Abstract
The Balloon Borne Experiment with a Superconducting Spectrometer (BESS) has measured the energy spectrum of cosmic-ray antiprotons between 0.18 and 4.20 GeV in eight flights between 1993 and 2002. Above about 1 GeV, models in which antiprotons are secondary products of the interactions of primary cosmic rays with the interstellar gas agree with the BESS antiproton spectrum. Below 1 GeV, the data show a possible excess antiproton flux compared to secondary model predictions, suggesting the presence of an additional source of antiprotons. The antiproton/proton ratios measured between 1993 and 1999, during the Sun's positive-polarity phase, are consistent with simple models of solar modulation. However, results from the 2000 flight, following the solar magnetic field reversal, show a sudden increase in the antiproton/proton ratio and tend to favor a charge-sign-dependent drift model. To extend BESS measurements to lower energies, an evolutionary instrument, BESS-Polar, is under construction for polar flight in 2004.
| Original language | English |
|---|---|
| Pages (from-to) | 135-141 |
| Number of pages | 7 |
| Journal | Advances in Space Research |
| Volume | 35 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2005 |
| Externally published | Yes |
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Keywords
- BESS
- Cosmic ray antiproton spectrum
- Solar modulation effects
ASJC Scopus subject areas
- Space and Planetary Science
- Astronomy and Astrophysics
Cite this
Precise measurements of the cosmic ray antiproton spectrum with BESS including the effects of solar modulation. / Mitchell, J. W.; Abe, K.; Anraku, K.; Asaoka, Yoichi; Fujikawa, M.; Fuke, H.; Haino, S.; Hams, T.; Ikeda, N.; Imori, M.; Itazaki, A.; Izumi, K.; Lee, M. H.; Maeno, T.; Makida, Y.; Matsuda, S.; Matsui, N.; Matsukawa, T.; Matsumoto, H.; Matsunaga, H.; Mitsui, T.; Moiseev, A.; Motoki, M.; Nishimura, J.; Nozaki, M.; Omiya, H.; Orito, S.; Ormes, J. F.; Saeki, T.; Sanuki, T.; Sasaki, M.; Seo, E. S.; Shikaze, Y.; Sonoda, T.; Stephens, S. A.; Streitmatter, R. E.; Suzuki, J.; Takasugi, Y.; Tanaka, K.; Tanizaki, K.; Ueda, I.; Wang, J. Z.; Yajima, Y.; Yamagami, T.; Yamamoto, A.; Yamamoto, Y.; Yamato, K.; Yoshida, T.; Yoshimura, K.
In: Advances in Space Research, Vol. 35, No. 1, 2005, p. 135-141.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Precise measurements of the cosmic ray antiproton spectrum with BESS including the effects of solar modulation
AU - Mitchell, J. W.
AU - Abe, K.
AU - Anraku, K.
AU - Asaoka, Yoichi
AU - Fujikawa, M.
AU - Fuke, H.
AU - Haino, S.
AU - Hams, T.
AU - Ikeda, N.
AU - Imori, M.
AU - Itazaki, A.
AU - Izumi, K.
AU - Lee, M. H.
AU - Maeno, T.
AU - Makida, Y.
AU - Matsuda, S.
AU - Matsui, N.
AU - Matsukawa, T.
AU - Matsumoto, H.
AU - Matsunaga, H.
AU - Mitsui, T.
AU - Moiseev, A.
AU - Motoki, M.
AU - Nishimura, J.
AU - Nozaki, M.
AU - Omiya, H.
AU - Orito, S.
AU - Ormes, J. F.
AU - Saeki, T.
AU - Sanuki, T.
AU - Sasaki, M.
AU - Seo, E. S.
AU - Shikaze, Y.
AU - Sonoda, T.
AU - Stephens, S. A.
AU - Streitmatter, R. E.
AU - Suzuki, J.
AU - Takasugi, Y.
AU - Tanaka, K.
AU - Tanizaki, K.
AU - Ueda, I.
AU - Wang, J. Z.
AU - Yajima, Y.
AU - Yamagami, T.
AU - Yamamoto, A.
AU - Yamamoto, Y.
AU - Yamato, K.
AU - Yoshida, T.
AU - Yoshimura, K.
PY - 2005
Y1 - 2005
N2 - The Balloon Borne Experiment with a Superconducting Spectrometer (BESS) has measured the energy spectrum of cosmic-ray antiprotons between 0.18 and 4.20 GeV in eight flights between 1993 and 2002. Above about 1 GeV, models in which antiprotons are secondary products of the interactions of primary cosmic rays with the interstellar gas agree with the BESS antiproton spectrum. Below 1 GeV, the data show a possible excess antiproton flux compared to secondary model predictions, suggesting the presence of an additional source of antiprotons. The antiproton/proton ratios measured between 1993 and 1999, during the Sun's positive-polarity phase, are consistent with simple models of solar modulation. However, results from the 2000 flight, following the solar magnetic field reversal, show a sudden increase in the antiproton/proton ratio and tend to favor a charge-sign-dependent drift model. To extend BESS measurements to lower energies, an evolutionary instrument, BESS-Polar, is under construction for polar flight in 2004.
AB - The Balloon Borne Experiment with a Superconducting Spectrometer (BESS) has measured the energy spectrum of cosmic-ray antiprotons between 0.18 and 4.20 GeV in eight flights between 1993 and 2002. Above about 1 GeV, models in which antiprotons are secondary products of the interactions of primary cosmic rays with the interstellar gas agree with the BESS antiproton spectrum. Below 1 GeV, the data show a possible excess antiproton flux compared to secondary model predictions, suggesting the presence of an additional source of antiprotons. The antiproton/proton ratios measured between 1993 and 1999, during the Sun's positive-polarity phase, are consistent with simple models of solar modulation. However, results from the 2000 flight, following the solar magnetic field reversal, show a sudden increase in the antiproton/proton ratio and tend to favor a charge-sign-dependent drift model. To extend BESS measurements to lower energies, an evolutionary instrument, BESS-Polar, is under construction for polar flight in 2004.
KW - BESS
KW - Cosmic ray antiproton spectrum
KW - Solar modulation effects
UR - http://www.scopus.com/inward/record.url?scp=20844431535&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=20844431535&partnerID=8YFLogxK
U2 - 10.1016/j.asr.2003.08.044
DO - 10.1016/j.asr.2003.08.044
M3 - Article
AN - SCOPUS:20844431535
VL - 35
SP - 135
EP - 141
JO - Advances in Space Research
JF - Advances in Space Research
SN - 0273-1177
IS - 1
ER -