High Energy Polarized Proton Beams: A Modern View / Edition 1

by Georg Heinz Hoffstaetter

Overview

This book deals with the acceleration and storage of polarized proton beams in cyclic accelerators. Polarized proton beams with hundreds of GeV are, for example, essential for resolving the “spin crisis,” i.e., for understanding the angular momentum distribution inside nucleons. Experience with the Relativistic Heavy Ion Collider at the Brookhaven NationalLaboratory(RHICatBNL)hasshownthatpolarizationat205GeV can be obtained, and tests at the pre-accelerating Alternating Gradient S- chrotron(AGS)haveshownthatatleastupto24GeV,thebeampolarization canbequiteundisturbedwhentheacceleratoriswelladjusted,exceptats- cial energies where resonances occur. In particular, it has not been necessary to study closely the variation of the protons’ spin directions across the phase space of the beam. However, at very high energies such as in RHIC, TEVA- TRON, HERA-p, LHC, or a future VLHC, new phenomena can occur that can lead to a significantly diminished beam polarization. For these high energies, it is necessary to look in more detail at the spin motion at each point in phase space, and for this the invariant spin field provestobeausefultool.Thisfieldgivesrisetoanadiabaticinvariantofsp- orbit motion, and it defines the maximum time-average polarization that is usable in a particle physics experiment. Furthermore, the invariant spin field allows the amplitude dependent spin tune to be defined and computed and thereby opens the way to a clear evaluation of the effects of higher-order spin orbit resonances. In particular, the strengths and the depolarizing effects of these resonances can only be determined once the amplitude-dependent spin tune has been computed.

Product Details

ISBN-13:	9780387346793
Publisher:	Springer New York
Publication date:	09/21/2006
Series:	Springer Tracts in Modern Physics , #218
Edition description:	2006
Pages:	177
Product dimensions:	6.10(w) x 9.25(h) x 0.02(d)

About the Author

The author teaches Physics at Cornell University and has specialized in the Physics of Beams and Accelerator Technology. He has worked in three internationally important facilities, the laboratory of elementary particle physics (LEPP) that operates the CESR e+/e- collider at Cornell University (New York State), the high energy physics laboratory DESY / Hamburg (Germany) that operates the HERA e/p collider and the nuclear physics facility NSCL / Michigan (USA). Together with colleagues from an international collaboration he has been analyzing the possibility of storing polarized protons at 920 GeV in HERA, a 6.3 km long high-energy accelerator in Hamburg, and in other large particle accelerators.

Table of Contents

Introduction.- Spin Dynamics: The Equation of Spin Motion. Spin Motion in Circular Accelerators.- First-Order Spin Motion: Linearized Spin-Option Motion. First-Order Resonance Spectrum. Optimal Choices of Siberian Snakes.- Higher-Order Spin Motion: Higher-Order Resonances and Snake Schemes. Obtaining N(Z) by Stroboscopic Averaging. Obtaining N(Z) by Anti-Damping.- Polarized Beams in Other Very-High-Energy Proton Accelerators: The Relativistic Heavy Ion Collider (RHIC). TEVATRON.LHC.- Index.