Azevedo, C. D. R., Baeza, A., Chauveau, E., Corbacho, J. A., Diaz, J., Domange, J., et al. (2020). Simulation results of a real-time in water tritium monitor. Nucl. Instrum. Methods Phys. Res. A, 982, 164555–7pp.
Abstract: In this work we present simulation results for a modular tritium in-water real-time monitor. The system allows for scalability in order to achieve the required sensitivity. The modules are composed by 340 uncladed scintillating fibers immersed in water and 2 photosensors in coincidence for light readout. Light yield and Birks' coefficient uncertainties for low energy beta particles is discussed. A study of the detection efficiency according to the fiber length is presented. Discussion on the system requirements and background mitigation for a device with sensitivity of 100 Bq/L, required to comply with the European directive 2013/51/Euratom, is presented. Due to the low energetic beta emission from tritium a detection efficiency close to 3.3% was calculated for a single 2 mm round fiber.
|
HAWC Collaboration(Abeysekara, A. U. et al), & Salesa Greus, F. (2023). The High-Altitude Water Cherenkov (HAWC) observatory in Mexico: The primary detector. Nucl. Instrum. Methods Phys. Res. A, 1052, 168253–18pp.
Abstract: The High-Altitude Water Cherenkov (HAWC) observatory is a second-generation continuously operated, wide field-of-view, TeV gamma-ray observatory. The HAWC observatory and its analysis techniques build on experience of the Milagro experiment in using ground-based water Cherenkov detectors for gamma-ray astronomy. HAWC is located on the Sierra Negra volcano in Mexico at an elevation of 4100 meters above sea level. The completed HAWC observatory principal detector (HAWC) consists of 300 closely spaced water Cherenkov detectors, each equipped with four photomultiplier tubes to provide timing and charge information to reconstruct the extensive air shower energy and arrival direction. The HAWC observatory has been optimized to observe transient and steady emission from sources of gamma rays within an energy range from several hundred GeV to several hundred TeV. However, most of the air showers detected are initiated by cosmic rays, allowing studies of cosmic rays also to be performed. This paper describes the characteristics of the HAWC main array and its hardware.
|
Lerendegui-Marco, J., Cisterna, G., Hallam, J., Babiano-Suarez, V., Balibrea-Correa, J., Calvo, D., et al. (2025). Imaging neutrons with a position-sensitive monolithic CLYC detector. Nucl. Instrum. Methods Phys. Res. A, 1079, 170594–12pp.
Abstract: In this work, we have developed and characterized a position-sensitive CLYC detector that acts as the neutron imaging layer and y-ray Compton scatterer of the novel dual Gamma-ray and Neutron Vision (GN-Vision) system, which aims at simultaneously obtaining information about the spatial origin of y-ray and neutron sources. We first investigated the performance of two large 50 x 50 mm2 monolithic CLYC crystals, 8 and 13 mm thick respectively, coupled to a pixelated SiPM in terms of energy resolution and neutron-gamma discrimination. The response of two different 95% 6Li-enriched CLYC detectors coupled to an array of 8 x 8 SiPMs was studied in comparison to the results of a conventional photo-multiplier tube. An energy resolution of about 6% with PMT and 8% with SiPMs for the 137Cs peak and a figure of merit of 3-4 for the neutron-gamma discrimination have been obtained. The spatial response of the CLYC-SiPM detector to y-rays and neutrons has also been characterized using charge modulation-based multiplexing techniques based on a diode-coupled charge division circuit. Average resolutions close to 5 mm FWHM with good linearity are obtained in the transverse crystal plane. Last, this work presents the first proof-of-concept experiments of the neutron imaging capability using a neutron pinhole collimator attached to the developed position sensitive CLYC detector.
|
Sajjad Athar, M., Ruiz Simo, I., & Vicente Vacas, M. J. (2011). Nuclear medium modification of the F2(x, Q^2) structure function. Nucl. Phys. A, 857(1), 29–41.
Abstract: We study the nuclear effects in the electromagnetic structure function F-2(x, Q(2)) in the deep inelastic lepton nucleus scattering process by taking into account Fermi motion, binding, pion and rho meson cloud contributions. Calculations have been done in a local density approximation using relativistic nuclear spectral functions which include nucleon correlations. The ratios R-F2(A) (x, Q(2)) = 2F(2)(A)(x, Q(2))/AF(2)(D)(x, Q(2)) are obtained and compared with recent JLab results for light nuclei with special attention to the slope of the x distributions. This magnitude shows a non-trivial A dependence and it is insensitive to possible normalization uncertainties. The results have also been compared with some of the older experiments using intermediate mass nuclei.
|
Sahin, E. et al, Gadea, A., & Algora, A. (2012). Structure of the N=50 As, Ge, Ga nuclei. Nucl. Phys. A, 893, 1–12.
Abstract: The level structures of the N = 50 As-83, Ge-82, and Ga-81 isotones have been investigated by means of multi-nucleon transfer reactions. A first experiment was performed with the CLARA PRISMA setup to identify these nuclei. A second experiment was carried out with the GASP array in order to deduce the gamma-ray coincidence information. The results obtained on the high-spin states of such nuclei are used to test the stability of the N = 50 shell closure in the region of Ni-78 (Z = 28). The comparison of the experimental level schemes with the shell-model calculations yields an N = 50 energy gap value of 4.7(3) MeV at Z = 28. This value, in a good agreement with the prediction of the finite-range liquid-drop model as well as with the recent large-scale shell model calculations, does not support a weakening of the N = 50 shell gap down to Z = 28.
Keywords: NUCLEAR REACTIONS U-238(Se-82, Ga-81), (Se-82, Ge-82), (Se-82, As-83), E=515 MeV; measured E-gamma, I-gamma (theta), gamma gamma-coin, reaction fragments, (fragment)gamma-coin using PRISMA magnetic spectrometer, gamma after deexcitation using Ge Compton-suppressed detectors of CLARA array, thin and thick target; deduced sigma(theta), levels, J, pi; calculated levels, J, pi using shell model
|
