Platform for high repetition rate proton stopping power measurements in Warm Dense Matter

We present a high-repetition-rate experimental platform for proton stopping-power measurements in warm dense matter in a regime where the projectile velocity approaches the electron thermal velocity and theoretical predictions remain highly uncertain. The platform combines laser-driven proton generation via target normal sheath acceleration with a compact magnetic energy selector to produce quasi-monoenergetic proton beams in the 0.3–0.6 MeV range with energy bandwidths of tens of keV and sub-nanosecond duration. Warm dense matter is generated by femtosecond laser heating of thin carbon foils and characterized using streaked optical pyrometry and x-ray pinhole grating spectroscopy, supported by radiation-hydrodynamic simulations. We further investigate the present limitations of the approach, including uncertainties in sample conditions, finite proton bunch duration, and proton scattering, and discuss pathways toward improved measurements. The results demonstrate a versatile and scalable approach for systematic, high-statistics studies of ion stopping power in warm dense matter relevant to inertial confinement fusion and charged-particle transport in high-energy-density plasmas.