The spreading of the invasive sacred ibis in Italy

The spreading of invasive species in new continents can vary from slow and limited diffusion to fast colonisations over vast new areas. We studied the sacred ibis Threskiornis aethiopicus along a 31-year period, from 1989 to 2019, with particular attention to the first area of release in NW Italy. We collected data on species distribution through observations by citizen science projects, population density by transects with distance method, breeding censuses at colonies, and post breeding censuses at roosts. The birds counted at winter roosts in NW Italy increased from a few tens up to 10,880 individuals in 2019. Sacred ibises started breeding in 1989, with a single nest in north-western Italy. The number of breeders remained very low until 2006, when both overwintering and breeding sacred ibises started to increase exponentially and expand their range throughout northern Italy with isolated breeding cases in central Italy. In 2019, the number of nests had increased to 1249 nests in 31 colonies. In NW Italy, the density of foraging birds averaged 3.9 ind./km2 in winter and 1.5 ind./km2 in the breeding period, with a mean size of the foraging groups of 8.9 and 2.1 birds respectively. Direct field observations and species distribution models (SDM) showed that foraging habitats were mainly rice fields and wetlands. A SDM applied to the whole Italian peninsula plus Sardinia and Sicily showed that the variables best related to the SDM were land class (rice fields and wetlands), altitude, and the temperature seasonality. The areas favourable for species expansion encompass all the plains of Northern Italy, and several areas of Tuscany, Latium, Sardinia, and Apulia

The ASTAROTH project

The most discussed topic in direct search for dark matter is arguably the verification of the DAMA claim. In fact, the observed annual modulation of the signal rate in an array of NaI(Tl) detectors can be interpreted as the awaited signature of dark matter interaction. Several experimental groups are currently engaged in the attempt to verify such a game-changing claim with the same target material. However, all present-day designs are based on a light readout via Photomultiplier Tubes, whose high noise makes it challenging to achieve a low background in the 1-6 keV energy region of the signal. Even harder it would be to break below 1 keV energy threshold, where a large fraction of the signal potentially awaits to be uncovered. ASTAROTH is an R\&D project to overcome these limitations by using Silicon Photomultipliers (SiPM) matrices to collect scintillation light from NaI(Tl). The all-active design based on cubic crystals is operating in the 87-150 K temperature range where SiPM noise can be even a hundred times lower with respect to PMTs. The cryostat was developed following an innovative design and is based on a copper chamber immersed in a liquid argon bath that can be instrumented as a veto detector. We have characterized separately the crystal and the SiPM response at low temperature and we have proceeded to the first operation of a NaI(Tl) crystal read by SiPM in cryogeny.Comment: proceedings of the LRT 2022 conferenc

Mechanical characterization of the tie rods for the ATLAS B0 model coil

The ATLAS Barrel Toroid (BT) consists of 8 superconducting coils of 25 m length and 5 m width. Each coil is equipped with eight titanium alloy tie rods acting as support for the magnetic forces, the intensity of which will be up to 180 t for the most loaded one. The B0 model coil is about 1/3 length scale of the BT, equipped with three tie rods. In order to simulate the behavior of the coil supports, a test facility has been built to test individual tie rods at cryogenic temperature. The initial aim was to verify the amount of stick and slip, the possibility of it occurring during the excitation and the flexion of the support at the anchoring point on the magnet. This was achieved by inducing in the support the same movements foreseen during the cool-down and the excitation of the magnet and loading with the same forces. Following the evolution of the project it was decided to test the tie rod simply in traction at 250 tons, without displacements. In this paper the test facility is described and the data of the tests of the B0 tie rods are reported. 3 Refs. --- 22 --- A

AC Losses Measurement of the DISCORAP Model Dipole Magnet for the SIS 300 Synchrotron at FAIR

Considerable attention has been paid in the last years to the development of fast-cycled superconducting magnets for future accelerators, leading to the design and construction by INFN and GSI of a 3.8-m-long prototype of a 4.5 T, 1 T/s, dipole magnet, for the SIS300 synchrotron of the FAIR facility (Darmstadt, Germany). This ramp-rate is 20-100 times higher than the one used in other superconducting synchrotrons like RHIC or LHC. Being operated at rather large dI/dt, these magnets are subjected to a wide spectrum of ac dissipation, taking place in the superconductor as well as in the metallic components of the mechanical structure, requiring the development of specialized superconducting cables and a careful consideration of the other aspects of the structural design. Between July and September 2012, the dipole magnet prototype has been subjected to a test at LASA laboratory (INFN Milan, Italy), during which it was successfully operated at current ramp rates as high as 0.7 T/s (the power supply limit). In this paper, we describe the V-I apparatus used to assess the dissipations within the magnet during the ac regime, the measurement results, and their comparison with the values expected from the design and on the basis of superconducting cable qualification results