Введение Физические задачи первого этапа...

14 February 2008 V.Kekelidze, Workshop at IHEP 1

Введение

Физические задачи первого этапа

Концептуальная схема установки MPD

«Барельная» часть MPD

Торцевые части MPD

Организационные аспекты

Заключение

Многоцелевой детектор

MMultiultiPPurposeurpose D Detector etector (статус проекта) В. Кекелидзе, ОИЯИ


Планируется исследовать свойства адронов в веществе и состояния ядерного вещества, включая поиск возможных проявлений:

- деконфаймента, - восстановления киральной симметрии, - фазовых переходов, - смешанной фазы и критической точки.

Исследования будут проводиться в процессах взаимодействий релятивиствских ионов

- с атомным весом от 1 до 238 (U92+) - путем сканирования по энергии реакции

в области SNN = 3-9 GeV Эти исследования важны как для понимания природы

взаимодействия тяжелых ионов, так и для решения вопросов космологии (эволюции Ранней Вселенной, формирования нейтронных звезд и др.)

Физическая мотивация


Physics motivation


Physics motivation

The phase diagram in terms of the reduced energy density

The trajectories calculated with hybrid model

o open markers: QGSM

steps:0.3 fm/c & 0.5 fm/c

• filled markers:evolution within

3D relativistic hydrodynamics


MPD

Collider NICA complex allocation


Collider NICA parameters


dedicated experiments

Fixed target experiments NA61 at SPS CERN and CBM at SIS100/300 GSI

advantages of collider experiments:

possibility to have 4acceptance !

energy scan do not introduce significant variation on critical density of detected

particles Collider experiments running at high energies: STAR & Fenix at RHIC BNL, ALICE at LHC CERN

STAR plans to run at low energies (SNN = 4-9 GeV, for U92+) Problem: luminocity falls down


Event-by-event fluctuation in hadron productions (multiplicity, Pt etc.)

HBT correlations indicating the space-time size of the systems involving π, K, p, Λ

(possible changes close to the de-confinement point)

Directed & elliptic flows for various hadrons

Multi-strange hyperon production: yield & spectra (the probes of nuclear media phases)

Experimental Tasks – the first stage targets

the effects to be studied on energy & centrality scanning:


longitudinal (z-axis) space limited by ~ 800 cm between collider optics

radial scale limited by engineering problems & cost

(R < 200 cm)

Initial constrains:

MPD – conceptual design

Solution:

compact solenoid with major parts of detector working in the magnetic

field

design of superconducting magnet with closed yoke geometry

to provide homogeneous magnetic field


~ 450

First stage of simulation based on UrQMD & GEANT4in the framework of MPD-Root shell:

Au+Au collisions with total energy of 4.5 + 4.5 AGeV Central interaction within b: 0 – 3 fm Minimum bias within b: 0 – 15.8 fm Collision rate at L=1027 cm-2s-1: ~ 6 kHz

Observables

all

B=0

<P>= 0.4 GeV/c

central collision |η| < 1, p >100 MeV/ccharged particle multiplicity (primary) momentum spectrum


Pseudorapidity spectra

Observables


Charged particles Multiplicity

Observables


General View


14 February 2008 V.Kekelidze, Workshop at IHEP 14limited by collider optics

2700


basic geometry preliminary

Defined as a compromise between:

-TOF requirement-tracker resolution

- magnetic field formation - the cost


Magnenic field

superconducting solenoidal magnet

magnetic field 0.5 T

cryostat inner radius ~ 1.5 m (region available for the detector)

iron yoke is used to form a homogeneous magnetic

field

color step 5 Gauss (~1 pm) - good homogeneity

feasible for TPC


Magnetic field




Towards 4p acceptance:to cover a wide pseudorapidity

range


Major tracker - TPC

+ Inner Tracker - silicon strip detector / micromegas chamber

for tracking close to the interaction region

+ Outer Tracker straw barrel (optional)

Time Of Flight RPC (+ start/stop sys.) for charged particle ID

ECAL shashlyk type - for e, , 0 reconstruction

MPD MPD Barrel part

tracking, precise momentum measurement &particle ID in the region -1 < <1


EE

400 V / cm

field cage

High Voltage electrode~ 25 kV

~80 000 readout channels

12 readoutChambers

Electric Field ~ 200 v/cm

Rout=110 cm

Rin=20 cm

TPC – major tracker


specification (preliminary)Outer radius ~ 110 cmInner radius

20 cmDrift length ~135 cmNumber of sections (each side) 12Total number of readout chambers 24 (12 – each side)Drift time ~ 20-30 sMultiplicity for charged particles (central collision) ~ 500Total pad/channels number ~ 80000dE/dx resolution ~ 6% (50 samples x 2cm)Special resolution ( x R x z) 3 x 0.4 x 3 mmMaximal rate 10 kHz

TPC – major tracker


Complementary detector for track precise reconstruction

in the region close to the interaction piont

Cylindrical geometry (4 layers) covering the interaction region ~ 50 cm along the

beam axis

Inner Tracker (silicon strips)

35 cm

Possible contribution to dE/dx measurements

for charged particles


Inner Tracker - MMGC (optional)

Number of double mesh chambers: 32

Covered area: 3,2 m2

N of RO channels: 20000


12 x 2 (R+L) double modulesoccupancy ~ 4%for segmented straw with the lengths: 330mm (central), 500 mm & 700 mm

FEE

FEE

70 50 33

FEE

FEE

70 50 33

OuterTracker - Straw barrel (optional)

to enhance tracking parameters in |η| < 1


Time of Flight

TOF Barrel system

TOF detector covers the region |η| < 1 with an acceptance ~ 93% The barrel surface ~ 30 m2 (length 4 m, radius of 1,3 m)The counters are placed in 12 modules, 560 counters in total The total number of readout channels is 27600Time resolution ~ 100 ps


Distribution of RPCs in the barrel

multigap RPCs distribution in the module box.

the basic element of RPC

multigap RPC counter is 7 cm x 67 cm,

it has 150 pads with size 2.3cm x 2 cm.

Time of Flight


Specification:

the RPC TOF system looks like barrel

with the length 4 m and radius of 1,3 m.

the barrel surface is about 33 m2

the dimensions of one RPC counter is 7 cm x 100 cm

it has 150 pads with size 2,3cm x 2 cm.

the full barrel is covered by 160 counters

the total number of readout channels is 24000

Time resolution ~ 100 ps

Time of Flight


Time of Flight track momenta

mass reconstruction for central events


Κ

πspectr N

NR

Κ

πplot mass N

NR

bluered

Time of Flight

momentum spectra ratios for primary K / particles

no essential bias on momentum

for the separation


Electromagnetic Calorimeter

0 1.0 2.0 GeV

photon energy spectrum 500 1000 1500 photon multiplicity

(from π0 decay in red)

requires high granularity:average occupancy in barrel for 3x3 cm crystals < 3%

Photons in the barrel


Electromagnetic Calorimeter

Requirements for 0 reconstruction


ECAL -Pb- scintillator 10x10 cm2 Module - 18 X0 ~ 30.6 cm

AMPD read-out

ECal Shashlyk


ECal PbWO4 (optional)

basic element -PbWO4 (3x3x16cm3), wrapped in Tyvek & coated with black tubea light detector is glued onto the outer face of the crystalOne module (24x24x22 cm3) - 64 crystals including light detectors & preamps The module has 0.5 mm thick walls of a folded Al plate fixed to the Al supportIn total 510 modules with 32640 crystals


End Cap Tracker Straw Wheels (stereo radial)

Beam Beam Counters for centrality determination & reconstruction of the interaction point

+ start /stop system for ToF

Zero Degree Calorimeter for centrality determination, measurement of fluctuations

MPD MPD End-Cap parts

for tracking & momentum measurement at | >1 + reaction plane determination


ECT straw wheels

occupancy /straw < 15 %

Carbon inner ring

Carbon outer ring

straw

Carbon inner ring

Carbon outer ring

straw


ECT straw wheel

Stereo wheel construction:

each stereo wheel contains4 layers of radial straws with different orientation


ECT straw wheel

Number of track hits = f(R)

is related to reconstruction efficiency

Pseudorapidity correlation with track hit numbers


Track reconstruction efficiency

TPC

ECT ECT

ECT complements TPC to extend pseudorapidity range


Pseudorapidy region: 1.5 4.5 (out of the TPC acceptance)

usable for centrality /min bias triggers

Beam Beam Counter

small tiles - within 12 cm diameter, large tiles x 4 larger .

R= 110 cm

Expected number of charged track accepted vs. impact parameter (Hijing predictions).


INR RAN

measurement of centrality: b ~ A - Nspect selection of centrality at trigger level

measurement of event-by-event fluctuations to exclude the fluctuation of participants

monitor of beam intensity by detecting

the neutrons from electromagnetic dissociation

εe / εh = 1 - compensated calorimeter

Lead / Scintillator sandwich

Zero Degree Calorimeter


Full beam intensity. -minimum 16 modules.

Zero Degree Calorimeter

XZ

Beam hole


DAQ & Computing

events ~2 10 10

disk space 10 000 TB PC’s ~ 1800L1 TTC

L2CTP

L0

DRE

LDC

DAQ NETWORK

DRE

LDC

DRE

LDC

GDC GDC GDC

TPC80 000ch4.5 GB/s

MICROMEGAS50 000 ch3 MB/s

ZDC300 ch55 MB/s

BBC78 ch

RPC27 600 ch20 MB/s

EMC41 700 ch70 MB/s

STRAW82 000 ch120 MB/s

MICROSTRIP215 500 ch3 MB/s

DDL

Au+Au6 000 ev/s

10 GbE

10 GbE

L1 TTC

L2CTP

L0

DRE

LDC

DAQ NETWORK

DRE

LDC

DRE

LDC

GDCGDC GDCGDC GDCGDC

TPC80 000ch4.5 GB/s

MICROMEGAS50 000 ch3 MB/s

ZDC300 ch55 MB/s

BBC78 ch

RPC27 600 ch20 MB/s

EMC41 700 ch70 MB/s

STRAW82 000 ch120 MB/s

MICROSTRIP215 500 ch3 MB/s

DDL

Au+Au6 000 ev/s

10 GbE

10 GbE

FEDL FEDL FEDLTRQ TRQ TRQ

DTTC

TTCL0DDL

READOUT CARD

FEC FEC FEC

FEDL FEDL FEDLTRQ TRQ TRQ

DTTC

TTCL0DDL

READOUT CARD

FEC FEC FEC


Engineering + auxiliaries

Require essential reconstruction of the intersection area to provide access for works & for necessary auxiliaries


Cost Estimation in k$(very preliminary)

Magnet - 3 138TPC - 9 500IT (SSD /MM) - 3 600 / 750OT - 4 000TOF - 4 000ECAL (shashlyk / crystal) - 5 624 / 14 356ECT - 7 900BBC - 390TDAQ - 3 000ZDC - 598Slow Control - 280Computing - 1 460Engineering - 2 000_________________ _________Total 41 490


At first approximation - all sub-detectors could be designed & constructed at JINR

based on the existing expertise & infrastructure

some sub-detectors could have alternative designs in order to provide possibility for potential collaborators to

substitute/accomplish corresponding groups in future

The first realistic draft of the Letter of Intent& the rough cost estimation =- are available

MPD – organizational aspects


Joint Institute for Nuclear Research

Institute for Nuclear Research Russian Academy of Science

Bogolyubov Institute for Theoretical Physics, NASUk

Nuclear Physics Institute of MSU, RF

Institute of Allied Physics, Academy of Science Moldova

__________///________ open for extension

MPD – Collaboration

A consortium involving GSI, JINR & other centers for IT module development & production is at the organizational stage


MPD Collaboration


Письмо о намерениях (Letter of Intent) - подготовлено и доступно

Работа над проектом продолжается- моделирование с целью оптимизации параметров

-интенсифицируются R & D, (особенно по ключевым детекторам)

Ведутся переговоры по расширению участников проекта

и организации соответствующего сотрудничества

Проведен ряд организационных мероприятий с рамках ОИЯИ

с целью укрепления коллективов, участвующих в работе над проектом

Выделены дополнительные ресурсы для работы

Заключение


Spin Program at NICA

in preparation


Spare


Possible indication on phase transition

measurements of related yields for charged kaons & pions

Some enhancement is indicated in the energy region around ~ Елаб = 30 А ГэВ


Physics motivation


momentum spectra for various particles

π+ π-

K+ K-

0 2.0 GeV/c 0 2.0 GeV/c

Observables


Relative yield of Charged kaons

Observables


Elliptic flow, v2

Observables


In-medium properties of hadrons & nuclear matter equation of state will be studied

including a search for possible manifestation of de-confinement

and/or chiral symmetry restoration, phase transition, mixed phase & critical end-point

in collisions of heavy ion (over atomic mass range A = 1-238)

by scanning of the energy region SNN = 3-9 GeV

These investigations are relevant for understanding of

the physics of heavy ion collisions, the evolution of the Early Universe

& formation of the neutron stars .

Physics motivation

Введение Физические задачи первого этапа...

Documents