S. Siem

Extraction of level density and

Abstract We present a new iterative procedure to extract the level density and the γ strength function from primary γ spectra for energies close up to the neutron binding energy. The procedure is tested on simulated spectra and on data from the 173 Yb ( 3 He ,α) 172 Yb reaction.

\gamma

The level density at low spin in the 161,162-Dy and 171,172-Yb nuclei has been extracted from primary gamma rays. The nuclear heat capacity is deduced within the framework of the canonical ensemble. The heat capacity exhibits an S-formed shape as a function of temperature, which is interpreted as a fingerprint of the phase transition from a strongly correlated to an uncorrelated phase. The critical temperature for the quenching of pair correlations is found at Tc=0.50(4) MeV.

strength function from primary

The density of accessible levels in the (

\gamma

^3

spectra

He,

Critical temperature for quenching of pair correlations

\alpha \gamma

Observation of thermodynamical properties in the Dy-162, Er-166 and Yb-172 nuclei

) reaction has been extracted for the

0(gs)+ -->2(1)+ transition strengths in 106Sn and 108Sn.

^{162}

Analysis of possible systematic errors in the Oslo method

Dy,

Observation of Large Scissors Resonance Strength in Actinides

^{166}