{
  "annotation_id": "9d009061-c5fb-47e4-a12f-1e52737435d3",
  "date_created": "2026-03-02T18:00:32.036000Z",
  "date_modified": "2026-03-02T18:00:32.036000Z",
  "file_hash": "de390c1643e4d067857afda5db9ca2caade7500ce7148ab7da7b504642935289",
  "private": false,
  "record": {
    "abstract": "Polarized proton beams at HERA can currently only be produced by extracting a\nbeam from a polarized source and then accelerating it in the three synchrotrons\nat DESY. In this paper, the processes which can depolarize a proton beam in\ncircular accelerators are explained, devices which could avoid this\ndepolarization in the DESY accelerator chain are described, and specific\nproblems which become important at the high energies of HERA are mentioned. At\nHERA\u0027s high energies, spin motion cannot be accurately described with the\nisolated resonance model which has been successfully used for lower energy\nrings. To illustrate the principles of more accurate simulations, the invariant\nspin field is introduced to describe the equilibrium polarization state of a\nbeam and the changes during acceleration. It will be shown how linearized spin\nmotion leads to a computationally quick approximation for the invariant spin\nfield and how to amend this with more time consuming but accurate\nnon-perturbative computations. Analysis with these techniques has allowed us to\nestablish optimal Siberian Snake schemes for HERA.",
    "arxiv_id": "physics/0006007",
    "authors": [
      "Georg H. Hoffstaetter"
    ],
    "categories": [
      "physics.acc-ph"
    ],
    "doi": "10.1016/S0375-9474(00)00029-4",
    "journal_ref": "Nucl.Phys. A666 (2000) 203-213",
    "title": "Polarized Protons in HERA",
    "url": "https://arxiv.org/abs/physics/0006007"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "d4566a12-662c-49e3-8882-a03353fc7ecf",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}