67 lines
No EOL
4.4 KiB
Markdown
67 lines
No EOL
4.4 KiB
Markdown
# 1. NQRduck Simulator Tutorial 🦆
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## Introduction
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This Tutorial gives a short overview of how to use the NQRduck Simulator. The NQRduck Simulator is a module of the NQRduck program that allows you to simulate NQR signals and spectra.
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## Requirements
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* All requirements from the [NQRduck Setup Tutorial](tutorial_0.md)
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## Steps (Linux)
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1. Switch to the Spectrometer module in the NQRduck program.
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| Figure: The `Spectrometer` module. The `Settings` are on the left side and the `Pulse Programmer` on the right side.|
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2. You can now see two different sections in the Spectrometer module:
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- The left side are the spectrometer `Settings`. These are values that don't change during a `Pulse Sequence`.
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- The right side is the `Pulse Programmer`. Here you can create sequences of pulses that are executed during the simulation.
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3. Create a simple Free Induction Decay (FID) sequence in the `Pulse Programmer` on the right side:
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- A sequence is made up of different `Events` that are executed subsequently. Different `Events` are rows in the `Pulse Programmer` table.
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- For every `Event` you can specify a certain duration and a name.
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- Every `Event` now has `Pulse Parameters` associated with it. For the Simulator, these are the TX and the RX Pulse Parameters.
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| <img src="../_static/tutorials/1_pulseprogrammer.png" width=50%> |
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|:-------------------------------------------------------------:|
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| **Figure:** An exemplary FID sequence. |
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| Description |
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| **a.) The different events:**<br>**Pulse:** Our TX Pulse excites the sample and is set active by adjusting the relative TX Amplitude to a value larger than 0 (usually 1.0).<br>**Blank:** Waiting time between the TX Pulse and RX Readout to await coil ringing.<br>**RX:** The ADC Readout that measures the signal. Without an RX event, the whole simulation appears in the plot.<br>**TR:** The repetition time between the different averages. Not strictly necessary for the simulation right now. |
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| **b.)** The Pulse Parameters for the selected event. |
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| **c.)** The Pulse Parameters for the Pulse Event. |
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| **d.)** The Pulse Parameters for the RX Event. |
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| **e.)** The duration of the different events. |
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You can add new `Events` by clicking on the `New Event` button. `Events` can be moved by clicking the purple Arrows. You can delete an `Event` by clicking on the garbage can icon. The `Event` duration and name can be changed.
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Advisable durations for the different events are:
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- **Pulse:** 3µs - Relative TX Amplitude: 1.0
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- **Blank:** 8µs
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- **RX:** 150µs
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- **TR:** 10ms (not strictly necessary for the simulation, be careful since this will also 'use up' your simulation points.)
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4. You can now adjust the settings of the Simulator on the right side. Different settings are for example the number of simulation points or the noise level.
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5. To start the simulation, switch back to the `Measurement` tab. Enter a `Target Frequency` of 83.56MHz and 100 `Averages`. Now press the `Start Measurement` button.
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6. You should see an exponential decay in the plot. This is the FID signal that you just simulated.
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- The signal might look weird if you didn't set the correct Pulse Parameters. Try to adjust either the length of your TX event or the pulse power to achieve a $\frac{\pi}{2}$ flip angle.
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If your resolution looks low, try adjusting the number of simulation points in the `Settings` tab.
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7. Try setting the experiment temperature to 77K and see how the signal changes.
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9. Save your pulse sequence by clicking on the `Save pulse sequence` button in the Pulse Programmer.
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8. Next try to implement a Spin Echo (SE) sequence. Try to center your RX event around the echo of the signal. Play around with relaxation times and see how the signal changes.
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10. If you found a pulse sequence that you like, you can save it by clicking on the `Save pulse sequence` button in the Pulse Programmer.
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11. We will now run these sequences on the real hardware. See [Tutorial 2](tutorial_2.md) for more information.
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## Notes:
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- With some of the last updates I broke the signal processing options. I will fix this in the next updates. For now, you can only simulate the signal and not process it.
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- The `Measurement Frequency` doesn't have any effect on the simulation right now. It is only used for the real hardware.
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<!-- TODO:
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Screenshot of the pulse programmer with a simple FID sequence
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--> |