BL08U

Experimental Techniques

• Standard Measurement
• Soft X-ray Absorption Spectroscopy (XAS)
• Soft X-ray Photoelectron Spectroscopy (XPS) – using AP-XPS equipment
• Advanced Measurement
• Ambient Pressure Photoelectron Spectroscopy (AP-XPS)
• Operando Soft X-ray Absorption Fine Structure (operando SX-XAFS)
• Soft X-ray Absorption, Fluorescence, and Resonant Imaging (SAFARI *Under development)

Overview

BL08U is a beamline that utilizes soft X-rays in the energy range of 180 to 2000 eV to analyze the electronic states of materials. It is designed to use vertical and horizontal linearly polarized light, as well as left and right circularly polarized light, generated by an APPLE-II type elliptical undulator (please ask us if you wish to use polarization other than horizontal linear polarization). The optical system employed has no energy dependence on the deflection angle or divergence, enabling soft X-ray spectroscopy measurements in a high-energy resolution mode and scanning imaging in a high-flux mode.

As for the experimental station, an Ambient Pressure X-ray Photoelectron Spectroscopy (AP-XPS) system is installed, which allows for the quantitative analysis of the chemical states of solids. The spot size on the sample is 30 µm (height) x 80 µm (width). Standard measurements are performed under ultra-high vacuum (10^-10 mbar), while advanced measurements can be conducted in the pressure range of 100 to 1023 mbar. The sample temperature during measurement can be controlled from room temperature up to 500°C.

Beam Characteristics

• Energy Range 180～2000 eV
• Flux As shown in the figure below (depends on energy and experimental conditions)
• Beam Size XPS: 30 µm (vertical) x 80 µm (horizontal)
  XAS: 1 mm (vertical) x 1 mm (horizontal), unfocused

Light Source and Optics

The light source is a 71-pole, 56 mm period APPLE-II type undulator, and monochromatic soft X-ray beams are available via a grating monochromator. The exit slit is located downstream of the monochromator, which can be used to adjust the energy resolution and as a virtual point source in scanning imaging.

Experimental Station

• Measurement Methods XPS: Approx. 2-3 minutes per spectrum
  
  AP-XPS: Approx. 15 minutes per spectrum
  
  SX-XAFS (Total Electron Yield, Partial Fluorescence Yield): Approx. 15 minutes per spectrum
  
  Measurement times are estimates and depend on sample form and element concentration.
• Sample dimensions XAS: Maximum 14 mm (height) x 12 mm (width) (thickness: several mm)
  XPS: Maximum 11 mm (height) x 11 mm (width)
• Sample Plates ・XPS　　　　　　　　・SX-XAFS(Standard Measurement)
  
  
  Sample Mounting (BL08U SX-XAFS)
• Sample Requirements XPS:
  ・Electrically conductive solid with the observation target located within 2 nm depth from the surface.
  
  SX-XAFS:
  ・Total Electron Yield: Electrically conductive solid with the observation target located within 5 nm depth from the surface.
  ・Partial Fluorescence Yield: Solid with the observation target located within 100 nm depth from the surface; compatible with insulating samples.

Transfer vessel (for standard SX-XAFS measurements)

Transfer vessel　　　　　　Sample bank

If you wish to use the transfer vessel, please indicate this in your beamtime request.

Measurement Steps (Standard Measurements)

・XPS

・SX-XAFS