Particle selection and beam collimation system for laser-accelerated proton beam therapy.

Area of Science:

• Medical Physics
• Particle Accelerator Technology
• Laser-Driven Ion Acceleration

Background:

• Laser-accelerated protons exhibit broad energy and angular distributions, unsuitable for direct therapeutic use.
• Effective proton therapy requires narrow pencil beams with precisely controlled energy spectra.
• A compact system for particle selection and collimation is essential for laser-based proton therapy.

Purpose of the Study:

• To characterize a superconducting magnet system for selecting and collimating laser-accelerated protons.
• To achieve desired energy spectra and pencil beam characteristics for therapeutic applications.
• To evaluate the dosimetric properties of the selected proton beams.

Main Methods:

• Designed and characterized a four-magnet superconducting system using NbTi wires (4.4 T field strength).
• Implemented entrance and exit collimation for particle selection and beam shaping.
• Utilized proton transport simulations and GEANT3 Monte Carlo code for analysis.

Main Results:

• The superconducting magnet system successfully spreads protons by energy and angle for selection.
• Selected protons were refocused onto the beam axis.
• Energy spread was found to be dependent on magnetic field strength and collimator size, reaching 25 MeV FWHM for 230 MeV protons.

Conclusions:

• The developed superconducting magnet system is effective for producing therapeutic-quality proton beams from laser acceleration.
• This technology advances the feasibility of compact laser-driven proton therapy systems.
• Further studies on dosimetric properties confirm potential clinical applications.