Measurement of the ionization probability of the 1sσ molecular orbital in half a collision at zero impact parameter

Abstract We have measured, for the first time, the ionization probability P 1s σ of the 1sσ molecular orbital on the way into a nuclear reaction (in half a collision at zero impact parameter) in a near symmetric collision 58 Ni+ 54 Fe at 230 MeV which leads to a compound nucleus of 112 Xe highly excited which decays first by sequential emission of charged particles and then by sequential emission of gamma rays. The determination of P 1s σ is based on the coincidence measurement between X-rays and γ-rays. The Doppler shift method is used to discriminate between the “atomic” and “nuclear” X-rays.