Strength of higher order spin-orbit resonances
| Autor: | Hoffstaetter, Georg H., Vogt, Mathias |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: | |
| DOI: | 10.3204/pubdb-2017-06670 |
| Popis: | Physical review / E 70(5), 056501 (2004). doi:10.1103/PhysRevE.70.056501 When polarized particles are accelerated in a synchrotron, the spin precession can be periodically driven by Fourier components of the electromagnetic fields through which the particles travel. This leads to resonant perturbations when the spin-precession frequency is close to a linear combination of the orbital frequencies. When such resonance conditions are crossed, partial depolarization or spin flip can occur. The amount of polarization that survives after resonance crossing is a function of the resonance strength and the crossing speed. This function is commonly called the Froissart-Stora formula. It is very useful for predicting the amount of polarization after an acceleration cycle of a synchrotron or for computing the required speed of the acceleration cycle to maintain a required amount of polarization. However, the resonance strength could in general only be computed for first-order resonances and for synchrotron sidebands. When Siberian Snakes adjust the spin tune to be 1/2, as is required for high energy accelerators, first-order resonances do not appear and higher-order resonances become dominant. Here we will introduce the strength of a higher-order spin-orbit resonance, and also present an efficient method of computing it. Several tracking examples will show that the so computed resonance strength can indeed be used in the Froissart-Stora formula. HERA-p is used for these examples which demonstrate that our results are very relevant for existing accelerators. Published by Inst., Woodbury, NY |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|