Beam–plasma interaction experiments using electromagnetically driven shock waves

Electromagnetically driven shock tubes compatible with in-beam experiments have been developed to examine the stopping power of hot or warm matter over a wide temperature range. The beam–plasma coupling constant γ was calculated under various operating conditions of the shock tube. We found that γ∼0.1 is achievable with 10 keV/u Pb ions and a fully ionized plasma produced by a shock wave with 70–80 km/s in a hydrogen gas of 6–9 kPa. The dissociation effect on the hydrogen stopping power for low-energy protons was also evaluated and a 40–50% increase in the stopping cross-section of dissociated hydrogen was predicted in a projectile energy region of 10–40 keV. For the demonstration of the energy loss measurement using shock-heated gas targets, the developed shock tube was embedded into the beam line and tested on its shock-production abilities. In the preliminary experiment using 375 keV/u carbon projectiles, we successfully detected the signal of a carbon ion penetrating a shock-heat hydrogen target and observed a decrease in the signal height, which probably corresponds to the energy loss.