We discuss recent advances in the development of cryogenic gaseousphotomultipliers (GPM), for possible use in dark matter and other rare-eventsearches using noble-liquid targets. We present results from a 10 cm diameterGPM coupled to a dual-phase liquid xenon (LXe) TPC, demonstrating - for thefirst time - the feasibility of recording both primary ("S1") and secondary("S2") scintillation signals. The detector comprised a triple Thick GasElectron Multiplier (THGEM) structure with cesium iodide photocathode on thefirst element; it was shown to operate stably at 180 K with gains above 10^5,providing high single-photon detection efficiency even in the presence of largealpha particle-induced S2 signals comprising thousands of photoelectrons. S1scintillation signals were recorded with a time resolution of 1.2 ns (RMS). Theenergy resolution ({\sigma}/E) for S2 electroluminescence of 5.5 MeV alphaparticles was ~9%, which is comparable to that obtained in the XENON100 TPCwith PMTs. The results are discussed within the context of potential GPMdeployment in future multi-ton noble-liquid detectors.
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