Scintillation detectors based on silicon microfluidic channels

Microfluidic channels obtained by SU-8 photolithography and filled with liquid scintillators were recently demonstrated to be an interesting technology for the implementation of novel particle detectors.The main advantages of this approach are the intrinsic radiationresistance resulting from the simple microfluidic circulation of theactive medium and the possibility to manufacture devices with highspatial resolution and low material budget using microfabricationtechniques.Here we explore a different technological implementation of thisconcept, reporting on scintillating detectors based on siliconmicrofluidic channels. A process for manufacturing microfluidicdevices on silicon substrates, featuring microchannel arrays suitablefor light guiding, was developed. Such process can be in principlecombined with standard CMOS processing and lead to a tight integrationwith the readout photodetectors and electronics in the future.Several devices were manufactured, featuring microchannel geometriesdiffering in depth, width and pitch. A preliminary characterizationof the prototypes was performed by means of a photomultiplier tubecoupled to the microchannel ends, in order to detect the scintillationlight produced upon irradiation with beta particles from a90Sr source. The photoelectron spectra thusobtained were fitted with the expected output function in order toextract the light yield.