Details

Autor(en) / Beteiligte

• Balata, M.
• Cadonati, L.
• Laubenstein, M.
• Heusser, G.
• Giammarchi, M.G.
• Scardaoni, R.
• Torri, V.
• Cecchet, G.
• de Bari, A.
• Perotti, A.

Titel

The water purification system for the low background counting test facility of the Borexino experiment at Gran Sasso

Ist Teil von

• Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment, 1996-02, Vol.370 (2), p.605-608

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

1996

Link zum Volltext

Quelle

Elsevier Journal Backfiles on ScienceDirect (DFG Nationallizenzen)

Beschreibungen/Notizen

• The Borexino experiment, for the study of solar neutrino physics, requires radiopurity at the level of 5 × 10 −16 g/g 238U equivalent (or 6 × 10 −9 Bq/kg) on a detector mass of many tons of scintillator. Feasibility studies are performed in a counting test facility now operating at LNGS, which consists of 4 t of liquid scintillator viewed by 100 photomultipliers and shielded by 100 t of water. The accomplishment of this goal requires the shielding liquid, water, to be at the 10 −13 g/g contamination level (1.2 × 10 −6 Bq/kg) or better. This paper describes the water purification system; it consists of a combination of several purification processes to remove particulate, radioactive ions, dissolved gases and other impurities. Residual contaminations are measured by analytical or direct-counting techniques. For radon measurement, particularly challenging at this low activity levels, a low background counting method has been developed.