Compact in-vacuum gamma-ray spectrometer for high-repetition rate PW-class laser-matter interaction

With the advent of high repetition rate laser facilities, novel diagnostic tools compatible with these advanced specifications are in demand. This paper presents the design of an active gamma-ray spectrometer intended for these high repetition rate experiments, with particular emphasis on functionality within a PW level laser-plasma interaction chamber's extreme conditions. The spectrometer uses stacked scintillators to accommodate a broad range of gamma-ray energies, demonstrating its adaptability for various experimental setups. Additionally, it has been engineered to maintain compactness, electromagnetic pulse resistance, and ISO-5 cleanliness requirements while ensuring high sensitivity. The paper also outlines the unfolding process, to recover the gamma-ray spectrum from the spectrometer's captured image thanks to a calibration using a $^{60}$Co source

Interferometry of Direct Photons in Central 280Pb+208Pb Collisions at 158A GeV

Two-particle correlations of direct photons were measured in central 208Pb+208Pb collisions at 158 AGeV. The invariant interferometric radii were extracted for 100<K_T<300 MeV/c and compared to radii extracted from charged pion correlations. The yield of soft direct photons, K_T<300 MeV/c, was extracted from the correlation strength and compared to theoretical calculations.Comment: 5 pages, 4 figure

Event-by-Event Fluctuations in Particle Multiplicities and Transverse Energy Produced in 158.A GeV Pb+Pb collisions

Event-by-event fluctuations in the multiplicities of charged particles and photons, and the total transverse energy in 158$\cdot A$ GeV Pb+Pb collisions are studied for a wide range of centralities. For narrow centrality bins the multiplicity and transverse energy distributions are found to be near perfect Gaussians. The effect of detector acceptance on the multiplicity fluctuations has been studied and demonstrated to follow statistical considerations. The centrality dependence of the charged particle multiplicity fluctuations in the measured data has been found to agree reasonably well with those obtained from a participant model. However for photons the multiplicity fluctuations has been found to be lower compared to those obtained from a participant model. The multiplicity and transverse energy fluctuations have also been compared to those obtained from the VENUS event generator.Comment: To appear in Physical Review C; changes : more detailed discussion on errors and few figures modifie

Centrality Dependence of Neutral Pion Production in 158 A GeV Pb + Pb Collisions

The production of neutral pions in 158AGeV Pb+Pb collisions has been studied in the WA98 experiment at the CERN SPS. Transverse momentum spectra are studied for the range 0.3 GeV/c < mT-m0 < 4.0 GeV/c. The results for central collisions are compared to various models. The centrality dependence of the neutral pion spectral shape and yield is investigated. An invariance of the spectral shape and a simple scaling of the yield with the number of participating nucleons is observed for centralities with greater than about 30 participating nucleons which is most naturally explained by assuming an equilibrated system.Comment: 5 pages, Latex, including 3 eps figures, submitted to Phys.Rev.Lett; updated pQCD comparison due to new input from the author, updated references, corrected plotting error in figure

Characteristics of the motivational value-based attitude of students towards physical education

El artículo explora las peculiaridades de la actitud motivadora basada en el valor de los jóvenes estudiantes modernos de Ucrania hacia las clases de educación física y el mantenimiento de un estilo de vida saludable. 501 estudiantes de tres instituciones de educación superior de Ucrania participaron en el estudio. La investigación fue realizada por los cuestionarios de los autores que permitieron estudiar la actitud de los estudiantes hacia la educación física tradicional, la salud física extracurricular y las actividades deportivas, así como para encontrar las razones que impiden a los estudiantes realizar ejercicios físicos regulares y mantener un estilo de vida saludable. Los resultados mostraron la falta de motivación de los jóvenes estudiantes de Ucrania para las clases tradicionales de educación física que conducen a un bajo nivel de aptitud física y salud de los futuros especialistas.&nbsp;The article explores the peculiarities of the motivational value-based attitude of modern student youth of Ukraine to the physical education classes and the maintenance of a healthy lifestyle. 501 students of three higher educational institutions of Ukraine participated in the study. The research was conducted by authors’ questionnaires that allowed to study the attitude of students to traditional physical education, extracurricular physical healthcare and sports activities, as well as to find the reasons that prevent students from regular physical exercises and maintenance of a healthy lifestyle. The results of the study showed the lack of motivation of the student youth of Ukraine for traditional physical education classes that leads to a low level of physical fitness and health of future specialists

Laser-Plasma Interactions Enabled by Emerging Technologies

An overview from the past and an outlook for the future of fundamental laser-plasma interactions research enabled by emerging laser systems