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Current Issue of Nature

Volume 595 Issue 7868, 22 July 2021
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Volume 595 Issue 7868, 22 July 2021

Compact source

Indispensable in fields such as structural biology and chemistry, X-ray free-electron lasers (FELs) generate intense, coherent beams of radiation at frequencies that are inaccessible to standard table-top lasers. But they require intense beams of high-energy electrons, which are produced by huge, expensive accelerators — so the equipment is available only at dedicated facilities. In this week’s issue, Wentao Wang and colleagues take a key step towards the creation of compact FELs with a dramatically reduced footprint that could make the technology more accessible. The researchers successfully generated coherent radiation with electron beams from a laser wakefield accelerator, which accelerates electrons through a plasma wave. The team achieved a roughly 100-fold increase in the power of the emitted radiation, meaning that the right conditions for the electrons to generate laser light were achieved at the end of a gas jet only 6 millimetres long — orders of magnitude shorter than the 3,000 metres or so used in current FELs.

Cover image: Julie Liu

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