| Name | Description | SRF Example (CM 2 Cavity 1) | Gun/Buncher Example |
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R | AT:GMAX | During acceptance testing, maximum gradient. [MV/m] | ACCL:L1B:0210:AT:GMAX | N/A |
R | AT:AMAX | During acceptance testing, maximum amplitude. [MV] | ACCL:L1B:0210:AT:AMAX | N/A |
R | AT:GUSE | During acceptance testing, usable gradient. [MV/m] | ACCL:L1B:0210:AT:GUSE | N/A |
R | AT:AUSE | During acceptance testing, usable amplitude. [MV] | ACCL:L1B:0210:AT:AUSE | N/A |
R | AT:FEON_GACT | During acceptance testing, gradient at which field emission begins. [MV/m] | ACCL:L1B:0210:AT:FEON_GACT | N/A |
R | AT:FEON_AACT | During acceptance testing, amplitude at which field emission begins. [MV] | ACCL:L1B:0210:AT:FEON_AACT | N/A |
R | AT:LIMIT | During acceptance testing, cavity limiting factor. 0 = Undefined, 1 = Quench, 2 = FE, 3 = SSA trip, 4 = Admin, 5 = RF power, 6 = Other | ACCL:L1B:0210:AT:LIMIT | N/A |
R | AT:Q0 | During acceptance testing, cavity Q0 measured at 16 MV/m | ACCL:L1B:0210:AT:Q0 | N/A |
R | AT:QPROBE | During acceptance testing, cavity probe Q external, cold | ACCL:L1B:0210:AT:QPROBE | N/A |
R | AT:QHOM_CPLR | During acceptance testing, Higher Order Mode coupler Q external, cold | ACCL:L1B:0210:AT:QHOM_CPLR | N/A |
R | AT:QHOM_PICKUP | During acceptance testing, Higher Order Mode pickup Q external, cold | ACCL:L1B:0210:AT:QHOM_PICKUP | N/A |
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| (from Chris Adolfsen. Garth wonders should this be a calibration attribute rather than physics interface?) Slow tuner start-up position prior to rf turn on - with the piezo voltages zeroed, the cavity would be tuned close to 1.3 GHz after the operating gradient is established - thus the initial detuning with rf off relative to 1.3 GHz is K*(operating gradient)^2 |
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| (from Chris Adolfsen. Garth wonders should this be a calibration attribute rather than physics interface?) Slow tuner park position - this is the position the tuner would be set if one wants to detune the cavity so it does not interact with the beam. | Q0 | Q0 measurement from partner labs, delivered with the cryomodule | Qext | Qext measured in-situ (last measurement – used to calibrate cavity probe signal based on discharge power) | LFD | Lorentz Force Detuning K factor(Hz/(MV/m)^2) measured in-situ |
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| Calibration of the slow tuner (Hz/step) measured in-situ |
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| Calibration of the piezo tuners (Hz/volt) measured in-situ |
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Per Cryomodule
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R | SN | Cryomodule serial number | ACCL:L1B:0200:SN | N/A |
Signal calibration. For SRF cavities, the PVs below are provided for CAV, FWD, REV, DRV signals. The SRF PV name examples below use CAV. |
Measured values |
R/W | <SIG>:CAL_ADC_10DBM | ADC counts at 10 dBm. EPICS software uses this to calculate RF power at full scale. | ACCL:L1B:0210:CAV:CAL_ADC_10DBM |
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R/W | <SIG>:CAL_LOSS_CABLE | Measured cable losses used in signal calibration. Positive value in dB. | ACCL:L1B:0210:CAV:CAL_LOSS_CABLE |
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R/W | <SIG>:CAL_LOSS_CPLR | Measured coupler loss used in signal calibration. Positive value in dB. | ACCL:L1B:0210:CAV:CAL_LOSS_CPLR |
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R/W | <SIG>:CAL_LOSS_ATTEN | Fixed attenuator used in signal calibration. Positive value in dB. | ACCL:L1B:0210:CAV:CAL_LOSS_ATTEN |
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R/W | <SIG>:CAL_LOSS_OTHER | Unattributed measured loss used in signal calibration. Positive value in dB. | ACCL:L1B:0210:CAV:CAL_LOSS_OTHER |
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EPICS-calculated values |
R | <SIG>:CAL_REF_PWR | RF power at ADC full scale. [dBm] | ACCL:L1B:0210:CAV:CAL_REF_PWR |
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R | <SIG>:CAL_LOSS_TOTAL | Total (of cable, coupler, atten, other) loss used in signal calibration. Positive value in dB. | ACCL:L1B:0210:CAV:CAL_LOSS_TOTAL |
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R | <SIG>:SCALE | Final calibration scale factor to convert raw ADC counts to amplitude. This also include the beam-based fudge factor | ACCL:L1B:0210:CAV:SCALE |
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For SRF, the signal calibration for Cavity Probe (CAV) can be calculated 2 ways: (1) using the above system losses, power at ADC full scale, and cavity probe Q or (2) calculated from the reverse signal decay. Experts can choose which method they would like to use per cavity |
R/W | CAVSCALE_SEL | Select between calibration methods: 0 = Qprobe, 1 = RevCal | ACCL:L1B:0210:CAVSCALE_SEL |
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R/W | QPROBE | Cavity probe Q. Used in Qprobe calibration method. | ACCL:L1B:0210:QPROBE |
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