Fig. 1.

Experimental overview. a Silicon chips covered with a monolayer of graphene and a layer of fibrils were mounted in vacuum at the CXI beamline at LCLS and scanned through the XFEL focus. b Fixed-targets were made of a square silicon frame patterned with an array of 12 × 13 windows. Scalebar is 5 mm. c A single window contained 81 holes of either 20 or 30 μm in diameter arrayed on a hexagonal lattice, resulting in 12,636 holes over a 2.54 × 2.54 cm area. Scalebar is 100 μm. d An atomic force microscope image of a hole covered with graphene and fibrils is shown. Fibrils were imaged next to the hole on the silicon frame, as tapping without the support destroys the graphene layer. Scalebar is 20 nm