A fast scintillation fiber-optic detector with the subtraction of the Cherenkov radiation contribution

摘要

A scintillation fiber-optic detector (FOD) of pulsed ionizing radiation with the Cherenkov radiation contribution subtracted from the scintillator response is described. The FOD time resolution has been measured using a subnanosecond accelerator. It is shown that the use of optic filters and a transparent mode converter inserted in the cable break improve the FOD time resolution. The time responses of the detector with an SPS-B18 scintillator and a 5-m-long optic cable and with an SPS-B16 scintillator and 10-m-long optic cable are tau(0.5) = 1.13 and 1.94 ns. The detector can be used for monitoring radiation of small-sized pulsed accelerators. The shape of the bremsstrahlung pulse from the ARSA accelerator has been recorded by means of the FOD.