ISISS station

Innovative Station for In Situ Spectroscopy

Fig. 1: picture of NAP-HE-XPS (courtesy of SPECS GmbH, Berlin)

Methods

Remote access

depends on experiment - please discuss with Instrument Scientist

Beamline data
Energy range	80 - 2000 eV
Energy resolution	>15,000 at 400eV
Flux	6x1e10 photons/s/0.1A with 111µm exit slit
Polarisation	linear horizontal
Focus size (hor. x vert.)	100x80 µm²
Phone	+49 30 8062 14905 / 14906
More details	ISISS
Station data
NAP-HE-XPS
Temperature range	room temperature up to 1000 K
Pressure range	Maximum pressure: 2000 Pa Minimum pressure: 10^-10 Pa Typical pressure: 100 Pa For more details contact the station manager.
Detector	2D delay line detector (2D DLD) (SURFACE CONCEPT, Mainz)
Manipulators	various, exchangeable with optimised for sample environments
Sample holder compatibility	Homemade concept. Check text below. For more details contact the station manager.
Additional equipment
gas analytics	electron impact mass spectrometer (differentially pumped) proton-transfer-reaction mass spectrometer (PTR-MS) gas chromatograph

Fig. 2: Scheme of the NAP-HE-XPS endstation installed at the ISISS beamline.<br> The spectrometer (right site) is displayed retracted from the XPS cell module (left side). <br><br><br>

Fig. 2: Scheme of the NAP-HE-XPS endstation installed at the ISISS beamline.
The spectrometer (right site) is displayed retracted from the XPS cell module (left side).

Table 1: Gas analytics

Table 1: Gas analytics

Table 2: Laboratory facilities at ISISS

Table 2: Laboratory facilities at ISISS

Obviously, the understanding of the interaction of a catalyst surface with the reactants plays a key role in a detailed description of catalytic processes. X-ray photoelectron spectroscopy (XPS) is a well-established powerful tool to study in detail the outermost surface of solids but it was traditionally restricted to high vacuum and low pressure conditions. However, recently a methodology based on a differentially pumped electrostatic lens system has gained much interest.

The Fritz-Haber-Institut der MPG has operated at BESSY such an instrument since 2002 at different undulator based beamlines. In 2007 a beamline (ISISS) dedicated to near ambient pressure XPS (NAP-XPS) experiments has been implemented at HZB/BESSY II. A further improved version of this instrument is installed as the ISISS beamline since June 2013. A picture of the set-up can be seen as Fig. 1 while Fig. 2 shows a sketch of the main components.

X-ray photoelectron spectroscopy (XPS) under high vacuum (p=10^-10 Pa) and near ambient pressure conditions (typically p=100 Pa).
X-ray aborption spectroscopy (XAS) at pressure up to 1k Pa with NAP-HE-XPS endstation. Installation of variable pressure XAS endstation instead of NAP-HE-XPS allows NEXAFS in electron yield mode at variable pressure between 1 - 100 kPa at temperatures up to 650K.