Noble-liquid detectors are among the most promising tools for current and future searches for physics beyond the Standard Model. We present two new detection concepts and experimental results - with potential applications in such experiments: the bubble-assisted Liquid Hole Multiplier (LHM) and the cryogenic Gaseous Photo-Multiplier (GPM). The first is a “local dual-phase” (liquid-gas) detection element in which a gas bubble induced in the liquid is supported underneath a “hole- electrode” (e.g. a Gas Electron Multiplier (GEM) or a Thick-GEM (THGEM)) immersed within the noble liquid. Radiation-induced ionization electrons and scintillation-induced photoelectrons extracted from a CsI-coated LHM surface, drift through the electrode's holes; they induce electroluminescence in the bubble, with tens of photons emitted per drifting electron. Such elements can provide light signals detectable with photo-sensors, e.g. with GPMs.

We will present LHM-prototype results in liquid xenon, demonstrating the stability of this new concept, its energy resolution and timing properties. We will also present recent results of a cascaded-THGEM GPM, with a UV CsI photocathode, coupled to a dual-phase xenon Time Projection Chamber (TPC). Its merits will be discussed in the context of future applications for rare-event searches and as a readout element for the LHM detector.