Initial results from the Caltech/DRSI balloon-borne isotope experiment

The Caltech/DSRI balloonborne High Energy Isotope Spectrometer Telescope (HEIST) was flown successfully from Palestine, Texas on 14 May, 1984. The experiment was designed to measure cosmic ray isotopic abundances from neon through iron, with incident particle energies from approx. 1.5 to 2.2 GeV/nucleon depending on the element. During approximately 38 hours at float altitude, 100,000 events were recorded with Z or = 6 and incident energies approx. 1.5 GeV/nucleon. We present results from the ongoing data analysis associated with both the preflight Bevalac calibration and the flight data

Study of the April 20, 2007 CME-Comet Interaction Event with an MHD Model

This study examines the tail disconnection event on April 20, 2007 on comet 2P/Encke, caused by a coronal mass ejection (CME) at a heliocentric distance of 0.34 AU. During their interaction, both the CME and the comet are visible with high temporal and spatial resolution by the STEREO-A spacecraft. Previously, only current sheets or shocks have been accepted as possible reasons for comet tail disconnections, so it is puzzling that the CME caused this event. The MHD simulation presented in this work reproduces the interaction process and demonstrates how the CME triggered a tail disconnection in the April 20 event. It is found that the CME disturbs the comet with a combination of a $180^\circ$ sudden rotation of the interplanetary magnetic field (IMF), followed by a $90^\circ$ gradual rotation. Such an interpretation applies our understanding of solar wind-comet interactions to determine the \textit{in situ} IMF orientation of the CME encountering Encke.Comment: 13 pages, 3 figures, accepted by the ApJ Letter

Initial Results from the Caltech/DSRI Balloon-Borne Isotope Experiment

The Caltech/DSRI balloonborne High Energy Isotope Spectrometer Telescope (HEIST) was flown successfully from Palestine, Texas on 14 May, 1984. The experiment was designed to measure cosmic ray isotopic abundances from neon through iron, with incident particle energies from ~1.5 to 2.2 GeV/nucleon depending on the element. During ~38 hours at float altitude, > 10^5 events were recorded with Z ≥ 6 and incident energies ≳ 1.5 GeV/nucleon. We present results from the ongoing data analysis associated with both the preflight Bevalac calibration and the flight data

A Cerenkov - ΔE/ΔX Experiment for Measuring Cosmic-Ray Isotopes from Neon Through Iron

A ballon-borne cosmic-ray experiment has been constructed to measure cosmic-ray isotope masses, It employs a pair of Cerenkov counters and a NaI scintillator stack to determine changes in ΔE in energy and Δγ in Lorentz factor for a traversing or stopping particle. Mass M = ΔE/Δγ. Mass resolution better than 0.3 a.m.u. is expected for incident elements from neon through iron, with incident Lorentz gammas ranging from 2.4 to 3.1, depending on the element. Using data obtained at the Berkeley Bevalac, the mass resolution ∂M ≈ 2 a.m.u., measured for ^(55)Mn ions with incident γ = 2.5

The Otterbein Miscellany - May 1967

https://digitalcommons.otterbein.edu/miscellany/1008/thumbnail.jp

Nova light curves from the Solar Mass Ejection Imager (SMEI) - II. The extended catalogue

We present the results from observing nine Galactic novae in eruption with the Solar Mass Ejection Imager (SMEI) between 2004 and 2009. While many of these novae reached peak magnitudes that were either at or approaching the detection limits of SMEI, we were still able to produce light curves that in many cases contained more data at and around the initial rise, peak, and decline than those found in other variable star catalogs. For each nova, we obtained a peak time, maximum magnitude, and for several an estimate of the decline time (t2). Interestingly, although of lower quality than those found in Hounsell et al. (2010a), two of the light curves may indicate the presence of a pre-maximum halt. In addition the high cadence of the SMEI instrument has allowed the detection of low amplitude variations in at least one of the nova light curves

Scientific Hybrid Realtiy Environments (SHyRE): Bringing Field Work into the Laboratory

The use of analog environments in preparing for future planetary surface exploration is key in ensuring we both understand the processes shaping other planetary surfaces as well as develop the technology, systems, and concepts of operations necessary to operate in these geologic environments. While conducting fieldwork and testing technology in relevant terrestrial field environments is crucial in this development, it is often the case that operational testing requires a time-intensive iterative process that is hampered by the rigorous conditions (e.g. terrain, weather, location, etc.) found in most field environments. Additionally, field deployments can be costly and must be scheduled months in advance, therefore limiting the testing opportunities required to investigate and compare science operational concepts to only once or twice per year

Moon Shadow by Cosmic Rays under the Influence of Geomagnetic Field and Search for Antiprotons at Multi-TeV Energies

We have observed the shadowing of galactic cosmic ray flux in the direction of the moon, the so-called moon shadow, using the Tibet-III air shower array operating at Yangbajing (4300 m a.s.l.) in Tibet since 1999. Almost all cosmic rays are positively charged; for that reason, they are bent by the geomagnetic field, thereby shifting the moon shadow westward. The cosmic rays will also produce an additional shadow in the eastward direction of the moon if cosmic rays contain negatively charged particles, such as antiprotons, with some fraction. We selected 1.5 x10^{10} air shower events with energy beyond about 3 TeV from the dataset observed by the Tibet-III air shower array and detected the moon shadow at $\sim 40 \sigma$ level. The center of the moon was detected in the direction away from the apparent center of the moon by 0.23$^\circ$ to the west. Based on these data and a full Monte Carlo simulation, we searched for the existence of the shadow produced by antiprotons at the multi-TeV energy region. No evidence of the existence of antiprotons was found in this energy region. We obtained the 90% confidence level upper limit of the flux ratio of antiprotons to protons as 7% at multi-TeV energies.Comment: 13pages,4figures; Accepted for publication in Astroparticle Physic