Measurements with Doppler shift techniques and a differential plunger are commonly performed to obtain lifetimes within few picoseconds range. This method relies in the precission we have to control the distance between the target and a second foil, and the recoil velocity between them. However, the large acceptance of modern mass spectrometers yields isotopes with a broad velocity distribution, propagating uncertainties and dependencies in the lifetime determination.
In this work we present a new technique we used for lifetime measurements in 238U fission fragments. The experiment, performed at GANIL, exploits the energy resolution of the AGATA detector array and the large acceptance VAMOS spectrometer to measure the lifetimes in a large set of isotopes centered in the 100Zr mass region.
José Javier Valiente Dobón