15 research outputs found
Low energy high angular resolution neutral atom detection by means of micro-shuttering techniques: the BepiColombo SERENA/ELENA sensor
The neutral sensor ELENA (Emitted Low-Energy Neutral Atoms) for the ESA
cornerstone BepiColombo mission to Mercury (in the SERENA instrument package)
is a new kind of low energetic neutral atoms instrument, mostly devoted to
sputtering emission from planetary surfaces, from E ~20 eV up to E~5 keV,
within 1-D (2x76 deg). ELENA is a Time-of-Flight (TOF) system, based on
oscillating shutter (operated at frequencies up to a 100 kHz) and mechanical
gratings: the incoming neutral particles directly impinge upon the entrance
with a definite timing (START) and arrive to a STOP detector after a flight
path. After a brief dissertation on the achievable scientific objectives, this
paper describes the instrument, with the new design techniques approached for
the neutral particles identification and the nano-techniques used for designing
and manufacturing the nano-structure shuttering core of the ELENA sensor. The
expected count-rates, based on the Hermean environment features, are shortly
presented and discussed. Such design technologies could be fruitfully exported
to different applications for planetary exploration.Comment: 11 page
Molecular pathways associated with the nutritional programming of plant-based diet acceptance in rainbow trout following an early feeding exposure
Dietary protein source or energy levels have no major impact on growth performance, nutrient utilisation or flesh fatty acids composition of market-sized Senegales sole
Publicado
Effect of feeding time on postprandial nitrogen excretion and energy expenditure in rainbow trout
Rosina - Rosetta Orbiter Spectrometer for Ion and Neutral Analysis
The Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) will answer important questions posed by the mission's main objectives. After Giotto, this will be the first time the volatile part of a comet will be analyzed in situ. This is a very important investigation, as comets, in contrast to meteorites, have maintained most of the volatiles of the solar nebula. To accomplish the very demanding objectives through all the different phases of the comet's activity, ROSINA has unprecedented capabilities including very wide mass range (1 to >300 amu), very high mass resolution (m/Î m > 3000, i.e. the ability to resolve CO from N2 and 13C from 12CH), very wide dynamic range and high sensitivity, as well as the ability to determine cometary gas velocities, and temperature. ROSINA consists of two mass spectrometers for neutrals and primary ions with complementary capabilities and a pressure sensor. To ensure that absolute gas densities can be determined, each mass spectrometer carries a reservoir of a calibrated gas mixture allowing in-flight calibration. Furthermore, identical flight-spares of all three sensors will serve for detailed analysis of all relevant parameters, in particular the sensitivities for complex organic molecules and their fragmentation patterns in our electron bombardment ion sources
First multispacecraft ion measurements in and near the Earthâs magnetosphere with the identical Cluster ion spectrometry (CIS) experiment
On board the four Cluster
spacecraft, the Cluster Ion Spectrometry (CIS) experiment measures the full,
three-dimensional ion distribution of the major magnetospheric ions (H+,
He+, He++, and O+) from the thermal energies
to about 40 keV/e. The experiment consists of two different instruments: a
COmposition and DIstribution Function analyser (CIS1/CODIF), giving the mass
per charge composition with medium (22.5°) angular resolution, and a Hot Ion
Analyser (CIS2/HIA), which does not offer mass resolution but has a better
angular resolution (5.6°) that is adequate for ion beam and solar wind
measurements. Each analyser has two different sensitivities in order to
increase the dynamic range. First tests of the instruments (commissioning
activities) were achieved from early September 2000 to mid January 2001, and
the operation phase began on 1 February 2001. In this paper, first results of
the CIS instruments are presented showing the high level performances and
capabilities of the instruments. Good examples of data were obtained in the
central plasma sheet, magnetopause crossings, magnetosheath, solar wind and
cusp measurements. Observations in the auroral regions could also be obtained
with the Cluster spacecraft at radial distances of 4â6 Earth radii. These
results show the tremendous interest of multispacecraft measurements with
identical instruments and open a new area in magnetospheric and solar
wind-magnetosphere interaction physics.Key words. Magnetospheric physics
(magnetopause, cusp and boundary layers; magnetopheric configuration and
dynamics; solar wind - magnetosphere interactions