The features of a newly designed UHV orange spectrometer that has been recently built in our group were chosen to optimise its usefulness for Depth Selective Conversion Electron Mössbauer Spectroscopy (DCEMS). Its is superior to electrostatic spectrometers that are usually used in this field. Furthermore, the effective transmission can be increased by the simultaneous registration of several energy channels in an energy interval of +- 4 % around the average energy setting E. This is possible due to the special focus geometry of the spectrometer and by using a position sensitive detection system. The new ultrahigh vacuum spectrometer is designed for electron energies up to 45 keV.

For applications other than DCEMS the orange spectrometer combines some special features which may be further optimised by the design of its magnetic coil. Especially the combination with an electrostatic retardation in the vicinity of the sample provides the possibility of an even higher energy resolution of electrons with primary energies of some keV. Due to the spatial freedom around the sample several methods like DCEMS, AES and XPS may also be integrated in one experimental set-up. The coincident detection of emitted x-rays may be considered.

For details please have a look at the following topics:

• Comparison with Electrostatic Spectrometers in the Field of DCEMS

• Photograph of the UHV Orange Spectrometer

• Some Electron Energy Spectra

• A DCEMS Mesh Plot of Experimental Data

The Orange Type Spectrometer ist still being further developed and in use at the Technical University of Darmstadt.