Investigation of strongly coupling effect on plasma stopping power

To investigate strongly coupling effect on plasma stopping power, we have developed a high-density plasma target using thin-foil-discharge (TFD) technique. An aluminum foil or a carbon foil was rapidly heated and ionized by a discharge current up to 20 kA. From observation of the plasma light using a fast framing camera, we estimated density and temperature of the TFD aluminum plasma to be respectively 4 x 1019 cm-3 and 0.5 eV at 330 ns after the ignition of the discharge. The plasma coupling parameter was determined to be 0.03 using SESAME equation-of-state library under an assumption of one-dimensional plasma expansion. Interaction experiments using iron or oxygen beams of 4.3 MeV/u were carried out at NIRS-HIMAC facility, and the energy loss of the heavy ions in the TFD plasma was measured using the TOF method. The results indicated that the TFD plasma target expanded one-dimensionally at the very early stage of discharge. No plasma effect could be observed because of low ionization degree of the target plasma. (author)