Medical Radioisotope Production with Laser-driven high-repetition-rate proton sources

We present a system for producing medical radioisotopes using high-repetition-rate laser-driven proton beams. Cyclotron radioisotope production has been the standard but can only produce a narrow range of common radioisotopes at a fixed energy. This rigidity restricts access to emerging, short-lived radioisotopes for novel imaging and therapy procedures and research.

Laser-based alternatives have traditionally been constrained by two factors: (1) low laser shot rate, and (2) solid targets that are destroyed with each shot, creating debris and requiring mechanical target replacement. Both challenges are being addressed with ≥1 kHz laser systems coming online and flowing liquid targets capable of sustaining these shot rates without debris or degradation.

Using measured proton spectra from this flowing target system, we performed Geant4 simulations to model isotope production. For the ¹⁸O(p,n)¹⁸F reaction using enriched water targets, simulations predict 5–100 kBq/shot. For the⁶⁴N(p,n)⁶⁴Cu reaction, simulations predict 5-60 kBq/shot. At the kHz repetition rates of upcoming laser systems this approaches a practical threshold for clinical procedures and research.

We describe the system architecture, simulation methods and results, and plans for future activation experiments. Compared to cyclotrons, our platform offers adaptability to a wide range of isotopes, potentially enabling local, on-demand production in research or clinical settings.