1st experimental determination of ionization potential of Lawrencium (Z=103) by a surface ionization technique.
The first ionization potential (IP) is a fundamental physical and chemical property of an element. Information on the IP of the heaviest elements can provide better understanding of relativistic effects which are significantly noticeable for heavy elements. The IP value of lawrencium (Lr, Z = 103) has not been measured because properties of the heaviest elements with atomic number Z > 100 must be studied on an atom-at-a-time scale owing to low production rates and short half-lives.
We have developed an ion-source as part of the JAEA-ISOL (Isotope Separator On-Line) setup, which is coupled to a He/CdI2 gas-jet transport system to determine the IP of Lr. We will report on the development of the new ion-source and on the first successful ionization and mass separation of 27-s 256Lr produced in the 249Cf+11B reaction. We will also mention the first determination of IP of Lr.