title: Neutron spectra around a tandem linear accelerator in the generation of (18)F with a bonner sphere spectrometer.
abstract: A Bonner sphere spectrometer was used to measure the neutron spectra produced at the collision of protons with an H2(18)O target at different angles. A unique H2(18)O target to produce (18)F was designed and placed in a Tandem linear particle accelerator which produces 8.5MeV protons. The neutron count rates measured with the Bonner spheres were unfolded with the MAXED code. With the GEANT4 Monte Carlo code the neutron spectrum induced in the (p, n) reaction was estimated, this spectrum was used as initial guess during unfolding. Although the cross section of the reaction (18)O(p,n)(18)F is well known, the neutron energy spectra is not correctly defined and it is necessary to verify the simulation with measurements. For this reason, the sensitivity of the unfolding method to the initial spectrum was analyzed applying small variation to the fast neutron peak.
authors.affiliation: Medical Applications Unit, CIEMAT, Av. Complutense 40, E-28040 Madrid, Spain. Electronic address: juanignacio.lagares@ciemat.es.
authors.forename: J I
authors.initials: JI
authors.lastname: Lagares
authors.affiliation: Ionizing Radiations Laboratory, CIEMAT, Av. Complutense 40, E-28040 Madrid, Spain.
authors.forename: J E Guerrero
authors.initials: JE
authors.lastname: Araque
authors.affiliation: Ionizing Radiations Laboratory, CIEMAT, Av. Complutense 40, E-28040 Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Méndez-Villafañe
authors.affiliation: Medical Applications Unit, CIEMAT, Av. Complutense 40, E-28040 Madrid, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Arce
authors.affiliation: Medical Applications Unit, CIEMAT, Av. Complutense 40, E-28040 Madrid, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Sansaloni
authors.affiliation: Medical Applications Unit, CIEMAT, Av. Complutense 40, E-28040 Madrid, Spain.
authors.forename: O
authors.initials: O
authors.lastname: Vela
authors.affiliation: Astroparticle Physics Division, Basic Research Department, CIEMAT, Av. Complutense 40, E-28040 Madrid, Spain.
authors.forename: C
authors.initials: C
authors.lastname: Díaz
authors.affiliation: Ionizing Radiations Laboratory, CIEMAT, Av. Complutense 40, E-28040 Madrid, Spain.
authors.forename: Xandra
authors.initials: X
authors.lastname: Campo
authors.affiliation: Technology Department, CIEMAT, Av. Complutense 40, E-28040 Madrid, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Pérez
keywords: Bonner spheres; Monte Carlo; Neutron spectra; PET; Radiation protection; Radioisotope production