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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 temporal behaviour of amplitudes of ReN1 (S), ImN1 (Dot), ReN2 (BDash), ImN2 (SDash).
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f3: The temporal behaviour of amplitudes of ReN1 (S), ImN1 (Dot), ReN2 (BDash), ImN2 (SDash).

Mentions: The determining parameters of the system are: the ratio of the mode frequency to the star rotation frequency w = ω1/Ω, and , and b. From our extensive numerical studies, we pick up two typical Mathematica plots (Fig. 2 and Fig. 3) in which ReN1, ImNI, ReN2, and ImN2 are plotted as functions of time. Time has been normalized to the inverse of the frequency ω1, the relativistic plasma frequency corresponding to the stream with lower γ (and much higher ambient density). The parameters for the illustrative cases are: For Fig. 2, w = b = 107, α = .01, and for Fig. 3, w = b = 108, α = .01. Since the x axis denotes time measured in their respective plasma time (inverse of ω1) - the “absolute” time scales in the two figures are different by a factor . For each case, we choose initial conditions (t = 0) for what we call the Sin solution: N1(0) = 0, N1′(0) = 1, N2(0) = 0, N2′(0) = α(cos b – i sin b); it is easy to verify that these constitute a consistent solution to the coupled differential equations in the limit t → 0.


Ultra high energy electrons powered by pulsar rotation.

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

The temporal behaviour of amplitudes of ReN1 (S), ImN1 (Dot), ReN2 (BDash), ImN2 (SDash).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f3: The temporal behaviour of amplitudes of ReN1 (S), ImN1 (Dot), ReN2 (BDash), ImN2 (SDash).
Mentions: The determining parameters of the system are: the ratio of the mode frequency to the star rotation frequency w = ω1/Ω, and , and b. From our extensive numerical studies, we pick up two typical Mathematica plots (Fig. 2 and Fig. 3) in which ReN1, ImNI, ReN2, and ImN2 are plotted as functions of time. Time has been normalized to the inverse of the frequency ω1, the relativistic plasma frequency corresponding to the stream with lower γ (and much higher ambient density). The parameters for the illustrative cases are: For Fig. 2, w = b = 107, α = .01, and for Fig. 3, w = b = 108, α = .01. Since the x axis denotes time measured in their respective plasma time (inverse of ω1) - the “absolute” time scales in the two figures are different by a factor . For each case, we choose initial conditions (t = 0) for what we call the Sin solution: N1(0) = 0, N1′(0) = 1, N2(0) = 0, N2′(0) = α(cos b – i sin b); it is easy to verify that these constitute a consistent solution to the coupled differential equations in the limit t → 0.

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