Laser acceleration of quasi-monoenergetic MeV ion beams
Laser acceleration of quasi-monoenergetic MeV ion beams
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DOI：
10.1038/nature04400
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发表时间：
2006-01-26
期刊：
影响因子：
64.8
通讯作者：
Fernández, JC
中科院分区：
文献类型：
--
作者：
Hegelich, BM;Albright, BJ;Fernández, JC
强烈的激光-等离子体相互作用对粒子的加速代表了一个快速发展的兴趣领域，最近激光驱动的单能电子相对论束的演示(1-4)就强调了这一点。超高强度激光器可以产生10 TV m(-1)（1 TV = 10(12) V）的加速场，超过传统加速器六个数量级。每个核子能量为几 MeV 的激光驱动离子也已被生产出来(5-9)。此类离子束表现出前所未有的特性 - 短脉冲长度、高电流和低横向发射率 (10) - 但其指数能谱几乎具有 100% 的能量扩散。这种巨大的能量扩散是迄今为止所使用的实验条件造成的，仍然是广泛使用该技术的最大障碍。在这里，我们报告了准单能激光驱动的 C5+ 离子的产生，其能量扩散大大降低了 17%。这些离子的平均能量为每个核子 3 MeV（半峰全宽，类似于每个核子 0.5 MeV），并且当脉冲持续时间短于 1 ps 时，纵向发射度小于 2 x 10(-6) eV s。这种激光驱动、高电流、准单能离子源可能会在紧凑型 MeV 离子加速器 (11)、新诊断 (12,13)、医学物理 (14)、惯性约束聚变和快速点火 (15-17) 的开发方面取得重大进展。
Acceleration of particles by intense laser - plasma interactions represents a rapidly evolving field of interest, as highlighted by the recent demonstration(1-4) of laser-driven relativistic beams of monoenergetic electrons. Ultrahigh-intensity lasers can produce accelerating fields of 10 TV m(-1) (1 TV = 10(12) V), surpassing those in conventional accelerators by six orders of magnitude. Laser-driven ions with energies of several MeV per nucleon have also been produced(5-9). Such ion beams exhibit unprecedented characteristics - short pulse lengths, high currents and low transverse emittance(10) - but their exponential energy spectra have almost 100% energy spread. This large energy spread, which is a consequence of the experimental conditions used to date, remains the biggest impediment to the wider use of this technology. Here we report the production of quasi-monoenergetic laser-driven C5+ ions with a vastly reduced energy spread of 17%. The ions have a mean energy of 3 MeV per nucleon (full-width at half-maximum, similar to 0.5 MeV per nucleon) and a longitudinal emittance of less than 2 x 10(-6) eV s for pulse durations shorter than 1 ps. Such laser-driven, high-current, quasi-monoenergetic ion sources may enable significant advances in the development of compact MeV ion accelerators(11), new diagnostics(12,13), medical physics(14), inertial confinement fusion and fast ignition(15-17).