Laser-plasma accelerators of only a centimetre’s length have produced nearly monoenergetic electron bunches with energy as high as 1 GeV. Scaling these compact accelerators to multi-gigaelectronvolt energy would open the prospect of building X-ray free-electron lasers and linear colliders hundreds of times smaller than conventional facilities, but the 1 GeV barrier has so far proven insurmountable. Here, by applying new petawatt laser technology, we produce electron bunches with a spectrum prominently peaked at 2 GeV with only a few per cent energy spread and unprecedented sub-milliradian divergence. Petawatt pulses inject ambient plasma electrons into the laser-driven accelerator at much lower density than was previously possible, thereby overcoming the principal physical barriers to multi-gigaelectronvolt acceleration: dephasing between laser-driven wake and accelerating electrons and laser pulse erosion. Simulations indicate that with improvements in the laser-pulse focus quality, acceleration to nearly 10 GeV should be possible with the available pulse energy.

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We present the design and performance of the Texas Petawatt Laser, which produces a 186 J 167 fs pulse based on the combination of optical parametric chirped pulse amplification (OPCPA) and mixed Nd:glass amplification. OPCPA provides the majority of the gain and is used to broaden and shape the seed spectrum, while amplification in Nd:glass accounts for >99% of the final pulse energy. Compression is achieved with highly efficient multilayer dielectric gratings.

Absorption by atmospheric NO3 at 6620Å has been detected at night using the moon as the light source. The absorption exhibits a <30% increase during the night which implies the NO3 observed to be in the stratosphere. The column abundance is 1 ± 0.2 × 1014cm−2, close to that predicted to exist in the stratosphere.

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