第十七届全国等离子体科学技术会议，2015.08.16-19，成都
Positron beam generated in ultra-intense laser
interacting with a special target
J.X.Liu†1，2, Y.Y.Ma1, J.Zhao1, X.H.Yang1, T.P.Yu1, L.F.Gan1, G.B.Zhang1, J.F.Yan1
1
College of Science, National University of Defense Technology, Changsha 410073, China
2
College of Electronic Engineering, Wuhan 430019, China
† liujianxun@nudt.edu.cn
A new scheme for generating high
quality positron beams is proposed. In
simulations with the relativistic PIC code
EPOCH, a 13nc Al plasma target with an
opening cone hollow is designed, whose
radiuses of the left and right hollow
K, Arber T, et al. Dense electron-positron plasmas
openings are 0 and 3λ0 , respectively,
where λ0 = 1μm is the wavelength of
the laser incident into the target. The
pulse duration is 30fs. Breit-Wheeler(BW)
process dominates the positron generation
interaction. In simulation with a laser
Plasma
intensity of 4 × 1023 W/cm2 , a beam
with 5.35 × 1015 positrons is generated,
whose yield is 5 orders higher than that
work with the same laser intensity[1], and
the beam divergence is 20°. When the
laser intensity increases to 8 ×
1023 W/cm2 , 3.75 × 1016 positrons
with a divergence of 14° are
propagating along the laser pulse. The
maximum density of the positron beam is
1.04 × 1021 cm−3 for the low laser
intensity, and 4.65 × 1021 cm−3 for the
higher. This scheme improves the quality
of the positron beam, and may have
potential applications, including nuclear
and
particle
physics,
laboratory
astrophysics, plasma physics, etc[2].
Reference:
[1] Ridgers C, Brady CS, Duclous R, Kirk J, Bennett
and bursts of gamma-rays from laser-generated
quantum electrodynamic plasmas[J]. Physics of
Plasmas. 2013,20(5):Article number 056701.
[2] Sarri G, Schumaker W, Di Piazza A, Poder K,
Cole J, Vargas M, et al. Laser-driven generation of
collimated ultra-relativistic positron beams[J].
Physics
2013,55(12):124017.
and
Controlled
Fusion.