Limits...
Ultra high energy electrons powered by pulsar rotation.

Mahajan S, Machabeli G, Osmanov Z, Chkheidze N - Sci Rep (2013)

Bottom Line: These waves, then, Landau damp on electrons accelerating them in the process.We show, by detailed calculations, that these are precisely the conditions for the parameters of the Crab pulsar.It is expected that the proposed mechanism may, unravel the puzzle of the origin of ultra high energy cosmic ray electrons.

View Article: PubMed Central - PubMed

Affiliation: Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA.

ABSTRACT
A new mechanism of particle acceleration, driven by the rotational slow down of the Crab pulsar, is explored. The rotation, through the time dependent centrifugal force, can efficiently excite unstable Langmuir waves in the electron-positron (hereafter e(±)) plasma of the star magnetosphere. These waves, then, Landau damp on electrons accelerating them in the process. The net transfer of energy is optimal when the wave growth and the Landau damping times are comparable and are both very short compared to the star rotation time. We show, by detailed calculations, that these are precisely the conditions for the parameters of the Crab pulsar. This highly efficient route for energy transfer allows the electrons in the primary beam to be catapulted to multiple TeV (~ 100 TeV) and even PeV energy domain. It is expected that the proposed mechanism may, unravel the puzzle of the origin of ultra high energy cosmic ray electrons.

No MeSH data available.


Related in: MedlinePlus

The distribution function versus the Lorentz factor.As is clear from the plot, the function consists of two parts: the first - wider region concerns the plasma component corresponding to the cascade processes of pair creation and the second one characterizes the primary Goldreich-Julian beam electrons.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3569628&req=5

f1: The distribution function versus the Lorentz factor.As is clear from the plot, the function consists of two parts: the first - wider region concerns the plasma component corresponding to the cascade processes of pair creation and the second one characterizes the primary Goldreich-Julian beam electrons.

Mentions: The height h of the gap region (where the electric field is nonzero) is, therefore, strictly limited imposing an upper limit on the maximum attainable electron energy. The potential difference in the gap has been estimated to be 10, where B12 ≡ B/1012 G ≈ 6.7 is the dimensionless magnetic induction. Thus in the potential difference predicted by the standard gap model, the electrons may reach Lorentz factors of ~ 4 × 106 - not sufficient to explain the observed very high energy (VHE) radiation. Figure 1 shows the schematic representation of the distribution function of plasma particles in standard models of the pulsar magnetosphere. The primary beam particles are shown by the narrow shaped area with the Lorentz factor γb. The wider region represents the distribution of secondary electron-positron pairs, characterized by a corresponding Lorentz factor, γp when the distribution function has a maximum value.


Ultra high energy electrons powered by pulsar rotation.

Mahajan S, Machabeli G, Osmanov Z, Chkheidze N - Sci Rep (2013)

The distribution function versus the Lorentz factor.As is clear from the plot, the function consists of two parts: the first - wider region concerns the plasma component corresponding to the cascade processes of pair creation and the second one characterizes the primary Goldreich-Julian beam electrons.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3569628&req=5

f1: The distribution function versus the Lorentz factor.As is clear from the plot, the function consists of two parts: the first - wider region concerns the plasma component corresponding to the cascade processes of pair creation and the second one characterizes the primary Goldreich-Julian beam electrons.
Mentions: The height h of the gap region (where the electric field is nonzero) is, therefore, strictly limited imposing an upper limit on the maximum attainable electron energy. The potential difference in the gap has been estimated to be 10, where B12 ≡ B/1012 G ≈ 6.7 is the dimensionless magnetic induction. Thus in the potential difference predicted by the standard gap model, the electrons may reach Lorentz factors of ~ 4 × 106 - not sufficient to explain the observed very high energy (VHE) radiation. Figure 1 shows the schematic representation of the distribution function of plasma particles in standard models of the pulsar magnetosphere. The primary beam particles are shown by the narrow shaped area with the Lorentz factor γb. The wider region represents the distribution of secondary electron-positron pairs, characterized by a corresponding Lorentz factor, γp when the distribution function has a maximum value.

Bottom Line: These waves, then, Landau damp on electrons accelerating them in the process.We show, by detailed calculations, that these are precisely the conditions for the parameters of the Crab pulsar.It is expected that the proposed mechanism may, unravel the puzzle of the origin of ultra high energy cosmic ray electrons.

View Article: PubMed Central - PubMed

Affiliation: Institute for Fusion Studies, The University of Texas at Austin, Austin, Texas 78712, USA.

ABSTRACT
A new mechanism of particle acceleration, driven by the rotational slow down of the Crab pulsar, is explored. The rotation, through the time dependent centrifugal force, can efficiently excite unstable Langmuir waves in the electron-positron (hereafter e(±)) plasma of the star magnetosphere. These waves, then, Landau damp on electrons accelerating them in the process. The net transfer of energy is optimal when the wave growth and the Landau damping times are comparable and are both very short compared to the star rotation time. We show, by detailed calculations, that these are precisely the conditions for the parameters of the Crab pulsar. This highly efficient route for energy transfer allows the electrons in the primary beam to be catapulted to multiple TeV (~ 100 TeV) and even PeV energy domain. It is expected that the proposed mechanism may, unravel the puzzle of the origin of ultra high energy cosmic ray electrons.

No MeSH data available.


Related in: MedlinePlus