Endstation

Scanning transmission x-ray microscope (STXM)

Energy range

130-2000 eV

Monochromator

Variable-included-angle PGM

Calculated flux (1.9 GeV, 400 mA)

~10⁹ photons/s

Resolving power (E/ΔE)

2500-7000

Characteristics

Used to make x-ray images and NEXAFS spectra of thin samples in transmission. Chemical mapping at 30-nm resolution. Polarization studies.

Spatial resolution

Scanning microscope with focusing by means of Fresnel zone plates; resolution determined by spot size, which is 30 or 40 nm with current zone plates. Single features of smaller dimension can be analyzed.

Detectors

Photon-counting detector behind the sample records the intensity of the transmitted radiation, generating an image pixel by pixel during the rastering. Fast avalanche photodiode to provide time-resolved measurements in multibunch mode.

Spot size at sample

30 or 40 nm with current zone plates

Samples

Format

Thin sections, films, and particulates (50–1000 nm thick); 3 x 3 mm in area

Preparation

No preparation chamber available

Sample environment

Helium up to 1 atm, vacuum to 10^-2 Torr, inert gas up to 1 atm

Special notes

Samples may be wet or dry; thin films may be deposited on silicon nitride windows or TEM grid. External magnetic field can be applied—up to 600 G.

Scientific applications

Molecular environmental science STXM, materials sciences, life sciences, magnetic materials

Experimental techniques

Imaging, NEXAFS in small spots; chemical mapping at 30-nm resolution