# PGM

BACK

The PGM (Planar Grating Monochromator) beamline is an experimental station dedicated to X-ray Spectroscopy in the soft X-rays (100 to 1500 eV) energy range, with applications to the study of the electronic, magnetic and structural properties of materials. It is well equipped with in-situ preparation facilities, making it particularly suited for surface science and thin films characterization. In addition to that, it is offers instrumentation for microscopy and photoemission on liquids.

PGM’s source is an elliptical polarization undulator with a 50 mm period (EPU50), which allows the photon polarization to be switched among linear horizontal, linear vertical or circular polarization. Its optics is based on a standard planar grating monochromator (PGM) equipped with a 1500 l/mm variable line spacing (VLS) diffraction grating. It serves two branches that operate independently but not simultaneously.

The beamline provides several experimental end stations to users. Systems are available for X-ray absorption and its variants (linear and circular dichroism), photoemission (XPS and ARPES), photoemission microscopy (PEEM), XPS on liquids and soft X-ray diffraction.

Furthermore, the beam line is equipped with a full featured in-situ preparation system, which allows the user to grow thin films and heterostructures by molecular beam epitaxy (MBE) with thermal evaporators and by pulsed laser deposition (PLD). The samples can then be transferred under ultra-high vacuum conditions and be characterized by the techniques available at the beam line.

## CONTACT

Beamline Email: N/A

Beamline Telephone Number: +55 19 3512 1146

Coordinator: Julio Criginski Cezar

Coordinator Email: julio.cezar@lnls.br

Coordinator Telephone Number: +55 19 3512 1292

For more information on the Beamline Team, check out the Beamline Team’s page here

# OPTICAL ELEMENTS

ElementTypePosition[m]Description
SourceInsertion DeviceInsertion Device U11A, APPLE II Elliptical Polarization Undulator (EPU50), built in-house, 50 mm period, 2.73 m long
M1Toroidal mirror13Au coated; water cooled
M2-GMonochromator15Au coated plane mirror and 1500 l/mm VLS grating
ESExit slit22-
M3a, M3bRefocussing toroidal mirrors29Au coated; used to switch between branches

# PARAMETERS

ParameterValueObs. | Condition
Energy range [keV]103 – 1500 eVLinear horizontal polarization
Energy range [keV]192 – 1500 eVLinear vertical polarization
Energy range [keV]127 – 1500 eVCircular polarization
Resolving power [E/$\Delta$E]1000 - 25000-
Beam size at sample [$\rm mm^{2}$, FWHM]0.1 x 0.5Vertical x horizontal
Flux at sample [ph/s]$10^{11}$ – $10^{13}$-

# INSTRUMENTATION

InstrumentTypeModelSpecificationsManufacturer
Superconducting magnet--$\pm 9 \rm T$ along the beam direction $\pm 4 \rm T$ perpendicular to the beam direction Fast field switching (less than 3 min) Sample temperature between 5 and 420 KOxford Instruments
Electron Analyzer--150 mm radius hemispherical analyzer; CCD detector Energy resolution $\approx$2.5 meV; Angular resolution $\approx$0.1 degree; Sample manipulator with six degrees of freedom; Sample temperature between 15 and 420 K.Phoibos 150 SPECS
Photoelectron Microscopy--Fields of view from 100 down to $0.7 \mu \rm m$; Sample temperature from 90 up to 1400 K during measurements; Some possibilities for in-situ preparation (Ar sputtering and e-beam evaporation).P 90 SPECS
Electron Analyzer for liquids sample---Scienta
Diffractometer--4 degree of freedom diffractometerLNLS in-house development

# CONTROL AND DATA ACQUISITION

All beamline controls are done through EPICS (Experimental Physics and Industrial Control System), running on a PXI from National Instruments. The data acquisition is done using a Red Hat workstation with the Py4Syn, developed at LNLS by SOL group. CSS (Control System Studio) is used as a graphical interface to display and control the beamline devices. The systems from SPECS GmbH run on the manufacturer software.

# APPLYING FOR BEAMTIME

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.