title: EDXRF imaging of Pb in glazed ceramics using a micropattern gas detector.
abstract: A new system for energy-resolved X-ray fluorescence imaging using a microhole and strip plate (MHSP), a new type of micropattern gas detector (MPGD), is proposed. It works as a single photon counting detector with position and energy detection capability. The interaction of X-rays with the gas medium produces electrons via the photoelectric effect, and the number of electrons is proportional to the absorbed X-ray energy. These electrons are further multiplied in the MHSP. Position detection is achieved using the charge division method. The detector has an active area of 28 x 28 mm(2) and shows good position resolution, about sigma = 125 microm, an intrinsic energy resolution of about 14% FWHM for 5.9 keV X-rays, and a counting rate capability of up to 0.5 MHz. The system has shown good properties for energy-dispersive X-ray fluorescence (EDXRF) applications, since it allows efficient energy and position detection of fluorescence X-rays from multielemental samples. In this work, the system was used to study lead depth distributions in eighteenth-century Portuguese faiences from the Santa Clara-a-Velha monastery. The fluorescence images were obtained by irradiating the samples, with a pinhole placed between the sample and the detector to focus the radiation into the detector. The results are presented here, including the elemental map distributions for different samples.
authors.affiliation: I3N-Physics Department, Aveiro University, 3810-193 Aveiro, Portugal. analuisa.silva@ua.pt
authors.forename: A L M
authors.initials: AL
authors.lastname: Silva
authors.forename: C A B
authors.initials: CA
authors.lastname: Oliveira
authors.forename: A L
authors.initials: AL
authors.lastname: Gouvêa
authors.forename: J M F
authors.initials: JM
authors.lastname: dos Santos
authors.forename: M L
authors.initials: ML
authors.lastname: Carvalho
authors.forename: J F C A
authors.initials: JF
authors.lastname: Veloso