A new type of very high energy (> a few 100 GeV) gamma-ray observatory, Milagro, has been built with a large field of view of >1 steradian and nearly 24 hours/day operation. Milagrito, a prototype for Milagro, was operated from February 1997 to May 1998. During the summer of 1998, Milagrito was dismantled and Milagro was built. Both detectors use a 80 m×60 m×8 mpond of water in which a 3 m×3 m grid of photomultiplier tubes detects the Cherenkov light produced in the water by the relativistic particles in extensive air showers. Milagrito was smaller and had only one layer of photomultipliers, but allowed the technique to be tested. Milagrito observations of the Moon’s shadow and Mrk 501 are consistent with the Monte Carlo prediction of the telescopes parameters, such as effective area and angular resolution. Milagro is larger and consists of two layers of photomultiplier tubes. The bottom layer detects penetrating particles that are used to reject the background of cosmic-ray initiated showers.
AIP Conference Proceedings
Digital Object Identifier (DOI)
Milagro: A TeV gamma-ray monitor of the Northern Hemisphere Sky Dingus, B. L. and Atkins, R. and Benbow, W. and Berley, D. and Chen, M. L. and Coyne, D. G. and Dorfan, D. E. and Ellsworth, R. W. and Evans, D. and Falcone, A. and Fleysher, L. and Fleysher, R. and Gisler, G. and Goodman, J. A. and Haines, T. J. and Hoffman, C. M. and Hugenberger, S. and Kelley, L. A. and Leonor, I. and McConnell, M. and McCullough, J. F. and McEnery, J. E. and Miller, R. S. and Mincer, A. I. and Morales, M. F. and Nemethy, P. and Ryan, J. M. and Shen, B. and Shoup, A. and Sinnis, C. and Smith, A. J. and Sullivan, G. W. and Tumer, T. and Wang, K. and Wascko, M. O. and Westerhoff, S. and Williams, D. A. and Yang, T. and Yodh, G. B., AIP Conference Proceedings, 510, 642-645 (2000), DOI:http://dx.doi.org/10.1063/1.1303280
© 2000 American Institute of Physics