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 |
| CMOD | Used for everything in the RF system that is part of the general physics and operations interface at the cryomodule level (Gang phase and LEM computations) |
| GUN | Used for everything in the gun |
| Buncher? | |
| PRC/RFS/RES/SSA | Used for engineering diagnostics related to a specific control chassis, such as chassis health monitors. They names correspond to the chassis types: Precision Receiver Chassis, RF Chassis, Resonance Chassis, Solid State Amplifier |
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
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 |
|---|---|
| GDES | Operation Gradient setpoint (MV/m) |
| GACT | Measured gradient from cavity probe (MV/m) |
| GMAX | Maximum allowable gradient (MV/m) |
| GCAL | Gradient calibration scale factor, nominally 1. Multiply by this when calculating raw register value to set, so increasing GCAL increases output. |
| ADES | Operation Amplitude setpoint (MV) |
| AACT | Measured amplitude from cavity probe (MV) |
| AMAX | Maximum allowable amplitude (MV) |
| ACAL | Amplitude calibration scale factor, nominally 1. Multiply by this when calculating raw register value to set, so increasing GCAL increases output. |
| 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 (detrees) |
| FDES | Cavity detuning setpoint (Hz) |
| FACT | Detune seen by the resonance system (Hz) |
| Mode | RF mode (off, pulsed, SEL, GDR) |
| RFCTRL | Master enable for an RF cavity (On, Off) \[How to distinguish this from the SSA specific RF enable register?] |
| 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? |
| Quench | Status showing when a cavity quenches, from interlocks (Normal, Quenched) |
| STAT | Status bits in software (define the bits) |
| HSTA | Hardware status |
| GTRACE | Gradient waveform from the cavity probe, which is used to calculate GACT (MV/m) |
| PTRACE | Phase waveform from the cavity probe, which is used to calculate PACT (degrees) |
| GFWDTRACE | Gradient waveform from SSA output (MV/m) |
| PFWDTRACE | Phase waveform from SSA output (degrees) |
| GREVTRACE | Reverse/reflected SSA output gradient waveform (MV/m) I'm favoring rev over ref because ref sounds to me like "reference" |
| PREVTRACE | Reverse/reflected SSA output phase waveform (degrees) |
| *ERRTRACE | Error waveforms corresponding to waveforms above, captured and put in a separate buffer when a fault is detected (degrees or MV/m) |
| Any of the above in I/Q equivalent of Amplitude/Phase | |
| PwrFwd | Forward power from SSA to cavity |
| PwrRev | Reflected/reverse power from cavity |
| PzWF | Waveforms from tuner piezo motors, useful for finding microphonics. Units TBD. |
| 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) |
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 | |
| Cables and couplers loss, combined with sensor sensitivity, as a scale factor to multiply raw reading by to get MV/m | |
| Attenuator value, combined with the above as a multiplier to convert raw to units. Probalby in dB | |
| 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 |
|---|---|
| VacStat | Vacuum interlock status (Good, Faulted) \[NOTE: Details needed for specifying which vacuum status bit, coupler or beamline] |
| TStat | Temperature interlock status (Good, Faulted) \[NOTE: Details needed for specifying which temperature status bit, coupler or stepper.] |
| Temperature interlock threhshold | |
| 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 |
