| ... | ... | @@ -6,15 +6,15 @@ This flow graph can be used to generate excitation signals for the purpose of tu |
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General notes:
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* Unhandled errors will cause the GUI to flash red, see console output for details
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* If you see lots of letters `U`, `O` or `D` printed on the console, this indicates a hardware performance issue. Please reduce the signal sampling rate (max supported is 5MSa/s) and if problem persists, report it to us.
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* If you see lots of letters `U`, `O` or `D` printed on the console, read [this](https://git.gsi.de/p.niedermayer/exciter/-/wikis/Troubleshooting#letters-o-d-u-l-or-s-frequently-appear-on-the-console)
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**Revolution frequency**
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- Can either be locked (with a PLL) to RF reference signal (connected to RF input 1)
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- Can either be locked (with a PLL) to RF reference signal (connected to RF input 2)
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or set by the operator to a fixed value
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**Excitation signal**
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- Excitation bandwidth is set in kHz and also shown in tune units
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This ensures it will become narrower during ramp to account for increased rigidity. This accounts for reduction in tune spread along the ramp
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This ensures the with (in tune units) will become narrower during the ramp to account for the increased rigidity, i.e. the reduction in tune spread
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- The fractional tune is set with respect to the revolution frequency
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Higher order sidebands are supported by values > 1, but best results have been found for baseband, e.g. q < 0.5
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- The signal levels can be set individually, usually Y requires less power
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| ... | ... | @@ -27,3 +27,8 @@ General notes: |
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The DAC is limited to ±1 V and signals are clipped if the level is too large, which results in broadband signals and will saturate the amplifiers.
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Make sure the output for both X and Y is not overloaded (overload ratio shows the percentage in time during which the DAC is overloaded and should stay below 1%).
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## Remarks
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If possible (i.e. more than one bunch in the ring), the excitation and tune measurement should be performed at different sidebands.
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E.g. excite at q=0.2 and measure at q=0.8. This improves the accuracy of the measurement, as the coupling between excited and measured frequencies is solely via the beam. |
