The MAMI source of polarized electrons

Aulenbacher, K.; Nachtigall, Ch.; Andresen, H. G.; Bermuth, J.; Dombo, Th.; Drescher, P.; Euteneuer, H.; Fischer, H.; Harrach, D. von; Hartmann, Péter; Hoffmann, J.; Jennewein, P.; Kaiser, K.-H.; Köbis, S.; Kreidel, H. J.; Langbein, J; Petri, M.; Plützer, S.; Reichert, E.; Schemies, M.; Schöpe, Hans Joachim; Steffens, K.; Steigerwald, Michael L.; Trautner, H.; Weis, Th

doi:10.1016/s0168-9002(97)00528-7

Cited by 127 publications

(50 citation statements)

References 28 publications

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“…We have used the apparatus of the A4 experiment at the MAMI accelerator in Mainz to make a measurement of the transverse beam spin asymmetry A ⊥ [21,22,23,24]. The polarized electrons were produced using a strained layer GaAs crystal which is illuminated with circularly polarized laser light [25] resulting in longitudinally polarized electrons. The sign of the electron beam polarization was switched between the two patterns (+ − −+) and (−++−) randomly by means of a fast Pockels cell in the optical system of the polarized electron source.…”

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confidence: 99%

Measurement of the Transverse Beam Spin Asymmetry in Elastic Electron-Proton Scattering and the Inelastic Contribution to the Imaginary Part of the Two-Photon Exchange Amplitude

Maas¹,

Aulenbacher²,

Baunack³

et al. 2005

Phys. Rev. Lett.

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We report on a measurement of the asymmetry in the scattering of transversely polarized electrons off unpolarized protons, A ⊥ , at two Q 2 values of 0.106 (GeV/c) 2 and 0.230 (GeV/c) 2 and a scattering angle of 30−6 . The first errors denotes the statistical error and the second the systematic uncertainties. A ⊥ arises from the imaginary part of the two-photon exchange amplitude and is zero in the one-photon exchange approximation. From comparison with theoretical estimates of A ⊥ we conclude that πN-intermediate states give a substantial contribution to the imaginary part of the two-photon amplitude. The contribution from the ground state proton to the imaginary part of the two-photon exchange can be neglected. There is no obvious reason why this should be different for the real part of the two-photon amplitude, which enters into the radiative corrections for the Rosenbluth separation measurements of the electric form factor of the proton.

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confidence: 99%

Measurement of the Transverse Beam Spin Asymmetry in Elastic Electron-Proton Scattering and the Inelastic Contribution to the Imaginary Part of the Two-Photon Exchange Amplitude

Maas¹,

Aulenbacher²,

Baunack³

et al. 2005

Phys. Rev. Lett.

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“…1(c), used at Amsterdam [4] and under development at Nagoya [5], and variations on the high-voltage connection, Fig. 1(d), as used at Mainz [6] and Bonn [7]. For a pulsed high-voltage gun, the Fig.…”

Section: Electron Sourcesmentioning

confidence: 99%

Recent advances in electron and positron sources

Clendenin¹

2001

AIP Conference Proceedings

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Recent advances in electron and positron sources have resulted in new capabilities driven in most cases by the increasing demands of advanced accelerating systems. Electron sources for brighter beams and for high average-current beams are described. The status and remaining challenges for polarized electron beams are also discussed. For positron sources, recent activity in the development of polarized positron beams for future colliders is reviewed. Finally, a new proposal for combining laser cooling with beam polarization is presented. Abstract. Recent advances in electron and positron sources have resulted in new capabilities driven in most cases by the increasing demands of advanced accelerating systems. Electron sources for brighter beams and for high average-current beams are described. The status and remaining challenges for polarized electron beams are also discussed. For positron sources, recent activity in the development of polarized positron beams for future colliders is reviewed. Finally, a new proposal for combining laser cooling with beam polarization is presented. Invited talk presented at

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“…Strained GaAs-based layers and superlattices are known to be most effective as photoemitters of spin-polarized electron beams which are required for highenergy experiments at many electron accelerator facilities [1,2,3]. Emitters of spin-polarized electrons will also be essential for future linear electron colliders (e.g.…”

Section: Introductionmentioning

confidence: 99%

Optical spin orientation in strained superlattices

Subashiev

Gerchikov

Ipatov

2004

Journal of Applied Physics

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Optical orientation in the strained semiconductor superlattices is investigated theoretically. The dependence of the features in spinpolarization spectra on the structure parameters is clarified. The value of polarization in the first polarization maximum in the SL structures is shown to grow with the splitting between the hh-and lh-states of the valence band, the joint strain and confinement effects on the hh1-lh1 splitting being strongly influenced by the tunneling in the barriers. In strained structures with high barriers for the holes initial polarization can exceed 95 %. Calculated polarization spectra are close to the experimental spectra of polarized electron emission.

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The MAMI source of polarized electrons

Cited by 127 publications

References 28 publications

Measurement of the Transverse Beam Spin Asymmetry in Elastic Electron-Proton Scattering and the Inelastic Contribution to the Imaginary Part of the Two-Photon Exchange Amplitude

Measurement of the Transverse Beam Spin Asymmetry in Elastic Electron-Proton Scattering and the Inelastic Contribution to the Imaginary Part of the Two-Photon Exchange Amplitude

Recent advances in electron and positron sources

Optical spin orientation in strained superlattices

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