中文摘要：

The fluorescence quantum yield of bis-MSB,a widely used liquid scintillator wavelength shifter,was measured to study the photon absorption and re-emission processes in a hquid scintillator.The re-emission process affects the photoelectron yield and distribution,especially in a large liquid scintillator detector,thus must be understood to optimize the liquid scintillator for good energy resolution and to precisely simulate the detector with Monte Carlo.In this study,solutions of different bis-MSB concentration were prepared for absorption and fluorescence emission measurements to cover a broad range of wavelengths.Harmane was used as a standard reference to obtain the absolution fluorescence quantum yield.For the first time we measured the fluorescence quantum yield of bis-MSB up to 430 nm as inputs required by Monte Carlo simulation,which is 0.926±0.053 at λex=350 nm.

英文摘要：

The fluorescence quantum yield of bis-MSB, a widely used liquid scintillator wavelength shifter, was measured to study the photon absorption and re-emission processes in a liquid scintillator. The re-emission process affects the photoelectron yield and distribution, especially in a large liquid scintillator detector, thus must be under- stood to optimize the liquid scintillator for good energy resolution and to precisely simulate the detector with Monte Carlo. In this study, solutions of different bis-MSB concentration were prepared for absorption and fluorescence emission measurements to cover a broad range of wavelengths. Harmane was used as a standard reference to obtain the absolution fluorescence quantum yield. For the first time we measured the fluorescence quantum yield of bis-MSB up to 430 nm as inputs required by Monte Carlo simulation, which is 0.926±0.053 at ;λex=350 nm.