GNO : Gallium Neutrino Observatory

 

Collaboration

Location of the experiment: LNGS for solar neutrino measurements, MPIK Heidelberg for proportional counter construction and absolute calibrations.

National Responsible: E.Bellotti (Mi)

1. Goal of the experiment

The goal of GNO is to monitor the low energy solar neutrino flux with a radiochemical gallium detector underground at Laboratori Nazionali del Gran Sasso. The measurement of the solar neutrino flux and their energy spectrum is crucial both for astrophysics and for particle physics (neutrino flavor oscillations). Gallium-based radiochemical detectors are the only working experiments able to detect the low-energy pp neutrinos, produced in the sun in the basic reaction of the hydrogen chain.

More on the experiment…

2.

Activities during 2001

The following physics items were achieved during 2001:

The following achievements have been obtained:

Routine solar and blank runs execution.

31-12-2001

100%

Development of new pulse and data analysis methods.

30-09-2001

100%

Milestones 2002:

 

Uninterrupted acquisition of solar runs 31-10-2002
Preliminary work to obtain a 51Cr neutrino source 31-10-2002
51Cr neutrino source production and Gallium solution irradiation (if possible, within 30/04/2003). 31-12-2002

3. INFN contribution to the experiment in terms of manpower and financial support

Manpower: 13 researchers (7.5 FTE), and support of the LNGS workshop and chemical labs

Budget for the year 2002:1216,5  kEuro

4.Publications in refereed journals (in 2001):

5. Number of conference talks (in 2001): 6

6. Undergraduate and PhD (italian groups):

Undergraduate students: 3 students completed their 'tesi di laurea' during 2001 (1 at Università degli Studi di Milano, 1 at Phys. Dep. of Università dell'Aquila, 1 at Chem. Dep. of Università dell'Aquila)

7. Leadership roles and primary responsibilities of the experiment

8. Innovative instruments

9. Competing experiments

Radiochemical gallium detectors are the only one presently able to detect pp solar neutrinos. Next generation real-time experiments able to lower the threshold to cover the pp energy region are still in a R&D phase and are not expected to start observations at least in the next 5 years.

The SAGE experiment, situated in the Baksan mine in Caucasus is the only other radiochemical gallium solar neutrino detector in the world. The gallium in SAGE is in metal form with a mass of about 50 tons.

10. International committee which has reviewed the experiment

The experiment is reviewed by the funding authorities of INFN and periodically by the Scientific Committee of the LNGS.