Light Collection R&D for SBND and DUNE

We are developing a new light detection system that employs light guides. In liquid argon, scintillation light is produced when charged particles in the event produce excimers that proceed to radiate 128 nm ultraviolet (UV) photons. The UV light must be shifted to the visible before detection. A coating is applied to acrylic bars with a matching index of refraction. This shifts the light to the blue, which is then captured and guided to the end where silicon photomultipliers read out. In the above photograph, a UV flashlight shines on the center of the lightguide. The glowing ends show the visible light that is guided. The image below illustrates how the lightguide works.

Our new system can replace the MicroBooNE-style systems that are commonly used in LArTPCs. A first major study of the system will occur in SBND (the Short Baseline Neutrino Detector), formerly known as LAr1ND. This experiment also act as a near detector for the MicroBooNE experiment, as well as make cross section measurements. Our system is under consideration for DUNE (Deep Underground Neutrino Detector), and a set of lightguides will be run in protoDUNE, the prototype experiment at CERN.

We originated the concept of lightguide detectors for liquid argon. Please read our latest paper here which is submitted to JINST.