On line neutron beam monitoring of the finnish BNCT facility

Vesa Tanner, Iiro Auterinen, Jori Helin, Antti Kosunen, Sauli Savolainen

    Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

    Abstract

    A Boron Neutron Capture Therapy (BNCT) facility has been built at the FiR 1 research reactor of VTT Chemical Technology in Espoo, Finland. The facility is currently undergoing dosimetry characterisation and neutron beam operation research for clinical trials. The healthy tissue tolerance study, which was carried out in the new facility during spring 1998, demonstrated the reliability and user-friendliness of the new on line beam monitoring system designed and constructed for BNCT by VTT Chemical Technology. The epithermal neutron beam is monitored at a bismuth gamma shield after an alurniniumfluoride-aluminium moderator. The detectors are three pulse mode U235-fission chambers for epithermal neutron fluence rate and one current mode ionisation chamber for gamma dose rate. By using different detector sensitivities the beam intensity can be measured over a wide range of reactor power levels (0.001-250 kW). The detector signals are monitored on line with a virtual instrumentation (LabView) based PC-program, which records and displays the actual count rates and total counts of the detectors in the beam. Also reactor in-core power instrumentation and control rod positions can be monitored via another LabView application. The main purpose of the monitoring system is to provide a dosimetric link to the dose in patient during the treatment, as the fission chamber count rates have been calibrated to the induced thermal neutron fluence rate and to the absorbed dose rate at reference conditions in a tissue substitute phantom.
    Original languageEnglish
    Title of host publication15th European TRIGA Conference
    Place of PublicationEspoo
    PublisherVTT Technical Research Centre of Finland
    Pages181-189
    ISBN (Print)951-38-5273-3
    Publication statusPublished - 2000
    MoE publication typeA4 Article in a conference publication
    Event15th European TRIGA Conference - Espoo, Finland
    Duration: 15 Jun 199817 Jun 1998

    Publication series

    SeriesVTT Symposium
    Number197
    ISSN0357-9387

    Conference

    Conference15th European TRIGA Conference
    CountryFinland
    CityEspoo
    Period15/06/9817/06/98

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    Cite this

    Tanner, V., Auterinen, I., Helin, J., Kosunen, A., & Savolainen, S. (2000). On line neutron beam monitoring of the finnish BNCT facility. In 15th European TRIGA Conference (pp. 181-189). VTT Technical Research Centre of Finland. VTT Symposium, No. 197