ARPES Instruments

He Lamp

This intrument is a workhorse of our group. It provides reasonable energy resolution, high precision and stability that allows for quantitative ARPES studies. The VUV light generated by tge He Electron Cyclotron Resonance (ECR) plasma is collected by large ellipsoidal mirror and focused to 1mm spot on the sample. The flux is ~10^13 photons/s. Six axis goniometer is cooled by closed cycle G-M cold finger to ~13K.

ARPES Helium Lamp Tool


Tunable VUV Laser ARPES Spectrometer

This is a very unique instrument that allows to acuire photon energy dependent ARPES data in the laboratory setting. The energy and momentum resolution is similar to other laser based ARPES systems, but here we can tune the enrergy of the photons between 5 eV and 7 eV. This allows tuning kz (momentum perpendicular to the sample surface) and access to significant portion of 3D Brillouin zone. In many cases the ability to choose best photon energy also helps to overcome problems with the matrix elements.

External view of tunable VUV laser spectrometer

The picture above shows the preparation chamber in the front, analysis chamber and R8000 electron analyzer to the righ and tunable VUV laser in the clean room tent on the left. The picture of the laser and fourth harmonic generator is shown below.

Detailed view of laser and fourth harmonic generator