Effect of Analysis Chamber Pressure on Experimental Data Quality of Atom Probe

The effect of analysis chamber pressure on the data quality was analyzed according to the working principle of three dimensional atom probe.A reactor pressure vessel steel sample was analyzed by atom probe tomography.The results show that the background had good linear relationship with the analysis chamber pressure,and the better vacuum,the less background could be obtained.The high background introduced serious analysis errors of elemental content,especially when the content of the element was very low.Therefor,maintaining the steady high vacuum of analysis chamber is very necessary for obtaining high quality experimental data.