1. Algorithms of data processing and controlling experimental equipment Magnetic Resonance Spectroscopy Popov Timophey Komolkin Andrey, Sukharjevskiy Stanislav

2. 1.Principles of Magnetic Field Resonances 2.Radio Frequency Pulse Method 3.Continuous Wave Method 4.Real-time Operating Systems Review 5.Why QNX? 6.Current ESR-project 1.Principles of Magnetic Field Resonances 2.Radio Frequency Pulse Method 3.Continuous Wave Method 4.Real-time Operating Systems Review 5.Why QNX? 6.Current ESR-project

3. Nuclear Magnetic Resonance Electron Spin Resonance Continuous Wave Method Radio Frequency Pulse Method

4. Nuclear Magnetic Resonance high energy low energy S N B B Before and after energy absorption M M M M   h M M – magnetization vector Relaxation Spin-spin relaxation Spin-lattice relaxationRelaxation Spin-spin relaxation Spin-lattice relaxation

5. NMR condition Nuclear Magnetic Resonance Field-frequency correlation for 1 H-nucleus Magnetic field: ~ 10 000 oersted Resonance frequency: ~ 42.5 MHz

6. Electron Spin Resonance SzSz Magnetic potential energy of electron spin in magnetic field: RF-induced transition Energy Increasing magnetic field B H0H0 Electron Spin: Splitting

7. Electron Spin Resonance Q-band spectrometers (wavelength 8 mm) Magnetic field: ~ 15 500 oersted Resonance frequency: ~ 35 GHz Integral intensity – proportional to quantity of unpaired electrons in a sample. Width of spectral line – characteristic of RF-energy absorption conditions. G-factor – using to initialize optional particles, participating in reactions with free radicals. X-band spectrometers (wavelength 3 cm) Magnetic field: ~ 3 400 oersted Resonance frequency: ~ 9,5 GHz

8. RF Generator Receiver & Amplifier Sweep Generator NS Continuous Wave Method Sweep Coils The oscillation of sweeping magnetic field must be far less then increasing of external field Sweep Coils The oscillation of sweeping magnetic field must be far less then increasing of external field Altering Magnetic Field We have to solve magnetic field scan linearization problem Altering Magnetic Field We have to solve magnetic field scan linearization problem

9. Continuous Wave Method t dA t dH 1 H Signal Sweep Magnetic Field Scan H I H I t t Magnetic Field Scan Linearization 1. First scan cycle: linearization 2. Second cycle: Slow H-field scan with sweeping H 1 -field and continuous transmission data to computer. Major condition: First derivative

10. Continuous Wave Method Double Integrating Evening-out Trend line Noise reduction Fourier Transform         Fast Fourier Transform Method is usually used for wide spectral lines and in ESR-spectrometry If we have 2 k measurements:

11. Receiver & Amplifier Smart Pulse Generator RF-pulse Method NS Features: Constant strong external magnetic field Free induction decay (FID) time ~ 10  s – 1 s Short RF-pulses (10-100 ms) Features: Constant strong external magnetic field Free induction decay (FID) time ~ 10  s – 1 s Short RF-pulses (10-100 ms) Interhardware communication We need guaranteed fast communication between all nodes in this experiment Interhardware communication We need guaranteed fast communication between all nodes in this experiment

12. Generating pulse sequence FID-waiting & Data buffering Controlling t Data processing RF-pulse Method Realization Smart Pulse Generator Receiver Amplifier ADC Time to data processing and updating visual information !!! Other processes are sleeping !!!

13. RF-pulse Method features         Fourier Transform of nuclear echoes (FID) FT Data Collecting Signal-to-noise ratio reduction Evening-out Real time visualization Characteristic decay time 10  s – 1s

14. Real Time Review

15. Real-time Review Criteria & Requirements: Interrupt latency (less than 1 ms) Context-switch time System Size Rebooting time Development and execution division Hard Real Time Systems – any delays and interrupts are not allowed on any conditions (e.g. aircraft navigation system) Soft Real Time Systems – some delays are allowed, but it results in increase production cost and decrease of system efficiency as a whole (e.g. computer network)

16. Real-time Review RT mechanisms: Priority system Scheduling algorithms Interprocess communication (IPC) Operating with timers and interrupts RT mechanisms: Priority system Scheduling algorithms Interprocess communication (IPC) Operating with timers and interrupts RT-System classes: Embedded systems (VXWorks, RTEMS) Real-time kernels (QNX, OS9) Real-time UNIXes (RTLinux, LynxOS) Real-time Windows (Windows Embedded) RT-System classes: Embedded systems (VXWorks, RTEMS) Real-time kernels (QNX, OS9) Real-time UNIXes (RTLinux, LynxOS) Real-time Windows (Windows Embedded)

17. Fundamental Principles System & Users’ Processes Kernel Architecture Device drivers microkernel architecture message-based interprocess communication microkernel architecture message-based interprocess communication message passing – the Kernel handles the routing of all messages among all processes throughout the entire system scheduling – the scheduler is a part of Kernel and is invoked whenever a process change state as the result of a message or interrupt message passing – the Kernel handles the routing of all messages among all processes throughout the entire system scheduling – the scheduler is a part of Kernel and is invoked whenever a process change state as the result of a message or interrupt Process manager Filesystem manager Device Manager Network Manager Process manager Filesystem manager Device Manager Network Manager choose to disappear at standard processes, simply becoming extensions to the system process they’re associated with retain their individual identity as standard process choose to disappear at standard processes, simply becoming extensions to the system process they’re associated with retain their individual identity as standard process

18. File system manager File system manager Device manager Device manager Process manager Process manager Network manager Network manager microkernel Interprocess communication (IPC) Single-computer model QNX is message-based OS Message – a packet of bytes passed from one process to another All messages contains information about its state and priority, runtime information, synchronizing the execution and so on. QNX is message-based OS Message – a packet of bytes passed from one process to another All messages contains information about its state and priority, runtime information, synchronizing the execution and so on. Entire process and message space among all incorporated QNX- computers Sensible distribution network resources amount executing real-time processes Entire process and message space among all incorporated QNX- computers Sensible distribution network resources amount executing real-time processes

19. My Current ESR Project S Resonator with sample Klystron (high radio frequency generator) Wave conductor Detector Strong magnetic field scan ADC Receiver Amplifier

20. Credits & References: Komolkin Andrey V. Sukharjevskiy Stanislav M. Quantum Magnetic Phenomena Department of Physical Faculty SPbSU SWD Software http://hyperphysics.phy- astr.gsu.edu/hbase/molecule/esr.html http://hyperphysics.phy- astr.gsu.edu/hbase/molecule/esr.html http://www.cem.msu.edu/~reusch/VirtualText/Sp ectrpy/nmr/nmr1.htm