Abstract
High-energy, long gamma-ray bursts (GRBs) can be generated by the core collapse of massive stars at the end of their lives. When they happen in the close-by universe they can be ...exceptionally bright, as seen from the Earth in the case of the recent, giant, long-lasting GRB221009A. GRB221009A was produced by a collapsing star with a redshift of 0.152: this event was observed by many gamma-ray space experiments, which also detected an extraordinary long gamma-ray afterglow. The exceptionally large fluence of the prompt emission of about 0.013 erg cm
−2
illuminated a large geographical region centered on India and including Europe and Asia. We report in this paper the observation of sudden electron flux changes correlated with GRB221009A and measured by the HEPP-L charged particle detector on board the China Seismo-Electromagnetic Satellite, which was orbiting over Europe at the time of the GRB event. The time structure of the observed electron flux closely matches the very distinctive time dependence of the photon flux associated with the main part of the emission at around 13:20 UTC on 2022 October 9. To test the origin of these signals, we set up a simplified simulation of one HEPP-L subdetector: the results of this analysis suggest that the signals observed are mostly due to electrons created within the aluminum collimator surrounding the silicon detector, providing real-time monitoring of the very intense photon fluxes. We discuss the implications of this observation for existing and forthcoming particle detectors on low Earth orbits.
Abstract
In this paper we report the detection of five strong gamma-ray bursts (GRBs) by the High-Energy Particle Detector (HEPD-01) mounted on board the China Seismo-Electromagnetic Satellite, ...operational since 2018 on a Sun-synchronous polar orbit at a ∼507 km altitude and 97° inclination. HEPD-01 was designed to detect high-energy electrons in the energy range 3–100 MeV, protons in the range 30–300 MeV, and light nuclei in the range 30–300 MeV n
−1
. Nonetheless, Monte Carlo simulations have shown HEPD-01 is sensitive to gamma-ray photons in the energy range 300 keV–50 MeV, even if with a moderate effective area above ∼5 MeV. A dedicated time correlation analysis between GRBs reported in literature and signals from a set of HEPD-01 trigger configuration masks has confirmed the anticipated detector sensitivity to high-energy photons. A comparison between the simultaneous time profiles of HEPD-01 electron fluxes and photons from GRB190114C, GRB190305A, GRB190928A, GRB200826B, and GRB211211A has shown a remarkable similarity, in spite of the different energy ranges. The high-energy response, with peak sensitivity at about 2 MeV, and moderate effective area of the detector in the actual flight configuration explain why these five GRBs, characterized by a fluence above ∼3 × 10
−5
erg cm
−2
in the energy interval 300 keV–50 MeV, have been detected.
The High-Energy Particle Detector (HEPD) module is designed to measure the pitch angle and energy of electrons and protons fluxes trapped in the Earth Magnetosphere with energies 3-100 MeV and 30-300 ...MeV respectively. Because of the launch of the CSES-02 satellite, an interesting option for improving the HEPD is to endow the tracking module with ALPIDE monolithic active pixel, specifically developed for the ITS upgrade of ALICE experiment at CERN. In this work we present the project of a modular and compact particle tracker made of 5 turrets, making use of 150-pixel sensors equipped with Hybrid Integrated Circuit (HIC) and supported by Carbon Fiber Reinforced Plastics (CFRPs) staves housed in an aluminum case. All envisaged solutions have been validated with an intense campaign of qualification tests, concerning vibrations and thermal stresses. The HEPD-02 tracker project foreruns the massive usage of CFRPs for space initiatives both of scientific and exploratory nature.
Abstract
The Limadou collaboration includes all Italian scientists working on the project CSES (China Seismo-Electromagnetic Satellite), a constellation of satellites equipped with the most advanced ...technologies for correlating ionosphere perturbations with the occurrence of seismic events 2. For the launch of CSES-02, scheduled for mid-2022, the collaboration is realizing the high-energy particle detector 1, aimed at detecting electrons and protons trapped in Earth’s magnetosphere, with energies 5 MeV–100 MeV and 30 MeV–300 MeV respectively. This payload consists of a particle tracker, a trigger system and a calorimeter, which work in time-coincidence to accurately identify particles and measure their energy and trajectory. The tracker is based on monolithic active pixel sensors ALPIDE 4, an innovative platform with superior performances in the field of pixel detectors, developed for the upgrade of the ALICE experiment 5 at the LHC, at CERN. The challenge in the construction of the tracker has been to adapt the ALPIDE technology to the space environment and to the specifications of the space register. Lightness and stiffness, essential features for structures in a tracker module, needed to balance with the need for withstanding structural and vibrational stress in the extended range of temperature occurring in the launch phase. Proper material choice with high thermal conductivity for the heat dissipation, innovative design of thermal paths and structural test results guided the project of mechanics. The modular particle tracker consists of 5 turrets, each one made of 3 stacked staves, with 150 pixel sensors in total. For readout and control purposes, ALPIDE sensors are wire-bonded to flexible printed circuits, which enhances the fragility of the system and makes handling critical. Sensor supports in carbon fiber reinforced plastic and an external aluminum frame preserve the mechanical integrity and provide the essential thermal bridges for heat dissipation. We provide results from the intense campaign of structural, thermal and vibrational qualification tests that have been performed in compliance with the procedures required by the space register. It regards structure, module and turret elements. The envisaged solution is a novelty in the field of space applications and paves the way for important developments for particle and astroparticle physics experiments.
Background: Measurement of left ventricular outflow tract (LVOT) diameter and area for estimation of aortic valve area (AVA) using transthoracic echocardiography (TTE) and the continuity equation ...assumes circular LVOT. The use of direct planimetric measurement of LVOT area by gated-CT can theoretically improve accuracy of AVA calculation.
Purpose: We aim to assess reproducibility of LVOT echo measurement and its correlation and agreement with Gated CT measurements. In the subgroup with aortic stenosis (AS) we secondarily assessed the potential change in AS severity using LVOT area by CT instead of TTE in the continuity equation.
Methods:We retrospectively studied 93 patients, 43 of whom with severe AS. LVOT Area was measured with 2D TTE by 2 expert echocardiographers and gated-CT by 2 expert radiologists; inter-reader agreement and inter-method (Echo vs gated CT) agreement and correlation were measured. Finally we used the measurement of CT scan in the continuity equation instead of TTE measurement to assess potential reclassification of AS severity.
Results:Mean age was 78±11. Table shows inter-reader and inter-method agreement and correlation.
The correlation between 2 echocardiophers for LVOT measurements was good (rho = 0,77) although not perfect. Out of 43 severe AS, defined as AVA<1 cm2 using TTE in the continuity equation, 18 were reclassified by gated-CT LVOT measurements into moderate AS. This was due to gated-CT LVOT area resulting on average 1.4 cm2 larger than LVOT area by TTE.
Conclusion:LVOT is elliptical and TTE tends to underestimate LVOT area and AVA due to the measurement of the shorter diameter of this ellipse. CT scan can provide more geometrically accurate measurement and requires different cut-offs compared with traditional TTE AVA measurement. By the way, in the current study the LVOT area by CT was on average 38% larger of the LVOT area measured by TTE. Such correcting factor (increase TTE LVOT area by 38%) should apparently be used to assess anatomical true planimetric area to be compared with gated-CT LVOT.
summary table
TTE Inter-reader correlation LVOT area (Spearman rho)
0.77
TTE reader A vs CT 3-chamber equivalent correlation (Spearman rho)
0.49
TTE reader B vs CT 3-chamber equivalent correlation (Spearman rho)
0.38
TTE reader A area vs CT planimetric area correlation (Spearman rho)
0.41
TTE reader B area vs CT planimetric area correlation (Spearman rho)
0.31
Mean LVOT Area by TTE reader A
3,60
SD 0,60
38%
Mean LVOT Area by CT scan
4,99
SD 0,98
Abstract P981 Figure.
The design of the Micro Vertex Detector for the PANDA experiment faces a number of challenging aspects. The high radiation level, the limited space and accessibility, the strict material budget ...combined with the absence of a trigger signal and thus the huge amount of data to be sent to the DAQ require innovative solutions. Hybrid silicon pixels based on epitaxial material are under study as a detector technology capable to sustain the expected radiation levels at room temperature. A reduced scale prototype for the readout ASIC in a CMOS
0.13
μ
m
technology has been designed and tested. Irradiation tests have been performed on both the detector and the readout ASIC.
The Micro Vertex Detector (MVD) for the PANDA experiment is designed and optimized to reconstruct the D mesons secondary vertices and to provide the maximum acceptance close to the interaction point. ...The experimental physics goals and setup require sophisticated solutions for the detector integration in order to minimise the material budget. The thermal power produced by the "on board" read-out electronics is fast removed using carbon foam as heat sink. Two types of carbon foam are under evaluation. The mechanical and thermal property behaviors after neutron irradiation test with neutrons have been studied. Results from finite element thermal analyses and test bench are also presented.
Abstract
A 37 years old woman was referred to our hospital due to the onset since the previous day of vertigo associated with nausea and headache.
Her previous history revealed an hospitalization ten ...years before for Tako Tsubo Cardiomyopathy, during which the diagnosis of left temporo-jugular catecholamine secreting paraganglioma was made.
Subsequently, there were several hospitalizations for multiple cardiac manifestations, such as acute coronary syndrome during hypertensive crisis, acute pulmonary oedema, one relapse for TakoTsubo syndrome and then an episode of torsade de pointes (TdP) during hypokalemia and elongated QT.
The surgical removal of the mass was always rejected by the patient, and therefore, only radiotherapy was performed with significant reduction of the tumour dimensions. Moreover, alpha and beta adrenergic blockers were always administrated.
At the admission, she complained neurological symptoms, in particular balance disorder and dysmetria.
Brain Computed tomography (CT) was performed and it showed left posterior cerebellar infarction in late acute clinical phase, without haemorrhage. The patient underwent angiography that excluded cerebral artery dissection but showed acute occlusion of posterior internal cerebral artery. Echocardiogram showed moderate left ventricular hypertrophy with normal global and segmental kinetics, left atrial dilatation; besides, left ventricular apical thrombus was excluded.
Holter ECG monitoring showed very frequent polymorphic ventricular and supraventricular extrasystolic beats.
Urinary metanephrines were markedly increased. In particular urinary normetanephrine was up to 9 times the upper limit of normality (4874 ug/L, normal range 162-527 ug/24 h).
Since the surgical intervention was always refused, this case is a rare documentation of the several different cardiovascular clinical manifestation due to catecholamine secretion in a single patient. Paraganglioma could be a catecholamine secreting tumour that arises from cromaffin tissue of the sympathetic nervous system.
Clinical manifestations of paraganglioma are extremely variable leading to its designation as "great mimic". Adrenal tumours are associated with several cardiovascular diseases including LV hypertrophy, myocardial infarction, cardiac arrhythmias, heart failure and Tako Tsubo cardiomyopathy. Cerebral accident is a rare manifestation of adrenergic crisis with several possible aetiologies such as vasospasm or cardioembolic events. In our clinical case, considering the type and localization of the cerebral ischemic injury, the stroke is likely to have a cardioembolic etiology. Apical left ventricular trombus and PFO were excluded.
Therefore, in view of left atrial enlargement and the frequent supraventricular ectopy, even in the absence of documented arrhythmia, an undiagnosed episode of catecholamines induced atrial fibrillation was suspected, with subsequent cardioembolic event.
Abstract P257 Figure.
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