Contribution Oral

9/7/2007 14:30 - 09:42

Merida, Mexico - Yucatan I (Fiesta Americana)

SH.3.1

SH 3.1

Solar Modulation of Low-Energy Antiproton and Proton Spectra Measured by BESS

Speakers

Dr. John W. MITCHELL

Primary authors

Dr. John W. MITCHELL (NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA)

Co-authors

Dr. Ko ABE (Kobe University, Kobe, Hyogo 657-8501 Japan)
Dr. Hideyuki FUKE (Institute of Space and Astronautical Science (ISAS/JAXA), Sagamihara, Kanagawa 229-8510, Japan)
Dr. Sadakazu HAINO (High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan)
Dr. Thomas HAMS (CRESST/USRA/Goddard Space Flight Center, Greenbelt, Maryland 20771, USA)
Mr. Atsushi HORIKOSHI (High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan)
Mr. Ki-Chun KIM (IPST, University of Maryland, College Park, Maryland 20742, USA)
Dr. MooHyun LEE (IPST, University of Maryland, College Park, Maryland 20742, USA)
Dr. Yashuhiro MAKIDA (High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan)
Dr. Shinya MATSUDA (High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan)
Dr. Alexander A. MOISEEV (CRESST/USRA/Goddard Space Flight Center, Greenbelt, Maryland 20771, USA)
Dr. Jun NISHIMURA (The University of Tokyo, Bunkyo, Tokyo 113-0044, Japan)
Dr. Mitsuaki NOZAKI (High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan)
Dr. Reiko ORITO (Kobe University, Kobe, Hyogo 657-8501 Japan)
Dr. Shuji ORITO (The University of Tokyo, Bunkyo, Tokyo 113-0044, Japan)
Dr. Jonathan F. ORMES (University of Denver, Denver, Colorado 80208, USA)
Mr. Kenichi SAKAI (The University of Tokyo, Bunkyo, Tokyo 113-0044, Japan)
Dr. Tomoyuki SANUKI (The University of Tokyo, Bunkyo, Tokyo 113-0044, Japan)
Dr. Makoto SASAKI (CRESST/USRA/Goddard Space Flight Center, Greenbelt, Maryland 20771, USA)
Dr. Eun-Suk SEO (IPST, University of Maryland, College Park, Maryland 20742, USA)
Dr. Yoshiaki SHIKAZE (Kobe University, Kobe, Hyogo 657-8501 Japan)
Dr. Robert STREITMATTER (NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA)
Dr. Junichi SUZUKI (High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan)
Mr. Kenichi TANAKA (High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan)
Ms. Neeharika THAKUR (University of Denver, Denver, Colorado 80208, USA)
Dr. Takamasa YAMAGAMI (Institute of Space and Astronautical Science (ISAS/JAXA), Sagamihara, Kanagawa 229-8510, Japan)
Dr. Akria YAMAMOTO (High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan)
Dr. Tetsuya YOSHIDA (Institute of Space and Astronautical Science (ISAS/JAXA), Sagamihara, Kanagawa 229-8510, Japan)
Dr. Koji YOSHIMURA (High Energy Accelerator Research Organization, Tsukuba, Ibaraki 305-0801, Japan)

Files

- icrc1149.pdf

Abstract content

The spectra of low-energy cosmic-ray protons and antiprotons have been measured by BESS in nine high-latitude balloon flights between 1993 and 2004. These measurements span a range of solar activity from the previous solar minimum through solar maximum and the onset of the present solar minimum, as well as a solar magnetic field reversal from positive to negative in 2000. Because protons and antiprotons differ only in charge sign, these simultaneous measurements provide a sensitive probe of charge dependent solar modulation. The antiproton to proton ratio measured by BESS is consistent with simple spherically symmetric models of solar modulation during the Sun's positive polarity phase, but favor charge-sign-dependent drift models during the negative phase. The BESS measurements will be presented and compared to various models of solar modulation.

If this papers is presented for a collaboration, please specify the collaboration

BESS

Reference

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 1 (SH), pages 455-458