1. The Large Aperture GRB Observatory (LAGO) Humberto Salazar for the LAGO collaboration August 11, 2011

2. Main goal:  Search for GRBs with gammas in the range energy 1 GeV - 1 TeV. Single particle technique High altitude water cerenkov detectors

4. Fermi-LAT, > 10 GeV photons event (1s) (1sec !

8. LAG0 : Single particle technique

9. LAGO Sites @ 2011 * 4550m asl 4470m asl 4780m asl 5250m asl 1400m asl * Bariloche, Colombia, Venezuela, Mexico and Guatemala have prototypes @ Universities

10. Chacaltaya´s LAGO WCDs array

11.  DAQ System (Old Auger electronics).  Rate; 5 ms (above 0.5 phe)  Calibration software

12. Sierra Negra Array  4550 asl.  4 Water Cherenkov Detectors (3 operating)

13.  DAQ System.  Rate; 5 ms

14. Marcapomacocha, Peru.

16. Some candidates But, No confirmation: Fluence limits Data analysis and results

17. SH2.6 1298 poster & SH4.5 920 poster

18. Present and Future plans for LAGO… Large area, New electronics. New sites. 40m2 4m2

19. New Detector Array @ Sierra Negra: 4x (40m2) x1.1m height

20. Rate vs distance Rate/seg distance to the center (cm) 7, 500 0 10, 300 120 11,700 180 15, 000 240 Threshold 0.9 phe For simulations of the performance of the detectors see OG2.5.274 poster

21. New 4 Channels electronics @ Sierra Negra. Baseline noise. Average rate (5seg)

22. New detectors and new sites @ Bolivia, Peru and Ecuador ? (>5000masl).

23. Conclusions An efficient dedicated experiment can be done at low cost by using WCD at high altitude.