1 / 20

Malkhaz Jabua

Institute for nuclear physics, Jülich scientific research centre. Georgian Technical University. GGSWBS’ 14. Ultimate Resolution X-ray Spectrometry. Malkhaz Jabua. PhD student at Georgian Technical University (GTU) and Forschungszentrum J ü lich (FZJ).

clinton-talley
Télécharger la présentation

Malkhaz Jabua

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Institute for nuclear physics, Jülich scientific research centre • Georgian Technical University GGSWBS’ 14 Ultimate Resolution X-ray Spectrometry • Malkhaz Jabua PhD student at Georgian Technical University (GTU) and Forschungszentrum Jülich (FZJ) Supported by Jülich – SRNSF Joint Fellowship Grant from 2012 Advisors : Prof. DetlevGotta (FZJ and the University of Cologne), Prof. LevanImnaishvili (GTU) July 10, 2014 Tbilisi, Georgia

  2. STRUCTURE OF PRESENTATION RESEARCH INTERESTS Exeriment at IKP, Forschungszentrum Actual results Activities planned in a nearest future Conclusion

  3. The main goal of research work Exploring the details of atomic shells Measurement of X-ray energies from various compounds at ultimate resolution Design of stable software and hardware components for precision measurements One of the target objects - Manganese and Barium Compounds

  4. Origin of X-rays K X-rays L X-rays Wavelength (λ): 0,01 – 10 nm M Shell N Shell K Shell L Shell • Photon energy • E= h · f

  5. Method of X-ray measurement (Bragg - diffraction) θ θ d – Lattice constant nλ Bragg Law : nλ = 2d • sinθ n = 1,2,3 …

  6. Features Energies in our experiment: Relative energy resolution of Bragg crystal: Close to theoretical limit Intensity ΔE Channels

  7. Bragg spectrometer in Johann setup Spherically bent crystal • Advantages: High efficiency of X-ray detection, due to the simultaneous measurement of an energy interval according to the source & detector width Rowland circle Possibility to measure X-rays at high energy interval Extended source 2 dimensional position sensitive detector X-rays reflected from the crystal are focused on detector’s sensitive surface at high precision Focusing condition: • Y=RC·sinθB

  8. IKP Bragg spectrometer scheme 8. LN2dewar Side view 7. Traction relaxation 5. Detector cryostat 1. Fluorescence target 6. Linear tables 2. X - ray tube Experimental conditions 3. Bragg crystal • Quartz crystal (1 0 -1) • Crystal diameter = 10 cm • Thickness of 200 μm • 30 mm thick glass lense of 120 mm in diameter Top view

  9. Labview based monitoring and control system of the Bragg spectrometer Crystal control Detector temperatures Arm control Crystal tilting CCD table control Data saving Screenshot of Labview

  10. IKP Bragg spectrometer realization Photo from IKP südhalle lab Crystal chamber Spectrometer monitoring and control system Target chamber HV generator for X-ray tube LN2 dewar Detector cryostat Spectrometer turbopump DAQ PC for the detector

  11. X-ray detectors – charge - coupled devices Bucket brigade association way from photon to the spectrum

  12. Detector construction Two CCDs CCD chips used now • Sensitive area of 24 mm x 24 mm 600 x 600 square pixel of size 40μm • Depletion depth - 30 μm

  13. Detector Setup Acting CCD chip High quantum efficiency (QE) Excellent charge collection Two-dimensional position resolution Single X-ray detection ability X-ray detector arrangement Good level of linearity

  14. Position spectrum of measured X-rays Hit pattern projection to the axis of dispersion yields a position distribution being equivalent to an energy spectrum Mn compound

  15. Results of the new measurements Different compounds and their corresponding Kα and Kβ transition energies MnO Kβ MnO Kα Experimental conditions Strong dependence of the line energy and the line shape on a chemical compound KMnO4 Kβ KMnO4 Kα

  16. New MnV measurements Intensity Intensity Mn metal compound MnV compound

  17. Comparison of chemical shift analysis results • of different researchers Its remarkable that because of an ultimate precision measurements conducted at IKP/FZJ, there are no errorbars for our measurements.

  18. Conclusion Flexible and reliable spectrometer and its monitoring and control system Peak energies determined to an accuracy of 10-20 meV confirming the known overall behavior of decreasing line energy with increasing ionization state of the Mn atom

  19. Future plans • Single to multiple chip CCD • 2 x3 array of sensitive chips • Research of X-rays from Mn(V) and various Ba compounds, including metallic barium and barium vapour

  20. Thanks For Attention

More Related