Crowborough War Memorial Hospital

The design and construction of electron spectrometers is a complex undertaking and will usually be left to one of the handful of specialist manufacturers worldwide, although many users specify minor modifications to suit their own requirements. The various modules necessary for analysis by electron spectroscopy are (in addition to a sample): a source of the primary beam (either X-rays or electrons), an electron energy analyser and detection system, all contained within a vacuum chamber, and a data system, which is an integral part of the instrument. Most commercial spectrometers are based on vacuum systems designed to operate in the ultra-high vacuum in a particular pressure range, and most X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) experiments are carried out in this pressure range. There are two types of electron energy analyser in general use for XPS and AES: the cylindrical mirror analyser and the hemispherical sector analyser.

Great care must be taken when preparing, transporting and mounting samples for surface chemical analysis. Surfaces are easily contaminated or damaged, by scratching, for example. Such damage can mask or even remove the intended analyte. Analysts should also be aware of the history of the sample so that the likelihood of damage or contamination can be assessed; it should be remembered that prior analysis can change the nature of the sample surface. Customers requiring X-ray photoelectron spectroscopy (XPS) or Auger electron spectroscopy (AES) analysis from consultancy laboratories should provide control of substances hazardous to health regulations documentation with their samples. XPS relies upon the emission of electrons from the surface of the sample. If this sample is an insulator, then the surface will develop a positive charge. It is therefore essential that sample charging is carefully controlled. A comprehensive guide to sample handling may be found in the International Standard ISO 20579-1.

If your project needs to operate a wireless communications system, you need to attach antennas to it. There are two important factors to consider. Firstly, the ARTIK boards need the mini-coaxial connectors to be coupled to approved antennas for broadcasting a wireless signal. Secondly, the SMA connectors on the developer board must have the correct kind of antennas installed. This chapter covers the relevant information regarding antennas.