Efficient, high resolution, position sensitive liquid argon detectors

This project will develop position-sensitive liquid argon detectors for a range of nuclear physics experiments. A particular need is for large area detectors with good energy, spatial and time resolution. Originally developed for calorimetry and the detection of neutrinos, weakly interacting massive particles and neutrinoless double beta decay, liquefied noble gas (LNG) detectors have several advantages over other technologies. LNG detectors provide a highly cost effective method of achieving large detector masses. Because the detectors can be made extremely thick, they are highly efficient. With the addition of charge readout, these detectors can provide excellent energy resolution, exceeding that of sodium iodide. Since the scintillation material is a liquid, these detectors are extremely radiation resistant. The differing response of the scintillation light due to neutrons and gammas allows for exceptional pulse shape and charge to light ratio discrimination, and the sharp leading edge of the pulses makes fast nanosecond timing resolution possible. Adelphi Technology, working with Yale University, has already built, constructed and operated large volume 0.2% xenon-doped liquid argon (LAr(Xe)) detectors for industrial portal screening applications. By introducing electrodes into the liquid argon and operating the detector as a time projection chamber, the investigators propose to provide energy resolutions approaching 2% and tracking ability with millimeter spatial resolution, in addition to the advantages already demonstrated. Phase I of the proposed project will include the design and implementation of charge readout in a LAr(Xe) detector, taking advantage of existing detectors and infrastructure. Phase II would include the construction of a full position-sensitive tracking detector. Commercial Applications and Other Benefits: The proposed detector platform presents a unique and broad range of capabilities, including high efficiency, excellent time, spatial and energy resolution, and it can be readily expanded to large scales. The resulting detector will provide excellent particle tracking and energy resolution when operated in a time projection chamber mode with both light and charge readout. Alternately, the detector could be operated with only light readout, for high-rate data acquisition and nanosecond timing. Such a detector could also be built with a thin window to allow rare ion implantation into the liquid argon for FRIB applications. Importantly, a layered array of detector planes could be built to create a medical imaging detector for nuclear medicine that could measure the position and direction of gammas from a patient, dramatically increasing imaging performance and reducing patient dose.