Low energy collective excitations in a superfluid trapped Fermi gas

We study low energy collective excitations in a trapped superfluid Fermi gas, that describe slow variations of the phase of the superfluid order parameter. Well below the critical temperature the corresponding eigenfrequencies turn out to be of the order of the trap frequency, and these modes manifest themselves as the eigenmodes of the density fluctuations of the gas sample. The latter could provide an experimental evidence of the presence of the superfluid phase.Comment: 5 pages, REVTeX, referencies correcte

Measurement of the neutron induced fission cross section on transuranic (TRU) elements at the n_TOF facility at CERN

During the 2004 campaign, the n_TOF collaboration measured neutron fission cross sections for U-233, Am-241,Am-243, Cm-245, as well as the fission standards U-235.238, using a sealed Fission Ionization Chamber (FIC). The setup included a total of 16 targets and 18 electrodes mounted together in a 50-cm length chamber, allowing the measurements of all isotopes at the same time, thus in the same experimental conditions. A brief description of the facility and of the detector setup will be presented followed by the preliminary results of the analysis of U-235, U-233,; (CM)-C-245 from thermal energies up to some tenths of MeV

The XXL survey: First results and future

The XXL survey currently covers two 25 deg(2) patches with XMM observations of similar to 10 ks. We summarize the scientific results associated with the first release of the XXL dataset, which occurred in mid-2016. We review several arguments for increasing the survey depth to 40 ks during the next decade of XMM operations. X-ray (z 1 cluster density. It will eventually constitute a reference study and an ideal calibration field for the upcoming eROSITA and Euclid missions