Experimental Observation of a Current-Driven Instability in a Neutral Electron-Positron Beam
- Queen's Univ., Belfast, Northern Ireland (United Kingdom). School of Mathematics and Physics
- Linkoping Univ., Norrkoping (Sweden). Dept. of Science and Technology (ITN)
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Ecole Polytechnique, Palaiseau (France). Lab. pour l'Utilisation des Lasers Intenses (LULI)
- Imperial College London, London (United Kingdom). John Adams Inst. for Accelerator Science, Blackett Lab.
- Univ. of Michigan, Ann Arbor, MI (United States). Center for Ultrafast Optical Science
- Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL), Central Laser Facility
- Univ. of Michigan, Ann Arbor, MI (United States). Center for Ultrafast Optical Science; Lancaster Univ. (United Kingdom). Physics Dept.
Here, we report on the first experimental observation of a current-driven instability developing in a quasineutral matter-antimatter beam. Strong magnetic fields (≥ 1T) are measured, via means of a proton radiography technique, after the propagation of a neutral electron-positron beam through a background electron-ion plasma. The experimentally determined equipartition parameter of εB ≈ 10-3 is typical of values inferred from models of astrophysical gamma-ray bursts, in which the relativistic flows are also expected to be pair dominated. The data, supported by particle-in-cell simulations and simple analytical estimates, indicate that these magnetic fields persist in the background plasma for thousands of inverse plasma frequencies. The existence of such long-lived magnetic fields can be related to analog astrophysical systems, such as those prevalent in lepton-dominated jets.
- Research Organization:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC02-76SF00515; EP/N-022696/1; EP/N-027175/1; EP/L-013975/1; EP/N-002644/1; EP/P-010059/1; NA-0002372; x-2016046960; NA0002372; x2016046960
- OSTI ID:
- 1410524
- Alternate ID(s):
- OSTI ID: 1408181
- Journal Information:
- Physical Review Letters, Vol. 119, Issue 18; ISSN 0031-9007
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
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