Varun Mapara is a joint postdoc with the Bergmann, Kawasaki, and Xiao labs at UW-Madison as part of our MRSEC collaboration. Varun specializes in ultrafast spectroscopy and the characterization of novel materials in high magnetic fields.
The X-FAST instrument is operated for user science by the Wisconsin MRSEC. X-FAST produces femtosecond optical pump pulses and wideband femtosecond extreme ultraviolet (XUV) probe pulses through high-harmonic generation. Transient-absorption spectroscopy in the XUV energy range of 40–120 eV can be performed at X-FAST. This range covers 3d transition metal M edges of other absorption edges of rare earth materials. The transmission measurements focus on thin (20-50 nm) samples including magnetic membranes.
Featuring a gas-cooled sample cell, the X-FAST instrument allows researchers to investigate the dynamics of thermally sensitive thin-film samples without compromising their integrity. X-FAST opens new avenues for studying electronic structure dynamics in materials and molecular systems at the femtosecond timescale with element-specific core-hole sensitivity.
MRFN.org is supported by the MRSEC Program of the National Science Foundation. Image in the header is courtesy of CRISP MRSEC.
