1,212 research outputs found

    The Advanced Gamma Ray Tracking Array AGATA

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    New accelerator facilities for radioactive–ion beams will enter into operation in the next few years, providing the opportunity to explore unknown territories of the nuclear landscape. The foreseen harsh experimental conditions require the construction of a new generation of γ–ray detector arrays based on the emerging technique of γ–ray tracking. The "Advanced GAmma Tracking Array" (AGATA), proposed in Europe, will be built out of 120 or 180 highly segmented Ge crystals operated in position sensitive mode by means of digital data techniques and pulse shape analysis of the segment signals. AGATA will be capable of measuring γ radiation in a large energy range (from ∼ 10 keV to ∼ 10 MeV), with the largest possible photopeak efficiency (25% at M γ = 30 ) and with good spectral response. The very good Doppler correction and background rejection capability of this γ–ray tracking array will allow to perform γ–ray spectroscopy experiments using fragmentation beams with sources moving at velocities up to β ∼ 0.5

    Simulation and analysis of pulse shapes from highly segmented HPGe detectors for the γ-ray tracking array MARS

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    A flexible program to calculate the pulse shapes from highly segmented HPGe detectors of various geometrical shapes has been developed. Signals originating from single points of interaction in both the quasi-true-coaxial and the closed-end part of the detector are discussed. In order to present the main features of these signals, we have introduced simplified characteristic curves. These curves are analysed with regard to the application of pulse shape analysis for three-dimensional position determination in detectors for a g-ray tracking array. # 2001 Elsevier Science B.V. All rights reserved

    The Advanced Gamma Ray Tracking Array AGATA

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    On behalf of the AGATA collaboration New accelerator facilities for radioactive-ion beams will enter into operation in the next few years, providing the opportunity to explore unknown territories of the nuclear landscape. The foreseen harsh experimental conditions require the construction of a new generation of γ-ray detector arrays based on the emerging technique of γ-ray tracking. The "Advanced GAmma Tracking Array" (AGATA), proposed in Europe, will be built out of 120 or 180 highly segmented Ge crystals operated in position sensitive mode by means of digital data techniques and pulse shape analysis of the segment signals. AGATA will be capable of measuring γ radiation in a large energy range (from ∼ 10 keV to ∼ 10 MeV), with the largest possible photopeak efficiency (25% at M γ = 30) and with good spectral response. The very good Doppler correction and background rejection capability of this γ-ray tracking array will allow to perform γ-ray spectroscopy experiments using fragmentation beams with sources moving at velocities up to β ∼ 0.5

    Performance of the Fully Digital FPGA-based Front-End Electronics for the GALILEO Array

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    In this work we present the architecture and results of a fully digital Front End Electronics (FEE) read out system developed for the GALILEO array. The FEE system, developed in collaboration with the Advanced Gamma Tracking Array (AGATA) collaboration, is composed of three main blocks: preamplifiers, digitizers and preprocessing electronics. The slow control system contains a custom Linux driver, a dynamic library and a server implementing network services. The digital processing of the data from the GALILEO germanium detectors has demonstrated the capability to achieve an energy resolution of 1.53 per mil at an energy of 1.33 MeV.Comment: 5 pages, 6 figures, preprint version of IEEE Transactions on Nuclear Science paper submitted for the 19th IEEE Real Time Conferenc

    Effects of Pairing in the Pseudo-SU(3) Model

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    An extended version of the pseudo-SU(3) model which includes both spin and proton-neutron degrees of freedom is used to study the influence of the pairing interaction on K-band mixing, B(E2) values and quadrupole moments. Using the asymmetric rotor model as a backdrop, specific consequences of a many-particle shell-model based description of these collective properties are demonstrated and fundamental limits of the collective model's approach are investigated. Finally, the pseudo-SU(3) model, including representation mixing induced by pairing, is used to calculate the energies of 140Ce and the results are compared to experimental data and other theories.Comment: 21 pages, Latex, 11 figures available on request via mail or fax, accepted by Nucl. Phys.

    Pilomatrix Carcinoma: Report of Two Cases of the Head and Review of the Literature

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    Background: Pilomatrix carcinoma (PC) is a rare skin tumor arising from hair follicle matrix cells. It is locally aggressive with a high rate of local recurrence after surgical excision. Few cases in the literature have been described and the management is not well defined. Objectives: The aim of this study was to present two cases of PC located on the head and review the relevant literature about epidemiology, clinical and dermoscopic evaluation, characteristics of local and distant metastases, local recurrence rate and management of this rare skin tumor. Methods: We consulted databases from PubMed, Research Gate and Google Scholar, from January 2012 to November 2022. We reviewed the literature and reported two additional cases. Results: We selected 52 tumors in middle-aged to older patients located mostly on the head. Dermoscopy evaluation was rarely performed in the pre-operative diagnostic setting. The most definitive treatment was wide local excision, but local recurrences were common. In total, we observed 11 cases of recurrences and 9 patients with locoregional or distant metastases. Four patients received adjuvant radiotherapy, two patients needed chemotherapy and local cancer therapy and one patient received radiochemotherapy. Conclusion: Our reports and the review of the literature can provide a better awareness and management of this rare tumor

    Co-existing structures in 105Ru

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    New positive-parity states, having a band-like structure, were observed in 105Ru. The nucleus was produced in induced fission reaction and the prompt gamma-rays, emitted from the fragments, were detected by the EUROBALL III multi-detector array. The partial scheme of excited 105Ru levels is analyzed within the Triaxial-Rotor-plus-Particle approach
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