Abstract
Collimation of positrons produced by laser-solid interactions has been observed using an externally applied axial magnetic field. The collimation leads to a narrow divergence positron beam, with an equivalent full width at half maximum beam divergence angle of 4° vs the un-collimated divergence of about 20°. A fraction of the laser-produced relativistic electrons with energies close to those of the positrons is collimated, so the charge imbalance ratio (ne-/ne+) in the co-propagating collimated electron-positron jet is reduced from ∼100 (no collimation) to ∼2.5 (with collimation). The positron density in the collimated beam increased from 5×107cm-3 to 1.9×109cm -3, measured at the 0.6m from the source. This is a significant step towards the grand challenge of making a charge neutral electron-positron pair plasma jet in the laboratory.
Original language | English |
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Article number | 040703 |
Journal | Physics of Plasmas |
Volume | 21 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2014 Apr |
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics