INDIUM DISILICATE, A NEW FAST SCINTILLATOR

We describe the luminescence and scintillation of indium disilicate (I n2Si2O7), an inorganic scintillator containing a large amount of In-11 5. The maximum fluorescence occurs in the near UV range at 335 nm with a complicated decay including a fast component of less than 100 ns an d a long one of more than a microsecond. Room temperature emission int ensity was quite weak while the quantum efficiency became reasonably g ood at cryogenic temperature. Scintillation was measured using cr-part icles of 6.09 MeV and 8.785 MeV from 300 to 4 K. A maximum of intensit y is observed at 50 K. A fast component (tau similar or equal to 20 ns ) with a constant intensity superimposes to a slow one of which the in tensity has a maximum at 50 K and for which the decay constant rises a s the temperature decreases.