| 1. |
|
|
| 2. |
- Abelev, Betty, et al.
(author)
-
Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
-
In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
-
Journal article (peer-reviewed)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
|
|
| 3. |
- Abelev, Betty, et al.
(author)
-
Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
-
In: Journal of High Energy Physics. - 1029-8479. ; :11
-
Journal article (peer-reviewed)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
|
|
| 4. |
- Abelev, Betty, et al.
(author)
-
Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
-
In: Journal of High Energy Physics. - 1029-8479. ; :7
-
Journal article (peer-reviewed)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
|
|
| 5. |
- Castelnuovo, Gianluca, et al.
(author)
-
What Is the Role of the Placebo Effect for Pain Relief in Neurorehabilitation? : Clinical Implications From the Italian Consensus Conference on Pain in Neurorehabilitation
- 2018
-
In: Frontiers in Neurology. - : Frontiers Media SA. - 1664-2295. ; 9
-
Research review (peer-reviewed)abstract
- Background: It is increasingly acknowledged that the outcomes of medical treatments are influenced by the context of the clinical encounter through the mechanisms of the placebo effect. The phenomenon of placebo analgesia might be exploited to maximize the efficacy of neurorehabilitation treatments. Since its intensity varies across neurological disorders, the Italian Consensus Conference on Pain in Neurorehabilitation (ICCP) summarized the studies on this field to provide guidance on its use.Methods: A review of the existing reviews and meta-analyses was performed to assess the magnitude of the placebo effect in disorders that may undergo neurorehabilitation treatment. The search was performed on Pubmed using placebo, pain, and the names of neurological disorders as keywords. Methodological quality was assessed using a pre-existing checklist. Data about the magnitude of the placebo effect were extracted from the included reviews and were commented in a narrative form.Results: 11 articles were included in this review. Placebo treatments showed weak effects in central neuropathic pain (pain reduction from 0.44 to 0.66 on a 0-10 scale) and moderate effects in postherpetic neuralgia (1.16), in diabetic peripheral neuropathy (1.45), and in pain associated to HIV (1.82). Moderate effects were also found on pain due to fibromyalgia and migraine; only weak short-term effects were found in complex regional pain syndrome. Confounding variables might have influenced these results.Clinical implications: These estimates should be interpreted with caution, but underscore that the placebo effect can be exploited in neurorehabilitation programs. It is not necessary to conceal its use from the patient. Knowledge of placebo mechanisms can be used to shape the doctor-patient relationship, to reduce the use of analgesic drugs and to train the patient to become an active agent of the therapy.
|
|
| 6. |
- Telloni, Daniele, et al.
(author)
-
Exploring the Solar Wind from Its Source on the Corona into the Inner Heliosphere during the First Solar Orbiter-Parker Solar Probe Quadrature
- 2021
-
In: Astrophysical Journal Letters. - : Institute of Physics Publishing (IOPP). - 2041-8205 .- 2041-8213. ; 920:1
-
Journal article (peer-reviewed)abstract
- This Letter addresses the first Solar Orbiter (SO)-Parker Solar Probe (PSP) quadrature, occurring on 2021 January 18 to investigate the evolution of solar wind from the extended corona to the inner heliosphere. Assuming ballistic propagation, the same plasma volume observed remotely in the corona at altitudes between 3.5 and 6.3 solar radii above the solar limb with the Metis coronagraph on SO can be tracked to PSP, orbiting at 0.1 au, thus allowing the local properties of the solar wind to be linked to the coronal source region from where it originated. Thanks to the close approach of PSP to the Sun and the simultaneous Metis observation of the solar corona, the flow-aligned magnetic field and the bulk kinetic energy flux density can be empirically inferred along the coronal current sheet with an unprecedented accuracy, allowing in particular estimation of the Alfven radius at 8.7 solar radii during the time of this event. This is thus the very first study of the same solar wind plasma as it expands from the sub-Alfvenic solar corona to just above the Alfven surface.
|
|
| 7. |
- Telloni, Daniele, et al.
(author)
-
Linking Small-scale Solar Wind Properties with Large-scale Coronal Source Regions through Joint Parker Solar Probe-Metis/Solar Orbiter Observations
- 2022
-
In: Astrophysical Journal. - : IOP Publishing Ltd. - 0004-637X .- 1538-4357. ; 935:2
-
Journal article (peer-reviewed)abstract
- The solar wind measured in situ by Parker Solar Probe in the very inner heliosphere is studied in combination with the remote-sensing observation of the coronal source region provided by the METIS coronagraph aboard Solar Orbiter. The coronal outflows observed near the ecliptic by Metis on 2021 January 17 at 16:30 UT, between 3.5 and 6.3 R (circle dot) above the eastern solar limb, can be associated with the streams sampled by PSP at 0.11 and 0.26 au from the Sun, in two time intervals almost 5 days apart. The two plasma flows come from two distinct source regions, characterized by different magnetic field polarity and intensity at the coronal base. It follows that both the global and local properties of the two streams are different. Specifically, the solar wind emanating from the stronger magnetic field region has a lower bulk flux density, as expected, and is in a state of well-developed Alfvenic turbulence, with low intermittency. This is interpreted in terms of slab turbulence in the context of nearly incompressible magnetohydrodynamics. Conversely, the highly intermittent and poorly developed turbulent behavior of the solar wind from the weaker magnetic field region is presumably due to large magnetic deflections most likely attributed to the presence of switchbacks of interchange reconnection origin.
|
|
| 8. |
- Amendola, Giandomenico, et al.
(author)
-
Low-Earth Orbit User Segment in the Ku and Ka-Band
- 2023
-
In: IEEE Microwave Magazine. - : Institute of Electrical and Electronics Engineers (IEEE). - 1527-3342 .- 1557-9581. ; 24:2, s. 32-48
-
Journal article (peer-reviewed)abstract
- Low-Earth orbit (LEO) constellations are revolutionizing the world of satellite communication (Satcom), providing new opportunities to manufacturers and operators and enabling innovative and attractive services to users.
|
|
| 9. |
- Artini, Cristina, et al.
(author)
-
Roadmap on thermoelectricity
- 2023
-
In: Nanotechnology. - : IOP Publishing Ltd. - 0957-4484 .- 1361-6528. ; 34:29
-
Journal article (peer-reviewed)abstract
- The increasing energy demand and the ever more pressing need for clean technologies of energy conversion pose one of the most urgent and complicated issues of our age. Thermoelectricity, namely the direct conversion of waste heat into electricity, is a promising technique based on a long-standing physical phenomenon, which still has not fully developed its potential, mainly due to the low efficiency of the process. In order to improve the thermoelectric performance, a huge effort is being made by physicists, materials scientists and engineers, with the primary aims of better understanding the fundamental issues ruling the improvement of the thermoelectric figure of merit, and finally building the most efficient thermoelectric devices. In this Roadmap an overview is given about the most recent experimental and computational results obtained within the Italian research community on the optimization of composition and morphology of some thermoelectric materials, as well as on the design of thermoelectric and hybrid thermoelectric/photovoltaic devices.
|
|
| 10. |
- Damiani, Claudia, et al.
(author)
-
Mosquito-Bacteria Symbiosis : The Case of Anopheles gambiae and Asaia
- 2010
-
In: Microbial Ecology. - : Springer Science and Business Media LLC. - 0095-3628 .- 1432-184X. ; 60:3, s. 644-654
-
Journal article (peer-reviewed)abstract
- The symbiotic relationship between Asaia, an alpha-proteobacterium belonging to the family Acetobacteriaceae, and mosquitoes has been studied mainly in the Asian malaria vector Anopheles stephensi. Thus, we have investigated the nature of the association between Asaia and the major Afro-tropical malaria vector Anopheles gambiae. We have isolated Asaia from different wild and laboratory reared colonies of A. gambiae, and it was detected by PCR in all the developmental stages of the mosquito and in all the specimens analyzed. Additionally, we have shown that it localizes in the midgut, salivary glands and reproductive organs. Using recombinant strains of Asaia expressing fluorescent proteins, we have demonstrated the ability of the bacterium to colonize A. gambiae mosquitoes with a pattern similar to that described for A. stephensi. Finally, fluorescent in situ hybridization on the reproductive tract of females of A. gambiae showed a concentration of Asaia at the very periphery of the eggs, suggesting that transmission of Asaia from mother to offspring is likely mediated by a mechanism of egg-smearing. We suggest that Asaia has potential for use in the paratransgenic control of malaria transmitted by A. gambiae.
|
|
| 11. |
- Dawson, Andreas, et al.
(author)
-
Development of a quality-assessment tool for experimental bruxism studies : reliability and validity
- 2013
-
In: Journal of Orofacial Pain. - : Quintessence. - 1064-6655 .- 1945-3396. ; 27:2, s. 111-122
-
Journal article (peer-reviewed)abstract
- AIMS: To combine empirical evidence and expert opinion in a formal consensus method in order to develop a quality-assessment tool for experimental bruxism studies in systematic reviews. METHODS: Tool development comprised five steps: (1) preliminary decisions, (2) item generation, (3) face-validity assessment, (4) reliability and discriminitive validity assessment, and (5) instrument refinement. The kappa value and phi-coefficient were calculated to assess inter-observer reliability and discriminative ability, respectively. RESULTS: Following preliminary decisions and a literature review, a list of 52 items to be considered for inclusion in the tool was compiled. Eleven experts were invited to join a Delphi panel and 10 accepted. Four Delphi rounds reduced the preliminary tool-Quality-Assessment Tool for Experimental Bruxism Studies (Qu-ATEBS)- to 8 items: study aim, study sample, control condition or group, study design, experimental bruxism task, statistics, interpretation of results, and conflict of interest statement. Consensus among the Delphi panelists yielded good face validity. Inter-observer reliability was acceptable (k = 0.77). Discriminative validity was excellent (phi coefficient 1.0; P < .01). During refinement, 1 item (no. 8) was removed. CONCLUSION: Qu-ATEBS, the seven-item evidence-based quality assessment tool developed here for use in systematic reviews of experimental bruxism studies, exhibits face validity, excellent discriminative validity, and acceptable inter-observer reliability. Development of quality assessment tools for many other topics in the orofacial pain literature is needed and may follow the described procedure.
|
|
| 12. |
- Donati, Mauro, 1966, et al.
(author)
-
Effect of immediate functional loading on osseointegration of implants used for single tooth replacement. A human histological study.
- 2013
-
In: Clinical Oral Implants Research. - : Wiley. - 0905-7161. ; 24:7, s. 738-45
-
Journal article (peer-reviewed)abstract
- Objective To analyze hard tissue reactions to immediate functionally loaded single implants that were installed either with a conventional drill preparation procedure or with an osteotome preparation technique. Materials and methods Thirteen subjects with two sites requiring single tooth rehabilitation by means of implants volunteered for the study. Each subject received one test (immediate functionally loaded) and one control (non-loaded) implant. In six subjects (group 1) the implants were placed using a conventional drilling procedure, whereas in the remaining seven subjects (group 2) an osteotome preparation procedure was performed. Block biopsies containing test and control implants and peri-implant bone tissues were collected at 1month in four of the subjects in group 1 and in five subjects of group 2. The remaining implant sites were sampled at 3months after implant placement. The biopsies were prepared for histological examination. Results Two implants of the test-2 group (osteotome preparation) representing 1month of healing and another test-2 implant representing 3months of healing failed to integrate. A multilevel multivariate statistical analysis demonstrated that no differences in bone-to-implant contact (BIC)% were found in between test and control implants, the density of newly formed peri-implant bone was significantly higher around test than control implants at 1 and 3months of healing. Sections representing osteotome technique sites showed fractured trabeculae and large amounts of bone particles. Conclusions It is suggested that immediate loading of implants does not influence the osseointegration process, whereas the density of newly formed peri-implant bone at such sites appears to be increased in relation to unloaded control implants. The use of an osteotome preparation technique during installation results in damage of peri-implant bone and enhances the risk for failure in osseointegration.
|
|
| 13. |
- Iannaccone, Marco, et al.
(author)
-
RNA Sequencing-Based Whole-Transcriptome Analysis of Friesian Cattle Fed with Grape Pomace-Supplemented Diet
- 2018
-
In: Animals. - : MDPI AG. - 2076-2615. ; 8:11
-
Journal article (peer-reviewed)abstract
- Grape pomace (GPO), the main by-product of the wine making process, is a rich source of polyphenols with potent antioxidant properties. Recently, GPO has emerged as a potential feed additive in livestock nutrition, with several reports describing its beneficial effects on animals' overall health status or production traits. However, little is known about it from a molecular biology standpoint. In the present study, we report the first RNA sequencing-based whole-transcriptome profiling of Friesian calves fed with a GPO-supplemented diet. We identified 367 differentially expressed genes (p < 0.05) in the GPO-supplemented calves (n = 5), when compared with unsupplemented control group (n = 5). The pathway analysis showed that cholesterol lipid biosynthesis' was the most negatively-enriched (p < 0.001) pathway in the GPO-supplemented animals. In specific terms, five important genes coding for cholesterol biosynthesis enzymes, namely the Farnesyl-diphosphate Farnesyltransferase 1 (FDFT-1), Squalene Epoxidase (SQLE), NAD(P)-dependent Steroid Dehydrogenase-like (NSDHL), Methylsterol Monooxygenase (MSMO)-1, and Sterol-C5-desaturase (SC5D), two major transcription factors (the Sterol Regulatory Element-binding Transcription Factor 1 and 2), as well as the Low-Density Lipoprotein Receptor (LDLR), were all downregulated following GPO supplementation. Such an effect was mirrored by a reduction of blood cholesterol levels (p = 0.07) and a lowered (p < 0.001) Malondialdehyde (lipid oxidation marker) level in carcasses. We provide evidence on the effects of GPO-supplemented diets on the whole-transcriptome signature in veal calves, which mainly reflects an antioxidant activity.
|
|
| 14. |
- Makarova, Tatiana, 1959-, et al.
(author)
-
Ageing effects in nanographite monitored by Raman spectroscopy
- 2008
-
In: Physica status solidi. B, Basic research. - : Wiley. - 0370-1972 .- 1521-3951. ; 245:10, s. 2082-2085
-
Journal article (peer-reviewed)abstract
- The structural relaxation of nanographite ball-milled in argon atmosphere and stored in evacuated ampoules, has been studied by monitoring the evolution of the Raman spectra. Reduction of some Raman bands associated with “in-plane” structural defects, such as vacancies, dislocations or grain boundaries, and those associated with “out-of-plane” defects, such as stacking faults, is accompanied by the rise of new bands around 1180 and 2000 cm–1. The development of these bands is suppressed in nanographite samples exposed to a flux of pure anhydrous hydrogen.
|
|
| 15. |
- Parise, Mauro, et al.
(author)
-
Accurate Computation of Mutual Inductance of Non Coaxial Pancake Coils
- 2021
-
In: Energies. - : MDPI. - 1996-1073. ; 14:16
-
Journal article (peer-reviewed)abstract
- The computation of self and mutual inductances of coils is a classic problem of electrical engineering. The accurate modeling of coupled coils has received renewed interest with the spread of wireless power transfer systems. This problem has been quite well addressed for coplanar or perfectly coaxial coils but it is known that the misalignment conditions easily lead to a sharp decrease in the efficiency. Hence, it is crucial to take misalignment into account in order to properly design the overall wireless power transfer system. This work presents a study to compute analytically the mutual inductance of non-coaxial pancake coils with parallel axes. The accuracy of the proposed methodology is tested by comparison with the numerical results obtained using the tool Fast-Henry. Then, a wireless power transfer system, comprising a full bridge inverter is considered, showing the impact of the misalignment on the coupling between two pancake coils and, thus, between the source and the load.
|
|
| 16. |
|
|
| 17. |
- Pullabhatla, Venu, et al.
(author)
-
De novo mutations implicate novel genes in systemic lupus erythematosus
- 2018
-
In: Human Molecular Genetics. - : Oxford University Press. - 0964-6906 .- 1460-2083. ; 27:3, s. 421-429
-
Journal article (peer-reviewed)abstract
- The omnigenic model of complex disease stipulates that the majority of the heritability will be explained by the effects of common variation on genes in the periphery of core disease pathways. Rare variant associations, expected to explain far less of the heritability, may be enriched in core disease genes and thus will be instrumental in the understanding of complex disease pathogenesis and their potential therapeutic targets. Here, using complementary whole-exome sequencing, high-density imputation, and in vitro cellular assays, we identify candidate core genes in the pathogenesis of systemic lupus erythematosus (SLE). Using extreme-phenotype sampling, we sequenced the exomes of 30 SLE parent-affected-offspring trios and identified 14 genes with missense de novo mutations (DNM), none of which are within the >80 SLE susceptibility loci implicated through genome-wide association studies. In a follow-up cohort of 10, 995 individuals of matched European ancestry, we imputed genotype data to the density of the combined UK10K-1000 genomes Phase III reference panel across the 14 candidate genes. Gene-level analyses indicate three functional candidates: DNMT3A, PRKCD, and C1QTNF4. We identify a burden of rare variants across PRKCD associated with SLE risk (P = 0.0028), and across DNMT3A associated with two severe disease prognosis sub-phenotypes (P = 0.0005 and P = 0.0033). We further characterise the TNF-dependent functions of the third candidate gene C1QTNF4 on NF-kappa B activation and apoptosis, which are inhibited by the p.His198Gln DNM. Our results identify three novel genes in SLE susceptibility and support extreme-phenotype sampling and DNM gene discovery to aid the search for core disease genes implicated through rare variation.
|
|
| 18. |
- Rahimi, Mostafa, et al.
(author)
-
A novel approach for brake emission estimation based on traffic microsimulation, vehicle system dynamics, and machine learning modeling
- 2023
-
In: Atmospheric Pollution Research. - 1309-1042. ; 14:10
-
Journal article (peer-reviewed)abstract
- Brake wear is known as the primary source of traffic-related non-exhaust particle generation. Its generation rate is influenced by parameters at different levels: subsystem (type of brakes, pads, materials, etc.), system (vehicles' dynamics, driving style etc.) and suprasystem (road geometries, traffic parameters, etc.). At the subsystem level, we proposed a neural network brake emission modeling, trained and validated through emission data collected from a reduced-scale dynamometer. At the system level, a model of a car dynamics was developed to calculate the wheels’ brake torques and angular velocities. At the suprasystem level, the traffic behavior in a sensitive urban area was characterized experimentally and simulated in a traffic microsimulation software. The vehicle traffic-based records were used to calculate the vehicle dynamic quantities, converted into brake emission through the neural network. To examine the overall traffic impacts on brake emission, the total particle number (PN) and total particle mass were estimated regarding the route choice in the sensitive area and in the whole transportation network. The findings of this study showed significant generation rate of brake emissions (in terms of mass and number) around congested areas (in the order of 10e9 #/s). The brake emission estimation in a real area provides fundamental information to the decision-makers to better insight into the rate of non-exhaust emissions generation.
|
|
| 19. |
- Romano, Daniele, et al.
(author)
-
Rigorous dc Solution of Partial Element Equivalent Circuit Models Including Conductive, Dielectric, and Magnetic Materials
- 2020
-
In: IEEE transactions on electromagnetic compatibility (Print). - : IEEE. - 0018-9375 .- 1558-187X. ; 62:3, s. 870-879
-
Journal article (peer-reviewed)abstract
- This paper presents a rigorous derivation of the dc solution of three-dimensional partial element equivalent circuit (PEEC) formulation extended to include simultaneously conductive, dielectric, and magnetic materials. The circuit interpretation of Maxwell’s equations provided by the PEEC method allows to reformulate the dc modeling task in such a way that physical phenomena are fully exploited. Indeed, since the displacements currents are identically zero in dielectrics, Kirchhoff’s current law is enforced in terms of charge conservation internally to dielectrics or at the interface between dielectrics and other materials. A well-posed problem is achieved by adding the charges as new unknowns and identifying the disconnected objects. Two numerical examples are presented demonstrating the accuracy of the proposed method when compared to the dc solution as extracted by the fast Fourier transform of the impulse response and a finite element method simulation.
|
|
| 20. |
- Soffitta, Paolo, et al.
(author)
-
XIPE : the X-ray imaging polarimetry explorer
- 2013
-
In: Experimental astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 36:3, s. 523-567
-
Journal article (peer-reviewed)abstract
- X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and temporal variability measurements and to imaging, allows a wealth of physical phenomena in astrophysics to be studied. X-ray polarimetry investigates the acceleration process, for example, including those typical of magnetic reconnection in solar flares, but also emission in the strong magnetic fields of neutron stars and white dwarfs. It detects scattering in asymmetric structures such as accretion disks and columns, and in the so-called molecular torus and ionization cones. In addition, it allows fundamental physics in regimes of gravity and of magnetic field intensity not accessible to experiments on the Earth to be probed. Finally, models that describe fundamental interactions (e.g. quantum gravity and the extension of the Standard Model) can be tested. We describe in this paper the X-ray Imaging Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a small mission with a launch in 2017. The proposal was, unfortunately, not selected. To be compliant with this schedule, we designed the payload mostly with existing items. The XIPE proposal takes advantage of the completed phase A of POLARIX for an ASI small mission program that was cancelled, but is different in many aspects: the detectors, the presence of a solar flare polarimeter and photometer and the use of a light platform derived by a mass production for a cluster of satellites. XIPE is composed of two out of the three existing JET-X telescopes with two Gas Pixel Detectors (GPD) filled with a He-DME mixture at their focus. Two additional GPDs filled with a 3-bar Ar-DME mixture always face the Sun to detect polarization from solar flares. The Minimum Detectable Polarization of a 1 mCrab source reaches 14 % in the 2-10 keV band in 10(5) s for pointed observations, and 0.6 % for an X10 class solar flare in the 15-35 keV energy band. The imaging capability is 24 arcsec Half Energy Width (HEW) in a Field of View of 14.7 arcmin x 14.7 arcmin. The spectral resolution is 20 % at 6 keV and the time resolution is 8 mu s. The imaging capabilities of the JET-X optics and of the GPD have been demonstrated by a recent calibration campaign at PANTER X-ray test facility of the Max-Planck-Institut fur extraterrestrische Physik (MPE, Germany). XIPE takes advantage of a low-earth equatorial orbit with Malindi as down-link station and of a Mission Operation Center (MOC) at INPE (Brazil). The data policy is organized with a Core Program that comprises three months of Science Verification Phase and 25 % of net observing time in the following 2 years. A competitive Guest Observer program covers the remaining 75 % of the net observing time.
|
|
