Production and trapping of radioactive atoms at the TRI μP facility

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 Na-21. A novel transmitting thermal ionizing device was developed to stop the energetic isotopes. Some 50% of stopped Na-21 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. (c) 2008 Elsevier B.V. All rights reserved.