Retarding field analyser

Fig. 10. Photoeleotron spectrum of oxygen using the helium resonance line (21-21 e.v.) obtained with a magnetic electron energy analyser (May and Turner, unpublished work). Ionization energy increasing from left to right. The spectrum reveals four levels of ionization and the vibrational structure associated with each state of the ion can be clearly distinguished. This spectrum may be compared with that obtained using an electrostatic retarding field analyser (Al-Joboury et al., 1965).

Figure 14.4 Auger KVV carbon peak in (a) a thick graphite layer covering a carbide (b) /J-WC, film with <41 mol% carbon (c) a /i-WC, v film with about 50 mol% carbon. Spectra were acquired with a retarding field analyser in the derivative mode, using a grazing incidence electron gun, with primary beam energy of 2.5 keV the modulation voltage was...

The energy of the primary electron beam was 2.5 keV and the energy of the Ar+ used in the depth profiles was 2 keV. The relative sensitivity factors were determined using pure standard samples and are presented in Table 14.1. Some samples were studied using an Auger spectrometer equipped with a retarding field analyser. The thickness of the films was... 

The final method of discrimination, as pointed out above in relation to the Detroit apparatus, is the use of a retarding field analyser. Its... 

Fig. 5. Schematic diagram of a retarding field analyser system using a channel plate. [After Waclawski et al. (34) and other groups.]...

Care must be taken in designing the collision apparatus and electron detector (normally a Faraday cup or retarding field analyser) to ensure that equation (2.9) is applicable and small-angle scattering is eliminated (Wagenaar and de Heer, 1985 Bederson and Kieffer, 1971). To allow for... 

Figure 8 Schematic illustration of a retarding-field analyser. Electrons transmitted through the probe hole are focused at the centre of a shielded hemispherical collector by the lens. The bias potential Vb is varied to obtain the energy spectrum of collected electrons...

Figure 9 Principle of the retarding-field analyser, (a) Only electrons with Z-directed energy E are collected, (b) Increasing Vb widens the range of energies collected thus increasing the collected current ip towards its saturation value when all emitted electrons are collected.

The measurement is carried out in an UHV chamber. Electrons from an electron gun in the energy range 50—2000 eV are directed onto the sample. The incident electron energy is gradually increased. In the case of DAPS, the elastically scattered primary electrons are detected using a retarding field analyser (RFA). As the energy... 

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