TABLE I. Example instrument X-ray bandwidths.

* Based on personal communication with Dr. J. Graf, Oncoatec (Bruker). ** Based on personal communication with Dr. W.G. Graves, Arizona State University.

Source	Typical Bandwidth ($\Delta \lambda ∕\lambda$ or $\Delta E∕E$, FWHM)	Typical pulse duration
Si 111 monochromator	<0.01%	Continuous
Cu anode $(\mathrm{K}\alpha )$ with multilayer mirrors*	5%	Continuous
Synchrotron multilayer monochromators (CHESS)54	0.6-1.3%	Continuous
Synchrotron Undulator (ESRF ID-09)55	1-3%	ps
Synchrotron dual undulators (BioCARS)56	5.5%	ps
SASE at XFELs57	0.1-0.3%	fs
Pink SSX (Pohang)58	1.2%	fs
SwissFEL pink59	1.8-2.2%	fs
Inverse Compton sources (MuCLS)60	3%	Continuous
Compact Femtosecond Compton sources (CXLS)61	0.1-5%	fs
Compact X-ray Light Source**	3, 10%	fs
Betatron source62	<100%	fs