Feb 12 – 14, 2007
CERN
Europe/Zurich timezone

Gamma Spectroscopy of the superdeformed shape isomers in 237Pu

Feb 14, 2007, 3:00 PM
20m
Council Chamber, 503/1-001 (CERN)

Council Chamber, 503/1-001

CERN

Speaker

Thomas James Morgan (Ludwig Maximilians University)

Description

While so far spectroscopic studies of fission isomers concentrated on even-even nuclei, high-resolution spectroscopy of odd-N fission isomers will allow to identify Nilsson orbitals in heavy actinide nuclei. As the first case ever studied for odd-N nuclei, the fission isomer in 237Pu (t1/2 = 110ns/1.1 ?s) was investigated using the 235U(alpha,2n) reaction with a pulsed alpha beam (Ealpha =24 MeV, pulse distance 400 ns) from the Cologne Tandem accelerator. A self-supporting thick metallic 235U target (3.7 mg/cm2) was used, where the 237Pu reaction products were stopped and fission products were emitted in opposite directions. The rare -rays from the second potential well in delayed coincidence with fission products were measured with the MINIBALL spectrometer. Due to the small population cross section of about 2 ?b a large solid angle coverage both for the -rays as well as for the fission fragments was required. A very compact 4Pi parallel plate detector array (diameter ca. 15 cm) was used for the fission fragment detection, allowing for a discrimination between the dominant prompt fission products and the rare isomeric fission events. Results, such as the identification of rotational bands, isomeric lifetimes and angular distributions etc., will be presented. *Supported by DFG under contract no. HA1101/12-1

Primary author

Thomas James Morgan (Ludwig Maximilians University)

Presentation materials