| Paper | Title | Page |
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| FR5REP113 | AG Focusing in the Thomas Cyclotron of 1938 | 5041 |
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It is sometimes asserted that Thomas's proposal to provide additional axial focusing in cyclotrons (to enable them to operate isochronously at relativistic energies) by introducing an azimuthal variation in the magnetic field was an early example of alternating-gradient focusing. While Thomas cyclotrons certainly exhibit alternating field gradients, it is shown that the alternating focusing produced is very much weaker than the edge focusing (everywhere positive) arising from orbit scalloping. |
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| FR5REP114 | FFAGs and Cyclotrons with Reverse Bends | 5044 |
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This paper describes tracking studies of FFAGs and radial-sector cyclotrons with reverse bends using the cyclotron equilibrium orbit code CYCLOPS. The results for FFAGs confirm those obtained with lumped-element codes, and suggest that cyclotron codes will prove to be important tools for evaluating the measured fields of FFAG magnets. The results for radial-sector cyclotrons show that the use of negative valley fields would allow axial focusing to be maintained, and hence allow intense cw beams to be accelerated, to energies of the order of 10 GeV. |