First successful ionization of Lr (Z = 103) by a surface-ionization technique

Area of Science:

• Nuclear Physics
• Atomic Physics
• Radiochemistry

Background:

• Determining the first ionization potential of heavy elements like lawrencium (Lr) is crucial for understanding atomic structure and chemical properties.
• Previous methods for ionization potential determination faced limitations with heavy, short-lived isotopes.

Purpose of the Study:

• To develop and test a novel gas-jet coupled surface ionization ion source for the JAEA-ISOL system.
• To measure the first ionization potential of lawrencium (Lr, Z=103).
• To achieve the first successful on-line ionization and mass separation of lawrencium isotopes.

Main Methods:

• Development of an improved surface ionization ion source with an additional filament for enhanced operational control.
• Coupling the ion source to a Helium/Cadmium Iodide (He/CdI2) gas-jet transport system.
• Production of 256Lr via the 249Cf + 11B nuclear reaction and subsequent on-line ionization and mass separation.

Main Results:

• Successful development and implementation of the new gas-jet coupled surface ionization ion source.
• Demonstration of good ionization efficiencies, comparable to those achieved for lanthanides with previous sources.
• First successful on-line ionization and mass separation of the 27-second isotope 256Lr.

Conclusions:

• The new JAEA-ISOL ion source is effective for on-line studies of heavy elements.
• This technological advancement opens new possibilities for determining fundamental properties of the heaviest actinides.
• The successful separation of 256Lr marks a significant step in the study of lawrencium.