AMS02 results after 4 years of data taking on the International Space Station

The AMS02 experiment is taking data on the International Space Station since May, 19, 2011. This report summarizes the key results published or presented in public conferences using the data collected in the first 4 years of the mission, trying to interpret them in terms of the latest models of Cosmic Ray (CR) propagation. In particular the fluxes of primary CR, like proton, Helium and Carbon, or of secondaries like Lithium and Boron, can be used to constraint the models and compare them with the observed anti-proton flux, to see if hints of Dark Matter (DM) can be identified. The same can be done in the lepton sector by looking at electrons and positrons. In the near future AMS02 will continue the observation of light nuclei, including isotopes like Deuterium, He-3 and He-4, and of anti-nuclei, like anti-Deuterium and anti-Helium, which represent, together with anti-protons and positrons, the golden channels in which to look for eventual Dark Matter or antimatter signals

Begging and parental care in relation to offspring need and condition in the barn swallow (Hirundo rustica)

Parents are selected to maximize their fitness by allocating care among their progeny in relation to the differential reproductive value of offspring. Nestlings have been hypothesized to signal need for parental care reliably through their begging behavior, but offspring condition as reflected by their reproductive value may likewise affect begging and hence provisioning. We assessed the relative importance of need and condition in determining begging behavior and feeding rate of nestling barn swallows (Hirundo rustica) through short-term starvation, a challenge to their immune system with a foreign antigen negatively affecting condition, and brood size manipulation. Food deprivation but not condition or brood size manipulation increased nestling begging rate. Parents fed offspring depending on both need and condition but only when feeding broods that were reduced or of normal size. In enlarged broods, offspring received less food per capita than in reduced broods, and parents did not discriminate among nestlings relative to their need or condition. Thus, nestlings signal their need by increased solicitation. Parents allocate food to offspring dependent on both need and condition, with these effects depending on parental workload as determined by experimental brood size

Results on Multiple Coulomb Scattering from 12 and 20 GeV electrons on Carbon targets

Multiple scattering effects of 12 and 20 GeV electrons on 8 and 20 mm thickness carbon targets have been studied with high-resolution silicon microstrip detectors of the UA9 apparatus at the H8 line at CERN. Comparison of the scattering angle between data and GEANT4 simulation shows excellent agreement in the core of the distributions leaving some residual disagreement in the tails.Comment: 14 pages, 16 figures. Updated to match published versio

The electromagnetic calorimeter of the AMS-02 experiment

The electromagnetic calorimeter (ECAL) of the AMS-02 experiment is a 3-dimensional sampling calorimeter, made of lead and scintillating fibers. The detector allows for a high granularity, with 18 samplings in the longitudinal direction, and 72 sampling in the lateral direction. The ECAL primary goal is to measure the energy of cosmic rays up to few TeV, however, thanks to the fine grained structure, it can also provide the separation of positrons from protons, in the GeV to TeV region. A direct measurement of high energy photons with accurate energy and direction determination can also be provided.Comment: Proceedings of SF2A conference 201

The FDM readout system for the TES bolometers of the SWIPE instrument on the balloon-borne LSPE experiment

We present the design and first tests of a prototype readout for the SWIPE instrument onboard the LSPE balloon-borne experiment. LSPE aims at measuring the linear polarization of the Cosmic Microwave Background (CMB) at large angular scales, to find the imprint of inflation on the B-mode CMB polarization. The SWIPE instrument hosts two focal planes hosting 163 TES Au/Mo spiderweb bolometers each, cooled at 0.3 K for the detection of microwave frequencies of 140, 220 and 240 GHz. To read all the detectors, a 16 channel frequency domain multiplexing readout system has been devised, consisting of LC resonators composed of custom Nb superconducting inductors and commercial SMD capacitors. A set-up consisting of 14 LC resonators shows that we can accommodate 16 channels in the frequency range between 200 kHz and 1.6 MHz, since the necessary line-widths can be achieved. A preliminary firmware for the generation and read-out of the biasing frequency comb is also discussed

Design and construction of new central and forward muon counters for CDF II

New scintillation counters have been designed and constructed for the CDF upgrade in order to complete the muon coverage of the central CDF detector, and to extend this coverage to larger pseudorapidity. A novel light collection technique using wavelength shifting fibers, together with high quality polystyrene-based scintillator resulted in compact counters with good and stable light collection efficiency over lengths extending up to 320 cm. Their design and construction is described and results of their initial performance are reported.Comment: 20 pages, 15 figure