Scintillating plastic optical fibers have increasingly been used as radiation detectors in nuclear and high energy physics research since they were first made in 1965- It is proposed to make fibers which are at least a factor of 2 brighter and thereby improve detection efficiency, spatial resolution and energy resolution- When radiation strikes existing plastic scintillator only the singlet excited states rather than the triplet excited states are used to produce scintillation light- This means only 25% of the deposited energy is available to produce scintillation light- Utilization of phosphorescent molecules should therefore drastically improve the light output- This process has been called triplet harvesting and has been successfully demonstrated in improving the light output of Organic Light Emitting Diodes, OLEDs- The objective of this proposal is to produce a bright scintillating fiber using triplet harvesting and a light output time constant of a few nanoseconds- In addition, an increase in the light containment will be achieved by using a new low refractive index cladding material-
