Tracking and Monitoring of the Alignment System Used for Nuclear Physics Experiments

The ELI-NP (Extreme Light Intensity—Nuclear Physics) project, developed at the Horia Hulubei National Institute for RD in Physics and Nuclear Engineering (IFIN-HH), has included one component dedicated to the study of interactions between brilliant gamma-ray and matter, with applications in nuclear physics and the science of materials. The paper is focused on the interaction chamber, an important part of the facility which hosts the experiment’s samples. The interaction chamber is endowed with a mobile sample support (holder), which automatically tracks the γ-ray beam. The γ-ray radiation source presents a slight variation of the direction of the emitted radiation in time. The built system ensures the permanent collimation between the γ-ray beam and the sample that is being investigated. This is done with two electric motors, which have a symmetrical movement with respect to the center of a rectangle. The specific measures taken by the design and implementation that permit to reach performances of tracking system are emphasized in the paper. The methodology considers the relative displacement between the detectors with which the laboratory is equipped and the absolute position in space of the sample boundary. The control of this motion is designed to respect the symmetry of the system. Both facets of the project (hardware and software) are detailed, emphasizing the way in which the designers ensured compliance with the system of real-time operation conditions of the tracking and monitoring system.

Microfluidization-Driven Changes in Some Physicochemical Characteristics, Metal/Mineral Composition, and Sensory Attributes of Sugarcane Juice

This work evaluated the effect of microfluidization at different pressure (50, 100, 150, and 200 MPa)-cycle (1, 3, 5, 7) combinations on the physicochemical (total soluble solids, titratable acidity, pH, and electrical conductivity), sensory, and metal/mineral composition of sugarcane juice which was previously unexplored. Juice extracted from blanched sugarcane stems (var Co 0238) was microfluidized, and the analysis for different parameters was conducted using standard protocols. The mineral/metal composition was determined using ICP-OES following a wet digestion method. Results showed that TSS decreased from 18.88 °Brix to a range of 10.15–15.7 °Brix with the former (lower value) being due to the release of insoluble matter after microfluidization which was further solubilised at higher processing cycles (as in the latter). The pH did not vary significantly as compared to control and was in the range of 5.2–5.7. However, a decrease in titratable acidity (0.1–0.26%) was found as compared to control (0.26%). The electrical conductivity of microfluidized sugarcane juice varied from 4.45 to 5.12 mS as compared to 4.95 mS for control. Metal/mineral analysis showed rich reserves of magnesium, phosphorus, potassium, and calcium in sugarcane juice which degraded after microfluidization perhaps due to filtration effect caused by the micropore in the interaction chamber of the microfluidizer. The sensory score showed acceptability of the juice after microfluidization (overall acceptability ∼7).

Distortion of Thomson Parabolic-Like Proton Patterns Due to Electromagnetic Interference

Intense electromagnetic pulses (EMPs) accompany the production of plasma when a high-intensity laser irradiates a solid target. The EMP occurs both during and long after the end of the laser pulse (up to hundreds of nanoseconds) within and outside the interaction chamber, and interferes with nearby electronics, which may lead to the disruption or malfunction of plasma diagnostic devices. This contribution reports a correlation between the frequency spectrum of the EMP and the distortion of Thomson parabola tracks of protons observed at the kJ-class PALS laser facility in Prague. EMP emission was recorded using a simple flat antenna. Ions accelerated from the front side of the target were simultaneously detected by a Thomson parabola ion spectrometer. The comparison of the two signals suggests that the EMP may be considered to be the source of parabolic track distortion.

Simultaneous observation of ultrafast electron and proton beams in TNSA

The interaction of ultra-intense high-power lasers with solid-state targets has been largely studied for the past 20 years as a future compact proton and ion source. Indeed, the huge potential established on the target surface by the escaping electrons provides accelerating gradients of TV/m. This process, called target normal sheath acceleration, involves a large number of phenomena and is very difficult to study because of the picosecond scale dynamics. At the SPARC_LAB Test Facility, the high-power laser FLAME is employed in experiments with solid targets, aiming to study possible correlations between ballistic fast electrons and accelerated protons. In detail, we have installed in the interaction chamber two different diagnostics, each one devoted to characterizing one beam. The first relies on electro-optic sampling, and it has been adopted to completely characterize the ultrafast electron components. On the other hand, a time-of-flight detector, based on chemical-vapour-deposited diamond, has allowed us to retrieve the proton energy spectrum. In this work, we report preliminary studies about simultaneous temporal resolved measurements of both the first forerunner escaping electrons and the accelerated protons for different laser parameters.

Preferential binding of unsaturated hydrocarbons in aryl-bisimidazolium·cucurbit[8]uril complexes furbishes evidence for small-molecule π–π interactions

Restricting the internal cavity size of cucurbit[8]uril with auxiliary guests sets up an intermolecular interaction chamber for hydrocarbons, which provides insights into dispersion, arene–hydrocarbon interactions, and desolvation effects.

Evaluation of Explosivity From Fuel Coolant Interaction Experiments in the TROI Facility

The explosivity of corium is evaluated from the fuel coolant interaction experimental data produced in the TROI facility. From 62 experimental datasets used to simulate the fuel coolant interaction under a partial flooded condition of the reactor, the explosivity when observing the dynamic pressure and/or force measured in experiments is qualitatively evaluated depending on the coolant depth, the shape of the interaction chamber, the free fall height of the melt jet, and the water temperature effect. For 12 of the experimental datasets produced under the OECD/SERENA Project, the explositivity is quantitavely evaluated using the conversion ratio. The conversion ratio is also evaluated for three experimental datasets to simulate the fuel coolant interaction under reactor flooded conditions. The corium system showed a relatively low explosivity compared to the ZrO2 or Al2O3 system. It also turned out that the flooding condition of the reactor cavity does not affect the change in explosivity.