Publication Type
Journal
Journal Name
Physical Review Letters
Publication Date
Page Number
162502
Volume
99
Issue
16
Abstract
The time delay in fission induced by bombardment of W with 180 MeV <sup>32</sup>S, 240-255 MeV <sup>48</sup>T and 315-375 MeV <sup>58</sup>Ni has been measured by observation of crystal blocking. There is a clear narrowing and a small increase in the minimum yield of the angular dips for fission compared with scaled dips for elastically scattered ions. This is interpreted as a fission delay of about 2 as, only weakly dependent on energy and atomic number. The delay is longer by one to two orders of magnitude than obtained from standard interpretations of measurements of pre-scission neutrons and giant-dipole-resonance gamma-rays and from calculations of the nuclear dynamics in heavy-ion reactions.