# OVERVIEW

BACK

Warning! This beamline is currently not available to users.

The SGM beamline is dedicated to the spectroscopy in the soft x-rays (250 to 1200 eV) energy range. It focus on the electron spectroscopy of surfaces and absorption spectroscopy of low atomic number elements and first row transition metals with applications to atomic and molecular physics, surface science, materials science and condensed matter physics.

The SGM is a 1.67T dipole beamline providing users with monochromatic tunable photon beam in the soft X-ray range with mild resolving power and sub-milimetric spot size. Different techniques can be employed at the SGM using the endstations available at the LNLS, including X-ray Absorption Spectroscopy (XANES), X-ray scattering and reflectivity, and Photoelectron Spectroscopy (XPS).

The soft x-rays produced at SGM are valued for the unique chemical state sensitivity to light elements such as carbon, oxygen and nitrogen highly important as constituents of life and involved in many technological applications from agriculture and environment to health and nanotechnology. The soft X-rays can also probe the absorption edges of first row transition metal and rare-earth lanthanides important for correlated electron materials, catalysis and energy storage. Moreover, in electron spectroscopy such as XPS, soft X-rays sources are valuable to generate low kinetic energy electrons with very high surface sensitivity up to few atomic layers.

## CONTACT

Coordinator: Tulio Rocha
Coordinator Email: tulio.rocha@lnls.br

# OPTICAL ELEMENTS

ElementTypePosition[m]Description
SOURCEBending Magnet0.0Bending Magnet D08 exit A (4°), 1.67 T
M1Spherical Horizontal Focusing Mirror2.8Au coated, R=94m, $\theta$=41mrad, side bounce
M2Spherical Vertical Focusing Mirror3.6Au coated, R=69.4m, $\theta$=49mrad, bounce down
SEEntrance slit6.8horizontal: 45 mm, vertical : 5 – 1000 $\mu \rm m$
GRSpherical Grating Monochromator8.8Pt coated, R=57 m, Included angle: 174° 746/1492 l/mm, bounce up
SXExit slit12.8movable horizontal: 90 mm, vertical : 5 – 1000 $\mu \rm m$
M3Toroidal focusing Mirror14.8Au coated, $\theta$=24.4mrad, Rm=52 m, Rs=0.043 m, bounce up

# PARAMETERS

ParameterValueObs. | Condition
Energy range [eV]250-500746 grating
Energy range [eV]500-12001492 grating
Energy resolution [$\Delta$E/E]$1 \times 10^{-3}$at 500 eV, 100 $\mu \rm m$ slit
Beam size at sample [$\mu \rm m^2$, FWHM]330 x 760at 500 eV
Beam divergence at sample [$\mu \rm rad^2$, FWHM]3 x 18at 500 eV
Flux density at sample [ph/s/$\rm mm^2$]$2.28 \times 10^{11}$at 500 eV

# INSTRUMENTATION

InstrumentTypeModelSpecificationsManufacturer
XAS endstation----
XPS endstation----
XRR endstation----

# CONTROL AND DATA ACQUISITION

The beamline is controlled with EPICS (Experimental Physics and Industrial Control System), running on a PXI from National Instruments. There is a graphical user interface in CSS (Control System Studio) to control the beamline parameters and display the multiple device readings.

The data is acquired using different software. For XAS experiments, a phython program using tools from the Py4Syn suit developed at LNLS read the EPICS variables and record to files. The XPS endstation uses a proprietary software SPECSLab2 from SPECS GmBH to control the spectrometer and record data. The XRR uses the software spec for instrument control and data acquisition.

# APPLYING FOR BEAMTIME

This beamline is currently not available to users.

Submission calls are usually announced twice per year, one for each semester. All the academic research proposals must be submitted electronically through the SAU Online portal. Learn more about how to submit a proposal here.