It is very nice to see that the carbon membranes, that we have devolped for x-ray windows, can also be used to create low energy photons for spectroscopy:
The article is here:
https://pubs.aip.org/aip/rsi/article-abstract/96/5/053101/3345485/Pyrolytic-carbon-membranes-enabling-novel-low
A novel low-energy photon source is enabled by the graphenic carbon membrane
