Result of the on-line experiment of the laser ion source

The importance of using a laser ion source in the on-line isotope separator, the principle of laser ion source, laser technique and the structure of hot capillary laser ion source and target chamber are introduced. A high repetition frequency copper vapor laser and three dye lasers were used. The capillary is made of Nb with inside diameter of 1.7 mm and effective length of 3 cm. It was heated by 50-100 A direct current and temperature of 1800-2700 K can be achieved. The nuclear reaction channel used in the first on-line experiment is 50 MeV/u 18O + natTa→167Yb(T1/2 = 17.5 min). A joint operation of accelerator, on-line isotope separator and laser system has been realized. A total separation efficiency of 0.2% is obtained by comparison of the measured yield of 167Yb with the calculated yield of 167Yb by using production cross-section, beam intensity, collection time and the thickness of target. A element selectivity of 3.2 is deduced from the ratio of the corresponding peak areas of 167Yb and 167Lu in the γ spectra of laser on and laser off. A new high spin isomer with long half-life of 167Yb was found. The methods that may be used to improve the efficiency of laser ion source are discussed