merge of astro-ph/0504240 and astro-ph/0504297 into one paperInternational audienceTaking advantage of recent technical progress which has overcome some of the difficulties encountered in the 1960s in the radio detection of extensive air showers induced by ultra-high-energy cosmic rays (UHECR), a new experimental apparatus (CODALEMA) has been built and operated. We will present the characteristics of this device and the analysis techniques that have been developed for observing electrical transients associated with cosmic rays. We find a collection of events for which both time and arrival direction coincidences between particle and radio signals are observed. The counting rate corresponds to shower energies $\geq 5 \times 10^{16}$ eV. The performance level which has been reached considerably enlarges the perspectives for studying UHECR events using radio detection

International audienceThe 4π array INDRA was used to detect nearly all charged products emitted in Ar + Ni collisions between 52 and 95 MeV/u. The charge, mass and excitation energy E∗ of the quasi-projectiles have been reconstructed event by event. Excitation energies up to 25 MeV per nucleon are reached

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International audienceCharged product multiplicities and Z distributions were measured for single multifragmenting sources produced in collisions between Full-size image (<1 K) and Full-size image (<1 K) at the same available energy per nucleon. Z distributions are found identical for both reactions while fragment multiplicities scale as the charge of the total systems. A complete dynamical simulation, in which multifragmentation originates in the spinodal decomposition of a finite piece of nuclear matter resulting from an incomplete fusion of projectile and target, well accounts for this experimental observation