New progress in X‐ray microscopy

SUMMARY Interest has recently revived in microscopy at X‐ray wavelengths, stimulated in part by work for microelectronic lithography. The use of synchrotron radiation and other intense sources of X‐rays, the development of plastic foils in place of photo‐emulsions for recording and the fabrication of Fresnel zone lenses for focusing X‐ray beams have all played a part. Some progress has already been made in improving the resolution and contrast of this method of microscopy, in the wavelength range 2–4 nm. The limitation imposed by radiation damage in biological specimens still has to be explored.