Instruments (Jun 2024)

Design and Implementation of an Energy Selector for Laser-Accelerated Protons

  • Alicia Reija,
  • David Esteban,
  • Aarón Alejo,
  • Jon Imanol Apiñaniz,
  • Adrián Bembibre,
  • José Benlliure,
  • Michael Ehret,
  • Javier García López,
  • M. Carmen Jiménez-Ramos,
  • Jessica Juan-Morales,
  • Cruz Méndez,
  • David Pascual,
  • M. Dolores Rodríguez Frías,
  • Mauricio Rodríguez Ramos,
  • Michael Seimetz

DOI
https://doi.org/10.3390/instruments8030036
Journal volume & issue
Vol. 8, no. 3
p. 36

Abstract

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Highly intense bunches of protons and ions with energies of several MeV/u can be generated with ultra-short laser pulses focused on solid targets. In the most common interaction regime, target normal sheath acceleration, the spectra of these particles are spread over a wide range following a Maxwellian distribution. We report on the design and testing of a magnetic chicane for the selection of protons within a limited energy window. This consisted of two successive, anti-parallel dipole fields generated by cost-effective permanent C-magnets with customized configuration and longitudinal positions. The chicane was implemented into the target vessel of a petawatt laser facility with constraints on the direction of the incoming laser beam and guidance of the outgoing particles through a vacuum port. The separation of protons and carbon ions within distinct energy intervals was demonstrated and compared to a ray tracing code. Measurements with radiochromic film stacks indicated the selection of protons within [2.4, 6.9] MeV, [5.0, 8.4] MeV, or ≥6.9 MeV depending on the lateral dispersion. A narrow peak at 4.8 MeV was observed with a time-of-flight detector.

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