The HPCAT 16-BM-B beamline is dedicated to white beam x-ray diffraction and radiography
research of materials under high pressure.
With the APS bending magnet white x-rays (5-120 keV), multi-angle energy
dispersive x-ray diffraction (EDXD) technique is extensively utilized to obtain
the structure factors up to Q=around 20 Å-1. A Paris-Edinburgh Cell (PEC)
(250 ton capability) is equipped for samples requiring a large scattering volume,
especially, for the high-temperature melt and amorphous structure. The range of
pressure and temperature is up to 7 GPa and 2300K. The PEC setup includes white
beam radiography system, which allows the structure measurement with EDXD to be
combined with radiographic volumetry, ultrasonic sound velocity measurement and/or
falling sphere viscosity measurement.
10-120 keV for parallel beam; 10-65 keV for focused beam
Beam size & focusing optics
50 μm x 50 μm to 2 mm x 2 mm for parallel beam (slit-limited) 10 micron (H) x 10 micron (V) FWHM with 200 mm Pt-coated Si KB- type mirror
Established techniques
Multi-Angle Energy Dispersive X-ray Diffraction, White Beam Radiography, Ultrasonic elastic wave velocity measurement, Falling sphere liquid viscosity measurement
Detectors
Ge Solid State Detector, CCD camera (Prosilica GC1380H), High-speed camera (Photron FASTCAM SA3)
Support equipment
Paris-Edinburgh type large volume press with resistive heating capacity (PE anvils, boron-epoxy gaskets, cylindrical graphite heater, 8V-220A power supplier; temperature and pressure range up to 2500 K under and 7 GPa)
The HPCAT 16-BM-B beamline hosts a Paris-Edinburgh (PE) press that allows
standardized sample asseblies to be pressurized and heated while conducting
in-situ x-ray characterization. This section describes different types of PE
experiments and optimized sample assemblies.
This login id and password will be required when re-logging in the computers (e.g., after rebooting the operating system), and can be provided by the beamline staff.
Note
The wireless mouse of the control PC has a battery saving feature and will turn off after prolonged idle period. The mouse has to switched back on by pressing the power button on the bottom.
On the Windows desktop of the control computer, users will find a shortcut named 16bmbMEDMPEC.
Note
MobaXterm program should be started or runnning in the background before opening the MEDM interface, otherwise
the interface will not start.
Note
If running in isolation mode, the EPICS/MEDM interface should be launched from MobaXterm.
In the MobaXterm go to the tab duesenberg(s16bmbuser).
Click Macros (located in either the top Menu bar or left-side tabs) and select StartMEDMfor16bmbPECusers.
Attached below is a screen shot of the PEC User Interface.
It interfaces the control widgets with 16-BM-B station shutters, SR status, EPS status, most demanded
motors for user experiments, intensity monitors with ion chambers and diode, and heater power supply controller and pressure control syringe pump.
Hint
Please be aware that when entering a new value into a field in an MEDM interface, the mouse cursor must hover over the field.
Then the Enter key on the keyboard needs to be pressed to accept the edited value. If the mouse cursor leaves the
field before the Enter key is pressed the edited value will revert to the original value.
Setup of slits and filter for EDXD and radiography measurement.
Open Slits/Filter Setup on the PEC user interface.
Input slit sizes and filter setup values in the ‘Preset Position’ window.
Warning
Please do not change other parameters (e.g., Tip X, Y, Z, and so on).
Setup 1 is for EDXD measurement and setup 2 is for radiography measurement. Filter value
is typically 0 (no filter) for EDXD measurement and -45 (100 μm molybdenum) for
radiography measurement. Please close the window after completion.
‘1st Hsize’, ‘1st Vsize’, ‘2nd Hsize’, ‘2nd Vsize’, ‘Filter’ setups change
simultaneously by clicking Slit for EDXD (EDXD) or For Camera (radiography).
Open ‘Manta Camera’ shortcut on desktop. This will opend a small launcher window with two buttons Manta Viewer
and Cam Control:
Click Manta Viewer in the launcher window to launch the viewer window.
Click Start to start camera. Adjust the ‘exposure, s’ if needed.
Click Cam Control in the launcher window to launch camera image file saving control.
Enter the ‘File path’ and the ‘File name’.
To save the image, click Save.
Note
The File path for saving the data should be /net/pantera/data/16bmb/PEC/Data/,
followed by the run number, eg. 2022-1, followed by beamtime category (GUP, etc.) and PI name.
Note
Be careful when copy-pasting the file path from the Windows Explorer into the file saving control.
The file saving control uses forward-slashes ‘ / ‘, while windows exlorer uses back-slashes ‘ \ ‘.
The Java-based HPCAT Bluediamond software is a real-time scan viewer program. The user
shortcut can be found on the Windows desktop. If the software is started fresh,
go to Configuration ‣ open to open the input configuration file named 16BMB.txt
in the C:\HPCATSoftware directory. Note that this directory is local, but can
be any directory in the network. The software is straightforward to use and most
of the menu items are self-instructing.
Various detectors can be displayed in the scan:
Beam intensity monitor by ‘Ion Chamber 1’ placed at the entrance of BMB hutch.
Beam intensity monitor by ‘Ion Chamber 2’ (used only in absorption density measurement).
Beam intensity monitor by ‘IC2 or Diode’ placed at the downstream of sample. This is mainly used for scanning sample Y and/or Z position by absorption contrast.
Intensity of ROI in MCA software. This is mainly used for scanning sample X position in EDXD measurement.
Note
The labels for these detectors can change based on the names of the ROIs. Bluediamond only refreshes the names for the detectors when it is started. If you change the name of the ROI in hpMCA the names will not be updated in Bluediamond until it is restarted.
To use line cursors (two vertical and two horizontal), select menu Util ‣ Markers ‣ Reset. Left and right cursors can be dragged.
The cursor feature is useful for graphical determination of the FWHM and peak center position. You can move sample position by clicking Move button at the ‘Center’ in the left column.
Sample X position can be adjusted by using intensity of sample or diffraction pattern. However, it is difficult to scan sample X with diffraction intensity of amorphous material. We recommend scanning sample X by using diffraction intensity of MgO ring. Followings are procedures:
Move Y -1.5 mm from sample Y center to see diffraction patterns of MgO.
Then, move Y -1.3 mm position from sample Y center (+0.2 mm Y from -1.5 mm position or move back to the sample Y center and move -1.3 mm Y).
In order to connect EPICS motor control and MCA software, please click ON in ‘Scan1 MCA Trigger Toggle’, and then input data acquisition time for each step in ‘Preset Real Time’ (typically, 2-5 second).
Open ‘Scan’ in ‘SAM X’, and input parameters (typically, Start=-1, End=1, #Pts=21).
Then, click LoadGo to start scan.
Sample X center is the location where MgO diffraction intensity is the minimum.
Note
After the scan, please do not forget to ‘OFF’ ‘Scan1 MCA Trigger Toggle’, and input 0 in ‘Preset Real Time’.
The PEC oil pressure is controlled by the Teledyne ISCO 30D dual syringe pump system.
The maximum pressure allowed is 14,000 psi (9,000 psi for ultrasound or grooved cells).
Syringe pump is controlled through the MEDM interface
Basic pump operation
Procedure for increasing, maintaining, and decreasing pressure.
Warning
Due to a problem with the pump controller, sometimes communication with the pump
gets lost and the indicators colors will change to white.
If this happens, please wait around 1-2 minutes, the communication should get re-established on its own.
Afterwards, you may need to re-do the last command.
Stop the Pressure Control before switching Mode. (Mode button is hidden while Pressure Control is in “Run” state).
Refill pumps A and B (click the button Refill for each pump).
Note
Wait until both pumps finish refilling.
Set Max flow for both pumps to 5ml/min.
Set the Oil pressure setpoint to 20 psi.
Set Pressure control to Run. Pump will go through the initial equalization sequence; this will take around 30 seconds to one minute.
Note
Pressure may go up to ~80 psi and fluctuate somewhat during this process.
Wait until the Actual oil pressure stabilizes at 20 psi.
Increase the Oil pressure setpoint to your required pressure (maximum allowed is 14,000psi). Pump will gradually reach the setpoint pressure and maintain the pressure continuously.
If you don’t want the pump to maintain the pressure continuously after reaching the setpoint, set the Maximum oil flow-rates for pumps A and B to 0.0001 ml/min.
Important
DO NOT switch Pressure Control to Stop.
To reach the next oil pressure setpoint, re-enable pressure control by setting Max flow rates back to 5 ml/min.
Wait around 1 minute before doing anything else.
After around 30 seconds, one of the pumps (A or B) will start emptying out (there will be a valve opening/closing sound).
Wait until the level in that pump reaches around 7.5 ml.
Set the setpoint pressure to 20 psi.
After the actual oil pressure is at 20 psi, switch pressure control to Stop.
Open the valves to vent the remaining oil pressure:
Open valve control from the main PEC interface menu “Pump control menu”
Toggle Valves 1-4 to Low.
Note
If the readback text for a valve is high (red), and pressed button is low: click the high button and then the low button.
Note
If the valve 1-4 buttons are hidden check the following conditions are met:
The Live valve is and electronically actuated valve in-line between the Syringe pump and the PE press.
The Line valve allows to keep the pressure in the PE press isolated from the Syringe pump when changing modes
(Compression <-> Decompression), when heating, or when leaviing the PE press unattended for an extended perions of time.
This subseciton describes the operation of the Line valve.
Before connection of cable, please confirm ‘Power Output’ in ‘PEC User Interface’ is ‘OFF’.
In hutch, please confirm ‘Heater Output Control Switch’ is ‘Disabled’.
See that the thick power cables are connected.
Turn On a fun on PE press for cooling of press body.
‘Enable’ on the ‘Heater Output Control Switch’.
Before starting heating, it is recommended to start ‘LogBook’ to save log of heating.
On ‘PEC User Interface’,
At first, please confirm ‘Voltage’ ‘Set Point (V)’=0, ‘Setpoint (Watt) on PID control = 0, and ‘Over Protection’ is ON.
‘Power Output’ ON
Input 200 in ‘Limit’ under ‘Current’. Please input again even if the value is 200.
Click Clear fault.
‘PID ON/OFF’ ON
Tweak ‘Setpoint (Watt)’ by 1 W to 3 W.
Check ‘Readback (Watt)’ is responding, and ‘Resistance’ is lower than 0.1 (typically, ~0.04-0.05 at ~1 W).
Note
Response of heater is slow particularly at <10W. Please wait a while.
Important
Increase of ‘Readback (Watt)’ may stop at <3W. If so, please check ‘Measured (Amp)’ under ‘Current’. If ‘Measured (Amp)’ value is 2.65, it is likely to forgot the procedure 3 (Input of 200 in ‘Limit’ of ‘Current’). In this case, please lower ‘Setpoint (Watt)’ to 0, turn OFF the ‘PID ON/OFF’, input 0 in Set Point (V), and turn Off the ‘Power Output’. Then, please restart the procedures.
If heater response and resistance is okay, increase ‘Setpoint (Watt)’ slowly (it is better to keep <5 difference between ‘Readback (Watt)’ and ‘Setpoint (Watt).).
Cooling can be done by
slow cooling by gradually decreasing ‘Setup (Watt)’ to 0, or
Turn OFF ‘Power Output’ to quench sample.
In both cases, after cooling,
Input 0 in ‘Setup (Watt)’.
‘PID On/OFF’ OFF
‘Power Output’ OFF
Input 0 in ‘Set Point (V) under ‘Voltage’.
‘Disable’ on the ‘Heater Output Control Switch’ in the hutch.
Danger
Do not touch on press until turning off the power of heater power supply.
Even after the power off, please take care.
If you heated more than 1000 °C for more than several hours, press body may be hot.
Please wait until the press body is cool.
A python program ‘multiangle.py’ is available for automatic data acquisition of EDXD pattern with varying 2θ angle.
Open the python program by running ‘multiangle.bat’ from the desktop shortcut.
You have the following 3 options:
Create a new setup automatically by clicking Setup in main window. In the pop-up window enter desired q-range and usable E range, and % overlap for the measurements. The built in algorithm will calculate optimal 2theta angles and populate the main window.
Load previously saved setup, click Load in main window
Add 2-theta angles manually by clicking Add in the main window for each angle.
Adjust the slit sizes and exposure times for each 2-theta
In preferences, please check ‘yes’ for ‘autosave when acquisition stopped’.
(hpMCA will save file for each angle data with the name suffix of ‘_001’, ‘_002’…).
Then, to start multiangle measurement,
On Multiangle control window, click Run
Important
After finishing the Multiangle collection, please do not forget to check ‘no’ for ‘autosave when acquisition stopped’.
If you want to stop the Multiangle measurement, click Stop.
A GUI porgram sonicPy is used for the ultrasound measurement. SonicPy allows to automatically record ultrasound ultrasound waveforms from the oscilloscope with varying exitation wave frequencies.
Before beginning, create a folder named US in your data folder where the ultrasound data will be saved to.
Open sonicPy by running the ultrasound measurement shortcut of the desktop.
Important
Check that the Scope-Instrument is DPO5104 and AFG-Instrument is AFG3251. If something else is displayed it means that the program could not communicate with the hardware. Check that the oscilloscope and the function generator are both powered on.
Check and update if needed the following settings values:
file system path to the US data folder which you created
Subdirectory
P-T condition (eg. “1000psi” or “2000psi_500watt”)
To check the ultrasound signal level, clear the scope and acquire a new ultrasound waveform by clicking Erase + ON above the waveform plot.
Note
Scope Vertical scale may need to be adjusted depending on the signal level to avoid saturation and to optimize the oscilloscope’s dynamic range relative to the signal level.
Set the ‘Next file #’ zero, if needed; and click Go in the Scan panel. The the frequency sweep will start and conclude on its own. To interrupt the scan mid-way click Go again.
Important
Remember to reset Next file # back to 0 before each scan.
A GUI program Log book can automatically log compression, heating, and other records whenever new EDXD
and/or radiography files are saved.
Open ‘Log book’ from desktop shortcut.
File ‣ New log
Next to ‘Log file’, click Browse… and choose the name for the log file,
typically a new file in your own experiment data folder.
Logging can occur either automatically or manually. The program will automatically
log a list of process variables (PV’s) and data file names each time a new data file is saved (EDXD, or radiography).
Alternatively, click Record at any time to log the then-current experimental parameters.
A time-stamped row of values will be appended to the log file each time.
LogBook allows recording any process variable (PV); however
a pre-defined list of PV’s is stored in setup *.env file in the program’s resources directory.
Text entered into the ‘Note’ field will also be logged each time.
The Note text can be changed by the user at any time and can be up to 80 characters long.
16-BM-B hutch is equiped with an overview camera with motion and zoom capabilities. To open the camera veiwer use shortcut WV-S6130 Network Camera on the desktop.
Moving (re-centering the image) of the camera is possible by clicking on the cam view image, the clicked point will become the new center. Zooming-in is possible by drawing a rectangle over the region of interest in the cam view.
Understand the data transfer and sync is one-way (source to target).
Two options (ask your local contact to setup):
Upload the data all at once after completing the experiment
Real time data upload and sync
During the real time upload and sync, creation of new folders and files,
and modification of the existing ones at source will be synced real-time
(with some latency depending on internet traffic).
Deletion of exiting ones, however, cannot be synced and may mess up the
folder trees at Globus endpoint. Use real-time sync with a caution.
Beamline scientist does energy calibration of the germanium solid state detector
by using Fluorescence lines of silver at 22.104 keV (K\({\alpha}\)) and
24.942 keV (K\({\alpha}\)1), and gammas from 109Cd (88.04 keV) and 57Co (122.10 keV)
at the beginning of each beamtime cycle. Parameters of energy calibration (\(Energy = CAL\_OFFSET + CAL\_SLOPE \cdot Channel\)) can
be found in the header of the EDXD data file.
Beamline scientist does 2\({\theta}\) angle calibration at 7°, 15°, 23°, and 31°
using unit-cell volume of Au, and make linear equation to calculate 2\({\theta}\) angle.
The following is the procedure for 2\({\theta}\) angle calibration:
Collect Au EDXD pattern.
Make ROIs for all Au peaks using JCPDS data at 0 GPa.
Select Control ‣ Calibrate 2theta… on Menu bar.
Please remove weak or overlapping peaks by unchecking them in the column ‘Use?’.
Note
Because the MCA does not have background subtraction feature, background slope at low energy (<~25 keV) probably due to absorption influences on determining peak position. It is better not to use low energy data for 2\({\theta}\) angle calibration. Typically, at 2\({\theta}\) of ~15 °, the first and second peaks show marked deviation from other peaks.
Click Compute 2-theta.
2\({\theta}\) value appears in the ‘2\({\theta}\)’ box.
Then, please click OK to apply the 2\({\theta}\) calibration.
Note
The 2\({\theta}\) calibration result is also saved in the header of the data file.
