dorsal/arxiv
View SchemaSome models of spin coherence and decoherence in storage rings
| Authors | K. Heinemann |
|---|---|
| Categories | |
| ArXiv ID | physics/9709025 |
| URL | https://arxiv.org/abs/physics/9709025 |
Abstract
I present some simple exactly solvable models of spin diffusion caused by synchrotron radiation noise in storage rings. I am able to use standard stochastic differential equation and Fokker-Planck methods and I thereby introduce, and exploit, the polarization density. This quantity obeys a linear evolution equation of the Bloch type, which is, like the Fokker-Planck equation, universal in the sense that it is independent of the state of the system. I also briefly consider Bloch equations for other local polarization quantities derived from the polarization density. One of the models chosen is of relevance for some existing and proposed low energy electron (positron) storage rings which need polarization. I present numerical results for a ring with parameters typical of HERA and show that, where applicable, the results of my approach are in satisfactory agreement with calculations using SLIM. These calculations provide a numerical check of a basic tenet of the conventional method of calculating depolarization using the n-axis. I also investigate the equilibrium behaviour of the spin ensemble when there is no synchrotron radiation. Finally, I summarize other results which I have obtained using the polarization density and which will be published separately.
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"abstract": "I present some simple exactly solvable models of spin diffusion caused by\nsynchrotron radiation noise in storage rings. I am able to use standard\nstochastic differential equation and Fokker-Planck methods and I thereby\nintroduce, and exploit, the polarization density. This quantity obeys a linear\nevolution equation of the Bloch type, which is, like the Fokker-Planck\nequation, universal in the sense that it is independent of the state of the\nsystem. I also briefly consider Bloch equations for other local polarization\nquantities derived from the polarization density. One of the models chosen is\nof relevance for some existing and proposed low energy electron (positron)\nstorage rings which need polarization. I present numerical results for a ring\nwith parameters typical of HERA and show that, where applicable, the results of\nmy approach are in satisfactory agreement with calculations using SLIM. These\ncalculations provide a numerical check of a basic tenet of the conventional\nmethod of calculating depolarization using the n-axis. I also investigate the\nequilibrium behaviour of the spin ensemble when there is no synchrotron\nradiation. Finally, I summarize other results which I have obtained using the\npolarization density and which will be published separately.",
"arxiv_id": "physics/9709025",
"authors": [
"K. Heinemann"
],
"categories": [
"physics.acc-ph",
"math-ph",
"math.MP"
],
"title": "Some models of spin coherence and decoherence in storage rings",
"url": "https://arxiv.org/abs/physics/9709025"
},
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"type": "Model",
"variant": "snapshot-2026-03-01",
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