MASS2 (Matter Antimatter Spectrometer)

MASS2 Drawing (10kB)
The MASS2 experiment was designed to measure antiprotons from about 4 - 20 GeV and positrons from about 4-10 GeV. It used the same experimental setup as the MASS1 experiment flown in 1989 (for more informations look at the NMSU homepage), except that the tracking system was improved by installing the driftchambers from Siegen. With this update the MDR of the spectrometer could be increased to about 200 GV.
Particle identification was derived with a gas-cherenkov filled with Freon-12 and a streamer-tube brass-calorimeter (filled with Isobutan).
The instrument was launched in september 1991 from Ft. Sumner, NM and had 23 hours float, but the magnet discharged after 10 hours.

MASS2 Drawing (10kB)	The MASS2 experiment was designed to measure antiprotons from about 4 - 20 GeV and positrons from about 4-10 GeV. It used the same experimental setup as the MASS1 experiment flown in 1989 (for more informations look at the NMSU homepage), except that the tracking system was improved by installing the driftchambers from Siegen. With this update the MDR of the spectrometer could be increased to about 200 GV. Particle identification was derived with a gas-cherenkov filled with Freon-12 and a streamer-tube brass-calorimeter (filled with Isobutan). The instrument was launched in september 1991 from Ft. Sumner, NM and had 23 hours float, but the magnet discharged after 10 hours.

Current situation of the antiproton/proton ratio

Collaborators

New Mexico State University

Tata Institute of Fundamental Research, Bombay

INFN, Laboratori Nazionali die Frascati

Università di Firenze and INFN, Firenze

Università di Perugia and INFN, Perugia

Università di Roma II and INFN, Roma

Goddard Space Flight Center

MASS2 Publications

"Measurements of the absolute energy spectra of cosmic-ray positrons and electrons above 7 GeV"
C. Grimani et al., Astronomy and Astrophysics, 392, 287-294 (2002)
"A MEASUREMENT OF THE PROTON AND HELIUM COMPONENTS IN THE ATMOSPHERE"
M. Circella et al., Proc. of the 26th ICRC, Salt Lake City, 1999, SH.3.6.18
"The Flux of Cosmic Ray Antiprotons from 3.7 to 24 GeV"
G. Basini et al., Proc. of the 26th ICRC, Salt Lake City, 1999, OG.1.1.21
"Balloon Measurements of Cosmic Ray Muon Spectra in the Atmosphere along with those of Primary Protons and Helium Nuclei over Mid-Latitude"
R. Bellotti et al., Phys. Rev. D, 60, 052002 (1999)
"Measurements of the Cosmic Ray Muon Component in the Atmosphere from Ground Level to Balloon Altitudes"
M. Circella et al., 25th International Cosmic Ray Conference (Durban), 6, 381 (1997)
"Measurements of Cosmic Ray Antiprotons from 3.7 to 19 GeV"
M. Hof, G. Basini, F. Bongiorno, F. Massimo Brancaccio, M. T. Brunetti, A. Codino, R. L. Golden, C. Grimani, M. Menichelli, J. W. Mitchell, W. Menn, A. Morselli, J. F. Ormes, C. Pfeifer, P. Papini, M. P. de Pascale, C. Pfeifer, S. Piccardi,P. Picozza, M. Ricci, M. Simon, P. Spillantini, S. J. Stochaj, S. A. Stephens, R.E. Streitmatter,
The Astrophysical Journal, 467:L33-L36, 1996 August 10
"Measurement of Electron and Positron Energy Differenetial Fluxes with MASS" Apparatus"
G.Basini, R. Bellotti, F.Bongiorno, M.T.Brunetti, F. Cafagna, M. Circella, A.Codino, G. de Cataldo, C. N. de Marzo, M. P. de Pascale, N. Finetti, N. Giglietto, R.L.Golden, C. Grimani, M.Hof, F. Massimo Brancaccio, M.Menichelli, J.W.Mitchell, A.Morselli, J.F.Ormes, P. Papini,S. Piccardi, P.Picozza, M.Ricci, I.Salvatori, M.Simon, P. Spillantini, P. Spinelli, A. S. Stephens, S.J.Stochaj, and R.Streitmatter, 1995, Proc. 24th International Cosmic Ray Conference, (Rome), 3, 1.
"Differential flux measurement of atmospheric pion, muon electron and positron energy spectra at balloon altitudes"
C.Grimani, P.Papini, S.A.Stephens, G.Basini, F.Bongiorno, F.Massimo Brancaccio, M.T.Brunetti, A.Codino, N.Finetti, R.L.Golden, M.Hof, M.Menichelli, J.W.Mitchell, A.Morselli, J.F.Ormes, M.P.De Pascale, C.Pfeifer, S.Piccardi, P.Picozza, M.Ricci, I.Salvatori, M.Simon, P.Spillantini, S.J.Stochaj, and R.Streitmatter, 1995, Proc. 24th International Cosmic Ray Conference, (Rome), 4, 1029.
"Measurement of the cosmic ray muon spectrum and charge ratio in the atmosphere from ground level to balloon altitudes"
G.Basini, R.Bellotti, F.Bongiorno, M.T.Brunetti, F.Cafagna, M.Circella, A.Codino, G.De Cataldo, C.N.De Marzo, M.P.De Pascale, N.Finetti, N.Giglietto, R.L.Golden, C.Grimani, M.Hof, F.Massimo Brancaccio, M.Menichelli, J.W.Mitchell, A.Morselli, J.F.Ormes, P.Papini, S.Piccardi, P.Picozza, M.Ricci, I.Salvatori, M.Simon, P.Spillantini, P.Spinelli, S.A.Stephens, S.J.Stochaj, and R.Streitmatter, 1995, Proc. 24th International Cosmic Ray Conference, (Rome), 1, 585.
"Atmospheric proton and deuterium energy spectra determination with the MASS2 experiment"
P.Papini, C. Grimani, G.Basini, F.Bongiorno, F.Massimo Brancaccio, M.T.Brunetti, F.Cafagna, M.Circella, A.Codino, N.Finetti, R.L.Golden, M.Hof,, M.Menichelli, J.W.Mitchell, A.Morselli, J.F.Ormes, M. P. de Pascale, C. Pfeifer, S.Piccardi, P.Picozza, M.Ricci, I.Salvatori, M.Simon, P.Spillantini, S.A.Stephens, S.J.Stochaj, and R.Streitmatter, 1995, Proc. 24th International Cosmic Ray Conference, (Rome), 4, 1033.
"Cosmic Ray Antiproton Measurements in the 4-19 GeV Energy Range using the NMSU/WiZard-Matter Antimatter Superconducting Spectrometer 2 (MASS2)"
M. Hof, C. Pfeifer, W. Menn, M.Simon, R.L. Golden, S.J. Stochaj, S.A. Stephens, G. Basini, M. Ricci, F. Massimo Brancaccio, P. Papini, S. Picardi, P. Spillantini, M.P. DePascale, A. Morselli, P. Picozza, M.T. Brunetti, A. Codino, C. Grimani, M. Menichelli, .W. Mitchell, J.F. Ormes, and R.E. Streitmatter, 1995, 24th Intern. Cosmic Ray Conf., (Rome), 3, 60
"Ground Level Observation of Electrons, Positrons and Protons"
G. Basini, F. Bongiorno, M.T. Brunetti, A. Codino, R.L. Golden, C. Grimani, B.L. Kimbell, F. Massimo Brancaccio, M. Menichelli, M. Miozza, A. Morselli, J.F. Ormes, P. Papini, M. P. DePascale, P. Picozza, M. Ricci, I. Salvatori, E. S. Seo, P. Spillantini, S. A. Stephens, S. Stochaj, R.E. Streitmatter, and W.R. Webber, 1993, Proc. 23rd Internat. Cosmic Ray Conf. (Calgary), 3, 773.

MASS2 Talks

" Balloon Measurements of Cosmic Ray Muons in the Atmosphere "
VIII International Workshop on "Neutrino Telescopes", February 23-26, 1999, Venice, Italy

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