# Carnaúba

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Carnauba (Copernicia prunifera) is an endemic tree of semiarid region of northeastern Brazil. (Foto: Otávio Nogueira)

Carnauba (Coherent X-rAy NAnoprobe BeAmline) is a beamline for multiple advanced techniques using X-ray absorption, scattering and emission, and combining coherent light with nano-focusing. It is the longest of Sirius beamlines, with 145 meters distance between the light source and the sample environment. This length is required to produce a high optical demagnification and attain a focus size of about 30 nm.

The Carnauba beamline cover the energy range of 2 to 14 keV, allowing the measurement of the K-edge of lighter elements, such as phosphorus and sulfur. The analysis of various types of nano-structured materials is possible, allowing 2D and 3D images with nanometer resolution of composition and structure using contrast absorption, emission and diffraction spectroscopy. These images are obtained by scanning the sample with nanometer precision in relation to the synchrotron radiation beam. Some of the main areas which will benefit from these techniques will be the Material Sciences (catalysts, magnetism, semiconductors); Nanotechnology (information, health); Environmental Sciences (geosciences, materials under extreme pressures, petrology); and Life Sciences (medical and biological applications).

The optical design of this beamline takes advantage of the low emittance of Sirius, allowing the beam at the sample to be at the same time nanometric and of relative low divergence, with a large depth of focus. The latter is an important aspect for the phase contrast diffraction technique.

Carnauba is in preliminary design phase. Its Conceptual Design Report (CDR) was presented and evaluated by the international Beamline Advisory Team (BAT) and adjusted according to their recommendations. All the main components have been specified and prototypes are being built.

# OPTICAL ELEMENTS

ElementTypePosition[m]Description
SOURCEInsertion DeviceDelta Undulator X-ray Source
M1First Mirror27Focusing
SSASecondary Source54Defining source aperture
M2Second Mirror56Deflection
4CMFour-bounce Monochromator136Monochromatization
KB MvVertical KB Mirror144.64Vertical Focusing
KB MhHorizontal KB Mirror144.88Horizontal Focusing

# PARAMETERS

ParameterValueObs. | Condition
Energy Range [keV]2-14Si(111)
Energy Resolution [$\Delta$E/E]$10^{-4}$ - $10^{-5}$
Harmonic Content < $10^{-5}$
Energy ScanYes
Beamsize at sample [ $\mu \rm m$ ]0,03 x 0,03 (0.12 x 0.12)8 keV (2 keV)
Beam Divergence at sample [mrad]< 2 (5 x 5)8 keV (2 keV)
Imaging Mode-
Coherence Modes~1-

# Experimental techniques

Some of the techniques that could be explored in this beamline will be:

• CDI – Coherent X-ray Diffraction Imaging;
• X-ray Ptychography;
• Diffraction and Element Contrast Scanning Tomography;
• X-ray Absorption, Emission, Scattering and Diffraction with nanofocus;