The Thermo Scientific ESCALAB Xi⁺ X-ray XPS combines high spectral sensitivity and resolution with high-resolution quantitative imaging and multi-technique capabilities.

For small-area spectroscopy, the ESCALAB uses three methods to define the analysis area:

• Source-defined area selection—The monochromated X-ray beam can be focused to spot sizes from 900 µm – 200 µm.
• Lens-defined area selection—Computer-controlled irises in the transfer lens deliver lateral resolution down to 20 µm.
• Retrospective spectroscopy from images—With high resolution parallel imaging, spectra can be obtained from even smaller areas.

Flood electron source

An electron source, co-axial with the analyzer input lens, is used for charge compensation when analysing non-conducting samples with the monochromatic X-ray source. A second flood source provides both low-energy ions for effective charge compensation and low-energy electrons while the magnetic lens is not being used.

Lens and analyser

The lens and analyser system is optimised for spectroscopy and parallel imaging. The single analyser path means that the same instrument parameters (eg pass energy) can be used for both spectroscopy and imaging.

Detectors

There are two detector systems:

• One optimised for spectroscopy – with an array of six-channel electron multipliers.
• One for parallel imaging – with a pair of channel plates and a continuous position-sensitive detector.

Ion gun

There are two options for fast, high-resolution depth profiling:

• Standard EX06 ion gun – optimised for monatomic ion sputtering and ion scattering spectroscopy.
• Optional monatomic and gas cluster ion source (MAGCIS) – for monatomic ion profiling, cluster ion profiling and ion scattering spectroscopy.

Remote analysis

All analytical functions are controlled using Thermo’s Windows-based Avantage software, so analysis can be performed remotely if necessary.

Alignment and calibration

A standards block with copper, silver and gold samples is used to check sensitivity, set the linearity of the analyser energy scale, calibrate the ion source, align the X-ray monochromator, and determine the transmission function of the analyser.

Sample stage movement is controlled by the software. A high-resolution digital video camera provides a view aligned exactly with the analysis position.

Sample treatment chambers

The standard Preploc chamber is a combined sample entry lock and preparation chamber. There are ports for a range of devices including heating/cooling probes, ion guns, high-pressure gas cells, sample parking and gas admission.