Explore the vast range of titles available.

The AEgIS experiment located at the Antiproton Decelerator at CERN aims to measure the gravitational fall of a cold antihydrogen pulsed beam. The precise observation of the antiatoms in the Earth gravitational field requires a controlled production and manipulation of antihydrogen. The neutral antimatter is obtained via a charge exchange reaction between a cold plasma of antiprotons from ELENA decelerator and a pulse of Rydberg positronium atoms. The current custom electronics designed to operate the 5 and 1 T Penning traps are going to be replaced by a control system based on the ARTIQ & Sinara open hardware and software ecosystem. This solution is present in many atomic, molecular and optical physics experiments and devices such as quantum computers. We report the status of the implementation as well as the main features of the new control system.

The primary goal of the AEgIS collaboration at CERN is to measure the gravitational acceleration on neutral antimatter. Positronium (Ps), the bound state of an electron and a positron, is a suitable candidate for a force-sensitive inertial measurement by means of deflectometry/interferometry. In order to conduct such an experiment, the impact position and time of arrival of Ps atoms at the detector must be detected simultaneously. The detection of a low-velocity Ps beam with a spatial resolution of (88 ± 5) μm was previously demonstrated [1]. Based on the methodology employed in [1] and [2], a hybrid imaging/timing detector with increased spatial resolution of about 10 μm was developed. The performance of a prototype was tested with a positron beam. The concept of the detector and first results are presented.

Data quality of the tokamaks diagnostics is often a neglected topic. In literature it is rather rare to find considerations regarding the data quality received from the diagnostic systems’ sensors. The scope of the paper is to provide a discussion regarding systems’ construction and analysis in scope of implementation of data quality monitoring methods for a new generation of diagnostics. Mainly considerations are performed regarding the necessity of DQM (Data Quality Monitoring) implementation, functionality, performance and required system resources. The covered topics are related to basics of system construction including: system layout and construction blocks, data processing stages, signal processing modes, system construction with resource estimation in scope of DQM implementation. Based on the covered points, it is possible to plan the extra resources or specific construction, to provide reliable design with data quality monitoring features. The data quality monitoring aspect is especially important in the modern diagnostics working with a real-time feedback loop. Such approach could be especially interesting for the ITER-like projects, since the quality of the data may directly influence the behavior of the control systems during plasma phenomena. The work is based on experience in design work of various high performance diagnostic systems for plasma physics and high energy physics.

Low-temperature antihydrogen atoms are an effective tool to probe the validity of the fundamental laws of Physics, for example the Weak Equivalence Principle (WEP) for antimatter, and -generally speaking- it is obvious that colder atoms will increase the level of precision. After the first production of cold antihydrogen in 2002 [1], experimental efforts have substantially progressed, with really competitive results already reached by adapting to cold antiatoms some well-known techniques pre- viously developed for ordinary atoms. Unfortunately, the number of antihydrogen atoms that can be produced in dedicated experiments is many orders of magnitude smaller than of hydrogen atoms, so the development of novel techniques to enhance the production of antihydrogen with well defined (and possibly controlled) conditions is essential to improve the sensitivity. We present here some experimental results achieved by the AEgIS Collaboration, based at the CERN AD (Antiproton Decelerator) on the production of antihydrogen in a pulsed mode where the production time of 90% of atoms is known with an uncertainty of ~ 250 ns [2]. The pulsed antihydrogen source is generated by the charge-exchange reaction between Rydberg positronium ( Ps* ) and an antiproton ( p¯ ): p¯ + P s * → H¯ * + e − , where Ps* is produced via the implantation of a pulsed positron beam into a mesoporous silica target, and excited by two consecutive laser pulses, and antiprotons are trapped, cooled and manipulated in Penning-Malmberg traps. The pulsed production (which is a major milestone for AEgIS) makes it possible to select the antihydrogen axial temperature and opens the door for the tuning of the antihydrogen Rydberg states, their de-excitation by pulsed lasers and the manipulation through electric field gradients. In this paper, we present the results achieved by AEgIS in 2018, just before the Long Shutdown 2 (LS2), as well as some of the ongoing improvements to the system, aimed at exploiting the lower energy antiproton beam from ELENA [3].

The main detector system at the Nuclotron-based Ion Collider fAcility (NICA) located in Dubna, Russia is the Multi-Purpose Detector (MPD). For better calibration reason, the MPD needs an additional trigger system for an off-beam calibration of MPD sub-detectors and for rejection (veto) of cosmic muons. The system should also be useful for practical astrophysics observations of cosmic showers. The consortium NICA-PL group defines goals and basic assumptions for the MPD Cosmic Ray Detector (MCORD). This article describes the conceptual design and simulation plans of the MCORD detector based on plastic scintillators with SiPM photodetectors and electronic digital system based on the MicroTCA crate.

BACKGROUND Time spent in sedentary pursuits such as sitting (SIT) is associated with an increased risk of cardiovascular disease independent of physical activity (PA). The purpose of this study was to examine the associations of PA and SIT with central hemodynamic burden in young adults. METHODS Aortic pressure waveforms were obtained using radial applanation tonometry and a generalized transfer function in 70 young healthy men (n = 41) and women (n = 29) (mean age = 23±1 years; body mass index = 24±1kg/m2). A wave separation technique that uses a physiologic pseudoaortic flow waveform was used to derive incident/forward wave pressure (Pf) and reflected/backward wave pressure (Pb). Levels of PA (metabolic equivalent, minutes per week) and SIT (sitting time per day) were obtained by self-report using the International Physical Activity Questionnaire. RESULTS A negative correlation existed between PA and Pf (r = −0.30; P < 0.05) and Pb (r = −0.36; P < 0.05). A positive correlation existed between SIT and Pf (r = 0.39; P < 0.05) and Pb (r = 0.44; P < 0.05). According to results from multiple regression, after adjusting for potential confounders (age, sex, height, heart rate, mean pressure) and PA, associations between SIT and Pf (P < 0.05) and SIT and Pb (P < 0.05) remained. CONCLUSIONS SIT is associated with higher forward wave pressure and backward wave pressure, 2 novel hemodynamic correlates of cardiovascular disease risk and target organ damage, in young apparently healthy men and women. This association is independent of PA.

Exposure of the arterial wall to retrograde shear acutely leads to endothelial dysfunction and chronically contributes to a proatherogenic vascular phenotype. Arterial stiffness and increased pressure from wave reflections are known arbiters of blood flow in the systemic circulation and each related to atherosclerosis. Using distal external compression of the calf to increase upstream retrograde shear in the superficial femoral artery (SFA), we examined the hypothesis that changes in retrograde shear are correlated with changes in SFA stiffness and pressure from wave reflections. For this purpose, a pneumatic cuff was applied to the calf and inflated to 0, 35, and 70 mmHg (5 min compression, randomized order, separated by 5 min) in 16 healthy young men (23 ± 1 years of age). Doppler ultrasound and wave intensity analysis was used to measure SFA retrograde shear rate, reflected pressure wave intensity (negative area [NA]), elastic modulus (Ep), and a single‐point pulse wave velocity (PWV) during acute cuff inflation. Cuff inflation resulted in stepwise increases in retrograde shear rate (P < 0.05 for main effect). There were also significant cuff pressure‐dependent increases in NA, Ep, and PWV across conditions (P < 0.05 for main effects). Change in NA, but not Ep or PWV, was associated with change in retrograde shear rate across conditions (P < 0.05). In conclusion, external compression of the calf increases retrograde shear, arterial stiffness, and pressure from wave reflection in the upstream SFA in a dose‐dependent manner. Wave reflection intensity, but not arterial stiffness, is correlated with changes in peripheral retrograde shear with this hemodynamic manipulation. e00022 Prolonged exposure of the arterial wall to retrograde shear leads to endothelial dysfunction and a pro‐atherogenic vascular phenotype. In this study, we explore several vascular and hemodynamic correlates of retrograde shear in the superficial femoral artery (an athero‐prone vessel). Findings indicate that pressure from wave reflections but not arterial stiffness is associated with retrograde shear in the superficial femoral artery.

Long-duration γ-ray bursts (GRBs) release copious amounts of energy across the entire electromagnetic spectrum, and so provide a window into the process of black hole formation from the collapse of massive stars. Previous early optical observations of even the most exceptional GRBs (990123 and 030329) lacked both the temporal resolution to probe the optical flash in detail and the accuracy needed to trace the transition from the prompt emission within the outflow to external shocks caused by interaction with the progenitor environment. Here we report observations of the extraordinarily bright prompt optical and γ-ray emission of GRB 080319B that provide diagnostics within seconds of its formation, followed by broadband observations of the afterglow decay that continued for weeks. We show that the prompt emission stems from a single physical region, implying an extremely relativistic outflow that propagates within the narrow inner core of a two-component jet. GRB 080319B: fit to burst The γ-ray burst GRB 080319B, the result of the violent collapse of a massive star to form a black hole, is the most luminous optical flash so far observed in the 40-year history of γ-ray astronomy. Discovered by the Swift satellite on 19 March 2008 and briefly visible to the naked eye, it produces energy across the entire electromagnetic spectrum. Now a reanalysis of the extraordinarily bright emissions of GRB 080319B within a few seconds of its formation, together with broadband observations of its decay over the following few weeks, provide the clearest picture yet of one of these events. The data clearly establish that the prompt optical flash was produced in the same physical region as the γ-ray burst itself. The afterglow properties cannot be explained by the standard simple models, but rather imply a multi-component jet interpretation. Long duration γ-ray bursts (GRBs) release copious amounts of energy across the entire electromagnetic spectrum, and provide a window into the process of black hole formation from the collapse of massive stars. Observations of the extraordinarily bright prompt optical and γ-ray emission of GRB 080319B shows that the prompt emission stems from a single physical region, implying an extremely relativistic outflow that propagates within the narrow inner core of a two-component jet.

In the context of the Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy (AEgIS) located at CERN, positron-positronium converters with a high positron-positronium conversion efficiency have been designed in both reflection and transmission geometries. The converters utilize nanochanneled silicon target technology with positron conversion efficiencies up to around 50% and around 16%, at room temperature and in the absence of magnetic fields, for reflection and transmission respectively. The positron-positronium converters allow for the pulsed production of antihydrogen ( H ¯ ) within the AEgIS experiment. This paper discusses the use of a pulsed H ¯ beam in a moiré deflectometer to perform a precise gravitational measurement on H ¯ at AEgIS. This work describes the principles and technical details of the current design of a moiré deflectometer using the pulsed H ¯ beam. The main goal of this work is to summarize the ongoing project of adding the described moiré deflectometer to the AEgIS experiment to further their efforts toward probing the material dependence of gravity and testing the weak equivalence principle (WEP).

The first successful demonstration of broadband laser cooling of positronium (Ps) atoms, obtained within the AEgIS experiment at CERN, is presented here. By employing a custom-designed pulsed alexandrite laser system at 243 nm featuring long-duration pulses of 70 ns and an energy able to saturate the 1 3 S–2 3 P transition over the broad spectrum range of 360 GHz, the temperature of a room-temperature Ps cloud was reduced from 380 K to 170 K in 70 ns. This advancement opens new avenues for precision spectroscopy, antihydrogen production, and fundamental tests with antimatter.