Swiss Light Source
X07DB In Situ Spectroscopy

The In Situ Spectroscopy beamline offers the possibility to perform ambient pressure x-ray photoelectron spectroscopy (APXPS) and near edge x-ray absorption fine structure (APNEXAFS) spectroscopy measurements. The photon energy range available (350-1500 eV) allows to reach a maximum pressure of approximately 5 mbar in the cell during in situ experiments.

The research at the In Situ Spectroscopy beamline is focused on the in situ characterization of solid-gas and solid-liquid interfaces. The solid-gas interface endstation, opened to external users, offers the possibility to investigate samples relevant for catalysis, environmental chemistry and electrochemistry. The system is versatile and other type of experiments can be planned according to the specific needs of users. Beamtime proposals can be prediscussed with the responsible scientist (Dr. Luca Artiglia). The solid-liquid interface endstation has been fully commissioned in 2019 and is open to external users upon discussion with the responsible sceintist (Dr. Zbynek Novotny). 

Beamline Energy Range
350 - 1500 [eV]
Max Flux On Sample
1 * 1012 [ph/s] @ 1050 [eV]
Spot Size On Sample Hor
200 - 300 [um]
Spot Size On Sample Vert
200 - 300 [um]
Endstations or Setup

Solid-gas interface endstation

This experimental chamber has been entirely designed and developed at the Paul Scherrer Institute. It consists of a small-volume, high-pressure cell connected to two vertical tubes having a diameter of 3.0 cm. The total volume (cell+tubes) is around 150 cc. With the sample placed in the middle of the cell, a gas flow can be created by opening the gas line upstream and pumping the exhaust downstream. The sample can be precisely moved while measuring in the mbar range (precision +- 10 microns).
Both environmental chemistry/surface chemistry and heterogeneous catalysis experiments can be carried out. The cell can operate in static mode (pumped only from the aperture of the analyzer) or in flow configuration. The maximum pressure while measuring depends on the excitation energy used. With soft x-rays, photoemission and absorption spectra can be acquired up to 5 mbar. Sample treatments are possible up to 50 mbar. The pressure is measured by means of Baratron capacitance heads.
The small volume of the experimental cell and the flow tube configuration allow fast gas switching from one mixture to another (in the second timescale), while acquiring photoemission spectra in fast-scan mode (fixed or swept mode). We were recently introducing time-resolved measurements, and could get information about the evolution of real samples (powder catalyst) in specific reaction mixtures as a function of time in the second range. Time resolution is one of the next frontiers in in-situ XPS and will make possible to follow dynamic structural changes that typically occur in catalysts. It will also provide quantitative structure-performance relations previously not accessible.
The endstation is equipped with a ScientaOmicron R4000 HiPP-2 electron analyzer ( with three differential pumping stages.
Base Pressure
5 * 10-8 [mbar]


Sample Type
Crystal, Fiber, Powder
Mounting Type
Crystal samples can be fixed to the sample holder by means of metallic clips.
Thin and homogeneous layers of powder samples can be drop cast (a spin coater is available at the beamline) on conductive and inert metal foils (e.g. Au, Ag). Such foils are then fixed to the sample holder by means of metallic clips.
Required Sample Size
X = 10 [mm], Y = 10 [mm], Z = 1 [mm]

Techniques usage

Absorption / NEXAFS
Partial electron yield NEXAFS spectroscopy can be acquired tuning a kinetic energy window (in fixed or in swept mode) of the electron analyzer on an Auger line or on the tail of an Auger line. A software allows the automatic acquisition of the spectrum, thus controlling and acquiring both the beamline and the electron analyzer parameters.
Photoelectron emission / Time-resolved studies
Tie-resolved XPS studies are possible under transient conditions. Thanks to the flow configuration and to the small volume of the experimental cell, fast switches from a gas/gas mixture to another are possible while acquiring a photoemission peak (transient conditions experiments).
Photoelectron emission / XPS
XPS can be acquired both in fixed (fixed kinetic energy window, acquisition time tunable with lowest frame rate corresponding to 40 ms) and in swept mode.

Manipulator or Sample stage

The sample is heated by means of a IR laser (976 nm, maximum power=25 W) projected on the back side of the sample holder. The highest temperature achieved strongly depends on the gas used and/or on the pressure in the experimental cell. For most of the experimental conditions, it is possible to work between 300 and 900 K. The temperature is measured by means of a Pt100 temperature sensor, and is set with a PID controller.

This manipulator insert, combined with the unique features of the flow reaction cell, is suited for surface chemistry and catalysis experiments.
Degrees Of Freedom
Positioning Precision
X = 10 [um], Y = 10 [um], Z = 10 [um]
Range Of Movement
X = 2 [mm], Y = 2 [mm], Z = 18 [mm]


Multichannel Place (MCP) coupled to CCD camera
Time Resolved


Detected Particle
Artiglia Luca
Photoelectron emission
  • Time-resolved studies
  • XPS
  • Catalysis
  • Electrochemistry
  • Physical Chemistry
control/Data analysis
Control Software Type
  • EPICS beamline control system, LabView endstation control system
Data Output Format
  • .txt, .ibw, hdf5
Softwares For Data Analysis
  • Igor Pro, Origin, Matlab