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Observation of Radially Emitted Proton Beams from Low-Mass X-Pinch Plasmas

D. Klir1,*, V. Munzar1, J. Novotny1, K. Rezac1, A. M. Bedel2, N. G. Chalmers3, J. M. Chen2, J. Cikhardt1, B. Cikhardtova1 et al.

N. M. Jordan2, V. Juras1, P. Kubes1, J. Malir1, L. R. Tafoya2, K. Turek4, D. A. Hammer3, and R. D. McBride2

  • *Contact author: daniel.klir@fel.cvut.cz
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Phys. Rev. Lett. 136, 145101 – Published 7 April, 2026

DOI: https://doi.org/10.1103/qdgp-tydj

Abstract

Ion acceleration in Z-pinch plasmas is traditionally linked to the axial direction of current. Here, we report the radial emission of MeV protons from a low-mass, hydrogen-containing X pinch. Proton energies up to 3 MeV are observed in a hybrid X pinch with a 30  μm polyethylene fiber at a 400 kA peak current. The low-mass load, correlation of protons with hard x-rays, and timing of hard x-ray emission point to proton acceleration driven by current disruption following fiber disintegration. A new insight into the acceleration mechanism arises from the use of an interelectrode gap that is too short for magnetic fields to bend axially accelerated protons by π/2 radians; thus, the observed radial emission implies a substantial radial acceleration component. The radial emission also enables X-pinch-driven proton radiography, the exceptional potential of which is demonstrated with exploding wires.

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Phys. Rev. Lett. 136, 145101– Published 7 April, 2026
  • Received 24 July 2025
  • Accepted 27 February 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

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