ARGO-YBJ: Italy (INFN) - China (CAS) collaboration

 

Collaboration:

Location: Yangbajing Cosmic Ray Laboratory, 4300 m a.s.l., Tibet (China)

1. Goal of the experiment

The ARGO-YBJ experiment is devoted to the search of cosmic ray sources by means of the observation of galactic and extragalactic neutral and charged radiation in the energy range 100 GeV - 1000 TeV with a detector based on Resistive Plate Chambers (RPC's) covering an area of 6500 m2 and providing a detailed space-time picture of the cosmic ray shower front. The detector is under construction at the Yangbajing Cosmic Ray Laboratory.

More on the experiment...

2.

Activities during the 2002
 

The following achievements have been obtained:


• Construction of 457 RPCs (76%) Comment: the assembling line at the provider has been stopped for about 3 months to solve technical problems related to the bakelite sheets.

• Installation of 40 Clusters (67%). Comment: about 10% of the RPCs shipped to Yangbajing broke down on the way. All the other chambers,successfully tested, have been installed.

• 36 Clusters connected to the electronics but only 16 of them put in data taking (32%). Comment: we had some DAQ problems which prevented us from increasing the trigger rate.

Milestones 2003

Construction of 600 RPCs 31-12-2003
100 clusters installed by the end of 2003 31-12-2003
50 clusters in operation with electronics 31-12-2003
36 clusters in data taking for physics run 31-12-2002

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

Manpower:

54 researchers (37 FTE), 4 technologists (2 FTE), 8 technicians (4.5 FTE) plus support from the mechanics and electronics workshops of Napoli and Roma-2.

Budget for the Year 2003: 4.1% of the CSNII total budget

4. Publications in refereed journal: 2
 
5. Conference talks: 1
 

6. Number of undergraduate and doctoral thesis on the experiment:

7. Leadership roles and primary responsibilities in the experiment

Lecce: Local Station electronics and trigger.

Napoli: DAQ, gas distribution system, analog read-out, trigger.

Roma-2: Front-End electronics, detector control system

Roma-3: Detector assembling, experiment layout, HV system, trigger distribution.

8. Innovative instruments

The ARGO-YBJ experiment has developed

Many of the technical solutions could be of general interest for experiments aiming to fully exploit the RPCs performance
 
 

9. Competing experiments

A similar approach to the g -astronomy ("full coverage" detector at high altitude, large field of view, ~ 100 % duty cycle) is already operating (MILAGRO (USA), 2600 m a.s.l., 4800 m2 water pool instrumented with PM tubes + array). The performance of ARGO-YBJ is expected to be definitely better, due to the high space-time granularity as well as to the higher elevation of the experimental site. However, a fast completion and commissioning of the detector is needed.

10. International committee which has reviewed the experiment

The ARGO-YBJ project has been examined and approved by the INFN Committee II and by the CAS Scientific Committee.