BL2B  Photoelectron Spectroscopy of Molecular Solids

▼Description
  This beamline previously dedicated for experiments in the field of gas phase photoionization and reaction dynamics. Then, thebeamline has been reconstructed for photoelectron spectroscopy of molecular solids with a new end station, and experiments can be performed from May 2014. The monochromator is a spherical grating Dragon type with 18-m focal length.High throughput (1 × 10¹⁰ photons s^-1) and high resolution (E/ΔE = 2000 - 8000) are achieved simultaneously under the condition of the ring current of 100 mA [1]. The optical system consists of two pre-focusing mirrors, an entrance slit, three spherical gratings (G1 - G3), two folding mirrors, a movable exit slit, and a refocusing mirror [2]. The monochromator is designed to cover the energy range of 23-205 eV with the three gratings: G1 (2400 lines mm^-1, R = 18 m) at 80-205 eV; G2 (1200 lines mm^-1, R = 18 m) at 40-100 eV; G3 (2400 lines mm^-1, R = 9.25 m) at 23-50 eV. The percentage of the second-order light contamination at hν = 45.6 eV is 23% for G2 or 7% for G3.
  A UHV chamber is placed downstream of the refocusing mirror chamber and equipped silicon photodiode, sapphire plate Au mesh and filters for absolute photon flux measurement, monitor the photon-beam position, relative photon flux measurements and attenuate higher order light, respectively.
  The new end station consists of a main chamber with a hemispherical analyzer (SCIENTA R3000) and a liquid-He-cooled cryostat (temperature range of 15-400 K) with 5-axis stage, a sample preparation chamber with a fast-entry load-lock chamber and a cleaning chamber with LEED, ion gun for sputtering and IR heating unit.
[1] M. Ono, H. Yoshida, H. Hattori and K. Mitsuke, Nucl. Instrum. Meth. Phys. Res. A 467-468 (2001) 577.
[2] H. Yoshida and K. Mitsuke, J. Synchrotron Radiation 5 (1998) 774.

▼Technical Data