Measurements of the cosmic-ray positron fraction from 1 to 50 GeV

S. W. Barwick; J. J. Beatty; A. Bhattacharyya; C. R. Bower; C. J. Chaput; S. Coutu; G. A. De Nolfo; J. Knapp; D. M. Lowder; S. Mckee; D. Müller; J. A. Musser; S. L. Nutter; E. Schneider; S. P. Swordy; G. Tarlé; A. D. Tomasch; E. Torbet

doi:10.1086/310706

Measurements of the cosmic-ray positron fraction from 1 to 50 GeV

S. W. Barwick, J. J. Beatty, A. Bhattacharyya, C. R. Bower, C. J. Chaput, S. Coutu, G. A. De Nolfo, J. Knapp, D. M. Lowder, S. Mckee, D. Müller, J. A. Musser, S. L. Nutter, E. Schneider, S. P. Swordy, G. Tarlé, A. D. Tomasch, E. Torbet

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Abstract

Two measurements of the cosmic-ray positron fraction as a function of energy have been made using the High-Energy Antimatter Telescope (HEAT) balloon-borne instrument. The first flight took place from Fort Sumner, New Mexico, in 1994 and yielded results above the geomagnetic cutoff energy of 4.5 GeV. The second flight, from Lynn Lake, Manitoba, in 1995, permitted measurements over a larger energy interval, from 1 to 50 GeV. We present results on the positron fraction based on data from the Lynn Lake flight and compare these with the previously published results from the Fort Sumner flight. The results confirm that the positron fraction does not increase with energy above ≈10 GeV, although a small excess above purely secondary production cannot be ruled out. At low energies the positron fraction is slightly larger than that reported from measurements made in the 1960s. This effect could possibly be a consequence of charge dependence in the level of solar modulation.

Original language	English (US)
Pages (from-to)	L191-L194
Journal	Astrophysical Journal
Volume	482
Issue number	2 PART II
DOIs	https://doi.org/10.1086/310706
State	Published - 1997

All Science Journal Classification (ASJC) codes

Astronomy and Astrophysics
Space and Planetary Science

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10.1086/310706

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Barwick, S. W., Beatty, J. J., Bhattacharyya, A., Bower, C. R., Chaput, C. J., Coutu, S., De Nolfo, G. A., Knapp, J., Lowder, D. M., Mckee, S., Müller, D., Musser, J. A., Nutter, S. L., Schneider, E., Swordy, S. P., Tarlé, G., Tomasch, A. D., & Torbet, E. (1997). Measurements of the cosmic-ray positron fraction from 1 to 50 GeV. Astrophysical Journal, 482(2 PART II), L191-L194. https://doi.org/10.1086/310706

@article{e01576f66f314458876852c35374fd7c,

title = "Measurements of the cosmic-ray positron fraction from 1 to 50 GeV",

abstract = "Two measurements of the cosmic-ray positron fraction as a function of energy have been made using the High-Energy Antimatter Telescope (HEAT) balloon-borne instrument. The first flight took place from Fort Sumner, New Mexico, in 1994 and yielded results above the geomagnetic cutoff energy of 4.5 GeV. The second flight, from Lynn Lake, Manitoba, in 1995, permitted measurements over a larger energy interval, from 1 to 50 GeV. We present results on the positron fraction based on data from the Lynn Lake flight and compare these with the previously published results from the Fort Sumner flight. The results confirm that the positron fraction does not increase with energy above ≈10 GeV, although a small excess above purely secondary production cannot be ruled out. At low energies the positron fraction is slightly larger than that reported from measurements made in the 1960s. This effect could possibly be a consequence of charge dependence in the level of solar modulation.",

author = "Barwick, {S. W.} and Beatty, {J. J.} and A. Bhattacharyya and Bower, {C. R.} and Chaput, {C. J.} and S. Coutu and {De Nolfo}, {G. A.} and J. Knapp and Lowder, {D. M.} and S. Mckee and D. M{\"u}ller and Musser, {J. A.} and Nutter, {S. L.} and E. Schneider and Swordy, {S. P.} and G. Tarl{\'e} and Tomasch, {A. D.} and E. Torbet",

year = "1997",

doi = "10.1086/310706",

language = "English (US)",

volume = "482",

pages = "L191--L194",

journal = "Astrophysical Journal",

issn = "0004-637X",

publisher = "IOP Publishing Ltd.",

number = "2 PART II",

}

Barwick, SW, Beatty, JJ, Bhattacharyya, A, Bower, CR, Chaput, CJ, Coutu, S, De Nolfo, GA, Knapp, J, Lowder, DM, Mckee, S, Müller, D, Musser, JA, Nutter, SL, Schneider, E, Swordy, SP, Tarlé, G, Tomasch, AD & Torbet, E 1997, 'Measurements of the cosmic-ray positron fraction from 1 to 50 GeV', Astrophysical Journal, vol. 482, no. 2 PART II, pp. L191-L194. https://doi.org/10.1086/310706

TY - JOUR

T1 - Measurements of the cosmic-ray positron fraction from 1 to 50 GeV

AU - Barwick, S. W.

AU - Beatty, J. J.

AU - Bhattacharyya, A.

AU - Bower, C. R.

AU - Chaput, C. J.

AU - Coutu, S.

AU - De Nolfo, G. A.

AU - Knapp, J.

AU - Lowder, D. M.

AU - Mckee, S.

AU - Müller, D.

AU - Musser, J. A.

AU - Nutter, S. L.

AU - Schneider, E.

AU - Swordy, S. P.

AU - Tarlé, G.

AU - Tomasch, A. D.

AU - Torbet, E.

PY - 1997

Y1 - 1997

N2 - Two measurements of the cosmic-ray positron fraction as a function of energy have been made using the High-Energy Antimatter Telescope (HEAT) balloon-borne instrument. The first flight took place from Fort Sumner, New Mexico, in 1994 and yielded results above the geomagnetic cutoff energy of 4.5 GeV. The second flight, from Lynn Lake, Manitoba, in 1995, permitted measurements over a larger energy interval, from 1 to 50 GeV. We present results on the positron fraction based on data from the Lynn Lake flight and compare these with the previously published results from the Fort Sumner flight. The results confirm that the positron fraction does not increase with energy above ≈10 GeV, although a small excess above purely secondary production cannot be ruled out. At low energies the positron fraction is slightly larger than that reported from measurements made in the 1960s. This effect could possibly be a consequence of charge dependence in the level of solar modulation.

AB - Two measurements of the cosmic-ray positron fraction as a function of energy have been made using the High-Energy Antimatter Telescope (HEAT) balloon-borne instrument. The first flight took place from Fort Sumner, New Mexico, in 1994 and yielded results above the geomagnetic cutoff energy of 4.5 GeV. The second flight, from Lynn Lake, Manitoba, in 1995, permitted measurements over a larger energy interval, from 1 to 50 GeV. We present results on the positron fraction based on data from the Lynn Lake flight and compare these with the previously published results from the Fort Sumner flight. The results confirm that the positron fraction does not increase with energy above ≈10 GeV, although a small excess above purely secondary production cannot be ruled out. At low energies the positron fraction is slightly larger than that reported from measurements made in the 1960s. This effect could possibly be a consequence of charge dependence in the level of solar modulation.

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VL - 482

SP - L191-L194

JO - Astrophysical Journal

JF - Astrophysical Journal

IS - 2 PART II

ER -

Measurements of the cosmic-ray positron fraction from 1 to 50 GeV

Abstract

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