab., Upton, NY 11973
BNL, Upton, Long Island, New York, USA
Tech-X, Boulder, Colorado, USA
Stepwise ray-tracing methods are being developed at C-AD, BNL, in view of benchmarking of existing spin codes and of spin dynamics simulations at RHIC. A status of that work is reported here.