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Alfredo Davide Ferella

Publications and source records attributed to Alfredo Davide Ferella.

4 recordsLinked to original sources

An LNGS Mobile Neutron Detector (ALMOND): Mapping Ambient Neutron Background of Gran Sasso National Laboratory

In deep underground laboratories, environmental neutrons, which are produced at the cavern walls, introduce a source of background to rare event searches. The flux and spectrum of the ambient neutrons vary considerably with time and location. Precise knowledge of this background is necessary to devise shielding and veto mechanisms, thereby improving the sensitivity of the neutron-susceptible underground experiments. ALMOND, currently in operation, is a low-flux mobile neutron spectrometer developed for the LNGS underground laboratory to measure the ambient neutron background of the entire facility. In this paper, an overview of the design, construction and calibration of ALMOND is given. Furthermore, the result of the first underground neutron measurement is shown along with an outlook for future measurements and analyses.

physics.ins-det↗

Commissioning of a mobile neutron spectrometer for LNGS

Environmental neutrons are a source of background for rare event searches in underground laboratories. Since the majority of the neutron background comes from the cavern walls due to the intrinsic radioactivity of concrete and rock, the flux is known to be time and location dependent. Therefore, a precise knowledge of the spectrum and of the total flux is needed to devise shielding and veto mechanisms for rare event searches. Here ALMOND (An LNGS Mobile Neutron Detector) is presented. It is a mobile neutron spectrometer, based on capture-gated spectroscopy and comprised of an array of plastic scintillator bars wrapped with gadolinium foils. The detector has been calibrated with Americium-Beryllium source at Karlsruhe Institute of Technology and with an Americium-Boron source and a D-D generator at ENEA Frascati. The results of the neutron calibration with the time of flight method and the D-D generator are shown here, alongside the first results on capture time profile. Moreover, the first results from the neutron background run in Hall A at LNGS are presented.

physics.ins-det↗

ABALONE Photosensors for the IceCube Experiment

The ABALONE Photosensor Technology (U.S. Pat. 9064678) is a modern, scalable technology specifically invented for cost effective mass production, robustness, and high performance. We present the performance of advanced fused silica ABALONE Photosensors, developed specifically for the potential extension of the Ice Cube neutrino experiment, and stress tested for 120 days. The resulting performance makes a significant difference: intrinsic gain in the high 100 million range, total afterpulsing rate of only 0.005 ions per photoelectron, subnanosecond timing resolution, single photon sensitivity, and unique radiopurity and UV sensitivity, thanks to the fused silica components, at no additional cost to the assembly process.

physics.ins-det↗

Dark matter spin determination with directional direct detection experiments

If the dark matter particle has spin 0, only two types of WIMP-nucleon interaction can arise from the non-relativistic reduction of renormalisable single-mediator models for dark matter-quark interactions. Based on this crucial observation, we show that about 100 signal events at next generation directional detection experiments can be enough to enable a $2σ$ rejection of the spin 0 dark matter hypothesis in favour of alternative hypotheses where the dark matter particle has spin 1/2 or 1. In this context directional sensitivity is crucial, since anisotropy patterns in the sphere of nuclear recoil directions depend on the spin of the dark matter particle. For comparison, about 100 signal events are expected in a CF$_4$ detector operating at a pressure of 30 torr with an exposure of approximately 26,000 cubic-meter-detector days for WIMPs of 100 GeV mass and a WIMP-Fluorine scattering cross-section of 0.25 pb. Comparable exposures are within reach of an array of cubic meter time projection chamber detectors.

hep-ph↗