52 research outputs found
The German Aerospace Center M-42 radiation detector—A new development for applications in mixed radiation fields
In the last few years, the Biophysics Working Group of the Institute of Aerospace Medicine of the German Aerospace Center (DLR) started
the development of a small low power consumption radiation detector system for the measurement of the absorbed dose to be applied in
various environments, such as onboard aircraft, in space, and also as a demonstration tool for students. These so called DLR M-42 detectors
are based on an electronics design, which can easily be adjusted to the user- and mission-requirements. M-42 systems were already applied
for measurements in airplanes, during two MAPHEUS (Materialphysikalische Experimente unter Schwerelosigkeit) rocket missions, and
are currently prepared for long term balloon experiments. In addition, they will be part of the dosimetry suite of the upcoming Matroshka
AstroRad Radiation Experiment on the NASA Artemis I mission. This paper gives an overview of the design and the testing of the DLR M-42
systems and provides highlighted results from the MAPHEUS campaigns where the detectors were tested for the first time under space flight
conditions. Results clearly show that the system design enables independent measurements starting upon rocket launch due to the built-in
accelerometer sensors and provides data for the relevant 6 min of μ-gravity as given for the MAPHEUS missions. These 6 min of the μ-gravity
environment at altitudes between 100 and 240 km lead to a total absorbed dose of 1.21 ± 0.15 μGy being equivalent to half a day of radiation
background measured with the M-42 in the laboratory at DLR, Cologne, Germany
Unfolding the Neutron Flux Spectrum on the Surface of Mars Using the MSL‐RAD and Odyssey‐HEND Data
Understanding the long-term radiation environment at the surface of Mars allows us to estimate
the exposure for future robotic and crewed missions. Typically, the radiation environment includes charged
particles (i.e., protons and heavier ions) and neutral particles (i.e., gamma rays and secondary neutrons).
Previous studies used in-situ measurements, models, or both to determine the characteristics of the radiation
at Mars. For example, the Mars Science Laboratory instrument, the Radiation Assessment Detector (RAD),
has provided invaluable in-situ data since landing in 2012. However, the RAD instrument is only sensitive
to neutrons with energies > ∼6 MeV and therefore misses what is expected to be a substantial flux of
lower-energy neutrons. To address this gap, we have developed an approach to derive the surface neutron
spectrum using the MSL RAD data augmented by orbital data from the High Energy Neutron Detector (HEND)
onboard Mars Odyssey (neutron energy < ∼10 MeV). Using a power law fit, we determine neutron flux spectra
that reproduce the measurements recorded by both RAD and HEND. Our approach involves a series of Monte
Carlo simulations to develop a set of atmospheric transmission functions that enables us to convert the on-orbit
HEND data to their corresponding surface neutron flux spectra. The combined RAD—HEND data present a
unique opportunity to obtain a complete picture of the surface neutron environment
Virtual Planetary Space Weather Service offered by the Europlant H2O2O Research Infrastructure
Under Horizon 2020, the Europlanet 2020 Research Infrastructure (EPN2020-RI) will include an entirely new Virtual Access Service, ?Planetary Space Weather Services? (PSWS) that will extend the concepts of space weather and space situational awareness to other planets in our Solar System and in particular to spacecraft that voyage through it. PSWS will make twelve new services accessible to the research community, space agencies, and industrial partners planning for space missions. These services will in particular be dedicated to the following key planetary environments: Mars (in support of the NASA MAVEN and European Space Agency (ESA) Mars Express and ExoMars missions), comets (building on the outstanding success of the ESA Rosetta mission), and outer planets (in preparation for the ESA JUpiter ICy moon Explorer mission), and one of these services will aim at predicting and detecting planetary events like meteor showers and impacts in the Solar System. This will give the European planetary science community new methods, interfaces, functionalities and/or plugins dedicated to planetary space weather as well as to space situational awareness in the tools and models available within the partner institutes. A variety of tools (in the form of web applications, standalone software, or numerical models in various degrees of implementation) are available for tracing propagation of planetary and/or solar events through the Solar System and modelling the response of the planetary environment (surfaces, atmospheres, ionospheres, and magnetospheres) to those events. But these tools were not originally designed for planetary event prediction and space weather applications. PSWS will provide the additional research and tailoring required to apply them for these purposes. PSWS will be to review, test, improve and adapt methods and tools available within the partner institutes in order to make prototype planetary event and space weather services operational in Europe at the end of 2017. To achieve its objectives PSWS will use a few tools and standards developed for the Astronomy Virtual Observatory (VO). This paper gives an overview of the project together with a few illustrations of prototype services based on VO standards and protocolsauthorsversionPeer reviewe
The Deuteron Spin-dependent Structure Function g1d and its First Moment
We present a measurement of the deuteron spin-dependent structure function
g1d based on the data collected by the COMPASS experiment at CERN during the
years 2002-2004. The data provide an accurate evaluation for Gamma_1^d, the
first moment of g1d(x), and for the matrix element of the singlet axial
current, a0. The results of QCD fits in the next to leading order (NLO) on all
g1 deep inelastic scattering data are also presented. They provide two
solutions with the gluon spin distribution function Delta G positive or
negative, which describe the data equally well. In both cases, at Q^2 = 3
(GeV/c)^2 the first moment of Delta G is found to be of the order of 0.2 - 0.3
in absolute value.Comment: fits redone using MRST2004 instead of MRSV1998 for G(x), correlation
matrix adde
The COMPASS Experiment at CERN
The COMPASS experiment makes use of the CERN SPS high-intensitymuon and
hadron beams for the investigation of the nucleon spin structure and the
spectroscopy of hadrons. One or more outgoing particles are detected in
coincidence with the incoming muon or hadron. A large polarized target inside a
superconducting solenoid is used for the measurements with the muon beam.
Outgoing particles are detected by a two-stage, large angle and large momentum
range spectrometer. The setup is built using several types of tracking
detectors, according to the expected incident rate, required space resolution
and the solid angle to be covered. Particle identification is achieved using a
RICH counter and both hadron and electromagnetic calorimeters. The setup has
been successfully operated from 2002 onwards using a muon beam. Data with a
hadron beam were also collected in 2004. This article describes the main
features and performances of the spectrometer in 2004; a short summary of the
2006 upgrade is also given.Comment: 84 papes, 74 figure
A new measurement of the Collins and Sivers asymmetries on a transversely polarised deuteron target
New high precision measurements of the Collins and Sivers asymmetries of
charged hadrons produced in deep-inelastic scattering of muons on a
transversely polarised 6LiD target are presented. The data were taken in 2003
and 2004 with the COMPASS spectrometer using the muon beam of the CERN SPS at
160 GeV/c. Both the Collins and Sivers asymmetries turn out to be compatible
with zero, within the present statistical errors, which are more than a factor
of 2 smaller than those of the published COMPASS results from the 2002 data.
The final results from the 2002, 2003 and 2004 runs are compared with naive
expectations and with existing model calculations.Comment: 40 pages, 28 figure
Measuring Cosmic Rays with the RadMap Telescope on the International Space Station
The RadMap Telescope is a new radiation-monitoring instrument operating in the U.S. Orbital
Segment (USOS) of the International Space Station (ISS). The instrument was commissioned in
May 2023 and will rotate through four locations inside American, European, and Japanese modules
over a period of about six months. In some locations, it will take data alongside operational,
validated detectors for a cross-check of measurements. RadMap’s central detector is a finely
segmented tracking calorimeter that records detailed depth-dose data relevant to studies of the
radiation exposure of the ISS crew. It is also able to record particle-dependent energy spectra of
cosmic-ray nuclei with energies up to several hundred MeV per nucleon. A unique feature of the
detector is its ability to track nuclei with omnidirectional sensitivity at an angular resolution of two
degrees. In this contribution, we present the design and capabilities of the RadMap Telescope and
give an overview of the instrument’s commissioning on the ISS
The responses of an anaerobic microorganism, Yersinia intermedia MASE-LG-1 to individual and combined simulated Martian stresses
The limits of life of aerobic microorganisms are well understood, but the responses of anaerobic microorganisms to individual and combined extreme stressors are less well known. Motivated by an interest in understanding the survivability of anaerobic microorganisms under Martian conditions, we investigated the responses of a new isolate, Yersinia intermedia MASE-LG-1 to individual and combined stresses associated with the Martian surface. This organism belongs to an adaptable and persistent genus of anaerobic microorganisms found in many environments worldwide. The effects of desiccation, low pressure, ionizing radiation, varying temperature, osmotic pressure, and oxidizing chemical compounds were investigated. The strain showed a high tolerance to desiccation, with a decline of survivability by four orders of magnitude during a storage time of 85 days. Exposure to X-rays resulted in dose-dependent inactivation for exposure up to 600 Gy while applied doses above 750 Gy led to complete inactivation. The effects of the combination of desiccation and irradiation were additive and the survivability was influenced by the order in which they were imposed. Ionizing irradiation and subsequent desiccation was more deleterious than vice versa. By contrast, the presence of perchlorates was not found to significantly affect the survival of the Yersinia strain after ionizing radiation. These data show that the organism has the capacity to survive and grow in physical and chemical stresses, imposed individually or in combination that are associated with Martian environment. Eventually it lost its viability showing that many of the most adaptable anaerobic organisms on Earth would be killed on Mars today
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