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From Beam to Bedside: Reinforcing Domestic Supply of $^{99}$Mo/$^{99m}$Tc using Novel High-Current D+ Cyclotrons for Compact Neutron Generation and $^{99}$Mo Production

Jarrett Moon, Daniel Winklehner, Jose Alonso, Claire Huchthausen, David McClain, Janet Conrad

TL;DR

This work addresses the fragility of the domestic $^{99}$Mo/$^{99m}$Tc supply by proposing a hospital-friendly, accelerator-based Mo-99 production pathway using a new class of high-current cyclotrons (HCHC-XX/HCDC-XX) originally developed for IsoDAR. By accelerating $D^+$ to $1.5$ MeV/amu and directing them at a thin Be target, a neutron flux near $10^{13}$ n/s is achievable, enabling fission-driven Mo-99 production in a compact, LEU-compatible target. The Mo-99 is produced in a self-thermalizing, aqueous uranyl-sulfate target, facilitating extraction and recycling, with simulations indicating an annual Mo-99 output on the order of $\sim$25 TBq and in-generator activity of $\sim$11–15 TBq for a mid-sized hospital. If validated experimentally, this approach could enable modular, near-site isotope production, reducing dependence on foreign reactors and improving resilience, safety, and patient access to essential medical isotopes.

Abstract

Technetium-99m ($^{99m}$Tc) is essential to more than 16 million diagnostic procedures performed annually in the United States. It is typically acquired on-site from generators containing $^{99}$Mo, in turn produced at nuclear reactor facilities. This supply chain involves multiple points of vulnerability, which can lead to shortages and delays with potentially negative patient outcomes. We report on the development of a new family of cyclotrons originally designed for the IsoDAR neutrino experiment, capable of operating at much higher current than typical cyclotrons. When operated with deuterons at 1.5 MeV/amu and an anticipated continuous beam current of 5 mA, simulations project that such a system would yield $\sim$10$^{13}$ neutrons per second using a thin beryllium target. This neutron yield is sufficient, in principle, to support $^{99}$Mo production without the use of highly enriched uranium or reliance on foreign reactors. Simulations and conceptual design studies suggest that the system's beam dynamics could make it a viable pathway toward decentralized, hospital-based isotope generation. The relatively low energy of the deuterons minimizes activation and safety concerns. This work presents the physics motivation, technical design considerations, and projected neutron yields, outlining a pathway from a neutrino-physics prototype to a biomedical isotope production platform.

From Beam to Bedside: Reinforcing Domestic Supply of $^{99}$Mo/$^{99m}$Tc using Novel High-Current D+ Cyclotrons for Compact Neutron Generation and $^{99}$Mo Production

TL;DR

This work addresses the fragility of the domestic Mo/Tc supply by proposing a hospital-friendly, accelerator-based Mo-99 production pathway using a new class of high-current cyclotrons (HCHC-XX/HCDC-XX) originally developed for IsoDAR. By accelerating to MeV/amu and directing them at a thin Be target, a neutron flux near n/s is achievable, enabling fission-driven Mo-99 production in a compact, LEU-compatible target. The Mo-99 is produced in a self-thermalizing, aqueous uranyl-sulfate target, facilitating extraction and recycling, with simulations indicating an annual Mo-99 output on the order of 25 TBq and in-generator activity of 11–15 TBq for a mid-sized hospital. If validated experimentally, this approach could enable modular, near-site isotope production, reducing dependence on foreign reactors and improving resilience, safety, and patient access to essential medical isotopes.

Abstract

Technetium-99m (Tc) is essential to more than 16 million diagnostic procedures performed annually in the United States. It is typically acquired on-site from generators containing Mo, in turn produced at nuclear reactor facilities. This supply chain involves multiple points of vulnerability, which can lead to shortages and delays with potentially negative patient outcomes. We report on the development of a new family of cyclotrons originally designed for the IsoDAR neutrino experiment, capable of operating at much higher current than typical cyclotrons. When operated with deuterons at 1.5 MeV/amu and an anticipated continuous beam current of 5 mA, simulations project that such a system would yield 10 neutrons per second using a thin beryllium target. This neutron yield is sufficient, in principle, to support Mo production without the use of highly enriched uranium or reliance on foreign reactors. Simulations and conceptual design studies suggest that the system's beam dynamics could make it a viable pathway toward decentralized, hospital-based isotope generation. The relatively low energy of the deuterons minimizes activation and safety concerns. This work presents the physics motivation, technical design considerations, and projected neutron yields, outlining a pathway from a neutrino-physics prototype to a biomedical isotope production platform.
Paper Structure (14 sections, 4 figures)

This paper contains 14 sections, 4 figures.

Table of Contents

  1. Introduction
  2. Background and Motivation
  3. Novel High Current Cyclotrons
  4. HCHC-XX
  5. HCDC-1.5
  6. Neutron Production & Mo-99 Generation
  7. HCDC-1.5 + Beryllium Target
  8. A Thermalizing Target
  9. Uranyl-Sulfate Target
  10. Simulated $^{99}$Mo Production
  11. Practical Comparisons
  12. Safety
  13. Conclusion
  14. Acknowledgements

Figures (4)

  • Figure 1: Design overview of an HCHC-60, showing ion source, low energy bream transport (LEBT), radiofrequency quadrupole (RFQ), and cyclotron with spiral inflector (SI) and RF cavities. From winklehnerIsoDARYemilabPreliminaryDesign2025
  • Figure 2: An illustration of the ion beam entering the RFQ where it is alternatively focused in the transverse and vertical planes. At beam exit, corresponding to the bunch between the vertical green lines, we see a clean bunch has formed.
  • Figure 3: Conceptual layout of the HCDC-1.5 with extraction line and thermalization sphere.
  • Figure 4: Simulated neutron energy and angular distribution for a 1.5MeV/amu D$^+$ beam on a Be target.