Letter | Published:

Optimum Disturbing Field for Synchrotron Beam Ejection

Nature volume 159, pages 636637 (10 May 1947) | Download Citation



SEVERAL methods have been suggested1,2,3 for using disturbing magnetic fields to eject an electron beam from a synchrotron or betatron. Important differences exist in these methods in the angular distribution of these disturbing fields. Thus the 'orbit expansion' method1,2 effectively applies a sudden decrease of field over the whole 360° of annulus, while the '+ field' method3 decreases the field over 180° of annulus, while increasing it over the other 180°. The considerations outlined in this communication lead to the suggestion of an 'optimum step field', that is, a disturbing field of angular length such that the required beam displacement is obtained with minimum reactive power in the ejector field coil.

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  1. 1.

    , , and , Phys. Rev., 70, 95 (1946). , Rev. Sci. Instr., 13, 387 (1942).

  2. 2.

    and , J. Appl. Phys., 17, 444 (1946).

  3. 3.

    , and , Phys. Rev., 70, 562 (1946).

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  1. Telecommunications Research Establishment, Ministry of Supply, Malvern, Worcs. Feb. 24.

    • F. K. GOWARD
    •  & J. DAIN


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