Names are broken down into the standard parts, DeviceType : Area : Position : Attribute
| Name | Description |
|---|---|
| SSA | Used for everything in the RF system that is part of the general physics and operations interface |
| PRC/RFS/RES | 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 |
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. |
| GCON | (suggestion from Chris Adolfsen that Garth is unclear on) Nominal Gradient (MV/m) in the currently loaded configuration |
| 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) |
| PMAX? | Could be included, staying parallel to GMAX, but is this useful? |
| PCON | See GCON above |
| FDES | Cavity detuning setpoint (Hz) |
| FACT | Detune seen by the resonance system (Hz) |
| FCON | See GCON above |
| (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. | |
| RFON | Master enable for an RF cavity (On, Off) |
| 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? |
| GactWF | Amplitude waveform from the cavity probe, which is used to calculate GACT (MV/m) |
| PactWF | Phase waveform from the cavity probe, which is used to calculate PACT (degrees) |
| GfwdWF | Amplitude waveform from SSA output (MV/m) |
| PfwdWF | Phase waveform from SSA output (degrees) |
| GrevWF | Reverse/reflected SSA output amplitude waveform (MV/m) |
| PrevWF | Reverse/reflected SSA output phase waveform (degrees) |
| *ErrWF | Error waveforms corresponding to waveforms above, captured and put in a separate buffer when a fault is detected (degrees or MV/m) |
| PzWF | Waveforms from tuner piezo motors, useful for finding microphonics. Units TBD. |
