1 news from the cern linear collider detector project konrad elsener cern

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News from the CERN Linear Collider Detector Project

Konrad ElsenerCERN

Outline: • Introduction

LCD @CERN: why, who ? CLIC 3 TeV detector issues

• LCD @ CERN: Status and Plans Collaboration with ILC LCD and FCAL LCD plans on other Hardware / Engineering R&D

• Summary

2News from LCD@CERN – presented by K. Elsener, FCAL meeting Zeuthen, 29-30 June 2009

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Introduction

News from LCD@CERN – presented by K. Elsener, FCAL meeting Zeuthen, 29-30 June 2009

Linear Collider Detector Project @ CERN

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Motivation:• Substantial CLIC accelerator effort towards Conceptual Design Report (CDR) for end 2010• Include CDR chapters on the CLIC physics potential, CLIC detector concepts and their related technological issues

CLIC detector concept will be similar to ILC ...… with a few challenging differences !

Note: many years of investment in ILC e+e- physics/detector simulations, hardware R&D and detector concept studies

LCD@CERN: Working together with the ILC detector concepts and with the linear collider detector technology collaborations to study modifications to the ILC concepts for CLIC energies and beam conditions.


Linear Collider Detector Project @ CERN

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Who are we ?Lucie Linssen (project leader) – project started in January 2009Dieter SchlatterKonrad Elsener (FCAL, MDI)Peter Speckmayer (fellow)Christian Grefe (PhD student)Andre Sailer (PhD student)Marco Battaglia (paid associate, 2009)+ three additional fellows hired (will start later in 2009)+ part time help from CERN staff+ CERN contribution to EUDET+ help from colleagues in FCAL, LC-TPC, CALICE, ILD and SiD, etc.

LAPP Annecy (J.J. Blaising, J. Blaha), ETH Zurich (A. Hervé)and many more.... (apologies !)


Linear Collider Detector web site:

http://www.cern.ch/lcd

CLIC detector issues

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Main differences with ILC:

• Energy 500 GeV -> 3 TeV• More severe background conditions (beam-beam effect)

• due to higher energy• due to smaller beam sizes

• Time structure of the accelerator• Synchrotron radiation in the magnetic field of the detector

3TeV e+e- -> W+W- -> qqqq


CLIC time structure

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Train repetition rate 50 Hz

CLIC

CLIC: 1 train = 312 bunches 0.5 ns apart 50 HzILC: 1 train = 2820 bunches 308 ns apart 5 Hz

Consequences for CLIC detector:• Need for detection layers with time-stamping

• Inner-most tracker layer with ~ns resolution• or …. all-detector time stamping at the 10 ns (?) level

• Readout/DAQ electronics will be different from ILC• Power pulsing has to work at 50 Hz instead of 5 Hz


CLIC 3 TeV Beam-induced background

Backgrounds: Due to the higher beam energy and small bunch sizes backgrounds are significantly more severeat CLIC.

Main backgrounds: • CLIC 3TeV beamstrahlung average energy loss: 29% (10×ILCvalue)

– Coherent pairs (3.8×108 per bunch crossing) <= disappear in beam pipe– Incoherent pairs (3.0×105 per bunch crossing) <= suppressed by strong solenoid-field– interactions => hadrons ( 3 hadron events per bunch crossing)

• Muon background from upstream linac– More difficult to stop due to higher CLIC energy (active muon shield ?)


CLIC 3 TeV centre-of-massenergy spectrum

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Due to beam-beam effects:• At 3 TeV only 1/3 of the luminosity is in the top 1% centre-of-mass energy bin

• asymmetric situation -> many events with large forward / backward boost


CLIC synchrotron radiation, solenoid, anti-DiD etc. …

3 TeV, crossing angle 20 mrad


Work by Barbara Dalena, CERN (CLIC study team):- PAC’09 contributed paper “Solenoid and Synchrotron Radiation Effects at CLIC”- presentation at ILC-CLIC LET Beam Dynamics Workshop, 24 June 2009 http://indico.cern.ch/contributionDisplay.py?contribId=20&sessionId=3&confId=56133

http://indico.cern.ch/contributionDisplay.py?contribId=20&sessionId=3&confId=56133

CLIC synchrotron radiation,solenoid, anti-DiD etc. …


Work by Barbara Dalena, CERN (CLIC study team):

CLIC20 mrad

CLIC synchrotron radiation,solenoid, anti-DiD etc. …

very recent results - preliminary


Work by Barbara Dalena, CERN (CLIC study team):

-> Anti-DiD is bad for luminosity at 3 TeV

Work by André Sailer (cf. talk later this afternoon):

-> Anti-DiD is badly needed (BG !)

PS. Barbara Dalena, PAC’09: A longer detector (solenoid) makes things worse !

CLIC IP intra-train feedback (?)


http://indico.cern.ch/materialDisplay.py?contribId=11&sessionId=10&materialId=slides&confId=56133

cf. Phil Burrows (Oxford)presentation at ILC-CLIC LET Beam Dynamics Workshop, 24 June 2009

avoid delays (“latency”)preferably BPM and Kickerat about 2 m from the IP

needs to be studied(additional source forbackscattering)


CLIC IP intra-train feedback (?)

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cf. Phil Burrows (Oxford)presentation at ILC-CLIC LET Beam Dynamics Workshop, 24 June 2009


LCD @ CERN :Status and Plans


LCD collaboration with ILC

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LCD@CERN has joined existing linear collider groups:• ILC detector concepts (LCD members signed LoI’s)

– ILD– SiD– 4th concept

• Technology collaborations (formal agreements / letters)

– LC-TPC (TPC development)– CALICE (calorimetry based on Particle Flow Analysis)– FCAL (very forward region studies)

• European project (CERN is member)

– EUDET


LCD project plans

Most of the R&D currently carried out for the ILC isalso relevant for CLIC.In several areas, the detectors for CLIC will be morechallenging than the detector concepts for ILC.

Besides extensive simulation studies and softwaredevelopment for the CLIC detector studies, CLIC-specifichardware and engineering development is required in a number of areas.

Current scenario:Conceptual Design Report: end 2010Technical Design Report: 2015


LCD working with FCAL


• initiated by Lucie Linssen in 2008• mask studies by Andrey Sapronov (summer 2008)• CLIC LumiCal studies by Iftach Sadeh• forward region and background studies by André Sailer

• near future: work on beam-beam effect on Bhabha events (BHSE);

other systematics on LumiCal measurements;improved understanding of BeamCal and backgrounds

• on our list of important topics: radiation hard sensors for BeamCal(start learning about sensors, e.g. this week)

LCD working with FCAL


what could CERN help with ? (with LCD as intermediary) --- we are open for discussion ---

Examples :• special printed circuits (layers e.g. on thin foils,

complex structures such as GEM, etc.)Rui de Oliveira in EN-ICE-DEM

• advice on conductive glue and its problems, alternatives• bonding laboratory (wide range of experience) Ian McGill, Michael Moll in PH-DT-TP

• invitations to CERN, e.g. to initiate contacts

other Hardware/Engineering R&D

Hardware/engineering R&D needed beyond present ILC developments:• Time stamping

– Most challenging in inner tracker/vertex region– Trade-off between pixel size, amount of material and timing resolution

• Power pulsing and other electronics developments– In view of the CLIC time structure

• Hadron calorimetry– Dense absorbers to limit radial size (e.g. tungsten)– PFA studies at high energy– Alternative techniques, like dual readout

• Solenoid coil– Reinforced conductor (building on, but beyond CMS/ATLAS)– Large high-field solenoid concept

• Precise stability/alignment studies– In view of sub-nm precision required for FF quadrupoles

• Overall engineering design and integration


News from LCD@CERN – presented by K. Elsener, FCAL meeting Zeuthen, 29-30 June 2009 2222

LCD in the CERN MTPapproved by Council on 18 June 2009

Summary

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CLIC physics & detector studies re-started in 2008;LCD@CERN: a project as of 2009, resources in CERN MTP(timely in view of CLIC accelerator effort and CDR deadline end 2010)

co-operation with ILC concepts and collaborations

LCD@CERN • integrates in on-going world-wide LC physics/detector studies• profits from investment in ILC physics/detector simulations, hardware R&D and detector concepts (e.g. FCAL)

Thank you very much for your help !


SPARE SLIDES

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CLIC Tracking

Vertex and Tracking issues:• Due to beam-induced background and short time between bunches:

– Inner radius of Vertex Detector has to become larger (~30 mm)– High occupancy in the inner regions

• Narrow jets at high energy– 2-track separation is an issue for the tracker/vertex detector– Track length may have to increase (fan-out of particles within jet)

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3TeV e+e- ->t tbar

Lucie Linssen, SPC, 15/6/2009

26Lucie Linssen, SPC, 15/6/2009

distance of leading particles in jets

Jean-Jacques Blaising, LAPP

Extrapolation ILC = > CLIC


Adrian Vogel, DESY

For full LDC detector simulation at 3 TeVSimulation of e+e- pairs from beamstrahlung

•Conclusion of the comparison:•ILC, use 100 BX (1/20 bunch train)•CLIC, use full bunch train (312 BX)

•CLIC VTX: O(10) times more background•CLIC TPC: O(30) times more background

LDC 3 TeV, with forward mask

<= 10% beam crossing in ILD detector at 500 GeV


Tentative long-term CLIC scenario

FirstBeam?

TechnicalDesignReport (TDR)

ConceptualDesignReport (CDR)

Project approval ?

2007 2008 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023

R&D on Feasibility Issues

Conceptual Design

R&D on Performance and Cost issues

Technical design

Engineering Optimisation&Industrialisation

Construction (in stages)Construction Detector

2009

Technology evaluation and Physics assessment based on LHC results for a possible decision on Linear Collider with staged construction starting with the lowest energy required by Physics

CLIC parameters


Alternative to PFA calorimetry

R&D on dual/triple readout calorimetry


Basic principle:•Measure EM shower component separately•Measure HAD shower component separately•Measure Slow Neutron component separately

Dual Triple

EM-part=> electrons => highly relativistic => Cerenkov light emission

HAD-part=> “less” relativistic => Scintillation signal

Slow neutrons => late fraction of the Scintillation signal

Requires broader collaboration on materials + concept

Precise alignment/stability

• Precise alignment studies/technologies– Beam focusing stability !!– How to link left-arm and right-arm?

• Lumical =>measurement using Bhabha scattering• Alignment of last quadrupoles at +- 3.5 m

– ILC alignment requirements => <4 μm (x,y), <100 μm (z)– CLIC requirement is be more severe

31Leszek Zawiejski, FCAL collab.Daniel Schulte CLIC08.

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SiD Forward Region

LumiCal20 layers of 2.5 mm W +10 layers of 5.0 mm W

BeamCal50 layers of 2.5 mm W

3cm-thick Tungsten Mask13cm-thick BoratedPoly

Centered on the outgoing beam line

ECA

L

Beampipe+/- 94 mrad (detector)+101 mrad, -87mrad (ext. line)



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1 news from the cern linear collider detector project konrad elsener cern

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