Estimation of true and accidental coincidences

Following the general discussion in Section 4.6.2, the rates of true and accidental coincidences can be estimated. This possibility is of special interest because it allows better control of the experiment, and it can open ways to improve the experimental conditions further. Using subscript 1 for photoelectrons and subscript 2 for Auger electrons, in the present case the following parameters for such an estimation of coincidences are needed  

Since the full photoelectron line is detected with the large-scale channelplate detector, each photoelectron contributes to the single counting rate /t which, therefore, becomes independent of the instrumental resolution and is given by 

According to the Auger yield wA, these photoelectrons are coincident with a subsequent Auger electron provided one scans over pass2 of the coincident Auger electrons (see Fig. 10.6). This yields the area Atrue of true coincidences (see equ. (10.65e)) 

Finally, the single counting rate I2 for the Auger electrons and the rate /acc of accidental coincidences follow from equs. (4.106b) and (4.103), respectively. Using the numerical values from above one gets 

02 = 90° and 2 = variable (these angles refer to the tilted coordinate frame of Fig. 1.15). Points with error bars are experimental data the solid line is a least-squares fit (see main 

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