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Accepted: 2015-02-11, 資料番号: SA1150127000

A direct $Q_{EC}$-value measurement of the superallowed $��^+$ emitter $^{22}$Mg was performed using TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN). The direct ground-state to ground-state atomic mass difference between $^{22}$Mg and $^{22}$Na was determined to be $Q_{EC}=4781.40(22)$~keV, representing the most precise single measurement of this quantity to date. In a continued push towards calculating superallowed isospin-symmetry-breaking (ISB) corrections from first principles, ab-initio shell-model calculations of the $A=22$ IMME are also presented for the first time using the valence-space in-medium similarity renormalization group formalism. With particular starting two- and three-nucleon forces, this approach demonstrates a level of agreement with the experimental data that suggests reliable ab-initio calculations of superallowed ISB corrections are now possible.

We study the backscattering of solar wind protons from the lunar regolith using the Solar Wind Monitor of the Sub keV Atom Reflecting Analyzer on Chandrayaan 1. Our study focuses on the component of the backscattered particles that leaves the regolith with a positive charge. We find that the fraction of the incident solar wind protons that backscatter as protons i.e. the proton backscattering efficiency has an exponential dependence on the solar wind speed that varies from 0.01 to 1 for solar wind speeds of 250 km/s to 550 km/s. We also study the speed distribution of the backscattered protons in the fast (550 km/s) solar wind case and find both a peak speed at 80 of the solar wind speed and a spread of 85 km/s. The observed flux variations and speed distribution of the backscattered protons can be explained by a speed dependent charge state of the backscattered particles.

Accepted: 2014-01-12, 資料番号: SA1140003000

The formation of electric potential over lunar magnetized regions is essential for understanding fundamental lunar science, for understanding the lunar environment, and for planning human exploration on the Moon. A large positive electric potential was predicted and detected from single point measurements. Here, we demonstrate a remote imaging technique of electric potential mapping at the lunar surface, making use of a new concept involving hydrogen neutral atoms derived from solar wind. We apply the technique to a lunar magnetized region using an existing dataset of the neutral atom energy spectrometer SARA/CENA on Chandrayaan-1. Electrostatic potential larger than +135 V inside the Gerasimovic anomaly is confirmed. This structure is found spreading all over the magnetized region. The widely spread electric potential can influence the local plasma and dust environment near the magnetic anomaly., 19 pages, 3 figures

We report the first observation of protons in the near (100--200 km from surface) and deeper (near anti-subsolar point) lunar plasma wake when the interplanetary magnetic field (IMF) and solar wind velocity ($v_{sw}$) are parallel (aligned flow, angle between IMF and ($v_{sw} \le 10^\circ$). More than 98% of the observations during aligned flow condition showed the presence of protons in the wake. These observations are obtained by the SWIM sensor of the SARA experiment on Chandrayaan-1. The observation cannot be explained by the conventional fluid models for aligned flow. Back-tracing of the observed protons suggests that their source is the solar wind. The larger gyro-radii of the wake protons compared to that of solar wind suggest that they were part of the tail of the solar wind velocity distribution function. Such protons could enter the wake due to their large gyro-radii even when the flow is aligned to IMF. However, the wake boundary electric field may also play a role in the entry of the protons in to the wake., Comment: 4 pages, 4 figures

The Sub keV Atom Reflecting Analyzer instrument on board the lunar orbiter Chandrayaan 1 provided a large number of measurements of lunar energetic neutral atoms (ENAs). These ENAs were formerly solar wind ions which were neutralized and backscattered from the lunar surface. The angles under which the ENAs are scattered strongly depend on the solar wind ions' incidence angle which corresponds to the solar zenith angle (SZA). Our large dataset provides us with a complete coverage of the SZA and almost complete coverage of the scattering angles. When combining all available measurements four distinct features are discernible with SZA increase: amplitude decrease less azimuthal uniformity bigger ratio of sunward versus anti sunward flux and shallower scattering. We analyzed more than 290'000 measurements and derived a mathematical description of the features and their dependencies on the SZA. Citation: Schaufelberger A. P. Wurz S. Barabash M. Wieser Y. Futaana M. Holmstrom A. Bhardwaj M. B. Dhanya R. Sridharan and K. Asamura (2011) Scattering function for energetic neutral hydrogen atoms off the lunar surface Geophys. Res. Lett. 38 L22202 doi:10.1029/2011GL049362.

Significant proton fluxes were detected in the near wake region of the Moon by an ion mass spectrometer on board Chandrayaan-1. The energy of these nightside protons is slightly higher than the energy of the solar wind protons. The protons are detected close to the lunar equatorial plane at a $140^{\circ}$ solar zenith angle, i.e., ~50$^{\circ}$ behind the terminator at a height of 100 km. The protons come from just above the local horizon, and move along the magnetic field in the solar wind reference frame. We compared the observed proton flux with the predictions from analytical models of an electrostatic plasma expansion into a vacuum. The observed velocity was higher than the velocity predicted by analytical models by a factor of 2 to 3. The simple analytical models cannot explain the observed ion dynamics along the magnetic field in the vicinity of the Moon., Comment: 28 pages, 7 figures

Der Beitrag beschreibt das interdisziplinare Feld der Sound Studies und ihr Verhaltnis zu den Science & Technology Studies. In einem ersten Schritt diskutiert er den Stand der Entwicklung und resumiert die Diskussion daruber, ob es sich bei den Sound Studies um eine eigenstandige Disziplin, ein interdisziplinares Forschungsfeld ohne stringenten Theorie- und Methodenkanon oder schlicht ein Schlagwort handelt, unter dem sich Arbeiten mit einem gemeinsamen Interesse an der Erforschung akustischer Phanomene versammeln. In einem zweiten Schritt stellt der Beitrag dann zentrale Themen und Konzepte der Sound Studies, wie Soundscape, Transducer oder audile technique, vor.

To assess frequency and severity of patient safety incidents in primary care. Study Design: Cross-sectional survey of health-care professionals in Swiss primary care offices.

The ESA-JAXA BepiColombo mission to Mercury will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric particle dynamics at Mercury as well as their interactions with solar wind, solar radiation, and interplanetary dust. The particle instrument suite SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) is flying in space on-board the BepiColombo Mercury Planetary Orbiter (MPO) and is the only instrument for ion and neutral particle detection aboard the MPO. It comprises four independent sensors: ELENA for neutral particle flow detection, Strofio for neutral gas detection, PICAM for planetary ions observations, and MIPA, mostly for solar wind ion measurements. SERENA is managed by a System Control Unit located inside the ELENA box. In the present paper the scientific goals of this suite are described, and then the four units are detailed, as well as their major features and calibration results. Finally, the SERENA operational activities are shown during the orbital path around Mercury, with also some reference to the activities planned during the long cruise phase.

Experimental Brain Research, 203 (1), ISSN:0014-4819, ISSN:1432-1106