King and Wells method

Information from beam exposures of the sample can be obtained a number of ways. For surface adsorption probabilities greater than 0.03, the King and Wells method [16] can accurately be employed to determine initial adsorption probabilities of a gas species. In short, a King and Wells measurement monitors the partial pressure of the scattering chamber before, during, and after exposure of the sample to the beam flux. A typical reflectivity measurement can be seen in Fig. 2. 

Fig. 2. Schematics for determining the sticking coefficient using the King and Wells method [72KIN]. The diagram on the right hand shows the mass spectrometer (QMS) signal after first opening flag FI and then flag F2.

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