Study of Superconductor Thin Film Growth and the manifestation Mechanism Using Super-Excited Atomic Oxygen (O^<****>) Beam

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In 1996 we modified the metastable beam source made in last year, built mechanical chopper in differential vacuum chamber to pulse the metastable beam. We also built photomultiplier (ceratron) at 50 cm downstream of the chopper, to obtain time-of-flight (TOF) spectrum of the metastable beam by integrating the signal, with the gate signal of the chopper as trigger. The obtained TOF spectra showed that the velocity avarage of He^<**> beam is 3000 m/s, whereas the distribution of O^<**> beam has two peak at the velocity avarage of 2000 and 500 m/s. In addition, we observed fine structures of the O^<**> TOF spectrum. This indicates that the O^<**> beam consists of several O^<**>'s each of which has different energy, and there is a possibility to devide an O^<**> atoms with different energy by TOF method. This result needs further investigation with laser technique etc.We have tried to connect the metastable beam source via a differential chamber with an UHV chamber for the production of superconductive thin film. We noticed that it is difficult to maintain UHV on flowing the O^<**> beam. Hence, we connect a turbo molecular pump with the UHV chamber.Furthermore, we have demonstrated that N^<**> or O^<**> with different excitation energy from that by the above technique can be produced from nitrogen or carbon dioxide gas, and the best condition of the metastable beams are on investigation.