Raio - x

2011 International Nuclear Atlantic Conference - INAC 2011 Belo Horizonte,MG, Brazil, October 24-28, 2011 ASSOCIAÇÃO BRASILEIRA DE ENERGIA NUCLEAR - ABEN ISBN: 978-85-99141-04-5

FLUCTUATIONS ON THE X-RAY INTENSITY BEAM USING A PORTABLE X-RAY PROBE BASED ON 6LiI(Eu) CRYSTAL.
Geraldo P. Araujo1, Arno H. Oliveira1, André C. Carneiro2, Clemente J. G. Carneiro2, Felix M. Milian2 e Fermin G. Velasco2.
1

Programa de Pós-Graduação em Ciências e Técnicas Nucleares - PCTN Universidade Federal de Minas Gerais - UFMG

[e-mail], [e-mail] Centro de Pesquisa em Ciências e Tecnologias das Radiações – CPqCTR Universidade Estadual de Santa Cruz – UESC Rodovia Ilhéus – Itabuna, KM 16 45662-900 Ilhéus, BA [e-mail], [e-mail], [e-mail], [e-mail]
2

Av. Antônio Carlos, 6627 Campus UFMG PCA 1 – Anexo Engenharia Pampulha – Belo Horizonte – MG CEP: 31.270-90

ABSTRACT

X-rays are produced by accelerating electrons with a high voltage and allowing them to collide with a metal target. This high voltage presents fluctuations that define peak, minimum, and average voltages. Different voltages are applied to the X-ray tube depending on the radiographic applications. A rectifier circuit converts the alternating high voltage to unidirectional high voltage to accelerate electrons in this tube. The fluctuations on the energy in the electron beam depend on the mode of rectification. Both energy of the electrons and X rays intensity fluctuates. A portable probe built with a 6LiI(Eu) detector coupled to a 10 m light guide and a Hamamatsu photon counting head H9319 was used to measuring X ray intensities. This system is designed to collect up to 10000 counts in intervals of 10 ms to 1 s. Counts were accumulated in time intervals of 10 ms during 10 s. The system starts the count before activating the X-ray apparatus, which is on during a time interval of 100ms. During this period, counts may