Plasma devices to guide and collimate a high density of MeV electrons

The development of ultra-intense lasers(1) has facilitated new studies in laboratory astrophysics(2) and high-density nuclear science(3), including laser fusion(4-7). Such research relies on the efficient generation of enormous numbers of high-energy charged particles. For example, laser - matter interactions at petawatt (10(15) W) power levels can create pulses of MeV electrons(8-10) with current densities as large as 10(12) A cm(-2). However, the divergence of these particle beams(5) usually reduces the current density to a few times 10(6) A cm(-2) at distances of the order of centimetres from the source. The invention of devices that can direct such intense, pulsed energetic beams will revolutionize their applications. Here we report high-conductivity devices consisting of transient plasmas that increase the energy density of MeV electrons generated in laser - matter interactions by more than one order of magnitude. A plasma fibre created on a hollow-cone target guides and collimates electrons in a manner akin to the control of light by an optical fibre and collimator. Such plasma devices hold promise for applications using high energy-density particles and should trigger growth in charged particle optics.