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Control of the PS 10 MHz system after LS1. Performance and reliability issues of the LLRF have triggered several developments around the PS 10 MHz:. Implies some hardware changes on low-level and power sides To be implemented coherently Objectives of today’s meeting:
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Control of the PS 10 MHz system after LS1 • Performance and reliability issues of the LLRF have triggered several developments around the PS 10 MHz: • Implies some hardware changes on low-level and power sides • To be implemented coherently • Objectives of today’s meeting: • Clarify new interfaces between low-level and high-power RF • Make sure that nothing has been overlooked or forgotten • Ensure that all interlock requirements are properly fulfilled • Show status of feedback board and measurements ( Damien)
10 MHz voltage program selector (matrix) • The existing hardware will be replaced by a digital voltage program generation and relay timings per cavity • No hardware selection system, matrix settings virtual • Signals are distributed as differential serial CVORB data streams PA.GSV10GLOBAL PA.GSV10RED Hereward damp. (analog/digital) Voltage program C10-11 PA.GSVMODC11 PA.GSVMODC36 Voltage program C10-36 PA.GSVMODC96 Voltage program C10-96 Vprog (C10-36) = [(GSV10GLOBAL GSV10RED) + Hereward] GSVMODC36
Signals today and with new 10 MHz matrix • Present status: • Software part successfully validated during 2013 run (thanks to Pablo Pera Mira from BE-CO-DA) • Board designs of hardware quasi finished (‘bureau d'études’); prototypes expected in March/April 2013
Present set-up of AVC and 1-turn feedback • Now: Loop + Interlock Drive path Return path (AVC) 1-turn feedback Final amplifier and cavity From beam controls M. Haase
New 1-turn delay feedback + AVC loop • Digital feedback board: • Filters and delays for 1-turn feedback • Digital loop implementation for AVC • No equipment protection functions • AVC surveillance board: • Interlock/protection functionality • Analog test outputs for Vprog, Vdet, etc. • Plugin compatibility with existing AVC • Interface between boards: • AVC surveillance generates DAC INHIBIT to shutdown the DACs of feedback board • No soft- or firmware involved Damien’s presentation Matthias + apprentice
New 1-turn delay feedback + AVC loop Drive path Return path (AVC and 1-turn FB) From cavity h (CVORB) Vprog (CVORB) To cavity via RF switch From beam controls Gap relay timings
Additional hardware • AVC surveillance (NIM) replacing present AVC • LHC-type VME crates (like test installation) per tuning group • Feedback boards (3, 3, 4, 1) • CTRV timing boards (1 or 2) • Men A20 processor • Crate Management module • Cabling (FSU) • Technical network • Clock h = 200 distribution • Differential data cabling of Vprog, harmonic number and phase (?) • Timing cables for gap relays (local?) • Location of VME crates? • Detailed cabling lists to be established soon
Summary • Important changes and modifications the signal distribution and the RF loops/feedbacks during LS1 • Objective: Start up with new • 10 MHz matrix, • 1-turn feedbacks and • Voltage control loops • with present performance at least. • Keep backwards compatibility of interlock signals • No compromises on equipment protection • Lots of potential for further improvements and new features following operational experience after LS1 start-up: • Impedance reduction with increased 1-turn feedback gain • Phase control loop around each cavity • …?