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nmr_probes [2019/10/17 10:29]
pereira [Manually setting Dipole Fields]
nmr_probes [2019/10/21 15:40]
pereira [Troubleshooting]
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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
  
 ==== 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)
 +
 +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, either analysis line (left) or Spectrograph (right). Connect the left BNC connector (field modulation) to CH1 in the oscilloscope and the right BNC connector (NMR signal) in CH2. Select XY display, and AC coupling.
 +
 +
  
 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, and then read off the field value in the front panel of the controller.   * 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, and then read off the field value in the front panel of the controller.
-  * Once you know the value of the field, type it (in Tesla) into the EPICS channel **I265DS_MAG.FELD**. Note that is what Daniel's program does whenever it finds  the resonance. +  * 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'NMR GUI program does whenever it finds  the resonance. 
   * Having done that, you can use the BARNEY 'match' button to match the magnet.   * Having done that, you can use the BARNEY 'match' button to match the magnet.
   * Repeat until satisfied.   * Repeat until satisfied.
nmr_probes.txt · Last modified: 2024/01/29 10:51 by swartzj