摘要:

We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180° about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1586671

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

This workshop’s focus is on considering ways for improving the proton beam polarization that the AGS delivers to the RHIC. This talk attempts to review the first decade of AGS polarization — the 1980’s; to briefly describe some aspects of the machine situation, the depolarization avoidance strategies employed and the success achieved in AGS from the perspective of one of those involved. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1586672

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

In the Brookhaven AGS, polarized protons are accelerated fromG&ggr; = 4.5 toG&ggr; = 46.5. During the acceleration, a total of 42 imperfection spin depolarization resonances and 7 intrinsic spin resonances are crossed. Currently, the depolarization at each imperfection spin resonance is overcome by a solenoid 5&percent; snake and full spin flips are induced at 4 out of the 7 intrinsic resonances by the AGS rf dipole to avoid the polarization loss. No correction schemes are applied at the remaining 3 weak spin resonances. In addition, coupling spin resonances are also observed due to the solenoidal field of the snake and no correction is applied for these spin resonances other than keeping the horizontal and vertical betatron tunes separated. In order to achieve ⩾ 50&percent; beam polarization out of AGS, all of those spin resonances need to be corrected. This paper proposes three correction methods to overcome the strong intrinsic spin resonances as well as the weak intrinsic spin resonances and the coupling spin resonances. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1586673

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

At the cooler synchrotron COSY, polarized protons and deuterons are accelerated up to 3.65 GeV/c. In a strong‐focusing synchrotron like COSY, imperfection and intrinsic resonances cause polarization losses during acceleration. During the acceleration of polarized protons, five imperfection resonances are crossed. The existing magnet system of COSY allows to overcome all imperfection resonances by exciting adiabatic spin flips without polarization losses. The number of intrinsic resonances depends on the superperiodicity of the lattice. A tune‐jump system consisting of two fast quadrupoles has been developed to handle intrinsic resonances in COSY. Vertically polarized proton beams with more than 75&percent; polarization have been delivered in recent years to internal as well as to external experiment areas at different momenta up to the maximum momentum of COSY. For the acceleration of polarized deuterons, additional correction provisions are not necessary to preserve polarization during acceleration. In this paper the techniques to overcome depolarizing resonances and the status of the polarized beam acceleration at COSY are discussed. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1586674

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

An 11.4&percent; partial Siberian snake was used to successfully accelerate polarized protons through a strong intrinsic depolarizing spin resonance in the AGS. No noticeable depolarization was observed. This opens up the possibility of using a 20&percent; to 30&percent; partial Siberian snake in the AGS to overcome all weak and strong depolarizing spin resonances. Some design and operation issues of the new partial Siberian snake are discussed. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1586675

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

A polarized proton beam was accelerated at the KEK‐PS in the late 1980’s. This report will review the activities for the polarized beam acceleration in both the 500 MeV booster and the 12 GeV Main Ring. Some depolarization resonances were passed using the spin‐flip techniques. The effects on the polarization caused by a synchrotron side‐band at a strong intrinsic resonance were observed. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1586676

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

This paper contains a brief discussion of the AGS polarized beam work in the 1980’s. It also suggests that it might be wise to again use the old pulsed quadrupoles to overcome the problematic weak intrinsic depolarizing resonances. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1586677

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

The polarization dilution by molecular ions which are produced in the ECR primary proton source is discussed. The molecular component can be reduced to about 5&percent; by ECR source‐operation optimization. It is further suppressed by optimization of the extraction electrode optics and by the decelerating einzel lens in the 35 keV LEBT line. As a result, the proton polarization of the accelerated beam was increased to over 80&percent;, as measured in the 200 MeV proton‐deuterium polarimeter. The OPPIS upgrade for 6 2/3 Hz repetition rate operation is also discussed. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1586678

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

Significant polarization losses are observed at weak intrinsic spin resonances in the AGS. The suppression of weak intrinsic resonances is explored using a family of 12 quadrupoles in the AGS. Experimental results using the existing family of 12 horizontal and vertical tune quadrupoles are presented and theoretical results for a possible extra family of 12 quadrupoles in the 15thlattice straight section of each superperiod are discussed. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1586679

出版商:AIP    

年代:1903

数据来源: AIP

摘要:

A new polarimeter is being installed in the Brookhaven AGS, based on the successful proton‐carbon polarimeters in RHIC. The polarimeter will measure the left‐right asymmetry for proton—carbon elastic scattering in the Coulomb‐nuclear interference (CNI) region, for vertically polarized protons in the AGS. The polarimeter offers a much higher figure of merit than the existing AGS polarimeter which is based on larger angle proton—proton elastic scattering. We expect to measure the polarization in the AGS with a single or a few acceleration cycles. We also plan to measure the polarization in 2 ms bins during the AGS acceleration ramp. Multiple ramps will be necessary, probably over 30 minutes to an hour. © 2003 American Institute of Physics

ISSN:0094-243X    

DOI:10.1063/1.1586680

出版商:AIP    

年代:1903

数据来源: AIP