| Paper | Title | Page |
|---|---|---|
| MOPC106 | Injection and Acceleration of Au31+ in the BNL AGS | 313 |
|
||
| Injection and acceleration of ions in a lower charge state reduces space charge effects, and, if further electron stripping is needed, may allow elimination of a stripping stage and the associated beam losses. The former is of interest to the accelerators of the GSI FAIR complex, the latter for BNL RHIC collider operation at energies lower than the current injection energy. Lower charge state ions, however, have a higher likelihood of electron stripping which can lead to dynamic pressures rises and subsequent beam losses. We report on experiments in the AGS where Au31+ ions were injected and accelerated instead of the normally used Au77+ ions. Beam intensities and the average pressure in the AGS ring are recorded, and compared with calculations for dynamic pressures and beam losses. The experimental results will be used to benchmark the STRAHLSIM dynamic vacuum code and will be incorporated in the GSI FAIR SIS100 design. | ||
| MOPC108 | AGS Polarized Proton Operation in Run 8 | 316 |
|
||
| A dual partial snake scheme has been used for AGS polarized proton operation for several years. It has provided polarized proton beams with 1.5*1011 protons per bunch and 65% polarization for the RHIC spin program. There is still residual polarization loss due to both snake resonances and horizontal resonances. Several schemes were tested in the AGS to mitigate the loss. This paper presents the experiment results and analysis. | ||
| WEPP063 | R-matrices of the Fast Beam Extraction Section of AGS | 2662 |
|
||
| The Fast Beam Extraction (FEB) system of the Alternating Gradient synchrotron (AGS) extracts the beam bunches from AGS into the AGS-to-RHIC (AtR) beam transfer line, and the extracted bunches are injected into the Relativistic Heavy Ion Collider (RHIC) synchrotron. In a particular section of the beam extraction line the beam bunches are transported through the fringe field region of three main AGS magnets. Optical characteristics of this section change with trajectory and momentum. Therefore the calculation of the R-matrices in this part of the extraction line requires special attention. To describe accurately the R-matrices, the magnetic field of the AGS main magnets was measured on the median plane of the AGS magnet in both, the circulating beam region and the fringe field region, where the extracted beam is transported. Using these magnetic field maps we describe the procedure we use to calculate the R-matrices at the beam extraction region. These R-matrices are used to calculate the beam parameters at the starting point of the AtR beam transfer line and the required quadrupole settings to match to RHIC’s acceptance. | ||
| WEPC089 | Status of the NSLS-II Injection System Design | 2198 |
|
||
| NSLS-II is a new ultra-bright 3rd generation 3GeV light source planned to be built at Brookhaven National Laboratory. The design of this facility is well under way. The requirement for the compact injector complex which has to continuously provide 3GeV electrons for top off injection into the storage ring is very demanding: high reliability, low loss, relatively high charge (10nC). The injector consists of linear accelerator, a full-energy booster, as well as transport lines and injection straight section. A large three dimensional dynamic aperture through the entire acceleration cycle in the booster synchrotron is required. Tolerances on pulsed magnets for the beam transfer are very tight in order to minimize injection losses and disturbance of the stored beam in the main ring. The components of the injector are optimized for high reliability and availability. In this paper we give an overview of the NSLS-II injector, discuss status, specifications and design challenges. | ||
| WEPP011 | Setup and Performance of RHIC for the 2008 Run with Deuteron and Gold Collisions | 2548 |
|
||
| This year deuterons and gold ions were collided in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) for the first time since 2003. The setup and performance of the collider for this run is reviewed with a focus on improvements that have led to an order of magnitude increase in luminosity since the 2003 run. | ||
| WEPP015 | Experience with IBS-suppression Lattice in RHIC | 2557 |
|
||
| An intra-beam scattering (IBS) is the limiting factor of the luminosity lifetime for RHIC operating with heavy ions. In order to suppress the IBS we designed and implemented new lattice with higher betatron tunes. This lattice had been developed during last three years and had been used for gold ions in yellow ring of the RHIC during d-Au part of the RHIC Run-8. The use of this lattice allowed both significant increases in the luminosity lifetime and the luminosity levels via reduction of beta-stars in the IPs. In this paper we report on the development, the tests and the performance of IBS-suppression lattice in RHIC, including the resulting increases in the peak and the average luminosity. We also report on our plans for future steps with the IBS suppression. | ||
| WEPP019 | RHIC Polarized Proton Performance in Run-8 | 2566 |
|
||
| During Run-8, the Relativistic Heavy Ion Collider (RHIC) provided collisions of spin-polarized proton beams at two interaction regions. Helical spin rotators at these two interaction regions were used to control the spin orientation of both beams at the collision points. Physics data were taken with different orientations of the beam polarization. We present recent developments and improvements as well as the luminosity and polarization performance achieved during Run-8. | ||
| THPC042 | Uncoupled Achromatic Tilted S-bend | 3071 |
|
||
|
A particular section of one of the electron beam transport lines, to be used in the e-cooling project* of the Relativistic Heavy Ion Collider (RHIC), is constrained to bend the beam simultaneously in both the horizontal and vertically planes and also be achromatic in both planes. The simultaneous horizontal and vertical achromatic bend is accomplished by rotating, about the longitudinal axis of the beam, the dipole and quadrupole elements of this section of the line. However such a rotation of the magnetic elements may couple the transported beam through the first order beam transfer matrix (linear coupling). In this paper we investigate for a sufficient condition, that the first order transport matrix (R-matrix) can satisfy, under which such a section of a beam transfer line is both achromatic and also constrains the beam at the exit of the line to emerge linearly uncoupled. We also provide a complete solution for the beam optics, of this part of the beam transfer line, which satisfies achromaticity and no first order beam coupling.
*htpp://www.bnl.gov/cad/eRhic/Documents/AD_Position_Paper_2007.pdf |