Hall Probe Calibration System Using LabVIEW Joseph Z. Xu August 11, 2003

APS INSERTION DEVICES The magnetic field spatial distribution profiles of the APS Insertion Devices (ID) are characterized with Hall Probe Magnetic Measurement System

Hall Effect and Hall Probe I B Electric current + _ Magnetic field V H B V H I Hall Effect Hall Probe Hall Probes are used to characterize the magnetic field spatial distribution profiles of the APS Insertion Devices (ID) The Hall Probe Calibration System is designed to calibrate the Hall Probes

Hall Probe Calibration System The Hall Probe Calibration System consists of: Dry Cooper A Magnetic Power Supply (MPS-853) An Electrical Magnet GPIB An NMR Teslameter (PT-2025) A Reference Teslameter (DTM-141) RS-232 A Motorized Probe Stage (SmartMotor) A Multimeter (HP-3458A)

NMR Theory of Operation B Applied magnetic field Spinning nucleus Precessionnal orbit Ground State Excited State ΔE = μB/I; f = ΔE/h = GB; G = μ/hI; B: static magnetic field I: spin quantum number μ: nuclear magnetic moment f: resonance frequency

Electric Magnet Top View Operation Procedure DTM-141 Probe Calibrating Hall Probe NMR Probes 1 2 3 4 5 6 Electric Magnet Motorized stage Electric Magnet Top View I’MPS B’EM B DTM IMPS B EM PSM B NMR VHall

What is LabVIEW? A graphical programming language Compiled graphical development environment Similar to flowcharting

Block Diagram: Source Code Virtual Instrument Each program is called a Virtual Instrument (VI) Each VI has a Front Panel and a Block Diagram Front Panel: User Interface (MEDM) Block Diagram: Source Code (IOC Application)

Front Panel: User Interface Graphical user interface Pre-built user interface objects

Block Diagram: Source Code Intuitive flowchart-like code Hundreds of pre-built measurement subVIs Self-documenting

Debugging Step in, single step, step out Highlight execution

Application Builder Compiler Creates: Installer Creates Application.exe and Application.ini files Installer Creates data.cab, install.msi InstMsi.exe, setup.ini, InstMsiW.exe, and setup.exe files

Hall Probe Calibration System Software Main Panel

Hall Probe Calibration System Software Reference Teslameter (DTM-141) DTM-141 Reference Digital Teslameter Panel

Hall Probe Calibration System Software NMR Teslameter (PT-2025) PT-2025 NMR High Precision Teslameter Panel

Hall Probe Calibration System Software Magnetic Power Supply (MPS-853) MPS-853 Magnetic Power Supply Panel

Hall Probe Calibration System Software MPS-853 Magnetic Power Supply Panel Interlock Pull Down Menu

Hall Probe Calibration System Software Multimeter (HP-3458A) HP-3458A Panel

Hall Probe Calibration System Software Motorized Probe Stage (SmartMotor) Motorized NMR Probe Stage Panel

Hall Probe Calibration System Software Plot Panel

Hall Probe Calibration System Contents System Hardware: Danfysik System 8000 MPS-853 Precision Magnet Power Supply System Electric Magnet Metrolab PT-2025 High Precision NMR Teslameter System Motorized NMR Probe Support Stage System Powered by Animatics SmartMotor Servo Motors Group 3 DTM-141 Digital Teslameter System HP 3458A Multimeter System PC with a GPIB PCI card, a RS-232 port, 600 MHz or higher CPU, 128 MB or more RAM, and 130 MB or more free HD. System Software and Documents: Windows XP/2K/NT/98 OS. PC based software package with installer on a CD User’s Guide Operation Method of Procedure

Next Project: Integral (Stretch Coil) Measurement System Upgrade Field integral (along the z direction) Theory of Operation Vertical Component Horizontal Component Y 4 1 X Y 3 2 4 1 3 2

Key System Requirements Motion Control: SmartMotor via RS-232 2x4 axis: x(0-400mm), y(0-400mm), z(0-6000mm), w(0-360) Motion Readout: Linear (x, y, and z) and Rotary (w) Encoders Linear encoder resolutions: 25 μm absolute position Rotary encoder resolutions: 0.1deg absolute angle position Linear stage speed: up to 50 mm/s at z direction Rotary stage speed: up to 1 revolution per second DAQ: Coil EM Voltage Measurement Resolution: 16 bit (5 digits) Sampling rate: 1.5 kS/s Synchronization: Absolute Angle Position vs. Coil Voltage Measurement w/ at 1.5 kS/s Triggering must be done in referencing of absolute positions. Digital I/O Noise Control: 10-7

Current System Architecture System A (on the 6 meter bench) Stepping Motor Drivers Stepping Motor Power Supplies To the Stepping Motors VME VME44 w-Encoder Board VMEX xyz-Encoder Board PCI NIVXI From the encoders PCI GPIB Magnetic Flux Integrator Amplifier From the Coil Current Issues: Flux start point and finish points (positions) are not well defined. Only 4 data points are measured and data analysis is not feasible. System is Windows 3.1 based and software is not upgradeable.

Current System Architecture System B (on the 3 meter bench) To the SmartMotors From the Coil RS-485 RS-232 to RS-485 Converter RS-232 PowerDAQ 16 bit PCI ADC Card Amplifier Current Issues: Positioning and measurements are “synchronized” by PC CPU time using software. (~ 3 ms?) Start and Finish positions/times are not well defined. System is RedHat Linux based and hard to maintain.

Proposed System Architecture From x, y, z, and w encoders TCP/IP PXI FPGA I/O w/ built in 16 bit ADC From the Encoders From the Coils RS-232 To the SmartMotors Key Features: Integrated real time encoder readout, triggering, and Coil voltage measurement. TCP/IP Interface, securely access the system remotely, anywhere, anytime. Commercial off-the-shelf components. Same hardware can be used for both 6 meter bench and 3 meter bench Hall Probe Measurement Systems.

Why PXI? PXI: PCI eXtensions for Instrumentation A specification designed explicitly for industrial test and control applications. Industry open standardized PCI backplane at 132 MB/s or 1 Gbps (32 bits@33MHz) plus integrated timing and triggering. Well supported by all major operating systems. Large selection of instruments and modules. Low cost and ease of use. See www.pxisa.org for detailed specifications

Hall Probe Calibration System Demo Diagram Conclusion For isolated control and data acquisition systems, PC based and/or PXI based platform with LabVIEW, Visual Basic, or Visual C++ development tools shall be adequate. Hall Probe Calibration System Demo Diagram TCP/IP RS-232 802.11 SmartMotor NMR Probes GPIB Magnetic Power Supply (MPS-853) Reference Teslameter (DTM-141) NMR Teslameter (PT-2025) Digital Multimeter (HP-3458A) Electric Magnet