Laboratory: Gran Sasso National Laboratory

National Responsible: M. Spinetti (LNF)

1. Goal of the experiment

MACRO is a large area multipurpose underground detector designed to search for rare events in the cosmic radiation. It has been optimized to look for the supermassive magnetic monopoles predicted by Grand Unified Theories (GUT) of the electroweak and strong interactions; it can also perform measurements in areas of astrophysics, nuclear, particle and cosmic ray physics. These include also the study of atmospheric neutrinos and neutrino oscillations. MACRO ended the data taking on December 2000.

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Activities during 2001

- Continuation of the analysis of the collected data and publication of the completed analysis: fulfilled with 3 publications

- Detector dismounting

Milestones 2002

Completion of new analysis and publication of the results 31-12-2002

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

- Manpower: 35 researchers (~8 FTE)

- Budget for the Year 2002: 83 kEuro

4. Publications in refereed journals (in 2001): 3

5. Conference talks (in 2001): 11

6. Number of undergraduate and doctoral thesis on the experiment

- Undergraduate thesis - Year 2001: 3

- Doctoral thesis - Year 2001: 3

7. Leadership roles and primary responsibilities in the experiment

G. Giacomelli - Co-Spokesman

M. Spinetti - Technical Supervisor and National Responsible

8. Innovative instruments

The experiment has been completed in 1995 and up-to-date techniques for particle detection have been used at the time of installation.

Examples: the largest (~20000 m2) tracking system, based on 3x3 cm2 limited streamer tubes, deployed in an underground laoratory; the data acquisition system based on a server/client architecture with VME computers distributed on a network, the readout of the streamer tube system based on custom modules; the processing of the scintillator signals based on 300 MCycles VME WFD; a scintillator signal processing and trigger system dedicated to the detection of stellar collapses with a live time close to 100%.

9. Competing experiments

For some physics items, like magnetic monopole search and the obsevation of penetrating cosmic ray radiation, MACRO has no competitors due to the large surface, the complementarity of the detection techniques and the location in an underground laboratory. For the neutrino oscillation physics MACRO is competitive with SK in the atmospheric neutrino energy range 5-100 GeV, given the accumulated statistics and comparable rates for upgoing muons.

MACRO has initiated, together with SK, the international network for early alarm in case of stellar collapse.

10. International committee which has reviewed the experiment

The experiment was reviewed by the funding authorities of INFN and DOE; it was also periodically reviewed by the Scientific Committee of the LNGS