Endstation one: Hector magnet
Dichroism end-station: Hector, an advanced high-field vector cryomagnet for XMCD
The dichroism end-station consists of a UHV-compatible cryomagnet, manufactured by Scientific Magnetics. The system is equipped with three orthogonal superconducting coils allowing for maximum fields of 6 T (in the horizontal plane along the beam direction, with a sweep rate of 2 T/minute) and 2 T (in the horizontal plane perpendicular to the x-ray beam and in the vertical plane, with a sweep rate of 0.6 T/minute). Simultaneous operation of the three coils will allow one to cover a sphere of 2 T, with a sweep rate of 0.4 T/minute (the integration of this operation mode into ALBA control is under progress).
The samples are in a UHV environment (with a base pressure of the order of 10^-10 mbar) and mount on a sample holder attached to the cold finger of a cryostat, with temperatures variable between approximately 2 K and 350 K. The sample is electrically insulated in order to perform drain current measurements. Moreover, four electrical contacts are provided on the sample holder for any type of 4-probe measurements. A special sample holder is permanently equipped with a Hall probe (limited to 300 K), for applications requiring precise knowledge of the field (or of the remnant field of the superconducting coils). A second special sample holder is permanently equipped with a Cernox temperature sensor, for direct "sample temperature" measurement instead of using calibrated values and offset based on the more indirect cold finger temperature sensor.
The system is equipped with a 3-chamber sample preparation/insertion set-up (load-lock, buffer, main). The load-lock chamber allows fast sample change at ambient pressure and reach high vacuum in a few minutes. The buffer chamber ensures a smooth transition from the high vacuum of the load-lock to the UHV of the main preparation chamber and is equipped with a parking for up to four samples. The main chamber, below the centre of the magnet, is equipped only with a good number of sample preparation tools: a cleaver, a scraper, evaporators for metals and organic molecules, a heating stage and an ion sputtering gun.
In the future, this chamber will be connected in UHV with the scattering end-station and with an STM system.
Installation of the magnet endstation
Photos of the Factory Acceptance Test of the XMCD cryomagnet (July 2011)
Photos of the installation of the XMCD support and common end-station platform (July 2011)
