Absence of E0 transitions around 1.8 MeV after collisions of 238U with 181Ta

Positron spectra from internal pair conversion observed in 238U + 181Ta collisions

“…al. [18]. The excitation probability, P γ (R min ), was determined as a function of the distance of closest approach, R min , by normalizing the γ-yield in certain R min intervals with the corresponding number of elastically scattered ions.…”

Towards detailed knowledge of atomic nuclei—the past, present and future of nuclear structure investigations at GSI

“…Large area position sensitive parallel plate proportional detectors (PPAC) were used to detect the scattered ions over a wide angular range. Most of the heavy ion induced Coulomb excitation experiments have employed variants of the experimental geometry [9,13] illustrated in figure 1.…”

“…Therefore, the main decay mode of excited levels of K=0 bands is expected to be interband conversion electrons, more than inband or interband γ-rays. E0 transitions have been measured for the 238 U+ 181 Ta collisions around the Coulomb barrier with an arrangement correcting for Doppler effects [42,43]. In 238 U one observes rotational bands based on two excited 0 + states (at 926 keV and at 997 keV) which are close in energy, but widely different in structure.…”

6 Modern Electron and Positron Spectrometers – Selected Aspects of a Broad Field

“…The experiment [50] was carried out in particular to search for conceivable K-conversion electrons from E0 transitions around 1. Artist's view of a multi-detector electron four-fold Mini-Orange system for Dopplercorrected spectroscopy of conversion electrons [50]. The systems face the target at large backward-angles to minimize the influence of δ-rays.…”

“…Doppler-corrected electron spectra[50] from a Coulex experiment of 238 U + 181 Ta at 6 MeV/ίί. Also shown is the transmission curve of the MOr with an absolute calibration point at 975 keV, taken with a 207 Bi source.…”