A standard Fricke dosimeter was used to measure the absorbed dose via the oxidation yields of Fe3+ ions in an aqueous environment induced by soft X rays within the "water window" spectral range. We also exploited the property of a neutral solution containing terephthalic acid as a tool for selective detection of OH radicals. Both dosimetric systems were irradiated using the experimental pulsed laser-plasma soft X-ray source as well as conventional 1.25-MeV gamma rays. Radiation chemical yields of Fe3+ ions and OH radicals were determined to be (5.13 ± 0.94) × 10-1 µmol·J-1 (4.95 ± 0.91 100eV-1) and (2.33 ± 0.35) × 10-2 µmol·J-1 (0.23 ± 0.03 100eV-1), respectively. Measurements were supported by Monte Carlo simulations to estimate the linear energy transfer of the water window radiation. The simulation results are in good agreement with expected linear energy transfer of ions inducing the same Fe3+ ion and OH radical radiation chemical yield.
- MeSH
- hydroxylový radikál chemie účinky záření MeSH
- ionty chemie MeSH
- lidé MeSH
- lineární přenos energie MeSH
- metoda Monte Carlo MeSH
- oxidace-redukce MeSH
- radiometrie * MeSH
- rentgenové záření škodlivé účinky MeSH
- voda chemie MeSH
- záření gama škodlivé účinky MeSH
- železo chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Short illumination wavelength allows an extension of the diffraction limit toward nanometer scale; thus, improving spatial resolution in optical systems. Soft X-ray (SXR) radiation, from "water window" spectral range, λ=2.3-4.4 nm wavelength, which is particularly suitable for biological imaging due to natural optical contrast provides better spatial resolution than one obtained with visible light microscopes. The high contrast in the "water window" is obtained because of selective radiation absorption by carbon and water, which are constituents of the biological samples. The development of SXR microscopes permits the visualization of features on the nanometer scale, but often with a tradeoff, which can be seen between the exposure time and the size and complexity of the microscopes. Thus, herein, we present a desk-top system, which overcomes the already mentioned limitations and is capable of resolving 60 nm features with very short exposure time. Even though the system is in its initial stage of development, we present different applications of the system for biology and nanotechnology. Construction of the microscope with recently acquired images of various samples will be presented and discussed. Such a high resolution imaging system represents an interesting solution for biomedical, material science, and nanotechnology applications.
- MeSH
- biologie metody MeSH
- fibroblasty cytologie MeSH
- karcinom patologie MeSH
- mikroskopie přístrojové vybavení metody MeSH
- myši MeSH
- nádory tračníku patologie MeSH
- nanotechnologie metody MeSH
- počítačové zpracování obrazu MeSH
- rentgenové záření MeSH
- uhlík MeSH
- voda MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
