BS ISO 16129:2018 pdf download

BS ISO 16129:2018 pdf download.Surface chemical analysis — X-ray photoelectron spectroscopy — Procedures for assessing the day-to-day performance of an X-ray photoelectron spectrometer
1 Scope
This document is designed to allow the user to assess, on a regular basis, several key parameters of an X-ray photoelectron spectrometer. It is not intended to provide an exhaustive performance check, but instead provides a rapid set of tests that can be conducted frequently. Aspects of instrument behaviour covered by this document include the vacuum, measurements of spectra of conductive or non-conductive test specimens and the current state of the X-ray source. Other important aspects of the instrument performance (e.g. lateral resolution) fall outside the scope of this document. The document is intended for use with commercial X-ray photoelectron spectrometers equipped with a monochromated Al Kα X‑ray source or with an unmonochromated Al or Mg Kα X‑ray source.
5 Initial instrument calibration, alignment and assessment
Before undertaking the procedure described in the following clauses, it is essential that the instrument be calibrated and aligned to an optimum performance level. This is achieved by following the relevant International Standards (References [5] to [9]) or the manufacturer’s instructions. Choose the two settings of the instrument operating conditions that are needed to obtain survey spectra and high- resolution spectra. These should be settings that you regularly use and are described in Clause 7. Since this is a rapid check, only these two settings are chosen, but these can show faults that are common to all settings. These settings shall always be used in future checks unless they are later found to be less effective than other settings. If the designated settings are changed, data at both the new and old settings shall be recorded at the time of change.
6.1 General information
Three types of test specimen are required for the full procedure described in this document: a conductive specimen, a non-conductive specimen and a specimen suitable for assessing the quality of the X-ray beam (e.g. X-ray spot size, shape and uniformity). The conductive specimen provides information that the basic energy and intensity calibrations of the instrument are consistent from day to day. When using a non-monochromatic X-ray source with more than one anode material, the survey spectrum shall be examined to check for peaks arising from specimen irradiation from the anode that is not currently being used (this is due to “cross-talk” within the X-ray source). Similarly, when anode coatings wear, X-rays can be emitted from the substrate material, which is often copper. The survey spectrum shall be examined for peaks arising from X-rays produced from the substrate material. When using a magnesium anode, there can be peaks due to radiation from O Kα arising from oxidation of the anode coating. These peaks are often called ghost peaks. In some instances, ghost peaks may be removed from the spectrum by degassing the X-ray source (following the instrument manufacturer’s recommended procedure). Table 1 shows the approximate positions of commonly encountered ghost peaks when acquiring an XPS spectrum from silver using Mg Kα radiation.