An original method using the second cyclotron of GANIL as a high resolution mass spectrometer was recently developed to measure the masses of exotic nuclei. This direct time of flight technique has been successfully used with A = 100 isobars in the vicinity of n,100Sn, produced via the fusion-evaporation reaction r50Cr + i58Ni at 255 MeV. The secondary ions were simultaneously accelerated and detected inside the cyclotron close to the extraction radius, using a silicon detector telescope mounted on a radially movable probe. The cyclotron was first tuned, using this detection system, with the r50Cr11+ primary beam degraded to the same velocity as the A = 100 secondary ions. This very critical and quite tricky preliminary tuning procedure, as well as the mass determination procedure, which are common to all the experiments using this method, are presented and discussed.
Nuclear Instruments and Methods in Physics Research B
- Pub Date:
- April 1996
- ISOCHRONOUS CYCLOTRON;
- DIRECT MASS MEASUREMENT