scintillating fiber 14 to the active portion or face 16 a of the pmt this piped light is measured by the pmt and the pmt produces a voltage output which gives an indication of the radiation dose rate produced by or total activity of the radiation source in conjunction with the translation of the additional scintillating fiber 28 relative to a radiation source a displacement difference dosimetry ddd signal processing method is preferably employed by the digital signal processor in the output circuitry 30 in order to provide fine spatial resolution and to minimize the adverse efects of cerenkov light on the measurement accuracy scintillating fiber dosimeter 10 a separate u s patent application directed to the ddd method entitled u201c radiation measurement within the human body u201d attorney docket no tes2 was filed on feb 28 2002 by the inventor hereof and is incorporated by reference herein a quality assurance qa advantage of scintillating fiber hdr dosimetry results from its fast response since hdr dose rates are up to 10 4 greater than ldr dose rates the signal strength produced by the pmt can be up to 10 4 greater and the signal averaging time to allow for signal integration can thus be u02dc 10 4 shorter than for ldr sources however this requires a light intensity measuring device with a 10 4 dynamic range and a 10 khz bandwidth if.