Neutron spectrometry in a PET cyclotron with a Bonner sphere system
F. Fernández (1), K. Amgarou (1), C. Domingo (1), M. J. García (1), G. Quincoces (2), J. M. Martí-Climent (2), R. Méndez (3) and R. Barquero (4)
(1) Grup de Física de les Radiacions. Departament de Física, Universitat Autónoma de Barcelona, E-08193 Bellaterra, Spain
(2) Servicio de Medicina Nuclear, Clínica Universitaria de Navarra, E-31008 Pamplona, Spain
(3) Ionizing Radiations Metrology Laboratory, CIEMAT, E-28040 Madrid, Spain
(4) Hospital Universitario Río Hortega de Valladolid, Valladolid, Spain
Positron emission tomography (PET) is a non-invasive medical imaging technique normally used for diagnostic purposes to determine the location and concentration of physiologically active compounds in a human body.
An unshielded cyclotron is used for PET at the Clinica Universitaria de Navarra to produce short-lived positron emitting radionuclides (15O, 13N, 11C and 18F) by bombarding appropriate target material with proton or deuteron beams with energies up to 18 and 9 MeV, respectively.
Subsequent nuclear reactions may generate undesirable neutrons that should be evaluated and controlled. In this study, the neutron measurements performed with an active and a passive Bonner sphere systems at different locations outside and inside the cyclotron vault during operation have been presented.
The neutron spectrum at each location was determined with an unfolding code developed by the authors.
CITATION Radiat Prot Dosimetry. 2007;126(1-4):371-5