LiXEdrom: Setup for High Resolution X-Ray Emission Spectroscopy on Liquid Samples from Micro-Jet
The LiXEdrom is a high resolution emission spectrometer of the next generation in the range of soft X-rays. The energy resolution is 350meV at an energy of 530eV.
The special characteristic of the LiXEdrom is the possibility to measure liquid samples, beside solid state samples. The solution is shot via a liquid-micro-jet into the vacuum. The emitting light of the liquid sample is detected energetically dissolved without being weakened by a membrane. Here a pressure difference of 10-5 mbar in the sample chamber and 10-9 mbar in the detector chamber is achieved.
The emission spectrometer LiXEdrom is based on the Rowland-Circle concept. The Rowland-Circle is a virtuell circle with a radius equal to half of the grating radius. If the sample and the detector are both located on the Rowland-Circle the emitted light will be focused on the detector. The detector is built up of a multi-channel-plate with a fluorescence screen and an optical CCD-camera in the back.
With the LiXEdrom X-ray emission spectroscopy (XES) can be realized in the range of 20eV up to 1000eV. This range is covered by 4 gratings, which are moved into the beam like a revolver. The gratings are split as following: grating 1: 20-50eV with 400 lines/mm and 2m radius, grating 2: 50-175eV with 600 lines/mm and 3.71m radius, grating 3: 175-400eV with 1200 lines/mm and 5m radius, grating 4: 400-1000eV with 1200 lines/mm and 7.5m radius.
The advantage of the liquid-micro-jet is the measuring of permanent exchanged and therefore fresh samples. This avoids radiation damage in the sample assembly. Samples with a high sensitivity to radiation damage can easily be measured. The applications range from pure liquids, to ions and nanomaterials in solution up to complex biochemical systems e.g. proteins in their natural environment.
Furthermore, soft X-ray absorption spectroscopy (XAS) can be done on solid states and on solutions. The solutions can be measured in different environments depending on the sensitivity to the radiation damage or to the amount of the liquid sample. XAS can be measured on liquid samples in a static cell, in a flow-cell or in the liquid-micro-jet.
Kathrin M. Lange, René Könnecke, Samira Ghadimi, Ronny Golnak, Mikhail A. Soldatov, Kai F. Hodeck, Alexander Soldatov, Emad F. Aziz. High resolution X-ray emission spectroscopy of water and aqueous ions using the micro-jet technique. Chemical Physics 377, 1-5 (2010)
