Beamline description - first draft

XRF_beamline.md

+
+#  X-Ray Fluorescence beamline (XRF)
+
+Ref: Milan Prica, Roberto Borghes, Valentina Chenda
+Last updated: Feb. 5, 2021
+
+## Experimental Activities
+
+XRF beamline is developed by Elettra Sincrotrone Trieste and operated in partnership 
+with the International Atomic Energy Agency (IAEA).
+
+X-Ray Fluorescence is a versatile technique which can investigate solids, liquids,
+artworks, air particulates, inks, etc… It provides information on the elemental
+composition of a sample. 
+
+At the XRF beamline, experiments can be carried out under ambient conditions or in 
+the ultrahigh vacuum (UHV) endstation, where the pressures can be lowered down to 10-9mbar.
+
+The UHV endstation is equipped with a 7-axes manipulator to adjust the
+sample orientation with respect to the X-ray beam and/or the detectors.
+
+Available techniques
+- 2D XRF and XANES: quantitative chemical analysis over different areas of the sample;
+- Grazing Incidence XRF and XANES: ideal for nano-layered structures or shallow dopants 
+in semiconductors with nm depth resolution.
+- Total Reflection XRF and XANES: for ultra-trace elemental/chemical characterization of 
+liquid samples residues and micro/nanoparticles on smooth surfaces;
+- X-Ray Reflectivity (XRR): for structural analysis of thin films and multi-layers.
+
+## Troubleshooting
+
+Fluorescence experiments are controlled by IAEA software running on their Windows machines. 
+We can reach IAEA tango database from our network and vice-versa. 
+IAEA Tango database is iaea-server.elettra.trieste.it:20000
+
+XRF Monochromator is prone to malfunctions due to a very complex design. It includes
+a collimator and a refocusing mirror in the same chamber with the monochromator. 
+The monochromator has 5 channels: Si, InSb, HE, ME and LE. For the first two, the crystal 
+separations may be regulated. Motor controllers include Galil, SmarAct, PI and Newfocus.
+
+On the xrf-desktop-01 workstation the network speed has changed a few times from gigabit 
+to the slowest setting, 10Kb/s. The cause is yet unknown.
+
+## **Control system machines**
+
+Beamline controls and EXAFS experiments run on Elettra hardware and software.
+- **xrf-control-01.blcs.elettra.trieste.it**: Virtual machine that hosts the Tango database
+(port 20000) and all the Tango devices (except the IAEA ones, see below). OS: Ubuntu 16.04.
+Development/admin user is controls. 
+
+- **iaea-server.elettra.eu**: is the old Windows PC located in the corner of the XRF control 
+room. Remote access is only possible with TightVNC. Beamline staff has the login credentials.
+Tango devices (all C++) for IAEA detectors and 7-axes manipulator run on the host. 
+An Astor-simulating application that starts and stops tango devices is running on the host. 
+Regular Astor cannot be used due to the starter issues but Jive is available.
+
+## **Beamline workstations**
+
+- **xrf-desktop-01.blcs.elettra.trieste.it**: Main workstation for controlling the
+beamline and the EXAFS experiments. OS: Ubuntu 16.04. Development/admin user is controls,
+while the beamline user is xrf. DonkiLog, DonkiLauncher, Taurus 4.6 panels and command-line 
+experiment control scripts run on it. Scripts are located in /home/xrf/Documents/scripts/.
+
+- **xrf-desktop-02.blcs.elettra.trieste.it**: Backup workstation with the same 
+setup as the main workstation but with a small screen.
+
+## **High level TANGO devices**
+
+- **xrf/monochromator/energy**: Tango device for the monochromator used to set the energy.
+The energy value is calculated from angle of incidence with the inversefunc method from the
+pynverse library as the position to energy formula based on the monochromator kinematics is not 
+invertible otherwise. The monochromator device controls channel selection, angle of incidence 
+and crystal separation values, while the pitch and roll motors of each crystal are excluded
+in the current implementation. An Executer script, xrf/monochromator/set_energy, is used to 
+avoid backlash when changing energy to a lower value by setting an even lower value first. 
+All the scans are performed by moving from lower to higher energies.
+
+- **xrf/acquisition/exafs_scan**: An Executer script that controls the EXAFS scans. 
+It is highly configurable and it may be run either from its Taurus GUI or from a command line
+tool that uses python properties files for configuration. The acquisition is performed
+by the **DonkiOrchestra**.
+
+## **High level CLI**
+
+- **exafs_scan.py**: A command line tool found on the two workstations that configures 
+and runs any number of EXAFS scans. Also controls the HOS and 7-axes manipulator. 
+It is entirely configurable with python's property files.
+
+## **Instrumentation TANGO devices**
+
+The following Tango devices run on the IAEA server and are controlled/acquired by both 
+IAEA and Elettra software:
+- BrukerSpectometer : Bruker detector
+- KeithleyPicoAmmeter : Photo-diode
+- ElettraPicoAmmeter : BMS
+- SevenAxesManipulator : controls the movements of 7 axes of the chamber manipulator.
+
+Used only from IAEA GUI:
+- AmptecSpettrometer : XRR (X-Ray Reflectivity) scans of theta/2theta. 
+- XiaXmapSpectrometer : not in use.
+
+## **Motion control Tango devices**
+
+- AxisG2: it is the new Galil C++ Tango device from A. Abrami. 
+All instances are configured so that the AxisInit command does the initialization.
+
+- PiezoPiE871: a modified C++ Tango device from DESY for the two PI positioners 
+that move pitch and roll of the first (Si111) crystal. Positioners are encoderless
+and the initialization is perfomed by a DefinePosition(Value).
+
+- NewFocusPicoAxis: A C++ Tango device for pitch and roll motors of all crystals 
+except the Silicon. They are automatically initialized.
+
+- SmaractMCS: A Python Tango device for MCS1 SmarAct positioner that moves the
+InSb crystal separation. It must be initialized with FindReferenceMark command.
+(If the motor cables were removed, a Calibrate command is necessary first.)
+