Elsevier

Nuclear Physics B

Volume 167, Issues 1–2, 5–12 May 1980, Pages 1-40
Nuclear Physics B

Influence of channeling on scattering of 2–15 GeV/c protons, π+, and π incident on Si and Ge crystals

https://doi.org/10.1016/0550-3213(80)90117-0Get rights and content

Abstract

The channeling effect has a dramatic influence on scattering phenomena for GeV particles. Multiple scattering for positive particles is strongly reduced for incident directions close to the crystal axes and planes, resulting in a very high transmitivity along such directions, whereas negative particles experience increased multiple scattering along these directions. Correlated scattering from the atoms in atomic rows results in ring-shaped intensity distributions (“doughnuts”) on the exit side which exist even for incident angles far beyond the critical angle for channeling. For such angles, we find a strongly increased multiple scattering for both positive and negative particles.

The yield from close-encounter processes such as wide-angle scattering and nuclear reactions is reduced to below 10% of normal yield for positive, channeled particles, whereas the yield is increased for negative particles. The measured dechanneling is found to be small even for a 4 mm thick Ge crystal. These results seem to agree fairly well with theoretical calculations based on a diffusion model. Computer calculations from a binary-collision model are in good agreement with experimental results. Also, blocking effects are measured and agree fairly well with the dips obtained for close-encounter processes.

References (28)

  • O. Fich et al.

    Phys. Lett.

    (1975)
  • H. Esbensen et al.

    Nucl. Phys.

    (1977)
  • H. Esbensen et al.

    Phys. Lett.

    (1978)
  • S.K. Andersen et al.

    Nucl. Phys.

    (1978)
  • E. Uggerhøj et al.

    Phys. Rev.

    (1970)
    S.K. Andersen et al.

    Phys. Rev.

    (1973)
  • N. Bohr

    Mat. Fys. Medd. Dan. Vid. Selsk.

    (1948)
    W.T. Scott

    Rev. Mod. Phys.

    (1963)
  • D. Allen

    Nuovo Cim. Lett.

    (1976)
  • O. Fich et al.

    Phys. Rev. Lett.

    (1976)
  • H. Esbensen et al.

    Phys. Rev.

    (1978)
  • S.K. Andersen et al.

    CERN-Proposal: Measurements of the influence of channeling on atomic and nuclear reaction yields

    (Sept. 1978)
  • V.M. Golovatyuk

    Investigation of possibility of bending and cooling of beams by single crystals, design of new type detectors for charged particles

    (1977)
  • C. Ankenbrandt

    Proposal to study channeling at Fermilab

    (Sept. 1975)
  • T.H. Braid et al.

    Phys. Rev.

    (1979)
  • I.A. Grishaev et al.

    ZhETF (USSR)

    (1977)
  • Cited by (0)

    View full text