Emission spectra characteristics and selective filtering studies of organic scintillators

The emission spectra of a matrix of NE111 doped with benzophenone, acetophenone, and piperidine each at concentrations of 0, 1, 2, 5, and 10% were measured using low-energy dc-electron excitation. Absorption spectra covering the region of 300-500 nm were also measured. Based on the systematics observed in the above spectra, response measurements were performed wherein the emission spectrum incident on a detector was filtered by selected narrow band (<=10 nm) filters. The scintillator fluorescence was excited by 0.2 ns pulses of X-rays (<=2 keV) produced in a laser plasma with the LPARL Nd:glass laser facility. Fast time response measurements were performed using an S20 streak camera. In addition, the ratio of the integral of the emitted fluorescence in the first 8 ns to the integral out to 1 s, was determined as a function of emission wavelength. In neither of these experiments was it possible to produce relevant changes in the scintillator response by the introduction of filters. (Auth.)