TY  - JOUR
AU  - Ye, Hong
AU  - Trippel, Sebastian
AU  - Di Fraia, Michele
AU  - Fallahi, Arya
AU  - Mücke, Oliver D.
AU  - Kärtner, Franz X.
AU  - Küpper, Jochen
TI  - Velocity-Map Imaging for Emittance Characterization of Multiphoton Electron Emission from a Gold Surface
JO  - Physical review applied
VL  - 9
IS  - 4
SN  - 2331-7019
CY  - College Park, Md. [u.a.]
PB  - American Physical Society
M1  - PUBDB-2018-01720
SP  - 044018
PY  - 2018
AB  - A velocity-map-imaging spectrometer is demonstrated to characterize the normalized emittance (root-mean-square, rms) of photoemitted electron bunches. Both the two-dimensional spatial distribution and the projected velocity distribution images of photoemitted electrons are recorded by the detection system and analyzed to obtain the normalized emittance (rms). With the presented distribution function of the electron photoemission angles, a mathematical method is implemented to reconstruct the three-dimensional velocity distribution. As a first example, multiphoton emission from a planar Au surface is studied via irradiation at a glancing angle by intense 45-fs laser pulses at a central wavelength of 800 nm. The reconstructed energy distribution agrees very well with the Berglund-Spicer theory of photoemission. The normalized emittance (rms) of the intrinsic electron bunch is characterized to be 128 and 14 nm rad in the X and Y directions, respectively. The demonstrated imaging spectrometer has the ability to characterize the normalized emittance (rms) in a few minutes with a fine energy resolution of 0.2 meV in the image center and will, thereby, foster the further development of x-ray free-electron-laser injectors and ultrafast electron diffraction, and it opens up opportunities for studying correlated electron emission from surfaces and vacuum nanoelectronic devices.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000429779300002
DO  - DOI:10.1103/PhysRevApplied.9.044018
UR  - https://bib-pubdb1.desy.de/record/402163
ER  -