UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

Guest
2024-11-21 20:49
 HOME     CONFERENCES     SEARCH            LOGIN     NEW USER     IMAGES   


Conference: Bucharest University Faculty of Physics 2008 Meeting


Section: Atmosphere and Earth Science; Environment Protection


Title:
A Dual-energy Computer Tomograph Dedicated to Investigate On-board of R/V Mare Nigrum Unconsolidated Sediments


Authors:
O.Duliu


Affiliation:
University of Bucharest, Faculty of Physics,P.O.BOX MG-11, Bucharest


E-mail


Keywords:
tomograph, X-rays, dual-energy mode


Abstract:
Within a joint project funded by the Romanian Ministry of Education and research, a dual-energy computer tomograph able to generate both tomographic and digital radiographic images of unconsolidated sediments cores with a diameter up to 12 cm and a height up to 1 ma was designed, built and commissioned. Although designated to work on board of R/V Mare Nigrum or of any oceanographic research vessel, this instrument can also be used with minimum adaptations in any stationary laboratory equiped with an adequate protection against hard X-rays. The computer tomograph is provided with a single X-ray tube with maximum anodic potential of 160 kV and two set of 200 in-line X-ray detectors separated by a copper shield which allowed obtaining tomographic as well as digital radiographic images depicting the distribution of both density and effective atomic number within investigated objects. In tomographic mode, the spatial resolution of reconstructed images of the linear attenuation coefficient is about 0.5 mm while in dual-energy mode, when reconstructed images depict the distribution of densities and effective atomic numbers, the spatial resolution is about 1 to 1.5 mm. The same spatial resolution was obtained also in digital radiographic mode. By using a set of standard samples with well known values of densities and effective atomic numbers we have estimated the precision in calculating the local values of these parameters to 8.7 % for density and 2% for the effective atomic number. By its performances and by its ability to work on-board, the tomograph could be very useful not only for oceanographic researches but also for any exploratory works performed on open sea.