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Browsing by Author "Polak, Wojciech"

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    Development of Kraków External Microbeam - Single Ion Hit Facility
    (Institute of Nuclear Physics Polish Academy of Sciences, 2004) Polak, Wojciech; Hajduk, Roman; Lebed, Sergey; Lekki, Janusz; Horwacik, Tomasz; Maranda, Stanisław; Pieprzyca, Tomasz; Sarnecki, C.; Stachura, Zbigniew; Szklarz, Zbigniew; Veselov, O.; Styczeń, Jan
    The main purpose of building the microbeam setup for the external (i.e out-of-vacuum) measurements is single cell with single ions irradiation. The single-ion hit facility is based on the existing Kraków microbeam setup characterized by the spatial resolutions of about 3 μm. Present work introduces the setup and the measurement chamber that was developed, constructed and assembled in IFJ PAN. The passage of single ions from vacuum to atmosphere (where the cell dish is located) is registered using the channeltron detector installed inside the chamber. Channeltron registers secondary electrons emitted from CsI layer covering the Si3N4 exit window. The system of very precise diaphragms reduces the beam intensity down to a fluence of about 103 protons/sec. The beam blanking, correlated with single proton passage is provided by the fast, electrostatic deflecting system. The precise 3D table, installed outside the chamber, allows positioning the cell dish at a 200 μm distance from the exit window and change the targeted cell with a sub-micrometer precision within the dish. The paper shows results of the preliminary investigations aimed towards optimization of the most important issues: resolution of external microbeam, proton registration efficiency, efficiency of deflecting system and accuracy of single-proton-hit system.
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    Development of the IFJ Single Ion Hit facility for cells ir r adiation
    (Institute of Nuclear Physics Polish Academy of Sciences, 2005) Veselov, O.; Polak, Wojciech; Ugenskiene, R.; Hajduk, Roman; Lebed, Kateryna; Lekki, Janusz; Horwacik, Tomasz; Dutkiewicz, Erazm; Maranda, Stanisław; Pieprzyca, Tomasz; Sarnecki, C.; Stachura, Zbigniew; Szklarz, Zbigniew; Styczeń, Jan
    In recent years a single ion hit facility (SIHF) has been constructed at the IFJ ion microprobe. The setup is used for the precise irradiations of living cells by a controlled number of ions. The facility allows investigations in various aspects of biomedical research, such as adaptive response, bystander effect, inverse dose-rate effect, low-dose hypersensitivity, etc. Those investigations have two very important requirements: (i) cells must be examined in their natural state and environment, i.e. without previously being killed, and preferentially, neither fixed nor stained, and (ii) a possibility of automatic irradiation of large number of cells with a computer recognition of their positions must be provided. This work presents some of the crucial features of the off-line and on-line optical systems, including self-developed software responsible for the automatic cell recognition. We also show several tests carried out to determine the efficiency of the whole setup and some segments. In conclusion, the results of our first irradiation measurements performed with living cells are demonstrated.