title: Standardisation and precise determination of the half-life of (44)Sc.
abstract: The half-life of the positron-emitter (44)Sc has been determined by following the decay rate with two measurement systems; an Ionisation Chamber and a HPGe detector. The combination of seven results gives a value of T1/2=4.042 (25)h, about 2% higher than the recommended value of T1/2=3.97 (4)h (Browne, 2011) and with a lower uncertainty. This radionuclide has also been standardised by coincidence counting, and liquid scintillation counting techniques. A (44)Ti/(44)Sc generator developed at CIEMAT was used to obtain the (44)Sc solutions used in all measurements.
authors.affiliation: Laboratorio de Metrología de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 40, Madrid 28040, Spain. Electronic address: e.garciatorano@ciemat.es.
authors.forename: E
authors.initials: E
authors.lastname: García-Toraño
authors.affiliation: Laboratorio de Metrología de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 40, Madrid 28040, Spain.
authors.forename: V
authors.initials: V
authors.lastname: Peyrés
authors.affiliation: Laboratorio de Metrología de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 40, Madrid 28040, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Roteta
authors.affiliation: Laboratorio de Metrología de Radiaciones Ionizantes, CIEMAT, Avda. Complutense 40, Madrid 28040, Spain.
authors.forename: A I
authors.initials: AI
authors.lastname: Sánchez-Cabezudo
authors.affiliation: Unidad de Aplicaciones Biomédicas y Farmacocinética, CIEMAT, Avda. Complutense 40, Madrid 28040, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Romero
authors.affiliation: Unidad de Aplicaciones Biomédicas y Farmacocinética, CIEMAT, Avda. Complutense 40, Madrid 28040, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Martínez Ortega
mesh_terms: D002138:Calibration / Q000592:standards; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006207:Half-Life; D011829:Radiation Dosage; D000072232:Radiation Dosimeters / Q000592:standards*; D011868:Radioisotopes / Q000032:analysis* / Q000592:standards*; D012015:Reference Standards; D015203:Reproducibility of Results; D012538:Scandium / Q000032:analysis* / Q000592:standards*; D012680:Sensitivity and Specificity; D013030:Spain
chemical_list: D011868:Radioisotopes; D012538:Scandium
keywords: Half-life; Positron emitters; Sc-44; Standardisation