I would expand on this to say that they propose to use an innovative cavity shape. Normal-conducting cavities can reach higher accelerating fields than superconducting cavities, but at much lower duty factors and with high voltage breakdown events. This new design would allow for lower power dissipation than typical normal-conducting structures, ultimately allowing higher RF duty factors.
There are still some downsides/tradeoffs compared to superconducting structures, including a much smaller beam aperture (5 mm diameter vs. ~100 mm for superconducting cavities), which disrupts the quality of the beam. Superconducting machines can also be run in continuous wave mode (100% duty factor), and state-of-the-art niobium cavities have been driven at ~50 MV/m in CW.
There are still some downsides/tradeoffs compared to superconducting structures, including a much smaller beam aperture (5 mm diameter vs. ~100 mm for superconducting cavities), which disrupts the quality of the beam. Superconducting machines can also be run in continuous wave mode (100% duty factor), and state-of-the-art niobium cavities have been driven at ~50 MV/m in CW.