2012 EPICS Timing Workshop

Transcription

1 2012 ICS Timing Workshop The Accelerator Timing System at SLAC: xperiences, Ideas & Future lans SLAC I&C Division / Department 1

2 Introduction This talk will focus on the SLAC Timing System giving a bit of history up to the development of the LCLS-I timing system and relate some of our experiences from that. This is followed by a description of our plans for LCLS-II and other systems Finally, I ll present some ideas/wishlist for new features 2

3 Background / History Legacy Timing System: Developed in the 1980s for the SLC: CAMAC-based, generates triggers based on six AC mains-derived Timeslot signals Whole system triggered off of 360Hz Fiducial (Generated from the three AC mains phases) Uses obsolete components *Still* in use (ran part of LCLS-I before upgrade and still running FACT) LCLS-I: Gave us the chance to develop a new timing system: Decision to use MRF vent System Had to co-exist with original SLC timing and was initially slaved to it (no longer following upgrade) This requirement affected some of our design decisions 3

4 ~ Linac Master Osc SLC MG LCLS-I Timing/vent System Architecture Master attern Generator Linac main drive line LCLS Master Oscillator N T µ SLC events N T D U Ι O C FIDO Raw 360 Hz 476 MHz 360 Hz Sync/Div LCLS events G ICS Network DU 119 MHz LCLS Timing System components are in RD LCLS Timeslot Trigger 119Mhz + FID Sq Wave on Coax 4 F A N Low Level RF fiber distribution Ι O C R SLC Trigs Fiber Cable Tx LCLS-I Timing as originally implemented / Slaved to SLC Timing: formed event codes from SLC Timing attern (NT) D TTL-NIM convert. TTL Rx 119Mhz + FID Sq Wave on Coax Rx TO: - Cav BM - MS BLM - MS IC - BCS Digitizer LLRF BMs Toroids Cameras Wire Scanner SLC klystrons

5 ~ Linac Master Osc LCLS-I Timing/vent System Architecture 60Hz Timeslot 1 Linac main drive line From MS (net) LCLS Master Oscillator M IRQ & T Timeslot G 476 MHz 360 Hz C U FIDO Raw 360 Hz LCLS events Sync/Div ICS Network LCLS-I Timing De-Coupled from the SLC System. MTG module provides Timeslot info and CU forms event codes directly. The LCLS-II Timing System will look very similar to this G DU LCLS Timeslot Trigger 119 MHz 119Mhz + FID Sq Wave on Coax 5 F A N C U Fiber distribution R Fiber Cable Tx D TTL-NIM convert. Rx 119Mhz + FID Sq Wave on Coax Rx TTL TO: - Cav BM - MS BLM - MS IC - BCS Digitizer LLRF BMs Toroids Cameras Wire Scanner SLC klystrons

6 LCLS-I Timing System Features & Comments: Has ~122 Rs across 1.5KM of machine (not counting dev units) 85 MC Rs 37 M Rs (LLRF & BM Subsystems) Due to distances, we had to use Single-Mode Fiber (replaced Multi-Mode SFs with SM) Developed Separate (Timing Reference Distribution) subsystem to provide 119MHZ w/360hz phase-modulated fiducial to systems that didn t need overhead of an R Developed Custom HW (Sync/Div,, MTG) in addition to MRF vent HW xtensive SW development effort (more so than the HW dev) Made some changes to MRF HW 6

7 LCLS-II Timing System LCLS-II will timing will be very similar to LCLS-I Have its own G LCLS-II will run on different timeslots than LCLS-I Both LCLS-I & -II timing systems will know about each other (via a synchronizing signal) Using utca platform as well as M 7

8 LCLS-II Timing System Micro TCA Will be used in at least the BM subsystem, possibly LLRF as well Development effort underway Interim timing solution: MC-R-200 on utca adapter lanning on using/adapting Stockholm University utca Timing Module (dev d for XFL) as final solution - Developed for XFL - Distributes triggers & clock on utca backplane - Double-wide (with RTM I/O) in development - Contains fiber phase stabilization mechanism 8

9 Other SLAC Machines & Future lans FACT: (1 st 2/3 rd of Linac) Uses SLC timing for all Legacy Systems Uses vent System for all new subsystems (accelerator controls as well as experiments) XTA: X-Band Test Accelerator (stand-alone machine) Uses vent System for timing / coupled to SLC timing SAR-III: Considering vent System for booster upgrade -X: Could/Would use vent System in some form Grand SLAC Timing System: Would tie together all related systems (don t know what this would look like yet ) 9

10 Desired Features: Timing Features Wishlist R Standby trigger capability FGA Gateware mod to R to support stby triggers (completed on M-R) Greater than 256 event codes xperiment support keeps asking for more Cs! Fanout Module Upgrade Added diagnostics for SF status readout & single-level fanout ports Fiber hase Stabilization SU utca module has this feature Additional Diagnostics on G side Readout of parameters (RF power, phase, fiducial rate, etc.) from Sync/Div chassis R SF (optical xcvr) Diagnostics Readout for maintenance Base Rate Triggers Triggers that are free-running (but sync d to the fiducial), w/o needing event codes to keep running 10