Development of a versatile method to produce spin-polarized radioactive nuclear beams

点击翻译按钮获取中文摘要

The feasibility of producing spin polarization for radioactive nuclear beams has been investigated. The prescription of this versatile method is (i) to spin-polarize the outermost electron in Rb via laser optical pumping and (ii) to transfer the electron to the radioactive nuclear beam ion and (iii) to polarize the nuclear spin through the hyperfine interaction. This method is quite successful for proton. Although the method is essentially applicable for a wide variety of nuclear species, no application has been tried for ions heavier than helium. The feasibility must be investigated on (i) how much we can reduce the depolarization effects after the electron transfer process and (ii) how high transmission efficiency we can achieve for the radioactive nuclear beams.We have constructed a test stand and started the feasibility test of this new method at Research Center for Nuclear Physics, Osaka University, prior to the completion of high intensity radioactive beam facilities such as ISAC at TRIUMF or E-arena at JHF. Instead of the radioactive nuclear beams, stable beams have been used. The nuclear polarization has been measured by the method of the beam-foil spectroscopy.The test stand has just completed. At the first trial we have successfully observed 2 % spin polarization for the 14N nucleus. The transmission efficiency was approximately 60%. These results are very promising for the practical application. We have started detailed investigation to increase the nuclear polarization.