LHC-BI Review Workshop Monday, 19 November 2001

19 November 2001 LHC-BI Review Workshop J.J. Savioz SL/BI

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LHC-BI Review WorkshopMonday, 19 November 2001

• Beam Instrumentation Timing Requirements

• Main Features & Component requirements

• Use of the Timing Trigger & Control (TTC) system

• Present Status, Planning & Issues

Beam Synchronous Timing ( BST )


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> Transmission to all acquisition crates of:

1- Machine Events & Machine Status.2- Time of day. 3- Beam Synchronous Clock: - Bunch Clock (40MHz) & Turn Clock (11KHz) With a maximum overall jitter < 1 ns.( rms)4- Beam Synchronous commands: - Injection Warnings.

- Acquisition triggers. - Real time settings. - Post Mortem triggers.

> Use a single distribution network.> Taking account of the different propagation delays.

BI Requirements ( What do we want ? )


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TTC system Overview ( What is it ?) > LHC Common Project RD12 started several years ago in order

to provide all signals necessary to synchronise the detectors : LHC 40 MHz Clock, Level 1 Trigger and arbitrary commands

which are all distributed on a single fibre network to end users.

• Use of the Timing Trigger & Control (TTC) system

FrameEncoder

Multiplexer

L1Trigger

LHC ClockBroadcast CommandsAddressed parameters

LASER

TREE COUPLER

TTCrx

optical fibre network

Recovered signals:- Delayed LHC Clock- Level 1 Trigger- Broadcast commands- Addressed parameters- Transmission status-….


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• Motivation:• Can we use an updated LEP BST system for LHC ? > NO

• Does TTC system cover Beam Instrumentation needs ? > YES– Profit from RD12 investment.– Common system for Experiments & accelerators.

– Use support facilities.

– Price < 1000FS / Channel (Without fibres)

> > Save time & money !

• Implementation: • New LHC Beam Synchronous Timing based on T.T.C.

• Use of the TTC system ( How to provide it ? )


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• TTC system provides a convenient way of distributing the 40 MHz clock and the Orbit Turn Clock from the central Prevessin Control Room (PCR) to both the LHC experiments and the beam instrumentation areas around the collider.

• In addition we profit from the TTC’s ability to transmit data by inserting a so-called BST message, containing commands and parameters that can be broadcast simultaneously to all instruments.

• A BST message consists of 32 consecutive broadcast commands

systematically transmitted at each Orbit Turn Clock.• A new TTC receiver interface for Beam Instrumentation (TTCbi),

including the TTCrx chip, is being designed to recover the two distributed clocks, decode and store all BST messages and make them available to the front-end controller.

• Use of the TTC system ( How to provide it ? )


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Bytes Description Data format Updated every

0 Machine Mode Enumerated type: No beam, filling, ramping, physic,… On change

1 Beam Type Enumerated type: Ion, Proton,… On change

2 Beam Energy 2 bytes in GEV On change

3 Beam Energy

4 Mean Current per Bunch 2 Bytes * 10E11 ppp

5 Mean Current per Bunch

6 Number of injected Bunches 2 Bytes integer On change

7 Number of injected Bunches

8 Next Batch to Inject 0 for no beam or 1 .. 12 On change

9 GPS Absolute Time 64 bits UTC format On change

10 GPS Absolute Time







17 Last Machine Timing Event 2 Bytes : Machine Timing Event number On reception

18 Last Machine Timing Event

19 BI Predefined received Events 2 bytes : corresponding to 16 predefined events table On reception

20 BI Predefined received Events

21 Main Trigger Byte 8 X 1 bit dedicated Trigger: warning injection, start post-mortem, … 1 Turn

22 BI devices dedicated Bytes 10 Bytes device dedicated commands or triggers : 1 Turn

23 BI devices dedicated Bytes Closed orbit capture, Single Turn trajectory measurement,….

24 BI devices dedicated Bytes








BST Message Contents


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Message Transmission

BST

MESSAGE

PROCESSOR

TTCVI

FIFO

TTC

TransmitterCRATE

LHC Clock40 MHz

Orbit Turn Clock 11 KHz

MachineEvents

BeamParameters

ProcessRequest

OpticalDistribution



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Message Reception > TTCbi

VME BUS

HardwareSignalsTTC

OpticalInput

PMCPCI

I/O

Front End Controller VME

CPU Board



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TTCbi Bloc Diagram

TTCrx

DeskewedCLOCK

L1A trigger OUT

EVENT COUNT

SUB ADDR

DATA

STATUS

I2C

OpticalInput

I2C BusInterface

40 MHzClock

Dual Ported

Memory

PCIBus

Interface

&

Controllogic

&

Hardware output

IRQ

PCIBUS

Coarse Delay LocalTurn Clock

Selected outputs

Message Generator



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BST Systems with different parameters are required• 1 for SPS & transfer lines

Bunch Clock :40 MHz = 200 MHz / 5

Turn Clock : 44 KHz = 200 MHz / 924

> THE 40 MHZ WILL VARY DURING THE ACCELERATION:

from 40.053 MHz at 26 GeV to 40.079 MHz at 450 GeV. ( ~ 26 KHz)

• 1 for each LHC Ring: Ring 1 & Ring 2

Injection: Bunch Clock : 40 MHz = 200 MHz / 5

Turn Clock : 11 KHz = 200 MHz / 17820

Ramping : Bunch Clock : 40 MHz = 400 MHz / 10

& Collision Turn Clock : 11 KHz = 400 MHz / 35640

> THE 40 MHZ WILL VARY DURING THE ACCELERATION :

from 40.0789 MHz to 40.0790 MHz at 7 TeV for protons ( ~ 100 Hz)

from 40.0783 MHz to 40.0790 MHz at 7 TeV for heavy ions (~ 700 Hz)

> The 2 RF signals will not be phase locked during injection phase or MDs


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Encoder&

Transmitter

1:32 S.M. Tree Coupler

TTC Repeater

To experiments

TTCvi

TTCRx

To all Acquisition Crates

BSTMASTER

S.M.F.O

Network

TTCbi

M.M. F.O.Network

Buildings :LHC Px,SPS BAx, Lab,...

PCR

Optical Att.

Same structure for the 3 BST systems.

RF Signals


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> Transmitter Crate : 5 (2)

> Repeater Crate : 40 (11)

TTCmx module : 100 (29)

TTCvi : 5 (2)

Including Spare parts (x)

> Receiver TTCbi : 300 (55)

TTCrx : 600 (300)TTCrx


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• Discussion within the context of Tim W.G.

• TTC Transmission tested

• TTC vi / BST compatibility tested

• Project approval (Tim WG) ( SLTC) (BITB)

• TTC transmission installed in SPS (40 MHz + Turn Clock)

• TTCbi design and test ready soon

• BST master design started

• Software design started

• 2002 : > Commissioning of all TTC & BST system in SPS

• 2003: > Everything should be operational for SPS startup for extraction

• 2004: > Everything should be operational for LHC ring1 > Sector 7 - 8

• 2005: > Everything should be operational for LHC ring1 & ring2



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> ATLAS and CMS have asked TTCbi modules.

> EP Pool will support the TTCbi as the other TTC components.

> Good example of collaboration between SL and EP divisions.

> Open question : Who will operate the TTC system ?


Documents

LHC-BI Review Workshop Monday, 19 November 2001