Names are broken down into the standard parts, DeviceType : Area : Position : Attribute
| Name | Description |
|---|---|
| ACCL | Used for everything in the RF system that is part of the general physics and operations interface at the cavity level |
| GUN | Used for everything in the gun |
See https://slacspace.slac.stanford.edu/sites/lcls/lcls-2/wd/dsg/Forms/AllItems.aspx, Naming Convention section 6.1.2.2
| Area | Physical Location |
|---|---|
| GUNB | LCLS-II Gun |
| L0B | LCLS-II L0 Accelerator Region |
| L1B | LCLS-II L1 Accelerator Region |
| BC1B | LCLS-II Bunch Compressor 1 |
| L2B | LCLS-II L2 Accelerator Region |
| BC2B | LCLS-II Bunch Compressor 2 |
| L3B | LCLS-II L3 Accelerator Region |
| SYS2 | Full LCLS-II Accelerator scope, e.g. global phase offset |
See https://slacspace.slac.stanford.edu/sites/lcls/lcls-2/wd/dsg/Forms/AllItems.aspx, Naming Convention section 6.1.2.3.2
The position of the gun is 100. The position of the buncher is 455.
The position of cavities is 4 numbers where the first two indicate the cryomodule and the second two the cavity. For example, 0430 is cryomodule 4, cavity 3.
Cryo Module # | Description |
01-35 | CM01-CM35, 1.3GHz cavity |
H1 | 3.9GHz Cryomodule 1, located in L1B and follows CM03 |
H2 | 3.9GHz Cryomodule 2, located in L1B and follows H1 |
Numbering of cavities within a cryomodule:
| Name | Description | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| GACT | Measured gradient from cavity probe (MV/m) | |||||||||||||||
| GMAX | Maximum allowable gradient (MV/m) - readback only | |||||||||||||||
| ADES | Operation amplitude setpoint (MV) | |||||||||||||||
| AACT | Measured amplitude from cavity probe (MV) | |||||||||||||||
| AMAX | Maximum allowable amplitude (MV) | |||||||||||||||
| PDES | Operation phase setpoint (degrees, where 0 is on-crest) | |||||||||||||||
| PACT | Measured phase from cavity probe (degrees) | |||||||||||||||
| PREF | a.k.a.gold, phase offset used by LLRF to convert measured phase to one relative to on-crest operation, adjusted by beam phasing (degrees) | |||||||||||||||
| DFDES | Cavity detuning setpoint (Hz) - is this needed? | |||||||||||||||
| DFACT | Detune seen by the resonance system (Hz) | |||||||||||||||
| RFMODECTRL | RF mode control (SEL, SELA, SELAP) | |||||||||||||||
| RFMODE | Readback of current RF mode | |||||||||||||||
| RFCTRL | Cavity on/off control. Off = LLRF drive set to 0. (SSA control will be different.) | |||||||||||||||
| RFSTATE | Readback of cavity RF on/off state | |||||||||||||||
| AWF | Waveform of cavity probe amplitude, which is used to calculate AACT (MV) | |||||||||||||||
| PWF | Waveform of cavity probe phase, which is used to calculate PACT (degrees) | |||||||||||||||
| FWD | Forward signal from SSA to cavity - amplitude | |||||||||||||||
| FWDPWR | Forward signal from SSA to cavity - power | |||||||||||||||
| REV | Reverse signal from cavity - amplitude | |||||||||||||||
| REVPWR | Reverse signal from cavity - power | |||||||||||||||
| ALEM | LEM computed integrated RF amplitude (MV) per cavity and per cryomodule | |||||||||||||||
| PLEM | LEM computed phase (deg) | |||||||||||||||
| EGLEM | LEM computed energy gain (MeV) | |||||||||||||||
| CHLEM | LEM computed chirp (MeV) | |||||||||||||||
| FUDG | Beam-based scale factor applied to cavity probe amplitude readback. Nominal value of 1. | |||||||||||||||
| In Progress/Tentative | ||||||||||||||||
| RFREADY | Status of RF controls, (Ready, Not Ready) set to ready when control loops are closed and RF is continuous. Or will we ever run with pulsed RF? | |||||||||||||||
STAT | Status bits in software (define the bits) | |||||||||||||||
| HSTA | Hardware status | |||||||||||||||
| DFDES | Cavity detuning setpoint (Hz) | |||||||||||||||
| ERRWF | Error waveforms corresponding to waveforms above, captured and put in a separate buffer when a fault is detected (degrees or MV) | |||||||||||||||
| PZWF | Waveforms from tuner piezo motors, useful for finding microphonics. Units TBD. | |||||||||||||||
| Latching SRF Interlocks | ||||||||||||||||
| QUENCH_FLT |
Cavity quench fault, from interlock chassis. Current status, latched status, and reset command | |||||||||||||||
| QUENCH_LTCH | ||||||||||||||||
| QUENCH_RESET | ||||||||||||||||
| CPLRVAC_FLT |
Coupler vacuum fault, from interlock chassis. Current status, latched status, and reset command | |||||||||||||||
| CPLRVAC_LTCH | ||||||||||||||||
| CPLRVAC_RESET | ||||||||||||||||
| BMLNVAC_FLT |
Beamline vacuum fault, from interlock chassis. Current status, latched status, and reset command | |||||||||||||||
| BMLNVAC_LTCH | ||||||||||||||||
| BMLNVAC_RESET | ||||||||||||||||
| STEPTEMP_FLT |
Stepper temperature fault, from interlock chassis. Current status, latched status, and reset command | |||||||||||||||
| STEPTEMP_LTCH | ||||||||||||||||
| STEPTEMP_RESET | ||||||||||||||||
| CPLRTEMP_FLT |
Coupler temperature fault, from interlock chassis. Current status, latched status, and reset command | |||||||||||||||
| CPLRTEMP_LTCH | ||||||||||||||||
| CPLRTEMP_RESET | ||||||||||||||||
| INTLK_RESET_ALL | Reset all latched faults from interlock chassis | |||||||||||||||
| Non-Latching SRF Interlocks | ||||||||||||||||
| HEPRES_FLT | Helium pressure fault, from cryo system PLC | |||||||||||||||
| HELEVEL_FLT | Helium level fault, from cryo system PLC | |||||||||||||||
| CRYOHRTBT | Cryo PLC heartbeat fault. Generated by RF software when cryo data stops updating or updates too slowly | |||||||||||||||
| Interlock Thresholds | ||||||||||||||||
| CPLRVAC_THRES_L | ||||||||||||||||
| CPLRVAC_THRES_H | ||||||||||||||||
| BMLNVAC_THRES_L | ||||||||||||||||
| BMLNVAC_THRES_H | ||||||||||||||||
| STEPTEMP_THRES_L | ||||||||||||||||
| STEPTEMP_THRES_H | ||||||||||||||||
| CPLRTEMP_THRES_L | ||||||||||||||||
| CPLRTEMP_THRES_H | ||||||||||||||||
| Waveform Signals | ||||||||||||||||
The PVs below will be provided for each waveform signal. Each cavity has the following waveform signals:
| ||||||||||||||||
| Waveform | <SIG>:AWF | Signal amplitude waveform | ||||||||||||||
Statistics | <SIG>:AMEAN | Mean of <SIG>:AF | ||||||||||||||
| <SIG>:ASTD | Standard deviation of <SIG>:AWF | |||||||||||||||
| <SIG>:AMIN | Minimum of <SIG>:AF | |||||||||||||||
| <SIG>:AMAX | Maximum of <SIG>:AWF | |||||||||||||||
| Waveform | <SIG>:PWF | Signal phase waveform | ||||||||||||||
| Statistics | <SIG>:PMEAN | Mean of <SIG>:PWF | ||||||||||||||
| <SIG>:PSTD | Standard deviation of <SIG>:PWF | |||||||||||||||
| <SIG>:PMIN | Minimum of <SIG>:PWF | |||||||||||||||
| <SIG>:PMAX | Maximum of <SIG>:PWF | |||||||||||||||
| Waveform | <SIG>:PWRWF | Signal power waveform | ||||||||||||||
| Statistics | <SIG>:PWRMEAN | Mean of <SIG>:PWRTRACE | ||||||||||||||
| <SIG>:PWRSTD | Standard deviation of <SIG>:PWRWF | |||||||||||||||
| <SIG>:PWRMIN | Minimum of <SIG>:PWRWF | |||||||||||||||
| <SIG>:PWRMAX | Maximum of <SIG>:PWRWF | |||||||||||||||
| Waveform | <SIG>:ITWF | Signal I waveform | ||||||||||||||
| Waveform | <SIG>:QTWF | Signal Q waveform | ||||||||||||||
By default, these should be write-protected during operation
| Name | Description |
|---|---|
| (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 | |
| (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 |
| Calibration of the slow tuner (Hz/step) measured in-situ | |
| Calibration of the piezo tuners (Hz/volt) measured in-situ | |
| FWD:SCALE | Calibration scale factor to convert forward raw ADC counts to amplitude in sqrt(Watts). Calculated internally by RF software, based on system losses and ADC power at full scale. |
| REV:SCALE | Calibration scale factor to convert reverse raw ADC counts to amplitude in sqrt(Watts). Calculated internally by RF software, based on system losses and ADC power at full scale. |
| DRV:SCALE | Calibration scale factor to convert drive (aka loopback) raw ADC counts to amplitude in sqrt(Watts). Calculated internally by RF software, based on system losses and ADC power at full scale. |
| CAV:CAL_SCALE | Calibration scale factor to convert cavity probe raw ADC counts to amplitude in MV. Calculated by LLRF calibration sequence. See CAV:SCALE for more info. |
| CAV:SCALE | Calibration scale factor to convert cavity probe raw ADC counts to amplitude in MV. Is equal to product of CAV:CAL_SCALE and beam-based FUDG scale factor. |
| FWD:CAL_REF_PWR | RF power at ADC full scale for forward measurement. In dBm. Analogous PVs exist for reverse and drive (aka loopback) signals. |
| FWD:CAL_LOSS_CABLE | Measured cable losses for forward measurement used in signal calibration. Positive value in dB. Analogous PVs exist for reverse signal. |
| FWD:CAL_LOSS_CPLR | Measured coupler loss for forward measurement used in signal calibration. Positive value in dB. Analogous PVs exist for reverse signal |
| FWD:CAL_LOSS_ATTEN | Fixed attenuator for forward measurement used in signal calibration. Positive value in dB. Analogous PVs exist for reverse and drive (aka loopback) signals. |
| FWD:CAL_LOSS_OTHER | Unattributed measured loss for forward measurement used in signal calibration. Positive value in dB. Analogous PVs exist for reverse and drive (aka loopback) signals. |
| FWD:CAL_LOSS_TOTAL | Total loss for forward measurement used in signal calibration. Positive value in dB. Analogous PVs exist for reverse and drive (aka loopback) signals. |
| Chassis and ADC scale factor, or polynomial coefficients. From lab measurements of chassis to convert ADC units to physics units | |
| PI(no D) loop parameters for amplitude and phase loops. Maybe PKp, PKi, GKp, GKi | |
| Open loop amplitude and phase DAC settings | |
| Control loop status (open, closed) | |
| Name | Description |
|---|---|
| V | Chassis power supply voltage |
| T | Chassis board temperature |
| DC | SSA enable/disable internal DC power |
SSA RF enable, how to distinguish from global RF enable? | |
| PzVout | Output voltage to the piezo tuning motor |
| PzHz | Expected tuning change from PzVout |
| Name | Description |
|---|---|
| Firmware MD5 | |
BMB7 board serial # | |
| Digitizer board serial # | |
| Chassis serial # and/or Depot number |
