Papers by Marianna Larosa
Journal of Physics G: Nuclear and Particle Physics, 2013
In this work we present data from the Sileye-3/Alteino detector on board the International Space ... more In this work we present data from the Sileye-3/Alteino detector on board the International Space Station (ISS), which was gathered following a recalibration after several years in orbit. We also measure the relative nuclei abundance and integratedflux,whichwerenormalizedtothesolarmodulationvaluesofAugust 2007. The measurements were made at different locations of the Russian part of the ISS. The relative nuclear abundances of C to Fe in relation to C, in an energyrangeabove � 60MeV/n,showshighlevelsofoddZparticlesinsidethe ISS and an under-abundance of C and O compared with the galactic spectrum, as presented by Simpson in 1983. In addition, the values of the integrated flux varies primarily according to location and detector orientation. An additional polyethylene shield also reduces the flux, although in a lower amount than changes in the orientation of the telescope. Data were taken as part of the ESA ALTCRISS project from late 2005 through to 2007.
The study and optimization of material effectiveness as radiation shield is a mandatory step towa... more The study and optimization of material effectiveness as radiation shield is a mandatory step toward human space exploration. Passive radiation shielding is one of the most important element in the entire radiation coun-termeasures package. Crewmembers will never experience direct exposure to space radiation; they will be either inside some shelter (the spacecraft, a ‘base’) or in an EVA (Extra Vehicular Activity) suit. Understanding the radiation shielding features of materials is therefore an important step toward an optimization of shelters and suits con-struction in the quest for an integrated solution for radiation countermeasures. Materials are usually tested for their radiation shielding effectiveness first with Monte Carlo simulations, then on ground, using particle accelerators and a number of specific ions known to be abundant in space, and finally in space. Highly hydrogenated materials perform best as radiation shields. Polyethylene is right now seen as the material that merges a high level of hydrogenation, an easiness of handling and machining as well as an afford-able cost, and it is often referred as a sort of ‘standard ’ to which compare other materials ’ effectiveness. Kevlar has recently shown very interesting radiation shielding properties, and it is also known to have important characteristics toward debris shielding, and can be used, for example, in space suits. We have measured in the ISS the effectiveness of polyethylene and kevlar using three detectors of the
Over the years many devices, using different technologies and various locations, have been used -... more Over the years many devices, using different technologies and various locations, have been used - and are still in use - on the International Space Station, ISS, to measure and map the radiation and cosmic particle flux which astronauts as well as sensitive electronics are exposed to. This presentation presents recent analyses and results from the SilEye-3/Alteino detector during the ESA-sponsored project ALTCRISS. Comparisons are made with data from other experiments, such as ALTEA and PADLES. Alteino is a Si-strip detector, developed from the two SilEye detectors that were operated on Mir, in particular for studies of the Light Flash phenomena. Alteino was used at several locations, and orientations, in the Russian segment of ISS from late 2005 through 2007. Many of the data sets were obtained with a shielding of 5 g/cm2 polyethylene in front of the detector. Data on nuclei from C to Fe in the energy range above ≃ 60 MeV/n show an increase in relative abundance for odd Z inside IS...
ALTEA (Anomalous Long Term Effects on Astronauts) is a multidisciplinary project aimed at studyin... more ALTEA (Anomalous Long Term Effects on Astronauts) is a multidisciplinary project aimed at studying the cosmic rays and their effects on the astronauts during the space missions, with a focus on the Light Flashes phenomenon. The ALTEA-Space is the main space experiment of the ALTEA project and its goal is the characterization of the radiation environment inside the International Space
Journal of Space Weather and Space Climate, 2014
Context. Solar activity poses substantial risk for astronauts of the International Space Station ... more Context. Solar activity poses substantial risk for astronauts of the International Space Station (ISS) both on board and during extravehicular activity. An accurate assessment of the charged radiation flux in space habitats is necessary to determine the risk and the specific type of radiation exposure of ISS crew members, and to develop ways to protect future crews for planetary missions, even in case of high solar activity. Aims. To reduce the present-day uncertainties about the nature and magnitude of the particle fluxes in space habitats during a solar event, it is fundamental to measure those fluxes in situ. Methods. The ALTEA (Anomalous Long Term Effects on Astronauts) experiment on board the ISS is an active detector composed of six silicon telescopes and is able to follow the dynamics of the radiation flux. During its operation in 2012 a number of flux peaks were detected in correspondence with solar events. Results. We present in this work an analysis of the ALTEA data measured during the March 7th, 2012 solar event, produced by NOAA AR11429. Conclusions. During this event, the flux was enhanced tenfold with respect to ''quiet Sun'' conditions, producing strong dose increases at high geomagnetic latitudes.
The Sileye3/Alteino experiment is devoted to the investigation of the light flash phenomenon and ... more The Sileye3/Alteino experiment is devoted to the investigation of the light flash phenomenon and particle composi-tion of the cosmic ray spectrum inside the ISS. The particle detector is a silicon telescope consisting of eight planes, each divided into 32 strips. Data acquisition was initiated in 2002 in the Russian Pirs module. The data on nuclei from C to Fe in the energy range above about 60 MeV/n presented here were taken as part of the ESA Altcriss project [1] from late 2005 through 2007. Here we report on LET, from different locations and orientations, in both the Pirs and Zvezda modules. Taking solar modulation into account the results are in agreement with ALTEA mea-surements from USLab [2].To convert the energy deposition in Si to the equivalent in water, the logarithmic relation between LET in Si and water adopted from [3]. In Fig. 1, the LET spectra in water for Alteino and ALTEA are com-pared with DOSTEL spectrum from 2001 [4], and we see a good overall agreement. We are...
High-energy charged particles represent a severe radiation risk for astronauts and spacecrafts an... more High-energy charged particles represent a severe radiation risk for astronauts and spacecrafts and could damage ground critical infrastructures related to space services. Different natural sources are the origin of these particles, among them galactic cosmic rays, solar energetic particles and particles trapped in radiation belts. Solar particle events (SPE) consist in the emission of high-energy protons, alpha-particles, electrons and heavier particles from solar flares or shocks driven by solar plasma propagating through the corona and interplanetary space. Ground-level enhancements (GLE) are rare solar events in which particles are accelerated to near relativistic energies and affect space and ground-based infrastructures. During the current solar cycle 24 a single GLE event was recorded on May 17th, 2012 associated with an M5.1-class solar flare. The investigation of such a special class of solar events permits us to measure conditions in space critical to both scientific and op...
I review the basic features of four dimensional Z2×Z2 (shift) orientifolds with internal magnetic... more I review the basic features of four dimensional Z2×Z2 (shift) orientifolds with internal magnetic fields, describing two examples with N = 1 supersymmetry. As in the corresponding six-dimensional examples, D9branes magnetized along four internal directions can mimic D5-branes, even in presence of multiplets of image branes localized on different fixed tori. Chiral low-energy spectra can be obtained if the model also contains D5-branes parallel to the magnetized directions. In the last few years, open-string models have considerably enlarged our view of consistent string vacua and have also acquired a valuable role for low-energy phenomenology. This is related to the presence of D-branes, where gauge and matter fields can be localized while gravity pervades the whole higher-dimensional bulk. Type I models can be described as orientifolds of the Type IIB string theory by the world-sheet parity transformation Ω [1], and compactifications on various toroidal
The ALTEA program is aimed at studying the interaction between cosmic radiations and astronaut&am... more The ALTEA program is aimed at studying the interaction between cosmic radiations and astronaut's cerebral functions, with a specific focus on the anomalous perception of Light Flashes in space. ALTEA-Space, the main on-space experiment of the ALTEA project, is devoted to investigate this phenomenon directly in space, detecting the charged particles that hit the astronaut's head concurrently with his/her brain
I review the basic features of four dimensional Z2×Z2 (shift) orientifolds with internal magnetic... more I review the basic features of four dimensional Z2×Z2 (shift) orientifolds with internal magnetic fields, describing two examples with N = 1 supersymmetry. As in the corresponding six-dimensional examples, D9branes magnetized along four internal directions can mimic D5-branes, even in presence of multiplets of image branes localized on different fixed tori. Chiral low-energy spectra can be obtained if the model also contains D5-branes parallel to the magnetized directions. In the last few years, open-string models have considerably enlarged our view of consistent string vacua and have also acquired a valuable role for low-energy phenomenology. This is related to the presence of D-branes, where gauge and matter fields can be localized while gravity pervades the whole higher-dimensional bulk. Type I models can be described as orientifolds of the Type IIB string theory by the world-sheet parity transformation Ω [1], and compactifications on various toroidal orbifolds have also allowed ...
The ALTEA silicon detector system has been active in the International Space Station (USLab) sinc... more The ALTEA silicon detector system has been active in the International Space Station (USLab) since 2006 [from August 2006 for 12 months, and from June 2009 to present]. The detector is able to measure energy released and trajectory of ions from H (within a 25-45 MeV input energy window) to Mo (relativistic). Real Time and off line software packages have
The ALTEA silicon detector system has been active in the International Space Station (USLab) sinc... more The ALTEA silicon detector system has been active in the International Space Station (USLab) since 2006 [from August 2006 for 12 months, and from June 2009 to present]. The detector is able to measure energy released and trajectory of ions from H (within a 25-45 MeV input energy window) to Mo (relativistic). Real Time and off line software packages have
The ALTEA (Anomalous Long Term Effects on Astronauts) program is devoted to characterize the radi... more The ALTEA (Anomalous Long Term Effects on Astronauts) program is devoted to characterize the radiation environment on board the International Space Station and to study the effects on astronauts of cosmic ray exposure, with a focus on the Light Flash phenomenon. The ALTEA-space experiment includes six silicon telescopes arranged in a 3D structure, capable to determine the energy loss and
Astronaut safety, one of the key points of space exploration, is strictly related to the characte... more Astronaut safety, one of the key points of space exploration, is strictly related to the characterization of the radiation environment. ALTEA (Anomalous Long Term Effects on Astronauts) is a multidisciplinary project devoted to the study of the radiation environment inside the ISS and of its possible effects on the astronauts, with a particular focus on the Light Flashes phenomenon. To minimize hazards during intense Solar Particle Events it is important to deploy devices capable of measuring radiation and of providing real-time results. A real-time recognition technique based on Landau distribution fits to identify ion species of particles releasing almost constant energy on ALTEA detectors will be presented. The results of this technique will be compared to classical analysis results from the spectra collected by ALTEA on the ISS between August 2006 and July 2007.
Journal of Radiation Research, 2014
The Sileye3/Alteino experiment is devoted to the investigation of the light flash phenomenon and ... more The Sileye3/Alteino experiment is devoted to the investigation of the light flash phenomenon and particle composition of the cosmic ray spectrum inside the ISS. The particle detector is a silicon telescope consisting of eight planes, each divided into 32 strips. Data acquisition was initiated in 2002 in the Russian Pirs module. The data on nuclei from C to Fe in the energy range above about 60 MeV/n presented here were taken as part of the ESA Altcriss project [1] from late 2005 through 2007. Here we report on LET, from different locations and orientations, in both the Pirs and Zvezda modules. Taking solar modulation into account the results are in agreement with ALTEA measurements from USLab [2]. To convert the energy deposition in Si to the equivalent in water, the logarithmic relation between LET in Si and water adopted from [3]. In Fig. 1, the LET spectra in water for Alteino and ALTEA are compared with DOSTEL spectrum from 2001 [4], and we see a good overall agreement. We are currently in the process of preparing a detailed paper on the dose and dose equivalent rates in different places inside the Zvezda and Pirs modules and a novel analysis of the contribution to the different doses as a function of strip hit multiplicity.
arXiv: High Energy Physics - Theory, 2001
Unabridged version of the Thesis presented to the University of Rome ``Tor Vergata'', in ... more Unabridged version of the Thesis presented to the University of Rome ``Tor Vergata'', in partial fulfillment of the requirements for the ``Laurea'' degree in Physics, May 2001.
37th COSPAR …, 2008
ALTEA-Space is the principal in-space experiment of an international and multidisciplinary projec... more ALTEA-Space is the principal in-space experiment of an international and multidisciplinary project called ALTEA (Anomalus Long Term Effects on Astronauts). The measurements were performed on the International Space Station between August 2006 and July 2007 and aimed at characterising the space radiation environment inside the station. The analysis of the collected data provided the abundances of elements with charge 5
Scientific reports, May 10, 2017
Passive radiation shielding is a mandatory element in the design of an integrated solution to mit... more Passive radiation shielding is a mandatory element in the design of an integrated solution to mitigate the effects of radiation during long deep space voyages for human exploration. Understanding and exploiting the characteristics of materials suitable for radiation shielding in space flights is, therefore, of primary importance. We present here the results of the first space-test on Kevlar and Polyethylene radiation shielding capabilities including direct measurements of the background baseline (no shield). Measurements are performed on-board of the International Space Station (Columbus modulus) during the ALTEA-shield ESA sponsored program. For the first time the shielding capability of such materials has been tested in a radiation environment similar to the deep-space one, thanks to the feature of the ALTEA system, which allows to select only high latitude orbital tracts of the International Space Station. Polyethylene is widely used for radiation shielding in space and therefore...
37Th Cospar Scientific Assembly, 2008
Astronaut safety, one of the key points of space exploration, is strictly related to the characte... more Astronaut safety, one of the key points of space exploration, is strictly related to the characterization of the radiation environment. ALTEA (Anomalous Long Term Effects on Astronauts) is a multidisciplinary project devoted to the study of the radiation environment inside the ISS and of its possible effects on the astronauts, with a particular focus on the Light Flashes phenomenon. To minimize hazards during intense Solar Particle Events it is important to deploy devices capable of measuring radiation and of providing real-time results. A real-time recognition technique based on Landau distribution fits to identify ion species of particles releasing almost constant energy on ALTEA detectors will be presented. The results of this technique will be compared to classical analysis results from the spectra collected by ALTEA on the ISS between August 2006 and July 2007.
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Papers by Marianna Larosa