Scintillation particle detection based on microfluidics

Abstract

a b s t r a c t A novel type of particle detector based on scintillation, with precise spatial resolution and high radiation hardness, is being studied. It consists of a single microfluidic channel filled with a liquid scintillator and is designed to define an array of scintillating waveguides each independently coupled to a photodetector. Prototype detectors built using an SU-8 epoxy resin have been tested with electrons from a radioactive source. The experimental results show a light yield compatible with the theoretical expectations and confirm the validity of the approach.

SU-8 as a Material for Microfabricated Particle Physics Detectors

“…When used in a detector they make for an active medium with virtually no radiation aging, as the scintillator can be easily renewed by recirculating new liquid in the detector. Recent advancements in the field of liquid scintillation detectors were made with the introduction of microfluidic scintillation detectors [14]. Such device consists in a single microfluidic channel with a serpentine geometry, patterned by SU-8 photolithography, in which a scintillating liquid is injected.…”

“…The high aspect ratio capabilities of SU-8 allowed to obtain narrow channel walls over a depth of 200 µm (Figure 4b), enabling a high fill-factor while keeping enough liquid thickness to produce and guide a light pulse with an efficacy comparable to small diameter scintillating fibres [15]. Thanks to the single-channel configuration, it is relatively easy to replace the liquid scintillator in the device, resulting in an increased radiation resistance.…”

“…The β autoradiography is a technique used in pharmacology and genetics to image the distribution of molecules labelled with 3 H or 14 C radioactive markers in biological tissues, by detecting the electrons emitted by β decay. Traditionally emulsion films or phosphor screens are used for the image production, but are limited by their exposition time and do not allow any adjustment of the image during acquisition.…”

“…A similar application is liquid scintillation counting, in which biological fluids are mixed with a scintillator cocktail to determine the presence of 3 H or 14 C marked molecules by detecting the optical photons emitted by scintillation. Thanks to their reduced internal volume, scintillation detectors based on microfluidic channels could provide a straightforward method for performing this kind of analysis on small volume liquid samples with high sensitivity.…”

Micro-channel cooling for high-energy physics particle detectors and electronics

“…On the other hand, thin and light microfluidic devices in silicon are in development for bio-chemical applications [3], but the typical values of the flow rate and pressure are much lower with respect to what is required for detector cooling applications. In addition, the presence of a low temperature fluid and of a high radiation level is unique to the application in HEP detectors [4]. Preliminary studies of two-phase flow in silicon microchannels have already shown the potential advantages of such systems with respect to standard cooling of particle detectors [5].…”