6533b833fe1ef96bd129c32e

RESEARCH PRODUCT

Production and characterization of a custom-made 228Th source with reduced neutron source strength for the Borexino experiment

Andreas ZimbalR. SantorelliRugard DresslerB. PraastM. TarkaKlaus EberhardtH. KellerW. ManeschgJochen SchreinerLaura BaudisR. LacknerRobert EichlerB Wiegel

subject

PhysicsNuclear and High Energy PhysicsPhysics - Instrumentation and DetectorsDosimeterIsotope530 PhysicsNeutron emission3105 InstrumentationRadiochemistryFOS: Physical sciencesThoriumchemistry.chemical_elementInstrumentation and Detectors (physics.ins-det)10192 Physics InstituteNuclear physicschemistryMeasuring instrumentNeutron source3106 Nuclear and High Energy PhysicsInstrumentationBorexinoIsotopes of thorium

description

A custom-made 228Th source of several MBq activity was produced for the Borexino experiment for studying the external background of the detector. The aim was to reduce the unwanted neutron emission produced via (alpha,n) reactions in ceramics used typically for commercial 228Th sources. For this purpose a ThCl4 solution was converted chemically into ThO2 and embedded into a gold foil. The paper describes the production and the characterization of the custom-made source by means of gamma-activity, dose rate and neutron source strength measurements. From gamma-spectroscopic measurements it was deduced that the activity transfer from the initial solution to the final source was >91% (at 68% C.L.) and the final activity was (5.41+-0.30) MBq. The dose rate was measured by two dosimeters yielding 12.1 mSv/h and 14.3 mSv/h in 1 cm distance. The neutron source strength of the 5.41 MBq 228Th source was determined as (6.59+-0.85)/sec.

yearjournalcountryeditionlanguage
2012-01-01Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
https://doi.org/10.1016/j.nima.2012.04.019