title: Characteristics of a tandem system of ionization chambers in X-ray beams, mammography level.
abstract: Two parallel plate ionization chambers (inserted in slab phantoms) recently assembled at IPEN were studied in relation to their operational characteristics for use in quality control of X-ray beams, mammography level. The chambers present only one difference: one has an inner collecting electrode made of graphite and the other, of aluminum. These chambers make up a tandem system, which may be employed to verify X-ray beams energy constancy, by the confirmation of half-value layers and effective energies, and to determinate air kerma rates. The chambers presented good results for the operational tests, as recommended internationally.
authors.affiliation: Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN), Comissão Nacional de Energia Nuclear, São Paulo, SP, Brazil. lafonso@ipen.br
authors.forename: L C
authors.initials: LC
authors.lastname: Afonso
authors.forename: V
authors.initials: V
authors.lastname: Vivolo
authors.forename: L V E
authors.initials: LV
authors.lastname: Caldas
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D008327:Mammography / Q000295:instrumentation*; D011829:Radiation Dosage; D011874:Radiometry / Q000295:instrumentation*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers; D014965:X-Rays