21 research outputs found
Active radiation measurements over one solar cycle with two DOSTEL instruments in the Columbus laboratory of the International Space Station
Two DOSimetry TELescopes (DOSTELs) have been measuring the radiation environment in the Columbus module of the International Space Station (ISS) since 2009 in the frame of the DOSIS and DOSIS 3D projects. Both instruments have measured the charged particle flux rate and dose rates in a telescope geometry of two planar silicon detectors. The radiation environment in the ISS orbit is mostly composed by galactic cosmic radiation (GCR) and its secondary radiation and protons from the inner radiation belt in the South Atlantic Anomaly (SAA) with sporadic contributions of solar energetic particles at high latitudes. The data presented in this work cover two solar activity minima and corresponding GCR intensity maxima in 2009 and 2020 and the solar activity maximum and corresponding GCR intensity minimum in 2014/2015. Average dose rates measured in the Columbus laboratory in the ISS orbit from GCR and SAA are presented separately. The data is analyzed with respect to the effective magnetic shielding and grouped into different cut-off rigidity intervals. Using only measurements in magnetically unshielded regions at low cut-off rigidity and applying a factor for the geometrical shielding of the Earth, absorbed dose rates and dose equivalent rates in near-Earth interplanetary space are estimated for the years 2009 to 2022
International Science Aboard Orion EM-1: The Matroshka AstroRad Radiation Experiment (MARE) Payload
No abstract availabl
The ALICE experiment at the CERN LHC
ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries. Its overall dimensions are 161626 m3 with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008
Update on DOSTEL measurements in COLUMBUS within the DOSIS/DOSIS3D projects
Two Silicon‐detector based DOSimetry TELescopes (DOSTELs) have been measuring the cosmic
radiation in the COLUMBUS module of the International Space Station since 2009 and have now
recorded data over more than one solar cycle covering the maxima of galactic cosmic ray intensity in
2009 and 2020 and the intensity minimum in between. Dose rates in the ISS orbit from galactic cosmic
radiation and trapped particles from the radiation belt in the South Atlantic Anomaly over this time
are presented. The variation of dose rates over the solar cycle and the dependency on the geomagnetic
shielding quantified by the cut‐off rigidity are investigated. Using dose rates measured at low
geomagnetic shielding and correcting for the altitude dependent shielding from Earth against cosmic
radiation, the expected dose and dose equivalent rates from galactic cosmic radiation in near‐Earth
interplanetary space are derived.
In addition to the data as measured with the DOSTEL instruments a short update for the data as
measured with the passive radiation detectors in the frame of the DOSIS and DOSIS 3D projects will be
provided as well
Experimental Analysis of Radiation Protection Offered by a Novel Exoskeleton-Based Radiation Protection System versus Conventional Lead Aprons
Purpose: To evaluate the radiation protection offered by an exoskeleton-based radiation protection system (Stemrad MD)
and to compare it with that offered by conventional lead aprons.
Methods: The experimental setup involved 2 anthropomorphic phantoms, an operator, a patient, and a C-arm as the x-ray
radiation source. Thermoluminescent detectors were used to measure radiation doses to different radiosensitive body parts
on the operator phantom both with the exoskeleton and a conventional lead apron at the left radial and right femoral
positions. Detected radiation doses for the exoskeleton and lead apron for different body parts and positions were
compared.
Results: At the left radial position, the mean radiation dose (mGy) reduction by the exoskeleton compared with that by the
lead apron was >90% for the left eye lens (0.22 ± 0.13 vs 5.18 ± 0.08; P < .0001), right eye lens (0.23 ± 0.13 vs 4.98 ± 0.10; P
< .0001), left head (0.11 ± 0.16 vs 3.53 ± 0.07; P < .0001), right head (0.27 ± 0.09 vs 3.12 ± 0.10; P < .0001), and left brain
(0.04 ± 0.08 vs 0.46 ± 0.07; P 90% for the left eye lens (0.14
± 0.10 vs 4.16 ± 0.09; P < .0001), right eye lens (0.06 ± 0.08 vs 1.90 ± 0.11; P < .0001), left head (0.10 ± 0.08 vs 4.39 ± 0.08; P
< .0001), left brain (0.03 ± 0.07 vs 1.44 ± 0.08; P < .0001), right brain (0.00 ± 0.14 vs 0.11 ± 0.13; P = .06), and thyroid (0.04 ±
0.07 vs 0.27 ± 0.09; P < .0001). Protection of the torso was equivalent to that offered by conventional lead aprons.
Conclusions: The exoskeleton-based system provided superior radiation protection to the physician compared with that
provided by conventional lead aprons. The effects are particularly impactful for the brain, eye lens, and head areas
Almost four years of data for the DLR RAMIS measurements in LEO and further updates on the DLR M‐42 detector family
The DLR RAMIS detector telescope has been measuring the radiation environment in a Earth polar
orbit at around 600 km altitude since December 2018 in the frame of the DLR Eu:CROPIS mission. For
almost four years now the data measured covered the last solar minimum in spring 2020 and now the
increasing solar maximum. With RAMIS we could measure the variation of trapped electrons in the
outer radiation belts, the solar cycle variation of the galactic cosmic radiation and in the last months
also several solar particle events for the new solar cycle.
In the last years DLR also developed the M‐42 radiation detector family as baseline detector for the
application during the MARE experiment on the NASA Artemis 1 mission scheduled to fly in summer
2022. Updates on new M‐42 developments (for example: increasing energy deposition range) and data
from flown balloon flight campaigns over Antarctica and during the DLR MAPHEUS missions will be
provided
1.6*10³ days of data for the DLR RAMIS measurements in LEO and further updates on the DLR M-42 Si-detector family
The DLR RAMIS detector telescope has been measuring the radiation environment in the
Earth’s polar orbit at around 600 km altitude since December 2018 within the DLR Eu:CROPIS
mission. For almost five years now the measured data cover the last solar minimum in spring
2020 and now the increase of the solar activity towards solar maximum is clearly visible. WithRAMIS we could measure the variation of trapped electrons in the outer radiation belts, the
solar cycle variation of the galactic cosmic radiation and in the last months also several solar
particle events for the new solar cycle.
In the last years DLR also developed the M‐42 radiation detector for the application during the
MARE experiment on the NASA Artemis 1 mission end of 2022. The updates on new M-42
family members
(e.g. with increased energy deposition range and recent development of low-power positionsensitive detection technology), future moon landing mission (Astrobotic/Peregrine) and data
from meteorological balloon flight campaigns over Finland and during the DLR MAPHEUS
sounding rocket mission will be presented
Questioning the radiation limits of life: Ignicoccus hospitalis between replication and VBNC
Radiation of ionizing or non-ionizing nature has harmful effects on cellular components like DNA as radiation can compromise its proper integrity. To cope with damages caused by external stimuli including radiation, within living cells, several fast and efficient repair mechanisms have evolved. Previous studies addressing organismic radiation tolerance have shown that radiotolerance is a predominant property among extremophilic microorganisms including (hyper-) thermophilic archaea. The analysis of the ionizing radiation tolerance of the chemolithoautotrophic, obligate anaerobic, hyperthermophilic Crenarchaeon Ignicoccus hospitalis showed a D₁₀-value of 4.7 kGy, fourfold exceeding the doses previously determined for other extremophilic archaea. The genome integrity of I. hospitalis after γ-ray exposure in relation to its survival was visualized by RAPD and qPCR. Furthermore, the discrimination between reproduction, and ongoing metabolic activity was possible for the first time indicating that a potential viable but non-culturable (VBNC) state may also account for I. hospitalis
DOSIS & DOSIS 3D: radiation measurements with the DOSTEL instruments onboard the Columbus Laboratory of the ISS in the years 2009–2016
The natural radiation environment in Low Earth Orbit (LEO) differs significantly in composition and energy from that found on Earth. The space radiation field consists of high energetic protons and heavier ions from Galactic Cosmic Radiation (GCR), as well as of protons and electrons trapped in the Earth’s radiation belts (Van Allen belts). Protons and some heavier particles ejected in occasional Solar Particle Events (SPEs) might in addition contribute to the radiation exposure in LEO. All sources of radiation are modulated by the solar cycle. During solar maximum conditions SPEs occur more frequently with higher particle intensities. Since the radiation exposure in LEO exceeds exposure limits for radiation workers on Earth, the radiation exposure in space has been recognized as a main health concern for humans in space missions from the beginning of the space age on. Monitoring of the radiation environment is therefore an inevitable task in human spaceflight. Since mission profiles are always different and each spacecraft provides different shielding distributions, modifying the radiation environment measurements needs to be done for each mission. The experiments “Dose Distribution within the ISS (DOSIS)” (2009–2011) and “Dose Distribution within the ISS 3D (DOSIS 3D)” (2012–onwards) onboard the Columbus Laboratory of the International Space Station (ISS) use a detector suite consisting of two silicon detector telescopes (DOSimetry TELescope = DOSTEL) and passive radiation detector packages (PDP) and are designed for the determination of the temporal and spatial variation of the radiation environment. With the DOSTEL instruments’ changes of the radiation composition and the related exposure levels in dependence of the solar cycle, the altitude of the ISS and the influence of attitude changes of the ISS during Space Shuttle dockings inside the Columbus Laboratory have been monitored. The absorbed doses measured at the end of May 2016 reached up to 286 μGy/day with dose equivalent values of 647 μSv/day
Photochemistry on the Space Station—Antibody Resistance to Space Conditions after Exposure Outside the International Space Station
Antibody-based analytical instruments are under development to detect signatures of life on planetary bodies.Antibodies are molecular recognition reagents able to detect their target at sub-nanomolar concentrations, withhigh affinity and specificity. Studying antibody binding performances under space conditions is mandatory toconvince space agencies of the adequacy of this promising tool for planetary exploration.To complement previous ground-based experiments on antibody resistance to simulated irradiation, weevaluate in this paper the effects of antibody exposure to real space conditions during the EXPOSE-R2 missionoutside the International Space Station. The absorbed dose of ionizing radiation recorded during the 588 days ofthis mission (220 mGy) corresponded to the absorbed dose expected during a mission to Mars. Moreover,samples faced, at the same time as irradiation, thermal cycles, launch constraints, and long-term storage. Amodel biochip was used in this study with antibodies in freeze-dried form and under two formats: free orcovalently grafted to a solid surface.We found that antibody-binding performances were not significantly affected by cosmic radiation, and morethan 40% of the exposed antibody, independent of its format, was still functional during all this experiment. Weconclude that antibody-based instruments are well suited for in situ analysis on planetary bodies. Key Words:Astrobiology—Cosmic rays—Biochip—Antibody—Planetary exploration. Astrobiology 19, 1053–1062