CLIC Controls – for the CDR Mick Draper Accelerator Control group, CERN

CLIC Controls Talk outline – Mea Culpa – Scope – Key points to address – Status

CLIC Controls – mea culpa I really came here to grab people who had not yet produced their CDR contribution – But got landed with this talk Since IWLC2010, in Geneva, there has been little concrete progress (at CERN) on the design on the CLIC control system: – J. Serrano has produced a final version of the “Fine-timing” section for the CDR. – There is a first draft of the CONTROLS section for the CDR. With the exception of the description of the ACM, the CDR draft is still qualitative than quantitative Really was meant as a draft for comments! – Waiting for the comments ! – No specific R&D has been done for a new control system

CLIC Controls – Scope The “CLIC control system” will be implicated in all areas of the CLIC complex. Will consist of several sub-systems which will take care of individual parts of the complex – Final organisation will be determined by the needs of the operations teams. For the moment, the working assumption is that most of the complex will need only standard or ‘state of the art’ controls solutions. – The exceptions are: The main linacs LLRF, some instrumentation & TBA which need fs-level timing

CLIC Controls – Challenges If all goes well, here we are talking about computer systems which will be deployed in years from now. – I don’t have a crystal ball so can’t know what tomorrow’s servers will look like, so we assume: we will see an evolution and not a revolution and that there will no radical move away from today’s architectures We assume that we will be using the same s/w technology as today – Must not fall into the trap of specifying architecture choices too soon or they will already be out of date before they are installed (c.f. LHC Front-end systems)

CLIC Controls – Challenges With the CERN accelerator complex, we have learned from many years of practical experience and so, I expect, the future CLIC Control system to based on the same principals: – Modularity Lets us re-use components throughout the complex – 3-tier architecture Equipment-tier – interaction with the h/w Middle-tier – contains the business logic (middleware) Client-tier – GUIs for operating the machines

CLIC Controls – Challenges Strict limitations of heat dissipation into Main Linacs tunnel. – Force us to adopt a novel architecture Development of the CLIC Front-End Acquisition nd Control Module (ACM) – see previous talk – Scale of the 3 TeV project Enormous numbers of instruments to be read-out – 50 Hz cycle-time How to handle the data rate Need to define well what we want to keep – The LHC experiments are the experts in data reduction so if we need help we know who to ask

CLIC Controls – Timing Challenges Timing (see Fine Timing section in CDR) – LLRF Reference clock signal distribution requires 50fs jitter – Beam Instrumentation Longitudinal profile monitors. – Clock precision of few 10s of femtoseconds – 2-beam acceleration Needs very precise synchronisation between MB and DM – Use kickers to modify the trajectory – Required precision is about 40fs

CLIC Controls – Timing Solutions Continuous Wave (CW) system Pulsed system – Technical issues Both systems have been tested only over several hundred metre long fibres – 25km needed for CLIC is well beyond the current state of the art Laser coherence length Brillouin scattering with the fibres – Limits optical power which can be transmitted (CW system) Should build demonstrators of both CW and Pulsed systems – Who wants to get involved ??

CLIC Controls – ACM LAPP (Annecy) working on prototype – See previous talk Having seen John Osborne’s CES chapter, we can use “stub caverns” (every 878m) – Keeps electronics away from radiation – Take signals from 400+ ACM’s via fibres – Concentrate and do first processing – Next level of concentration will be at the surface buildings. – Final data concentration will be in “server farm” close to the control centre

CLIC Controls – Future Plans The 2 CERN Controls groups have not yet “engaged” with the wider CLIC community; – There is contact between CERN and CRNS for the ACM Need to start a more formal collaboration Make sure that h/w developments are compatible – Or at least minimize the incompatibilities – First contacts between the CERN Timing team and DESY DESY are the experts on the CW approach to fs timing – There is a Fieldbus working group at CERN Mostly dominated by the CERN experiments Need to establish CLIC’s requirements as part of this group Decide how/if CERN’s “White Rabbit” initiative can be integrated We need to create an active CLIC Controls Collaboration to discuss: – Architecture issues – potential showstoppers – How best to harness existing efforts and expertise !!

CLIC Controls

CLIC Controls – Scope The proposed 3TeV CLIC is a very large accelerator complex; consisting of: – Sources – Injectors – Damping and Combiner rings – Transfer lines – Main Beam (MB) and Drive Beam (DB) linacs – Experimental area(s)