1,280 research outputs found
Measuring the muonic H ground state hyperfine splitting with FAMU
The FAMU experiment will measure the hyperfine splitting in the
ground state of muonic hydrogen \u394Ehfs(\u3bc
12
p)1s with a precision \u3b4\u3bb/\u3bb < 10
125
providing rZ, the Zemach radius of the proton with higher precision, than what was
previously possible, disentangling discordant theoretical values. The aim is to set
a cornerstone result about not yet explained anomalies on the charge radius rch of
the proton. The Zemach radius rZ and the charge radius rch are the only proton
shape-related values that can be directly extracted from experimental data, and rZ
is the only one that gives information about the proton\u2019s magnetic dipole moment
distribution. The status of the experiment is presented
The effect of the displacement damage on the Charge Collection Efficiency in Silicon Drift Detectors for the LOFT satellite
The technology of Silicon Drift Detectors (SDDs) has been selected for the
two instruments aboard the Large Observatory For X-ray Timing (LOFT) space
mission. LOFT underwent a three year long assessment phase as candidate for the
M3 launch opportunity within the "Cosmic Vision 2015 -- 2025" long-term science
plan of the European Space Agency. During the LOFT assessment phase, we studied
the displacement damage produced in the SDDs by the protons trapped in the
Earth's magnetosphere. In a previous paper we discussed the effects of the Non
Ionising Energy Losses from protons on the SDD leakage current. In this paper
we report the measurement of the variation of Charge Collection Efficiency
produced by displacement damage caused by protons and the comparison with the
expected damage in orbit.Comment: 17 pages, 7 figures. Accepted for publication by Journal of
Instrumentatio
Assessing enigmatic boulder deposits in NE Aegean Sea: importance of historical sources as tool to support hydrodynamic equations
Due to their importance in the assessment of coastal hazards, several studies have focused on geomorphological and sedimentological field evidence of catastrophic wave impacts related to historical tsunami events. Among them, many authors used boulder fields as important indicators of past tsunamis, especially in the Mediterranean Sea. The aim of this study was to understand the mechanism of deposition of clusters of large boulders, consisting of beachrock slabs, which were found on the southern coasts of Lesvos Island (NE Aegean Sea). Methods to infer the origin of boulder deposits (tsunami vs. storm wave) are often based on hydrodynamic models even if different environmental complexities are difficult to be incorporated into numerical models. In this study, hydrodynamic equations did not provide unequivocal indication of the mechanism responsible for boulder deposition in the study area. Further analyses, ranging from geomorphologic to seismotectonic data, indicated a tsunami as the most likely cause of displacement of the boulders but still do not allow to totally exclude the extreme storm origin. Additional historical investigations (based on tsunami catalogues, historical photos and aged inhabitants interviews) indicated that the boulders are likely to have been deposited by the tsunami triggered by the 6.7 <i>M</i><sub>s</sub> Chios-Karaburum earthquake of 1949 or, alternatively, by minor effects of the destructive tsunami produced by 1956's Amorgos Island earthquake. Results of this study point out that, at Mediterranean scale, to flank numerical models with the huge amount of the available historical data become a crucial tool in terms of prevention policies related to catastrophic coastal events
Diagnosis, Clinical Features and Management of Interstitial Lung Diseases in Rheumatic Disorders: Still a Long Journey
: Interstitial lung disease (ILD) is one of the most frequent pulmonary complications of autoimmune rheumatic diseases (ARDs), and it is mainly associated with connective tissue diseases (CTDs) and rheumatoid arthritis (RA) [...]
Measuring the muonic H ground state hyperfine splitting with FAMU
The FAMU experiment will measure the hyperfine splitting in the ground state of muonic hydrogen ΔEhfs(μ−p)1s with a precision δλ/λ < 10−5 providing rZ , the Zemach radius of the proton with higher precision, than what was previously possible, disentangling discordant theoretical values. The aim is to seta cornerstone result about not yet explained anomalies on the charge radius rch of the proton. The Zemach radius rZ and the charge radius rch are the only proton shape-related values that can be directly extracted from experimental data, and rZ is the only one that gives information about the proton’s magnetic dipole moment
distribution. The status of the experiment is presented
Assessing enigmatic boulder deposits in NE Aegean Sea: Importance of historical sources as tool to support hydrodynamic equations
Due to their importance in the assessment of coastal hazards, several studies have focused on geomorphological and sedimentological field evidence of catastrophic wave impacts related to historical tsunami events. Among them, many authors used boulder fields as important indicators of past tsunamis, especially in the Mediterranean Sea. The aim of this study was to understand the mechanism of deposition of clusters of large boulders, consisting of beachrock slabs, which were found on the southern coasts of Lesvos Island (NE Aegean Sea). Methods to infer the origin of boulder deposits (tsunami vs. storm wave) are often based on hydrodynamic models even if different environmental complexities are difficult to be incorporated into numerical models. In this study, hydrodynamic equations did not provide unequivocal indication of the mechanism responsible for boulder deposition in the study area. Further analyses, ranging from geomorphologic to seismotectonic data, indicated a tsunami as the most likely cause of displacement of the boulders but still do not allow to totally exclude the extreme storm origin. Additional historical investigations (based on tsunami catalogues, historical photos and aged inhabitants interviews) indicated that the boulders are likely to have been deposited by the tsunami triggered by the 6.7 M s Chios-Karaburum earthquake of 1949 or, alternatively, by minor effects of the destructive tsunami produced by 1956's Amorgos Island earthquake. Results of this study point out that, at Mediterranean scale, to flank numerical models with the huge amount of the available historical data become a crucial tool in terms of prevention policies related to catastrophic coastal events. © 2012 Author(s). CC Attribution 3.0 License
Hyper-velocity impact test and simulation of a double-wall shield concept for the Wide Field Monitor aboard LOFT
The space mission LOFT (Large Observatory For X-ray Timing) was selected in
2011 by ESA as one of the candidates for the M3 launch opportunity. LOFT is
equipped with two instruments, the Large Area Detector (LAD) and the Wide Field
Monitor (WFM), based on Silicon Drift Detectors (SDDs). In orbit, they would be
exposed to hyper-velocity impacts by environmental dust particles, which might
alter the surface properties of the SDDs. In order to assess the risk posed by
these events, we performed simulations in ESABASE2 and laboratory tests. Tests
on SDD prototypes aimed at verifying to what extent the structural damages
produced by impacts affect the SDD functionality have been performed at the Van
de Graaff dust accelerator at the Max Planck Institute for Nuclear Physics
(MPIK) in Heidelberg. For the WFM, where we expect a rate of risky impacts
notably higher than for the LAD, we designed, simulated and successfully tested
at the plasma accelerator at the Technical University in Munich (TUM) a
double-wall shielding configuration based on thin foils of Kapton and
Polypropylene. In this paper we summarize all the assessment, focussing on the
experimental test campaign at TUM.Comment: Proc. SPIE 9144, Space Telescopes and Instrumentation 2014:
Ultraviolet to Gamma Ray, 91446
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