An experimental study of sodium aerosol detection sensitivity by laser induced breakdown spectroscopy (II)

not registered ; not registered 

A Laser-induced breakdown spectroscopy Leak Detection technique (abbreviated LLD) of sodium is accomplished by plasmafying the sodium aerosol and then selectively detecting the sodium specific optical spectrum. This method is potentially more reliable as a means of detecting of sodium small leakage. This report describes test results of detection characteristics of LLD using sodium aerosol. The test was carried out following LLD detection sensitivity evaluation test in last year. The main results are as follows: (1)The LLD signal appeared insensitive to the effect of carbon dioxide concentration in the examined range. (2)With the rise in the atmosphere (sampling gas) temperature, the sodium detection sensitivity of LLD tended to be lower. However, it seems to be a peculiar problem of this LLD system, because of decrease of breakdown reaction rate in higher temperature condition of sampling gas (atmosphere temperature). Further evaluation will be needed for this point. (3)LLD showed the fast-response for the aerosol which arose with the sodium combustion as well as for the aerosol which was created on the basis of the sodium vapor. According to the test result, detection property of LLD for very small quantity sodium aerosol was clarified.