status&of&future&heavy&ion& experiments&

Status of future Heavy ion Experiments

Anand Kumar Dubey , Variable Energy Cyclotron Centre (VECC),

Kolkata

XXI DAE Symposium in High Energy Physics, GuahaG 1 08/01/15

Outline: 1.  IntroducGon 2.  The “terra incognita” in the QCD phase diagram 3.  Future experiments -‐-‐-‐ Status and Development in CBM expt. -‐-‐-‐ Status of CBM-‐ MUCH 4. Summary

Heavy ion Collisions

•  By colliding two heavy nuclei at ultrarelaGvisGc Energies, the aim is to study the properGes of ma]er at such extreme condiGons of temperature and density.

•  The strongly interacGng ma]er formed is called Quark Gluon Plasma(QGP).

•  Such condiGons of high temperature and density prevailed in the early Universe, a few micro seconds a^er its formaGon.

•  mimicing this situaGon in the laboratory. The main goals that we study in heavy ion physics. -‐-‐ to understand theory of strong interacGon -‐-‐ QCD. -‐-‐ to study the parton-‐hadron transiGon and the nature of confinement -‐-‐ to understand the underlying mechanism of chiral-‐symmetry breaking. XXI DAE Symposium in High Energy Physics,

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Ø  The quest for QGP took off in 1986 at CERN (SPS) and BNL (AGS) first with light ions (mass =30) and later in 1990 with heavy ions (mass =200) Ø  ‘compelling evidence’ of the existence of such a new state of ma]er, which possessed

many CharacterisGc feature of QGP was found in the SPS experiment at CERN – year 2000.

Ø  At RHIC (√sNN =200 GeV) several of these signatures were seen and several new ones,

like jet quenching, Ncq scaling, etc. confirming the existence of a partonic medium was observed – QGP finally seen. It was concluded that the newly formed ma]er was “Strongly coupled” or sQGP and had properGes more of a perfect liquid rather than that of a gas.

Ø  At LHC, at much higher beam energies, high energy densiGes and temperatures, with

the plasma having greater lifeGme -‐-‐ an opportunity to invesGgate the QGP properGes in greater details. Planned upgrades in these experiments focus on precision measurements in future.

XXI DAE Symposium in High Energy Physics,

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Exploring the QCD Phase Diagram


Tsung-Dao Lee (Nobel Prize 1957): „The challenge for the next century physics is: explain confinement and broken (chiral) symmetry“

Frank Wilczek (Nobel Prize 2004): „But perhaps the most interesting and surprising thing about QCD at high density is that, by thinking about it, one discovers a fruitful new perspective on the traditional problem of confinement and chiral-symmetry breaking”.

Steven Weinberg (Nobel Prize 1979): „Go for the messes – thats were the action is“ (One of his four golden rules for scientists)

08/01/15 XXI DAE Symposium in High Energy Physics, GuahaG 6

XXI DAE Symposium in High Energy Physics, GuahaG 8

"5·1011/s; 1.5-2 GeV/u; 238U28+

" factor 100-1000 increased intensity " 4x1013/s 90 GeV protons " 1010/s 238U 35 GeV/u (Ni 45 GeV/u)

"rare isotopes 1.5 - 2 GeV/u; "factor 10 000 increased intensity "antiprotons 3(0) - 30 GeV

FAIR: the international Facility for Antiproton and Ion Research

primary beams

secondary beams

" rapidly cycling superconducting magnets " high energy electron cooling " dynamical vacuum, beam losses

accelerator technical challenges

PANDA

NuSTAR

CBM/HADES

APPA

FAIR will provide intense beams of rare isotopes, relativistic heavy ions and antiprotons for a wide range of expts. in particle, nuclear and atomic physics

08/01/15


The CBM Experiment@FAIR

10

Dileptons at FAIR -‐ the aim

no ρ,ω,φ → e+e- (µ+µ-) measurement between 2 and 40 AGeV no J/ψ → e+e- (µ+µ-) measurement below 158 AGeV

Study EM radiation (+ heavy flavor) in baryon dominated matter at moderate temperature as accessible by FAIR!

•  Photons: access to early

temperatures •  Low-mass vector mesons: in-

medium properties of ρ •  Intermediate range: acces to

fireball radiation •  J/ψ: charm as a probe for dense

baryonic matter

So far :


Randrup and Cleymans arXiv:1107.2624

•  I. Tserruya, arXiv::0903.0415v3 •  Phase diagram of strongly interacGng ma]er arXiv:0801.4256v2, P. Braun-‐Munziger et. al. •  Ryugo S. Hayano, Rev.Mod.Phys.82:2949,2010

Particle multiplicity x branching ratio for min. bias Au+Au collisions at 25 A GeV (from HSD and thermal model)

SPS Pb+Pb 30 A GeV STAR Au+Au √sNN=7.7 GeV

Experimental challenges


Dipole magnet

The Compressed Baryonic Matter Experiment

Ring Imaging Cherenkov Detector

Transition Radiation Detector

Resistive Plate Chambers (TOF) Electro-

magnetic Calorimeter (parking position)

Silicon Tracking Stations

Muon Detection System (parking position)

Projectile Spectator Detector Vertex

Detector

HADES XXI DAE Symposium in High Energy Physics,

GuahaG 13 08/01/15

08/01/15 GEM R&D for CBM MUCH-‐-‐ IWAD,VECC, Kolkata, 2014 14

Constraints and Challenges in Detector Design for CBM

High interac:on rates •  105 – 107 Au+Au collisions/sec.

Fast and radia:on hard detectors

Free streaming read-‐out •  Gme-‐stamped detector data •  high speed data acquisiGon

On-‐line event reconstruc:on •  powerful compuGng farm •  4-‐dimensional tracking •  so^ware triggers

Challenges in Muon detection Main issues:

Ø  High collision rates ~ 10 MHz Ø  The first plane(s) have a high density of tracks granularity ~ average hit rate is about 0.4 hit/cm2 Ø  Should be radiaGon resistant – high neutron flux à ~1013 n.eq./sq.cm/year Ø  Large area detector – with modular arrangement Ø  Data to be readout in a self triggered mode -‐-‐ a must for all CBM detectors. -‐-‐ and event reconstructed offline by grouping the Gmestamps of the detector hits. For the first two sta:ons GEM based detectors have been envisaged.

08/01/15 15 XXI DAE Symposium in High Energy Physics, GuahaG

CBM Technical Developments Micro-‐Vertex Detector: Frankfurt, Strasbourg

SC Magnet: JINR Dubna Silicon Tracking System: Darmstadt, Dubna, Krakow, Kiev, Kharkov, Moscow, St. Petersburg, Tübingen

RICH Detector: Darmstadt, Giessen, Pusan, St. Petersburg, Wuppertal

MRPC ToF Wall: Beijing, Bucharest, Darmstadt, Frankfurt, Hefei, Heidelberg, Moscow, Rossendorf, Wuhan

Muon detector: Kolkata + 13 Indian Inst., Gatchina, Dubna

Forward calorimeter: Moscow, Prague, Rez

DAQ and online event selecGon: Darmstadt, Frankfurt, Heidelberg, Kharagpur, Warsaw

TransiGon RadiaGon Detector: Bucharest, Dubna, Frankfurt, Heidelberg, Münster


STS integraGon concept


•  8 staGons, volume 2 m3, area 4 m2

•  896 detector modules -  1220 double-‐sided microstrip sensors -  ~ 1.8 million read-‐out channels -  ~ 16 000 r/o STS-‐XYTER ASICs -  ~ 58 000 ultra-‐thin r/o cables

•  106 detector ladders with 4-‐5 modules •  power dissipaGon: 42 kW (CO2 cooling)

building block: “module”

self-‐triggering r/o ASICs

sensor

8 tracking staGons ladder mech. unit

material budget in physics aperture [%X0]

ultra-‐thin r/o cables

08/01/15

Detector performance simulaGons


track reconstrucGon efficiency momentum resoluGon

•  detailed, realisGc detector model based on tested prototype components •  CbmRoot simulaGon framework •  using Cellular Automaton / Kalman Filter algorithms

08/01/15


CBM Muon Chambers (MUCH)

CBM Experiment @ FAIR

PSD

Dipole Magnet

MuCh TRD RPC

(TOF)

STS ≡ 7.5 λI

Fe

Dipole

STS

Muon Chamber (MUCH)

08/01/15 XXI DAE Symposium in High Energy Physics, GuahaG

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Aim: to detect dimuon signals from low mass vector mesons and J/ψ

(13.5 λI)


ParGcle Density at Different MUCH staGons

Radius (cm)

3 layout op:ons for SIS100 and SIS300

Basic SIS100 Extended SIS100

SIS300

Lengths: 6.4m (SIS100) 7.3m (SIS300)

TOF wall



Figure 3.1: RelaGve gain of a MWPC as a funcGon of rate.

Comparison of technology op:ons

GEM


Gas Electron Multiplier (GEM) and its working principle

l  Active medium is a gas mixture. l  electron multiplication takes place in holes of two copper foils separated by kapton l  Amplification may use 2 or 3 stages.

–  Maximum size ~100 cm x ~50 cm

70µm

140um 140µm

a 50 micron polyimide foil with a 5 micron Cu layer deposited on both sides of polyimide Basic elements of a GEM chamber:

1. Drift plane 2. Amplifying element – GEM 3. Readout Plane Cascaded GEMs can give higher gains and have lesser spark proability

GEM detectors have potential applications

in medical imaging

70um

08/01/15


Prototype fabrica:on at VECC

Readout plane 256 Pads 8 mm x 3.5 mm

10 ohm Resistors for protec:on

Outer side view GEMS 1 2 3

CERN made framed GEMs 10 cm x 10 cm Gas -‐ Ar/CO2 – 70/30

inner side 512 pads 3 mm x 4 mm

Outer side view

MulGlayered Readout PCB

Picture of the triple GEM prototype chambers


built at VECC built at GSI

(GEMS stretched and framed at GSI)

Parameter GEM chamber (VECC) GEM chamber (GSI)

Dri^ gap 3 mm 3 mm

Transfer gap-‐1 1 mm 2 mm

Transfer gap-‐2 1 mm 2 mm

InducGon gap 1.5 mm 2 mm

SegmentaGon 3 mm x 3 mm 6 mm x 6 mm

Number of pads 512 256

MPV=24 (HV = 3600)

Results from Lab tests at VECC (using conven:onal electronics)

Ra:o

of coinciden

ce cou

nts-‐ Eff(%)

X-‐ray source

Test with Cosmic muons in VECC lab

gain MPV=60


A.K. Dubey, et. al. GEM detector development for CBM experiment at FAIR Nucl.Instrum.Meth. A718 (2013) 418-‐420

Beam test of GEM prototype chambers

Aim : -‐-‐ to test the response of the detector to charged par:cles. mainly in terms of efficiency, cluster size, gain uniformity, rate handling capability -‐-‐ tes:ng with actual electronics for CBM : nXYTER nXYTER is a 32 MHz, 128 channel self triggered ASIC first developed by DETNEE collabora:on for neutron measurements. – coupled to ROC(ReadOut Controller) and then fed to the DAQ. -‐-‐ tes:ng with the actual CBM DAQ 08/01/15 XXI DAE Symposium in High Energy Physics,

GuahaG 29

The nXYTER ADC spectra is inverted as compared to conven:onal picture, this has to be subtracted from a baseline value channel by channel


DAQ Schematic

31

Test setup at Jessica beamline at COSY (Julich)

GEM chambers

STS station


Test Beam Set Up (CERN/ H4 beam line )

08/01/15 XXI DAE Symposium in High Energy Physics,

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Test Results

gain

Time correlaGon

Efficiency

Cluster size vs. voltage

self triggered mode

Published in NIMA

Pulse height spectra

Cluster size

Ageing/stability tests at GSI


Rate test using high intensity Cu X-ray

source in RD51 lab at CERN, with conventional electronics


Gain remains almost stable with rate Highest Rate in this picture ~ 1.4 MHz/cm2

95 kHz/sq.cm

1.38 MHz/sq.cm HV = 3200 V, Vgem~358 V, gas-‐ Ar/CO2(70/30)

Published in JINST-‐2014

30 kHz MPV = 124

253 kHz MPV=122

25 kHz MPV=240

357 kHz MPV=227

GEM 2

GEM 3

Vgem = 359 V -‐-‐ A constant baseline value of 2000 was taken for all of the above -‐-‐ Vb� set to 180


Rate test with high intensity protons (COSY Dec. 2013) Using self triggered readout FEB

Test with absorbers – MiniMUCH at CERN SPS, H4 beamline. Pion beams of GeV/c(with some muons and

electrons)

Team : VECC + Colleagues from GSI


Test beam setup @CERN SPS H4 beamline, Oct-‐Nov 2012

beam


Gem1 Gem2 Gem3

Residuals for GEM2 beam

Reconstruc:ng the track using GEM1 and GEM3 and Projec:ng the hits at plane_GEM2 and finding the distribu:on of residuals 08/01/15 XXI DAE Symposium in High Energy Physics,

GuahaG 39

•  -‐-‐-‐ in collaboraGon T. Bandopadhyay and R. Ravishankar of the Health Physics group at VECC.

•  Triple GEM detector, delta_Vgem ~340V. Ar/CO2, premixed gas (70/30).

•  Beam : α (40 MeV) on Tantalum target •  Neutrons measured with BF3 counters for flux esGmates from(50 –

500 nA). The counter was then replaced by GEM detector •  Data taken at varying neutron intensiGes -‐-‐ for currents from 50

nA to 5 uA. For any parGcular beam Intensity, data taken for about 15-‐20 min. ,then beam stopped and acGvity spectra recorded every two minutes, for about 15 minutes for each case.

•  Detector exposed to neutron radiaGon for about 4 days.

Test of triple GEM detector with Neutrons


Neutron tests -‐-‐ The Test Setup @cave1, VECC

Tantallum target

Lead Shield

Triple GEM detector


GEM_hits vs beam intensity

On an average ~350 GEM hits for a neutron intensity ~10^5 neutrons/sq.cm/s. In CBM the expected rate is 10^5 neutrons per 10^6 collisions So one would expect 0.0035 GEM hits/event due to neutrons

For each current se�ng, there were three irradiaGon file segments recorded just to check systemaGcs, if any.


Inching towards actual size of MUCH sector


MUCH station layout


Towards making a large size GEM chamber


31 cm x 31 cm GEM foil 12 HV seg.

~ Sector based readout. 1200 pads with progressive increasing size -‐-‐ 9 FEBs placed at the three sides of the board -‐-‐ coupled to 5 ROC’s

Thermal stretching and framing of 30 cm x 30 cm large size GEMs at VECC


Strip1

Strip2 Strip3


A Large size 30 cm x 30 cm single GEM chamber under test

Single GEM

ADC


Rela:ve gain Vgem ~353 V

Large size(31 cm x 31 cm) triple GEM chamber – X-‐ray test using 55Fe source in lab

Triple GEM

ADC

gas– Ar/CO2, Vgem ~525 V

Rela:ve gain

31 cmx 31 cm Large Size Triple GEM Detector


STS staGons

Beam

GEM 3 GEM 2

08/01/15 GEM R&D for MUCH, Bose InsGtute 52

Beamtest of Large size chamber at COSY—Dec. 2013

Beam spot for high intensity runs, 2.3 GeV/c protons

• 

GEM 2 GEM 3

Beam profiles as seen by 10 cm x 10 cm prototype and 31 cm x 31 cm prototype (right)



Large Size GEM modules would be made for CMS experiment, also for other experiments.


Readout PCB inner side

Readout PCB outer side

08/01/15

Towards making a Real size GEM Prototype

08/01/15 GEM R&D for CBM MUCH-‐-‐ IWAD,VECC, Kolkata, 2014 56

31 cm x 31 cm GEM foil 12 HV seg.

~ Sector based readout. 1200 pads with progressive increasing size -‐-‐ 9 FEBs placed at the three sides of the board -‐-‐ coupled to 5 ROC’s

Real size GEM foil For CBM MUCH -‐-‐ having GEM foils having 24 HV SegmentaGon.


Response of the real size prototype to Fe55 X-‐rays

Status of Different detector systems


Recently approved

FAIR Civil Construction

P. Senger, FAIR workshop@Worms, Germany

Summary : Ø  at LHC, condiGons are opGmal to study QGP in regions of

small baryon densiGes – corresponding to the early universe scenario, upgrades are on to carry out precision studies.

Ø  Several experiments are planned (one is running) to

invesGgate the regions of high density – corresponding to neutron star scenario.

Ø  Development and status of CBM detectors, in parGcular of Muon Tracker (MUCH) has been discussed. GEM based R&D for the first few staGons of MUCH has been discussed. Successful operaGon in a self triggered mode of

The CBM Physics Book Foreword by Frank Wilczek Springer Series: Lecture Notes in Physics, Vol. 814 1st Edition., 2011, 960 p., Hardcover ISBN: 978-3-642-13292-6

Electronic Authors version: http://www.gsi.de/documents/DOC-2009-Sep-120-1.pdf



Backups

Ø  Several triple GEM detector prototypes have been built and tested. Ø Response to MIPs: using cosmics an efficiency of 95 % achieved using conventional electronics. Prototypes tested with proton, pions, muon beams. Ø Beam test results – charged particle detection efficiency of ~95 % using self triggered readout. Ø  First Beamtest with absorbers: Track reconstruction possible and the residuals are in line with expectations. Ø Stretching, framing and testing large size GEM (31cm x 31 cm) – -- built one such triple GEM prototype, Used thermal stretching technique. Beam Test results –Gain remains quite stable for low and high intensity cases. and efficiency of > 90 % has been achieved. -- may adopt “ns2” stretching technique being developed by RD51 for CMS. Ø  Next Steps:

-- Building of a real size MUCH sector prototype using ns2 technique – first prototype expected in September. -- Building a dummy sector-module with realistic dimensions

Ø  GEM foils – CERN made foils for SIS100 would be provided by RD51. As a parallel effort, we are collaborating with ECIL, Hyderabad to produce GEM foils in India.

Ø  GEM frames – we have started probing Indian companies. Part of it can as well be done at VECC, a 31 cm x 31 cm frame has been made.

SUMMARY


Station # for

SIS100

Layer #

Total no of

pads

R1 (cm)

Pad size (min)

R2 (cm)

Pad size (max)

Area (sq.mt)

No of 128 channel

FEB/layer

(round off)

No of Sector

per layer

1 1 28800 25 4.36mm 100.25 17.48mm 2.95 240 16

2 28800 25 4.36mm 100.25 17.48mm 2.95 240 16

3 28800 25 4.36mm 100.25 17.48mm 2.95 240 16

2 1 30600 34.5 5.9mm 146.9 25.4mm 6.4 240 24

2 30600 34.5 5.9mm 146.9 25.4mm 6.4 240 24

3 30600 34.5 5.9mm 146.9 25.4mm 6.4 240 24

Station # for

SIS300

Layer #

Total no of

pads

R1 (cm)

Pad size (min)

R2 (cm)

Pad size (max)

Area (sq.mt)

No of 128 channel

FEB/layer

(round off)

No of Sector

per layer

1 1 28800 25 4.36mm 100.25 17.48mm 2.95 240 16

2 28800 25 4.36mm 100.25 17.48mm 2.95 240 16

3 28800 25 4.36mm 100.25 17.48mm 2.95 240 16

2 1 30240 29.5 5mm 123.5 21.3mm 4.5 240 20

2 30240 29.5 5mm 123.5 21.3mm 4.5 240 20

3 30240 29.5 5mm 123.5 21.3mm 4.5 240 20

# of sectors, FEB, area, etc.


LHC Physics in the Next Ten Years

66

Run 2 Run 3

Pb+Pb Pb+Pb/p+Pb Pb+Pb/p+Pb/Ar+Ar

sPHENIX measurements well Gmed with LHC Run-‐3 measurements

Very good for enabling theory focus on simultaneous understanding

RHIC

XXI DAE Symposium in High Energy Physics, GuahaG 08/01/15

Figure 3. The STAR Beam Energy Scan Phase II White Paper details the motivation and the plans to return to energy scans at RHIC in years 2018 and 2019.

Collision Energy (GeV)

Fixed Target √sNN

Center of Mass

Rapidity

Single Beam Kine:c

Chemical Poten:al Collider

Chemical Poten:al µB

(MeV)

19.6 4.471 1.522 8.87 206 589 17.2 4.214 1.456 7.67 230 608 14.5 3.904 1.370 6.32 264 633 13.0 3.721 1.315 5.57 288 649 11.5 3.528 1.253 4.82 316 666 9.1 3.196 1.134 3.62 375 699 7.7 2.985 1.049 2.92 422 721

successfully installed a gold target in the STAR detector in 2014.

This fixed-‐target program will enable STAR to make key measurements related to the phase diagram of QCD ma]er below the reported onset of deconfinement at √sNN = 7.7 GeV.


Development of detector components


Silicon microstrip sensors Detector module

•  300 µm thick, n-‐type silicon •  double-‐sided segmentaGon •  1024 strips of 58 µm pitch •  strip length 6.2/4.2/2.2 cm •  angle front/back: 7.5 deg •  read-‐out from top edge •  rad. tol. up to 1014 neq/cm2

71 (+3) components

module produc:on: most work intensive part of

STS construc:on

08/01/15

Performance of open charm measurement


D0 →Kπππ D± →Kππ

D0 →Kπππ D± →Kππ D0 →Kπ

p+C collisions, 30 GeV (SIS100)

Au+Au collisions, 25 AGeV (SIS300)

1012 centr.

08/01/15

sPHENIX in a Nutshell

72

BaBar Magnet 1.5 T

Coverage |η| < 1.1

All silicon tracking Heavy flavor tagging

ElectromagneGc Calorimeter

Two longitudinal Segment Hadronic

Calorimeter

Common Silicon PhotomulGplier readout for Calorimeters Full clock speed digiGzers, digital informaGon for triggering

High data acquisiGon rate capability ~ 10 kHz XXI DAE Symposium in High Energy Physics, GuahaG 08/01/15

sPHENIX Run Plan

73

Two years of physics running 2021 and 2022 with 30-‐cryo week runs 20 weeks Au+Au @ 200 GeV 10+ weeks p+p @ 200 GeV [comparable baseline staGsGcs] 10+ weeks p+Au @ 200 GeV [comparable baseline/new physics stats] sPHENIX maintains very high PHENIX DAQ rate sPHENIX maintains fast detector capability – no pile up problems If we just record Au+Au minimum bias events (no trigger bias), in 20 weeks with current RHIC performance and PHENIX liveGme, we record 50 billion events within |z| < 10 cm [opGmal for silicon tracking] Note this is not sampled, but recorded. Full range of differenGal measurements and centraliGes with no trigger biases.

XXI DAE Symposium in High Energy Physics, GuahaG 08/01/15

Preliminary Spectrometer Design

74

Muon tracker

Solenoid (BL=1Tm)

2m

2m

1.5m

0.3m

30o

TOF (5m from target)

10o

TOF

EMCAL GEM Trackers

RICH

hadron-‐ID (θ<117o) e-‐ID : θ<30o µ-‐ID : θ<25o 20o = mid rapidity

1m

ZCAL

Muon dipole

1m

RICH Aerogel +gas

Top View Dipole (BL=1.5Tm)

Centrality MC + ZCAL

target

Silicon pixel/strip trackers

GEM trackers

Mul:plicity counter

status&of&future&heavy&ion& experiments&

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