LUCIA

Technical data

Energy range

0.6 – 8 keV

Source

Undulator HU52 "Apple II" type, 32 periods, gap 15 – 150mm, variable linear polarization, left and right circular polarizations, operating on harmonics 3 to 21

Optics

Spherical mirror for horizontal de-magnification; two planar mirrors act as a low pass filter to remove higher harmonics. Their angle of incidence can be varied from 0.4^o to 1.3^o. All mirrors are silicon coated with nickel.

Monochromator

Double crystal monochromator built by Kohzu. Its design is based on a double cam which provides a fixed exit geometry and covers a large angular range (5^o- 75^o). Up to five different crystals, namely KTP(011), MGM (Multilayer Grating Monochromator), InSb(111), Si(311) and Si(111) fit into the water cooled holders.

Energy resolution

A table describing the energy ranges and resolution for each monochromating system can be accessed

Focusing optics

The final focusing is done with a "Kirkpatrick-Baez" (KB) reflecting mirrors system. It is based on an ESRF-design, and was modified to be high vacuum compatible.

Spot size on the sample

3 x 2 mm² for the macro-beam

2.5*2.5 µm²  for the micro-beam

Flux on the sample

8.0*10¹⁰ ph/s/400mA @ 4000eV in 2.5*2.5 µm²
1.6*10¹¹ ph/s/400mA @ 4000eV in 1.5*1.5 mm²

Sample environment

Measurements are always performed in a primary vacuum chamber (primary vacuum or secondary vacuum for cryogenic analyses or if the samples require it)

It is rather spacious and can accept a variety of setups. A motorized (x,y,z)-stage allowing the precise (µm) and reproducible (coders present) positioning of the sample for mapping purposes. The following environments can be added: 

• A liquid / electrochemical cell
• An oven
• A He/N₂ cryostat
• A peltier

Separate UHV chambers for surface science and chamber for electrochemistry are also available, they are mounted downstream of the main chamber. 

Detection

µXRF: measurement of the fluorescence spectra: SDD (silicon drift diode) 80 mm² Bruker
µXAS: measurement of the fluorescence yield (FY), of the sample drain current (TEY) and measurement of the transmitted photons flux (diode)

Sample holders

Generalities

Most of the LUCIA sample holders are based on a copper plate put in two rails of the sample stage. The yellow area must be consequently left free. The copper plate is vertical in the sample stage.

Flat, simple Cu plate

Used to stick adhesive carbon tape with powder, to press indium foil with powder or to stick samples with adhesive double-sided tape. Ultralene foil must covered powered samples.

Detection allowed: fluorescence and TEY modes.

Plate for pellets

Four 10 mm diameter pellets can be placed on the plate and a platelet is screwed using 4 screws (steel or molybdenum screws). All pellets mounted on a plate must have the same thickness.

Detection allowed: fluorescence, TEY and transmission modes.

Thick plate for “large” samples

Used for samples larger than 20 mm in diameter. There are still some sample size constraints in the three directions (maximum size is 5 cm both in vertical and horizontal). Check the size of your samples with your local contact.

Detection allowed: fluorescence and TEY modes.

Thick plate with holes for biological cryo thin sections

Three cryo thin sections can be sandwiched between two Ultralene foils and fixed with a ring system on Cu platelets. Cu platelets are screwed on Cu thick plate using two screws (steel or molybdenum screws). Diameter of the holes of the platelet is 6 mm and of the holes of the Cu thick plate is 5 mm.

Other type of thin samples can be also placed on Ultralene foil stick on PEEK platelets, screwed using two screws (steel or molybdenum screws). The square opening is 5 x 5 mm².

Detection allowed: fluorescence mode.

Thick plate with wells for frozen solution

Three solutions can be put in the wells of the sample holder. The volume of a well is 25 µL. The sample holder is plunged in liquid N₂ to freeze the sample. Then, on the front of the sample holder, Cu platelets with Ultralene foil are screwed using two screws (steel or molybdenum screws).

Detection allowed: fluorescence mode.

Plate for 1 mm thick - 16 mm diameter slide

The slide is fixed on its sides by four screws. It was designed for a SMIS-LUCIA combination. The ZnSe disc inserted in the centre is compatible with certain analyses on SMIS.

Detection allowed: fluorescence mode.