Parallel Imaging

Using this method, photoelectrons are collected from the whole of the field of view simultaneously. A combination of lenses before and after the energy analyser focus the photoelectrons on a channel plate detector. The hemisherical analyser permits electrons with only a narrow band of energy to reach the detector.  Neither the X-rays nor the photoelectrons are scanned to produce an image. Spectroscopy and imaging use the same analyser to avoid any risk of misalignment.
In ESCALAB 250 images are formed on a channel plate detector. When using spectroscopy an array of channel electron multipliers is used.

This method has many advantages: 

• Because the whole of the field of view is imaged simultaneously, this method produces images very much more quickly than the conventional methods (for comparable spatial resolution).    
• Image spatial resolution is decoupled from the minimum field of view and so spatial resolution is far superior.    
• Using an electron flood source it is possible to get a physical image of exactly the same position as the images but in real time (i.e. close to TV rate). This makes setting up experiments much quicker.    
• Acquisition times do not have to be set in advance, they can be chosen "on the fly".    
• There is no necessity for software to be written to compensate for design shortcomings.