Measuring the efficiency of interatomic coulombic decay in Ne clusters

The efficiency of interatomic coulombic decay (ICD) in Neon clusters with a mean size of 〈N〉 = 480 is measured directly. By detecting the photoelectrons and the ICD electrons in coincidence and normalizing their ratio using the detection probability of the respective electrons we show that the relaxation of Ne 2s vacancies in Ne clusters by ICD has an efficiency of unity.