Organic scintillators with long luminescent lifetimes for radiotherapy dosimetry

Anders Ravnsborg Beierholm, Lars René Lindvold, Claus Erik Andersen

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    Organic scintillators with long luminescent lifetimes can theoretically be used to temporally filter out radiation-induced luminescence and Cerenkov light (the so-called stem signal) when used as fibre-coupled radiotherapy dosimeters. Since the medical linear accelerators (linacs1) used for radiotherapy treatments deliver pulsed beams, the stem signal can be suppressed using dosimeter materials with luminescent lifetimes much longer than that of the stem signal. However, producing organic scintillators with long luminescent lifetimes has proven difficult in practice. We report on the results of experiments performed using two organic scintillators, one commercially available and one custom made. The luminescent lifetimes of the scintillators have been measured using i) optical excitation by pulsed UV light, and ii) irradiative excitation using high-energy X-rays from a linac. A luminescent lifetime component on the order of 20 μs was estimated for the custom-made organic scintillator, while the commercial scintillator exhibited a fast component of approximately 5 ns lifetime (7 ns as stated by the manufacturer) and an approximate 10 μs lifetime slow component. Although these lifetimes are not long enough for practical applications in radiotherapy dosimetry, this study supports that the stem signal can be greatly reduced by applying a temporal gating.
    Original languageEnglish
    JournalRadiation Measurements
    Volume46
    Issue number12
    Pages (from-to)1982-1984
    ISSN1350-4487
    DOIs
    Publication statusPublished - 2011

    Keywords

    • Radiation physics

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