nmr_probes
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nmr_probes [2019/10/17 10:29] pereira [Manually setting Dipole Fields] |
nmr_probes [2023/02/13 11:23] noji [Description] Updated to reflect recent changes as to how to run the NMR GUI. |
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| ====== NMR Control ===== | ====== NMR Control ===== | ||
| - | Two digital oscilloscopes are dedicated to NMR readout – one for the analysis line NMRs and one for the spectrograph NMRs. The scopes are located in data-U6, in upper two shelves on the right electronics rack. They are isolated from clean ground because this signals from the NMR probes are on a dirty ground. | + | Two digital oscilloscopes are dedicated to NMR readout – one for the analysis line NMRs and one for the spectrograph NMRs. The scopes are located in the S3 mezzanine. They are isolated from clean ground because this signals from the NMR probes are on a dirty ground. |
| ===== Motivation ===== | ===== Motivation ===== | ||
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| ===== Description ===== | ===== Description ===== | ||
| - | The NMR running programs for both the S800 analysis line and spectrograph dipoles can be started from the desktop of computer [[Software# | + | The NMR running programs for both the S800 analysis line and spectrograph dipoles can be started |
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| + | $ ssh [your-user-name-on-EXP]@exp-s3-nmr -Y | ||
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| + | and typing, for the analysis line dipoles | ||
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| + | $ / | ||
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| + | and for the spectrograph dipoles | ||
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| + | $ /usr/bin/wish /srv/s3-nmr/spectrograph/ | ||
| Sometimes the initialization of these applications fail. In that case check section [[nmr probes# | Sometimes the initialization of these applications fail. In that case check section [[nmr probes# | ||
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| ===== Troubleshooting ===== | ===== Troubleshooting ===== | ||
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| + | ==== NMR GUI does not start ==== | ||
| The NMR program is connected to the following devices and systems: | The NMR program is connected to the following devices and systems: | ||
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| + | ==== NMR GUI does not communicate with NMR controllers ==== | ||
| + | * This can be seen, for instance, when the NMR controller finds a resonance, but the NMR GUI keeps trying forever. | ||
| + | * Most likely, you need to reboot the terminal server located in S3 | ||
| + | * Go to the mezzanine level, where the NMR controllers are located | ||
| + | * The terminal server is behind the NMR controllers | ||
| + | * Simply turn it off, wait few seconds, and turn it back on | ||
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| + | ==== Spectrograph NMR GUI " | ||
| + | * This is typically the case when the thresholds in the NMR GUI are not set properly. If they are too low, the program may lock in noise. Conversely, if the thresholds are too high, it may miss a weak resonance. | ||
| + | * Threshold for the Spectrograph resonance can be adjusted by hand in the Spectrograph NMR GUI. In general, a threshold 0.15 mV is good for normal NMR signals, whereas 0.10 mV may be necessary if the signal are too weak. | ||
| ==== Manually setting Dipole Fields | ==== Manually setting Dipole Fields | ||
| (Based on notes from Mathias Steiner with some extra info included) | (Based on notes from Mathias Steiner with some extra info included) | ||
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| + | You will need to get access to the NMR controllers in the mezzanine level of S3 (see picture below). You will also have to connect an oscilloscope to one of the NMR controllers, | ||
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| Let’s assume that you want to set the dipole I265DS (first dipole (D1) of S800 Spectrograph) to the rigidity (Brho) 3.7965 Tm (this works for any dipole in the S800) | Let’s assume that you want to set the dipole I265DS (first dipole (D1) of S800 Spectrograph) to the rigidity (Brho) 3.7965 Tm (this works for any dipole in the S800) | ||
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| * Set EPICS channel **I265DS_MAG.BSET** to 13.5454 (note, the default value of this channel is always an (impossible) 9999.1111, which is ignored. Typing 13.5454 will cause the magnet to go to 257.577 A, and **I265DS_MAG.BSET** goes back to 9999.1111. Setting the magnet this way will get you to plus or minus half a percent of where you want to be. | * Set EPICS channel **I265DS_MAG.BSET** to 13.5454 (note, the default value of this channel is always an (impossible) 9999.1111, which is ignored. Typing 13.5454 will cause the magnet to go to 257.577 A, and **I265DS_MAG.BSET** goes back to 9999.1111. Setting the magnet this way will get you to plus or minus half a percent of where you want to be. | ||
| * At that point, the quickest way may be to use the FINE knob in the NMR controller to find the actual field value. Just turn the knob until the resonance is centered in the oscilloscope, | * At that point, the quickest way may be to use the FINE knob in the NMR controller to find the actual field value. Just turn the knob until the resonance is centered in the oscilloscope, | ||
| - | * Once you know the value of the field, type it (in Tesla) into the EPICS channel **I265DS_MAG.FELD**. Note that is what Daniel' | + | * Once you know the value of the field, type it (in Tesla) into the EPICS channel **I265DS_MAG.FELD**. Note that this is what Daniel' |
| * Having done that, you can use the BARNEY ' | * Having done that, you can use the BARNEY ' | ||
| * Repeat until satisfied. | * Repeat until satisfied. | ||
nmr_probes.txt · Last modified: 2024/06/01 16:35 by swartzj
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