- Open Access
Circular accelerators with effective dc induction acceleration
Phys. Rev. Accel. Beams 29, 040401 – Published 7 April, 2026
DOI: https://doi.org/10.1103/r4w4-qypt
Abstract
Technical details of a recently proposed system for direct current (dc) induction acceleration are described. This dc induction acceleration system comprises two induction cells, each with two insulating gaps; one acts as an acceleration gap, and the other is placed on the outer cage of the induction cell to act as a resetting gap. Both gaps are bridged by diodes. The system is energized by a bipolar switching power supply. Continuous dc acceleration is limited by the saturation of magnetic materials distributed along the beam line, such as the beam-guiding magnets that act as effective absorbers of the magnetic flux that is released into the surrounding area upon resetting of the induction acceleration cell core. A secondary loop current (the primary loop current being the current that excites the magnetic core of the induction acceleration cell) necessarily flows on the metal beam-chamber surface distributed along the accelerator ring. This secondary loop current tends to degrade the resetting of the induction acceleration core and must be canceled by an artificially added tertiary loop current, whose loop passes symmetrically through the guiding magnets but bypasses the dc induction acceleration cells. In this way, resetting of the induction cores is secured at the expense of magnet saturation. dc induction acceleration can be performed via intermittent operation to release the absorbed extra flux. The effects of this externally absorbed flux on the beam orbit and optics are discussed. Applications of the dc induction acceleration are of practical interest. In addition, proposals are made for a dc induction microtron and a fixed field alternating gradient accelerator for heavy ions, which could replace existing electrostatic accelerators such as Van de Graaff or tandem accelerators, and an isochronous storage ring with dc induction acceleration for electrons/positrons, which could lead to the ultimate form in efficient continuous wave free-electron laser.
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