[en] Results from tests characterizing the performance and radiation hardness of the HS9008RH flash analog to digital converter (FADC) are presented. These tests were performed primarily to evaluate the suitability of this device for use in the GEM Central Tracker at the SSC experiment. Basic performance characteristics and susceptibility of these characteristics to radiation were examined. Performance test results indicate that the device integral nonlinearity is sampling rate dependent and worsens rapidly above rate of 15 megasamples per second (MSPS). No degradation in performance of the device was observed after its exposure of up to 81 Mrad of 1.25 MeV γ radiation from a ⁶⁰Co source. Exposure of the device to a reactor fast neutron fluence (E > 100keV) of 5 x 10¹⁴/cm² resulted in no significant observed performance degradation as well

[en] GRACE is a five element arra of air Cherenkov light collectors designed to measure the energy of primary cosmic rays and operate on the terrain over the deep underground muon tracking detector. MACRO, at the Gran Sasso National Laboratory in Italy. The coincidence detection of air Cherenkov photons and deep underground muons produced in extensive air showers will allow an association of the primary energy with the muon events observed underground. We present detailed Monte Carlo calculations of the expected signal, a complete description of our detectors and test results of their initial deployment at the University of Michigan Peach Mountain Observatory. (orig.)

[en] We present a new measurement of the cosmic-ray positron fraction at energies between 5 and 15 GeV with the balloon-borne HEAT-p-bar instrument in the spring of 2000. The data presented here are compatible with our previous measurements, obtained with a different instrument. The combined data from the three HEAT flights indicate a small positron flux of nonstandard origin above 5 GeV. We compare the new measurement with earlier data obtained with the HEAT-e^± instrument, during the opposite epoch of the solar cycle, and conclude that our measurements do not support predictions of charge sign dependent solar modulation of the positron abundance at 5 GeV

[en] Results from tests characterizing the performance and radiation hardness of the HS9008RH flash analog to digital convertor (FADC) are presented. These tests were performed primarily to evaluate the suitability of this device for use in the GEM Central Tracker at the SSC experiment. Basic performance characteristics and susceptibility of these characteristics to radiation were examined. Performance test results indicate that the device integral nonlinearity is sampling rate dependent and worsens rapidly above a sampling rate of 15 megasamples per second (MSPS). No degradation in performance of the device was observed after its exposure of up to 81 Mrad of 1.25 MeV γ radiation from a ⁶⁰Co source. Exposure of the device to a reactor fast neutron fluence (E>100 keV) of 5x10¹⁴/cm² resulted in no significant observed performance degradation as well. ((orig.))

[en] The Cosmic Ray Energetics And Mass (CREAM) mission is planned for launch in 2015 to the International Space Station (ISS) to research high-energy cosmic rays. Its aim is to understand the acceleration and propagation mechanism of high-energy cosmic rays by measuring their compositions. The Top Counting Detector and Bottom Counting Detector (T/BCD) were built to discriminate electrons from protons by using the difference in cascade shapes between electromagnetic and hadronic showers. The T/BCD provides a redundant instrument trigger in flight as well as a low-energy calibration trigger for ground testing. Each detector consists of a plastic scintillator and two-dimensional silicon photodiode array with readout electronics. The TCD is located between the carbon target and the calorimeter, and the BCD is located below the calorimeter. In this paper, we present the design, assembly, and performance of the T/BCD

[en] Primary cosmic-ray elemental spectra have been measured with the balloon-borne Cosmic Ray Energetics And Mass (CREAM) experiment since 2004. The third CREAM payload (CREAM-III) flew for 29 days during the 2007–2008 Antarctic season. Energies of incident particles above 1 TeV are measured with a calorimeter. Individual elements are clearly separated with a charge resolution of ∼0.12 e (in charge units) and ∼0.14 e for protons and helium nuclei, respectively, using two layers of silicon charge detectors. The measured proton and helium energy spectra at the top of the atmosphere are harder than other existing measurements at a few tens of GeV. The relative abundance of protons to helium nuclei is 9.53 ± 0.03 for the range of 1 TeV/n to 63 TeV/n. This ratio is considerably smaller than other measurements at a few tens of GeV/n. The spectra become softer above ∼20 TeV. However, our statistical uncertainties are large at these energies and more data are needed.

[en] The Cosmic Ray Electron Synchrotron Telescope (CREST) high-altitude balloon experiment is a pathfinding effort to detect for the first time multi-TeV cosmic-ray electrons. Such would be the markers of nearby cosmic accelerators, as energetic electrons from distant Galactic sources are expected to be depleted by radiative losses during interstellar transport. Electrons will be detected indirectly by the characteristic signature of their geomagnetic synchrotron losses, in the form of a burst of coaligned x-ray photons intersecting the plane of the instrument. Since the primary electron itself need not traverse the payload, an effective detection area is achieved that is several times the nominal 6.4 m² instrument. The payload is composed of an array of 1024 BaF2 crystals surrounded by a set of veto scintillator detectors. A long-duration balloon flight in Antarctica is planned for the 2011-12 season.

[en] The first MACRO lower supermodule has been sensitive to antineutrinos from stellar gravitational collapse since spring 1989. The results with the 44 tonnes of liquid scintillator which have been instrumented to search for stellar gravitational collapse are discussed here. (orig.)

[en] The characteristics of MACRO are reviewed. Results on a search for gravitational stellar collapse and on UHE-astronomy are presented. The MACRO upgrading is discussed. (orig.)

[en] We present the analysis of multiple-muon events collected with one supermodule (1013 h live time) and two supermodules (1195 h live time) of the MACRO detector at Gran Sasso, Italy. Multimuon rates are shown to be sensitive to primary-cosmic-ray energies between ∼50 TeV and several thousand TeV. Experimental data are compared with the expected rates from two composition models: a light (i.e., proton-rich) and a heavy (i.e., Fe-rich) composition. The predictions are based on a Monte Carlo simulation of the hadronic interactions of cosmic-ray nuclei, followed by a detailed tracking of the muons through the rock and the experimental apparatus. The results show good sensitivity of the MACRO detector to primary composition. The data exhibit a preference towards the light composition model