Dispersive variable wavelength

A diagram of the optical system of the Perkin-Elmer LC 95 dispersive, variable wavelength detector is shown in Figure 7. Light from a UV source, a deuterium lamp, falls onto a concave mirror that collimates the beam onto a diffraction grating. The dispersed beam is then focussed by means of another concave mirror, through an aperture in a plane mirror, onto another plane mirror, through the sample cell and then onto a photo cell. 

Figure 7. Optical system of the Perkin-Elmer LC 95 dispersive, variable wavelength detector.

Anomalous dispersion experiments require use of a variable wavelength, and highly precise measurements because of the small size of the effects. Stability of the source and optics is here, therefore, the prime requirement even if this means that the data measurements take many shifts of beam time. A bending magnet on such a machine as the ESRF has considerable virtue for this kind of experiment (chapter 9). 

Tuning the monochromator for variable wavelength anomalous dispersion experiments... 

Variable wavelength anomalous dispersion methods and applications... 

Variable wavelength anomalous dispersion methods and applications Combining equations (9.6) and (9.8)... 

Variable wavelength approaches to phase determination using anomalous dispersion were discussed in the late 1950s by Okaya and Pepinsky as well as Mitchell, in the 1960s by Herzenberg and Lau and Karle and pioneered by Hoppe and Jakubowski. Technically these methods and others have only become really feasible with the synchrotron. 

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