Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Home
Search
Quick Search
Advanced
Fulltext
Browse
Collections
Persons
My eDoc
Session History
Login
Name:
Password:
Documentation
Help
Support Wiki
Direct access to
document ID:


          Institute: MPI für Kernphysik     Collection: Theoretical Astrophysics     Display Documents



  history
ID: 51228.0, MPI für Kernphysik / Theoretical Astrophysics
Particle acceleration through multiple conversions from a charged into a neutral state and back
Authors:Derishev, E.V.; Aharonian, F.A.; Kocharovsky, V.V.
Language:English
Date of Publication (YYYY-MM-DD):2003-08
Title of Journal:Physical Review D.
Journal Abbrev.:Phys. Rev. D.
Volume:68
Start Page:1
End Page:12
Sequence Number of Article:043003
Title of Issue:Particles, Fields, Gravitation, and Cosmology -15
Copyright:AMERICAN PHYSICAL SOC, ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA.
Review Status:not specified
Audience:Experts Only
Abstract / Description:We propose a new means for a quick and efficient acceleration of protons and/or electrons in relativistic bulk flows. The maximum attainable particle energies are limited either by radiative losses or by the condition of confinement in the magnetic field. The new mechanism takes advantage of a conversion of particles from the charged state (protons, electrons or positrons) into a neutral state (neutrons or photons) and back. In most cases, the conversion is photon induced and requires the presence of intense radiation fields, but under special circumstances the converter acceleration mechanism may operate via other charge-changing reactions, for example, inelastic nucleon-nucleon collisions. As in the traditional, "stochastic" (or diffusive) acceleration models, the acceleration cycle in the proposed scenario consists of the escape of particles from the relativistic flow followed by their return back after deflection from the ambient magnetic field. The difference is that the charge-changing reactions, which occur during the cycle, allow accelerated particles to increase their energies in each cycle by a factor much larger than 2 and usually roughly equal to the bulk Lorentz factor squared. The emerging spectra of accelerated particles can be very hard and their maximum energy in some cases is larger than in the standard mechanism. This significantly reduces the required energy budget of the sources of the highest-energy particles observed in cosmic rays. The proposed acceleration mechanism has a distinctive feature-it unavoidably creates neutral beams, consisting of photons, neutrinos, or neutrons, whose beam pattern may be much broader than the inverse Lorentz factor of the relativistic flow. Also, the new mechanism may serve as an efficient means of transferring the energy of bulk motion to gamma radiation and, if the accelerated particles are nucleons, inevitably produces high-energy neutrinos at a relative efficiency approaching greater than or similar to50%
Free Keywords:Energy cosmic-rays. Active galactic nuclei. Bursts. Jets.
External Publication Status:published
Document Type:Article
Affiliations:MPI für Kernphysik/Group H. J. Völk/Theoretical Astrophysics (F. Aharonian, J. Kirk)
External Affiliations:Institute of Applied Physics RAS, 46 Ulyanov St., 603950 Nizhny Novgorod, Russia
Department of Physics, Texas A&M University, College Station, Texas 77843-4242, USA
Identifiers:ISSN:0556-2821
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.