VO 260 066 Detector and detector systems for particle and ... · VO 260 066 Detector and detector...

VO 260 066

Detector and detector systems for particle and nuclear physics I

E-mail: johann.zmeskal@oeaw.ac.at

Detector 1

Friday 9.1.2015

PARTICLE DETECTION

2

Particle cannot be seen or measured „directly“

Only the result of an interaction with matterwill be observed.

In the end, everything is converted to optical pictures electric signals

Particle Detection Principle

The detection of particles happens via theirenergy loss in the material it traverses ...

Charged particles Ionization, Bremsstrahlung, Cherenkov ...

Hadrons Nuclear interactions

Photons Photo, Compton effect, pair production

Neutrinos Weak interactions

3

Measurement of Particle Properties

• Charge– direction

• Momentum B, radius

• Lifetime– measurement of path length

• Velocity time of flight (TOF)

LB

NL I

mage L

ibra

ry

Discovery of the Positron1932 Carl Anderson,

Noble Prize 1936

4

pvmRBq

DETECTOR TYPES

Scintillation detectors

Semiconductor detectors

Gaseous detectors

Calorimeter

ECAL: Electromagnetic calorimeter

HCAL: Hadronic calorimeter

Tracking detectors

(tracks momentum, charge, decay)

Multipurpose detectors / high precision experiments

combination of different detectors

(FAIR PANDA)5

Detector 6

coverage of full solid angle (no cracks, fine segmentation)

measurement of momentum and/or energy

detect, track and identify all particles (mass, charge)

fast response, no dead time

practical limitations (technology, space, budget) !

end products

charged particles

neutral particles

photons

The ‘ideal’ particle detector should provide…

Detector 7

• number of particles

• event topology

• momentum / energy

• particle identity

cannot be achieved

with a single detector

detector

system

Detector systems

GEOMETRY

Magnet concepts

Imagnet

B

coil

Imagnet

B

µ

µ

Solenoid (air-core) Toroid

CMS, KLOE, FOPI, PANDA ATLAS

+ strong and homogeneous field

- massive iron return yoke

- limited in size (cost)

- solenoid thickness (radiation length)

+ large air core, no iron, less material

- additional solenoid in the inner parts

-- inhomogeneous field

- complex structure

8

ATLAS and CMS magnet coils

ATLAS toroid coils

Autumn 2005

CMS solenoid(5 segments)

9

CMS: SC, 4.0T, Ø5.9m, L 12.5mAtlas: D=9m; L=24m

Exploded View of CMS

MUON BARREL

CALORIMETERSECAL

PbWO4

crystals

Cathode Strip Chambers

Resistive Plate Chambers Drift Tube

Chambers Resistive Plate

Chambers

SUPERCONDUCTING

COIL

IRON YOKE

TRACKER

Silicon micro-strips

pixles

MUON

ENDCAPS

Total weight : 12,500 t

Overall diameter : 15 m

Overall length : 21.6 m

Magnetic field : 4 Tesla

HCAL

Plastic scintillator/brass

sandwich

10

Slice through the CMS detectorParticle interaction and reconstruction

different detectors for different particles

11

12

CMS

Detectors interleaved with the magnet yoke steel layers

13Detector

Collider versus fixed target

14Detector

Detector parameters

• solid angle

• granularity

• dead time / rate capability

• resolution

• efficiency

• material budget

• radiation tolerance

• COST !!

Example for a collider and a fixed target experiment

KLOE at DANE

PANDA at FAIR

15Detector

16

DANE

e+-e-

collider

Accu.

Hadron 2013

K+

K-

e

e ee

ee

e

e

e

e

e+

e+

e+

e+

e+

e+e+

e+

DANE principle

• operates at the centre-of-mass energy of the mesonmass m = 1019.413 ± .008 MeVwidth = 4.43 ± .06 MeV

• produced via e+e- collision with(e+e- → ) ~ 5 µb

production rate 2.5 x 103 s-1

monochromatic kaon beam (127 MeV/c) bremsstrahlung loss per turn ~ 14 keV

17

About strange particles…

The quark eigenstates are:

The CP eigenstates are:2

KKK ,

2

KKK

00

2

00

1

+

00 K ,K

M. Gell-Mann A. Pais

19Detector

The KLOE Detector

20Detector

The KLOE Detector

Electromagnetic

calorimeter

Interaction

region

Drift

chamber

Iron

yoke

Superconducting

coils

21Detector

22Detector

KLOE calorimeter

KLOE calorimeter

density ~ 5.0 g/cm3

total length of fibres ~ 15000 kmread out by ~ 5000 mesh PM SiPMs

Photon energy resolution (E)/E = 5.7%xE(GeV)-1/2

time resolution t/t = 54 [ps]xE(GeV)-1/2

+

+

0

000

sK

Determination of the neutral kaon mass, by measuring 4 gammas

Neutron detection efficiency

Threshold at 1 MeV

Threshold at 3 MeV

MC simulation, confirmed with measurements at TSL (Uppsala)

PANDA Detector @ FAIR

27Detector

Anti-Proton

ANnihilation at

DArmstadt

Facility for Antiproton and Ion Research

28Detector

Particle physics

Hadron physics

Nuclear physics

Study the strong interaction with antiprotons

Questions ...

Mechanism of confinement ?

Inner structure of hadrons ?

Origin of mass and spin (macroscopic properties) ?

Exotic colour neutral objects?

Physics goals of PANDA

29Detector

Hadron SpectroscopyExperimental Goals: mass, width & quantum numbers of

resonances

Charm Hadrons: charmonia, D-mesons, charm baryons

to understand new XYZ states, Ds(2317) and others

Exotic QCD States: glueballs, hybrids, multi-quarks

Spectroscopy with Antiprotons:

Production of states of all quantum numbers

Resonance scanning with high resolution

Physics goals of PANDA

30Detector

31

Nuclear Physics

Charm in the MediumMesons in nuclear matterMasses change in nuclei

D-mass lowerLower D D threshold

J/ψ absorption in nuclei

Hypernuclei3rd dimension in nuclear chartDouble hypernucleiproduction via Ξ- capture Λ Λ interaction in nucleus

Other topicsShort range correlationsColor transparency

Physics goals of PANDA

Detector

Detector 32

33Detector

Physics goals of PANDA

Hadron StructureGeneralized Parton Distributions

➔ Formfactors and structure functions

Timelike Nucleon Formfactors

Drell-Yan Process

full PWA or polarized beam/target

PANDA Physics Report www-panda.gsi.de

34Detector

35Detector

PANDA - detection concept

Detector 36

Stochastic cooling

Stochastic cooling

Injection

Electroncooler

High Energy Storage Ring

Up to 1011 stored antiprotons

Beam momentum: (1.5 ... 15) GeV/c

Phase-space cooling

Fixed internal target

Operation modes

a) High luminosity: L = 2 · 1032 cm-2 s-1 p/p 10-4

b) High resolution: L = 1031 cm-2 s-1 p/p 4 · 10-5

PANDA @ HESR

Detector 37

TARGET SPECTROMETER FORWARD SPECTROMETER

DipoleMuon ID

RICHVertex

Central TrackerElectromag.

Calorimeters

Muon

Range System

Drift ChambersSolenoid

Target

DIRC

The PANDA Spectrometer

38

Superconducting magnet Central field: |B| = Bz = 2 T

High field homogeneity: 2%

Dimensions inner bore: 1.9 m / length: 2.7 m

Coil and cryostate

zbeam axis

Target pipewarm hole

Outer yoke dimension: 2.3 m / length: 4.9 m

Total weight: ~ 300 t

Iron flux

return yoke

Laminated layers for

muon range system

PANDA - Solenoid

39

Superconducting magnet

Field integral (bending power): 2 Tm

Deflection of antiprotons with p =15 GeV/c: 2.2°

Bending variation: 15%

Vertical acceptance: 5°

Horizontal acceptance: 10°

Total weight: 200 t

Forward tracking detectors partly integrated

PANDA – Dipole magnet

40

Beam pipe

Target pipe

Target dumping

system

Target production

Vacuum pumps(VP)

(VP)

(VP)

(VP)

~ 2

m

Injectionpoint

• Primary target setup

Appropriate cut-outs

in solenoid magnet

Beam-target cross

Design compatible

with all different options

PANDA – Target system

The new INFN-SMI-GSI cluster jet

Cluster-jet nozzle at GSI

max = 1,4·1015 atoms/cm2

(29,7 K and 15 bar)

43

Forward

spectrometerTarget spectrometer

Micro-Vertex

Detector

Central tracking (Helix fit)

Forward tracking(Straight lines)

Straw-tube

layers

Outer

tracker

GEM

stations

PANDA – Tracking

44PhiPsi2011 BINP, Novosibirsk

Design of the MVD

4 barrels and 6 disks

Continuous readout

Inner layers: hybrid pixels

(100x100 µm2)

Outer layers:

double sided strips:

Rectangles & trapezoids

NXYTER readout

Mixed forward disks

(pixel/strips)

Challenges

Low mass supports

Cooling in a small volume

Radiation tolerance

PANDA – Micro Vertex Detector

45

Central Tracker σrφ~150µm , σz~1mm

δp/p~1% (with MVD)

Material budget ~1% X0

Straw Tube Tracker

27 µm thin mylar tubes, 1 cm Ø

Stability due to 1 bar overpressure

GEM Time Projection Chamber

Continuous sampling

GEMs to reduce ion feedback

Online track finding

Forward GEM Tracker Large area GEM foils Ultra thin coating

PANDA – Central tracker

46

Detector Layout 4500 straws in 20-26 layers

Tube made of 27 µm thin

Al-mylar, Ø=1cm

Rin= 150 mm, Rout= 420 mm

l=1500 mm

Self-supporting straw double

layers at ~1 bar overp.(Ar/CO2)

Material BudgetMax. 26 layers,

0.05 % X/X0 per layer

Total 1.3% X/X0

Detector performance r/ resolution: 130 µm

z resolution: ~ 1 mm

Prototype test at COSY-TOF

PANDA – Straw tubes

47Detector

The PANDA Detector - GEM-TPC

48

PANDA PID Requirements:

Particle identification essential

Momentum range 200 MeV/c – 10 GeV/c

Different processes for PID needed

PID Processes:

Cherenkov radiation: above 1 GeV

Radiators: quartz, aerogel, C4F10

Energy loss: below 1 GeV

Best accuracy with TPC

Time of flight

Problem: no start detector

Electromagnetic showers:

EMC for e and γ

PANDA – Particle IDentification

49PhiPsi2011 BINP, Novosibirsk

Forward spectrometerTarget spectrometer

Barrel DIRC RICH

D etection of I nternally R eflected C herenkov

light

Radiator material: Fused silica 3 /K separation

0.8 GeV/c p 5 GeV/c

Radiator materials: Aerogel / C14F10

/K separation2 GeV/c p 15 GeV/c

R ingI magingCH erenkov

detector

Disc DIRC

PANDA – Cherenkov detectors

50

Forward spectrometerTarget spectrometer

Barrel EMC Shashlyk

calorimeter

Endcap

structures

Operated at -25°C

Cristal: PbWO4

~ 15,000 cristals

Lead-scintillator sandwiches351 modules

(13 rows / 27 columns)

PANDA – Calorimeter

51PhiPsi2011 BINP, Novosibirsk

Barrel Calorimeter

11000 PWO Crystals

LA-SiPM readout, 2x1cm2

σ(E)/E~1.5%/√E + const.

End cap

4000 PWO crystals

High occupancy in center

LA-SiPM or VPT

PANDA PWO Crystals

PWO is dense and fast

Low γ threshold

Increase light yield:

- operation at -25°C (4xCMS)

Challenges:

- temperature stable to 0.1°C

- control radiation damage

- low noise electronics

Delivery of crystals started

PANDA – Calorimeter

52

Forward spectrometerTarget spectrometer

Barrel tile hodoscope

Time resolution: (50...100) psScintillator slabs or

pads of multigap resistive plate chambers (RPC)

Scintillator wall

Scintillator slabsTime resolution: ~ 50 ps

Quad module

Scintillator

SiPM

PANDA – Time-of-flight systems

Detector 53

Detector arrangement

54Detector

Cross section

55Detector

Cross section

56Detector

Luminosity

Interaction with matter

hadroncomptonphotoeffpairradcolltot dx

dE

dx

dE

dx

dE

dx

dE

dx

dE

dx

dE

dx

dE

57

58

Interaction of particles with matter

hadroncomptonphotoeffpairradcolltot dx

dE

dx

dE

dx

dE

dx

dE

dx

dE

dx

dE

dx

dE

som

e ex

amp

les

Bethe-Bloch Formula

Z

C

I

Tvmz

A

ZcmrN

dx

dE eeea 22

2ln2 2

2

max

22

2

222

][1535.02 1222 gMeVcmcmrN eea

222

222

max

)(121

2

M

m

M

m

cmT

ee

e

+++

Tmax head-on or knock-on collisions

59Detector

ZeVI )10(

mean excitation potential

Hans Bethe Felix Bloch

(Relativistic) charged particles other than electrons lose energy in matter

primarily by ionization and atomic excitation. The mean rate of energy loss

(or stopping power) is given by the Bethe-Bloch equation:

Mean excitation energies

60Detector

ICRU - International Commission on

Radiation Units and Measurements

Energetic knock-on electrons ( - rays):

The distribution of secondary electrons with kinetic energies T >> I

is given by:

22

22 )(1

2

1

T

TF

A

ZKz

dTdx

Nd

for I<<T≤Tmax

For example:

for a 500 MeV pion on a silicon detector with thickness x = 0.3mm,

on average one -ray (with 12 keV) is produced per particle crossing

integrating above Eq. from Tcut(=12 keV) toTmax

on average 0.0475 - ray (with 116 keV) are produced per particle

integrating Tcut (=116 keV) to Tmax

(116 keV is the mean energy loss in 0.3mm silicon for MIPs)61Detector

Mean energy loss rate

kinematical term 1/β2

MIPs ~3-4

relativistic rise ln(β22)

Z/A=1

Z/A~0.5

62Detector

Detector 63

Energy loss of muons

Fermi-plateau

Detector 64

Summary Bethe-Bloch

• BB valid for “heavy” particles ( m>~mµ)

• mean energy loss dE/dx normally given in MeVcm2/g

• dE/dx independent of the mass of the projectile

• Energy transfer within I < dE < Tmax

(I...mean excitation energy ~ 10·Z eV)

Detector 65

Mean range - range straggling

The range can be determine by passing a beam of particle with the

desired energy through different thicknesses of the material in question

and measure the ratio of transmitted to incident particles.

Detector 66

Bragg curve and mean range

intensity as

function of x

Energy loss

per length unit

Bragg peak

The energy loss of a charged particle passing an absorber is rising, most

of the energy is deposited at the “end” (important for radiotherapy)

Integration of the Bethe-Bloch formula gives

the mean range <R>:dE

dE

dxR

E0

Range of charged particles in matter

67DetectorR....mean range

M...mass of projectile

68Detector

For thin layers or low density materials:

Few collisions, some with high energy transfer

Energy loss distributions show large

fluctuations towards high losses:

”Landau tails”

For thick layers and high density materials:

Many collisions

Central Limit Theorem , Gaussian shaped

distributions

• Real detectors (limited granularity) can not measure <dE/dx> !

• In a detector the deposited energy ΔE in a layer of finite thickness x

is measured.

Interaction of charged particles

69Detector

Energy loss of electrons and positrons

Like heavy particles electrons and positrons also suffer collisional

energy loss when passing through matter.

But also, because of their small mass, an additional energy loss

mechanism comes into play: the emission of electromagnetic radiation

arising from scattering in the electric field of the nucleus

(bremsstrahlung).

collradtot dx

dE

dx

dE

dx

dE

+

Classically: bremsstrahlung can be explained as deviation of the

electron from its straight-line caused by the electric attraction of the

nucleus field.

Detector 70

Collision loss

For electrons the Bethe-Bloch formula has to be modified:

• the assumption that the incident particle remains un-deflected during

the collision process is not valid (due to the small e mass)

• for electrons the collisions appear between identical particles,

therefore their indistinguishability has to take into account

+

+

Z

CF

cmIA

ZcmrN

dx

dE

e

eea 2)()/(2

)2(ln

12

22

2

2

22

with the kinetic energy of the incident electron/positron in units mec2

))2(

4

)2(

10

)2(

1423(

122ln2)(

)1(

2ln)12(8/1)(

32

2

2

22

++

++

++

+

++

ßF

rßF for electrons

for positons

71

Energy loss by radiation - Bremsstrahlung

At energies below a few hundred GeV electrons and positrons are the

only particles for which radiation contributes substantially to the

energy loss of the particle.

e.g. for muons (m = 106 MeV) the radiation loss is ~ 40000 times

smaller than for electrons

Detector 72

Energy loss of electrons in copper

Detector 73

Radiation length

Is defined as the distance over which the electron energy is reduced

by a factor 1/e due to radiation loss:

0/

0

XxeEE

dxNE

dErad

x....travelled distance

X0..radiation length

74

Interaction of photons

The behaviour of photons in matter is quite different from

that of charged particles, as photons have no electric

charge there are no inelastic collisions with atomic

electrons.

The main interactions of X-rays and -rays in matter are:

• photoelectric effect

• Compton scattering

• pair production

Detector 75

Photoelectric effect

Photoelectric cross

section for lead

The photoelectric effect involves the absorption of a photon by an atomic

electron and the subsequent ejection of the electron from the atom.

The energy of the outgoing electron is : E = h - B.E.

Detector 76

scattering on a quasi-free e-

Compton scattering

Klein-Nishina formula used to

calculate Compton scattering

cross section

Energy distribution of Compton recoil electrons

Compton edge

W.R. Leo, Techniques for Nuclear andParticle Physics Experiments

Detector 77

Pair productionThe process of pair production involves the

transformation of a photon into an electron-positron pair.

In order to conserve momentum, this can occur only in

the presence of a third body (e.g. nucleus).

54

1

Z

183ln

9

7Zr4

3/1

22

enucl,pair

22 cmE epair production

cross section in

lead

W.R. Leo, Techniques for Nuclear andParticle Physics Experiments

54

109

cm

E2ln

9

7Zr4

2

e

22

enucl,pair

3/12

e Z

1

cm

E:for

3/12

e Z

1

cm

E:for

Photoelectric effect

→ Z4 to Z5 → E-3.5 to E-1

Compton scattering

→ Z → E-1

Pair production

→ Z2 → ln E

78Detector

photoelectric

Compton

pair

Total photon absorption cross section in lead

W.R. Leo, Techniques for Nuclear andParticle Physics Experiments

79Detector

The photon mass attenuation length

)/exp(0 tII

80Detector

Interaction of neutrons

81

Interaction of neutrons