Production and trapping of radioactive atoms at the TRI\muP facility

TL;DR

The TRIμP facility produces and traps radioactive atoms for precision measurements, achieving high separation efficiency and developing novel ionization techniques to facilitate atom trapping.

Contribution

The paper presents the completed TRIμP facility, innovative separation and ionization methods, and demonstrates the trapping of radioactive atoms for fundamental physics research.

Findings

Separation efficiency up to 99.95% for $^{21}$Na

50% extraction efficiency of stopped $^{21}$Na ions

Successful demonstration of atom trapping principle with stable Na

Abstract

The structures for the TRI$\mu$P facility have been completed and commissioned. At the facility radioactive nuclides are produced to study fundamental interactions and symmetries. An important feature is the possibility to trap radioactive atoms in order to obtain and hold a pure substrate-free sample for precision measurements. In the TRI$\mu$P facility a production target is followed by a magnetic separator, where radioactive isotopes are produced in inverse reaction kinematics. Separation up to 99.95% could be achieved for $^{21}$Na. A novel transmitting thermal ionizing device was developed to stop the energetic isotopes. Some 50% of stopped $^{21}$Na could be extracted and transported as low energy singly charged ions into a radio frequency quadrupole cooler and buncher with 35% transmission efficiency. The ions are transported lossless via a drift tube and a low energy electrostatic beam line into the experimental setup. Such ions can be neutralized on hot metal foils and the resulting atoms can be stored in a magneto-optical trap. The functioning of that principle was demonstrated with stable Na extracted from the thermal ionizer, radioactive beams will follow next.