[en] In the fully stripped cosmic rays, the electron capture decay of ⁵⁴Mn (τ_1/2=312d) is strongly suppressed. In this situation the β^- decay channel dominates; however, this half-life has never been measured in the laboratory. Some lower limits have been placed on it previously. Using the cosmic-ray data from the Ulysses spacecraft high-energy telescope (HET) and a self-consistent model of the galactic transport of cosmic rays, this partial lifetime can be determined. The best-fit β^- partial decay lifetime is dependent on the interstellar gas density, but is constrained to be between 1 endash 2x10⁶ yr. This is consistent with, but much more restrictive than, earlier limits placed on the lifetime (approx-gt 3x10⁴ and approx-gt 2.95x10⁵ yr) from direct and indirect methods, respectively. This determination using the cosmic-ray data requires laboratory verification for which there appears to be interest. copyright 1996 The American Physical Society

[en] Calculations of the width of avoided crossings (pseudocrossings) in the quadratic Zeeman spectrum of hydrogen are presented. By using a noncompact Lie group that reflects the approximate symmetry of the Hamiltonian, semiquantitative agreement with accurate calculations is obtained over a wide dynamic range of splittings

[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] We present a new measurement of atmospheric muons made during an ascent of the High Energy Antimatter Telescope balloon experiment. The muon charge ratio μ⁺/μ^- as a function of atmospheric depth in the momentum interval 0.3-0.9 GeV/c is presented. The differential μ^- intensities in the 0.3-50 GeV/c range and for atmospheric depths between 4-960 g/cm² are also presented. We compare these results with other measurements and model predictions. We find that our charge ratio is ∼1.1 for all atmospheric depths and is consistent, within errors, with other measurements and the model predictions. We find that our measured μ^- intensities are also consistent with other measurements, and with the model predictions, except at shallow atmospheric depths

[en] We report new limits on cosmic neutrino fluxes from the test flight of the Antarctic Impulsive Transient Antenna (ANITA) experiment, which completed an 18.4 day flight of a prototype long-duration balloon payload, called ANITA-lite, in early 2004. We search for impulsive events that could be associated with ultrahigh energy neutrino interactions in the ice and derive limits that constrain several models for ultrahigh energy neutrino fluxes and rule out the long-standing Z-burst model

[en] This article presents the design of the Radio Neutrino Observatory Greenland (RNO-G) and discusses its scientific prospects. Using an array of radio sensors, RNO-G seeks to measure neutrinos above 10 PeV by exploiting the Askaryan effect in neutrino-induced cascades in ice. We discuss the experimental considerations that drive the design of RNO-G, present first measurements of the hardware that is to be deployed and discuss the projected sensitivity of the instrument. RNO-G will be the first production-scale radio detector for in-ice neutrino signals. (paper)

[en] The Cosmic Ray Energetics And Mass (CREAM) experiment was designed and constructed to push spectral measurements of individual cosmic-ray nuclei from H to Fe to energies approaching the 'knee' in a series of balloon flights. A cumulative exposure of 70 days was achieved during two circumpolar flights in Antarctica in 2005 and 2006. Direct measurements at the top of the atmosphere allow event-by-event determination of the incident cosmic-ray particle charge and energy. The objective is to investigate whether and how the knee structure is related to the mechanisms of particle acceleration, propagation, and confinement. The recovered payload is being refurbished for its third flight, which is scheduled for launch in December 2007. The combination of sophisticated particle detectors and long duration balloon flight capabilities now promise high quality measurements over an energy range that was not previously accessible

[en] The use of detectors based on plastic scintillator with photomultiplier tubes (PMTs) is common in cosmic-ray experiments to differentiate particle charges. However, in the presence of a calorimeter, the standard method of pulse charge integration over a time longer than a PMT pulse is hampered by abundant albedo particles. The Cosmic Ray Energetics and Mass (CREAM) instrument surmounts this problem by measuring the peak voltage of the PMT pulse within ∼3ns of a threshold crossing in the readout of a timing charge detector (TCD). The design and performance of the TCD is presented. A charge resolution of 0.2e for oxygen and 0.4e for iron is obtained for through-going cosmic-ray particles.

[en] During its second Antarctic flight, the CREAM (Cosmic Ray Energetics And Mass) balloon experiment collected data for 28 days, measuring the charge and the energy of cosmic rays (CR) with a redundant system of particle identification and an imaging thin ionization calorimeter. Preliminary direct measurements of the absolute intensities of individual CR nuclei are reported in the elemental range from carbon to iron at very high energy.

[en] The Cosmic Ray Energetics And Mass (CREAM) experiment is designed to investigate high-energy (10¹²∼10¹⁵ eV) cosmic rays over the elemental range from hydrogen to iron (1≤Z≤26), through a series of long balloon flights. Originally planned to be flown on the first of the new Ultra Long Duration Balloons (ULDB) being developed by NASA, the CREAM instrument was launched as a Long Duration Balloon (LDB) payload from McMurdo Station, Antarctica on December 16, 2004 and flew for a record-breaking 42 days. A second CREAM flight one year later lasted 28 days. The CREAM design is unique in that it obtains two independent energy measurements using a tungsten/scintillator sampling calorimeter and a Transition Radiation Detector (TRD) with up to four independent charge measurements of incident particles using a novel Timing-based scintillator Charge Detector (TCD), a plastic Cherenkov Detector (CD), scintillating fiber hodoscopes, and a Silicon Charge Detector (SCD). The energy limits are determined by trigger efficiency and telemetry bandwidth at the low end and by statistics at the high end