Hadron Calorimetry and Very-Forward Calorimetry in CMS Hadron Calorimetry and Very-Forward...

Hadron Calorimetry and Hadron Calorimetry and Very-Forward Calorimetry in Very-Forward Calorimetry in

CMSCMSIPM09: 1st IPM Meeting On LHC Physics,

20-24 Apr 2009, Isfahan Mithat KAYAMithat KAYA

Kafkas University, Kars/TurkeyKafkas University, Kars/Turkey((member through Bogazici University))

On behalf of HCAL collaborationOn behalf of HCAL collaboration

• Physics Objectives of Hadron Calorimetry• Construction and overview of HCAL and Very-

Forward Calorimetry(HB, HE, HO, HF, CASTOR and ZDC).

• Some Samples from Test Beam and Cosmic data.

Mithat KAYAIPM09: 1st IPM Meeting On LHC Physics, 20-24 Apr 2009, Isfahan

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Outlines

• Had Barrel: HB• Had Endcaps: HE• Had Forward: HF• Had Outer: HO


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CASTORCASTOR

Collar Collar shieldingshielding

(5.32 < < 6.86)

ZDCZDC(z = 140 m)

BeamsBeams

EMEM

HADHAD

ECAL Scintillating PbWO4 crystals

ECAL Scintillating PbWO4 crystals

HCALPlastic scintillator/brass sandwich

HCALPlastic scintillator/brass sandwich

HFQuartz fibers/iron

HFQuartz fibers/iron

Eta CoverageHadronic Barrel: HB barrelHadronic Endcaps: HE(endcap)Hadronic Forward: HF(forward)Hadronic Outer: HOouterCASTOR5.32 < < 6.86

Hcal Thickness:~5.5 𝜆 @ =0~ 10.8 𝜆 @ =1.3~ 11 𝜆 in endcap~ 10 𝜆 @ 165 cm HF

Hcal Thickness:~5.5 𝜆 @ =0~ 10.8 𝜆 @ =1.3~ 11 𝜆 in endcap~ 10 𝜆 @ 165 cm HF

Hadron Calorimetry and Very-Forward Calorimetry


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Responsibilities of CMS Collaborators

• HE: absorber manufacture, megatile production (optics) : Russia and Dubna Member States • HO installation brackets & tooling, megatiles (including scintillator), optical cables & connectors:

India• HF absorber manufacture and installation tooling: Russia• HF shielding, support structure: CERN, Russia, Turkey, Iran• HF quartz fiber installation: Hungary• HB/HE/HF: HV Supply Engineering: Bulgaria• HB: absorber, megatile production (optics), optical cables & connectors, readout boxes,

photodetectors (HPD’s), front end electronics, trigger/DAQ electronics, power supplies, controls: US CMS

• HE brass (75%) & scintillator acquisition (only): US CMS• HE optical cables (materials) & connectors, readout boxes, photodetectors (HPD’s), front end

electronics, trigger/DAQ electronics, power supplies, controls: US CMS• HO readout boxes, photodetectors, front end electronics, trigger/DAQ electronics, power

supplies, controls: US CMS• HF and HF shielding mechanical design: US CMS• HF quartz fiber (Plastic cladding): US CMS• HF readout boxes, photomultipliers, front end electronics, trigger/DAQ electronics, power

supplies, controls: US CMS


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Responsibilities of HCAL Collaborators

Andris Skuja Lv.2 HCAL Project Manager’s Overview US CMS Annual Meeting Riverside, CaliforniaMay 19, 2001

• The Hadron Calorimeter plays an important role in the CMS detectors.

• Mainly to participate a Higgs boson measurement especially masses between 100 and 800 GeV.

• It plays an important role to discover new physics such as supersymmetry, darkmatter and so on…..

• Without the hardon calorimeter it is impossible to study Jet physics.

• It plays an also essential role in the identification and measurement of quarks, gluons, and neutrinos by measuring the energy and direction of jets and of missing transverse energy flow in the events.

• To Measure the Missing energy will help to understand the new physics such as superre of new particles, like the supersymmetric partners of quarks and gluons.


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Physics objectives ofHadron Calorimetry

• The Hadron Calorimeter (HCAL) measures the energy of “hadrons”, particles made of quarks and gluons (for example protonsprotons, neutronsneutrons, pionspions, and kaonskaons).

• It provides indirect measurement of the presence of non-interacting, uncharged particles such as neutrinosneutrinos.

• Measuring these particles can tell us if new particles such as the Higgs Boson Higgs Boson or Supersymmetric particles Supersymmetric particles have been formed.


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Physics Objectives ofHadron Calorimetry


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Transverse slice through CMS detectors

• The HCAL is organized into barrel (HB and HO), endcap (HE) and forward (HF) sections.

• It consists of 11 separate physical pieces1. The positive and negative barrels : HB+ and HB-.2. The positive and negative endcaps : HE+ and HE-.3. The positive and negative forward calorimeters : HF+ and HF-.4. The five rings of the outer HCAL : HO2-, HO1-, HO0, HO1+, and HO2+.

Mithat KAYA IPM09: 1st IPM Meeting On LHC Physics, 20-24 Apr 2009, Isfahan 9

Construction of Hadron Calorimeter

• 36 barrel “wedges”, each weighing 26 tones are located inside the magnetic coil.

• a few additional layers, the outer barrel (HO), sit outside the coil, ensuring no energy leaks out the back of the HB undetected.

• Similarly, 36 endcap wedges measure particle energies as they emerge through the ends of the solenoid magnet.

• The two hadronic forward calorimeters (HF) are positioned at either end of CMS, to pick up the myriad particles coming out of the collision region at shallow angles relative to the beam line.


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Construction of Hadron Calorimeter

• HCAL Readout system is dominated by mostly Hybrid Photodetectors and conventional phototubes.

• The light from scintillators is transported to the plastic fibers to the Hybrid Photodetectors (HPD’s) for HB, HE and HO.

• The response of HPDs is linear and they can operate in a high magnetic field, when the field is aligned with the applied electric field.

• HPDs have fiberoptic front window, conventional photocathode, pixelated diode (19 channels/device).

• The signals for HF are Cherenkov radiation in quartz fibers read by conventional phototubes.

• The essential electronics 2 elements are QIE’s(charge integrator and encoder), HTR’s (trigger and readout module) and event builder card (DCC- data concentrator card).


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HCAL READOUT system


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HCAL Segmentation

5.0

3.0

Sampling Calorimeter:Scintillator(active)&Brass(passive) -1.3< <1.3𝜂 Two half barrels, each composed of 18 identical 20 degree

wedges in Phi. The wedges composed of flat brass alloy absorber plates

parallel to the beam axis. The innermost and outermost absorbers are made of

stainless steel for structural strength. 17 active plastic scintillator tiles inserted between the steel

and brass absorber plates. The individual tiles of scintillator are machined to a size of

Δ xΔ =0.087x0.087 and instrumented with a single 𝜂 𝜙wave length shifting fibers


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Hadronic Barel

for 𝜋

The HB is divided into two half-barrel sections, each half-section being inserted from either end of the barrel cryostat of the super-conducting solenoid.

The HB consists of 36 identical azimuthal wedges (Δ =20𝜙 0 ) which form two half-barrels (HB+ and HB–). Each wedge is segmented into four azimuthal angle (Δ =5𝜙 0 ) sectors.


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Hadronic BarelMarch 2007

Since the barrel HCAL inside the coil is not sufficiently thick to contain all the energy of high energy showers, additional scintillation layers (HOB) are placed just outside the magnet coil.

• The full depth of the combined HB and HOB is app. 11 𝜆.• 1-cm thick Bicron BC408 scintillator tiles used. • Each tile is read out with 4 wave-length shifting (WLS) fibers of 1.35 mm

diameter, one in each quadrant of the tile. • The WLS fibers are placed in groves which follow the boundary of each quadrant.

Mithat KAYAIPM09: 1st IPM Meeting On LHC Physics, 20-24 Apr 2009, Isfahan 15

Hadronic Outer(HO)

An HO scintillator tile divided into quadrants, each with light collection a WLS optical fiber.


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• The HO system is divided into six sections that follow the division of the barrel muon system.

• Ring 0 (+ and −) are in the central muon system and are composed of two layers of scintillators one immediately outside of the magnet cryostat and the other layer after a 15-cm thick iron layer.

• Ring 0 in the muon barrel system YB0 (the central part of CMS) covers the |η| range of 0 to 0.35.

• Rings +1, −1, +2 and −2 are single layer scintillators inserted in the muon barrel systems YB1 and YB2 on both positive and negative sides of CMS immediately inside the first muon iron layer covering the |η| range of 0.35 to 1.2.

• Scintillation light from the tiles is collected using multi-clad Y11 Kuraray wave-length shifting (WLS) fibres, of diameter 0.94 mm, and transported to the photo detectors located on the structure of the return yoke by splicing a multi-clad Kuraray clear fibre (also of 0.94 mm diameter) with the WLS fibre.

Hadronic Outer(HO)

18 wedges


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•The hadron calorimeter endcaps (HE) cover the rapidity range, 1.3 < |η| < 3a region containing about 34% of the particles produced in the final state.

•The hadron calorimeter endcaps (HE) cover the rapidity range, 1.3 < |η| < 3a region containing about 34% of the particles produced in the final state.

HE is inserted into the ends of a 4T solenoidal magnet. C26000 cartridge brass(70% Cu and 30% Zn )non magnetic material used for the absorber

Int. length~ 11 𝜆Weight: ~ 300 Ton

HE is inserted into the ends of a 4T solenoidal magnet. C26000 cartridge brass(70% Cu and 30% Zn )non magnetic material used for the absorber

Int. length~ 11 𝜆Weight: ~ 300 Ton

Hadronic Endcap(HE)


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Total 20916 tiles1368 Megatiles

Total 20916 tiles1368 Megatiles

Hadronic Endcap Construction

Light emission from the tiles is in the blue violet, with wavelength in the range λ = 410-425 nm. This light is absorbed by the wave-shifting fibers which fluoresce in the green at λ= 490 nm. The green, waveshifted light is conveyed via clear fiber waveguides to connectors at the ends of the megatiles.

Light emission from the tiles is in the blue violet, with wavelength in the range λ = 410-425 nm. This light is absorbed by the wave-shifting fibers which fluoresce in the green at λ= 490 nm. The green, waveshifted light is conveyed via clear fiber waveguides to connectors at the ends of the megatiles.

79 mm

9 mm


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• Megatiles are large sheets of plastic scintillator which are subdivided into component scintillator tiles, of size ∆η x ∆φ = 0.087 x 0.087 to provide for reconstruction of hadronic showers. Scintillation signals from the megatiles are detected using waveshifting fibers. The fiber diameter is just under 1 mm.

HE η-φ illustration

• HF covers a large pseudorapidity range, 3 ≤|η| ≤ 5, and thus significantly improve jet detection and the missing transverse energy resolution which are essential in top quark production studies, Standard Model Higgs, and all SUSY particle searches

• Higgs boson production through weak boson fusion as a potential Higgs discovery channel requires identification of high energy quark jets by the forward calorimeters.


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Forward Hadron Calorimeter(HF)

• The forward calorimeter (HF) is essential for Missing Energy determination as well as for tagging Higgs production

• HF is also an optical device, but a Cherenkov light device, sitting in a very high radiation environment.

• The Cherenkov light is produced and transmitted via quartz fibers to photomultipliers. The entire electronics and calibration chain for HF is similar/identical to that of HB.


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Forward Hadron Calorimeter(HF)

HAD (143 cm)EM (165 cm)5mm


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The HF calorimeter is based on steelabsorber with embedded fused-silica-core and polymer hard-clad optical fibersFiber diameter 0.6 mmWire spacing 5 mmHalf a million of fiber will be read out by an about 2000 Phototubes(PMT)The Front face is located at 11.2 m from the interaction point

Light is generated by Cherenkov effect in quartz fibersSensitive to relativistic charged particles (Compton electrons...)

Amount of collected light depends on the angle between the particle path and the fiber axis

HF ConstructionTC (30 cm)

5 mm thick grooved steel plates


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Wedge

Fibers

Source tube

HF Fiber Insertion

Half a million fiber inserted on to the 36 wedges(18 HF+ and 18 HF-)

Ferrules


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HF Tower Mapping

large radius low eta (3.5-2.9) ieta= 29-32; High_Gain PMT

medium radius mid eta (4.2-3.5) ieta= 33-36Mid_Gain PMT

small radiushigh eta (5.2-4.2)ieta= 37-41Low_Gain PMT

HF divided in to a 4 quadrants

iEta29

iEta30

ieta31

iEta32

iEta33iEta34

iEta35iEta36iEta37iEta38iEta39iEta40iEta41

Physical Eta


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HF lowering Nov 2 2006

HF Construction


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HF Construction


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100 GeV electron Beam 100 GeV Proton beam

HF Simulated Showers

Magnetic field TEST 3 different test has been done


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1.)Fringe Field at HF ROBoxes increases to 100 Gauss as expected

2.)LED test:Stability of LED(B)/LED(0) is app 1 PMT shielding is GOOD

3.)Raddam test: Stability of RADDAM(B)/RADDAM(0) (≈ 1) → RADDAM Fibers not damaged through B field ramp-up/down

HF PMT's @ CRAFT and at 4 Tesla Kerem Cankocak Ferhat Ozok, Sercan SenHCAL DPG Meeting 17 Nov. 2008

Magnetic field effect On HF

• For the Normal pedestal runs we expect a signal just sitting on the pedestal region but sometime we are getting an unwanted signal besides pedestal. This signal can be one or more single photoelectron(spe) .This is called Light Leak. For instance at the following figure it is clearly seen.


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PedestalLight Leak

HF Light Leak Study

This Light Leaks are disappeared After closed the HF


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Not a clear indication of a possible Light leak

HF Light Leak Study@Craft


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From interaction point

magnetic field in CASTOR measured to be 0.1T - 0.16TCASTOR effort: mesh type PMT’s (R5505/R7494 of Hamamatsu)radius: 3.7cm to 14cm around beam pipe, 1.5m long ( 10 λI(

magnetic field in CASTOR measured to be 0.1T - 0.16TCASTOR effort: mesh type PMT’s (R5505/R7494 of Hamamatsu)radius: 3.7cm to 14cm around beam pipe, 1.5m long ( 10 λI )

sampling calorimeter with tungsten and quartzcoverage of pseudo-rapidity: 5.2 < η < 6.6 Cherenkov light read out by PMT’selectronic chain handles pulses for every bunch crossing

sampling calorimeter with tungsten and quartzcoverage of pseudo-rapidity: 5.2 < η < 6.6 Cherenkov light read out by PMT’selectronic chain handles pulses for every bunch crossing

more details on:CMS-Note 2008/022

Very Forward CalorimetryCASTOR(Centauro And STrange Object Research)

CASTOR has 14 azimuthal sectors(semi-octants) which are mechanically organized in two halfcalorimeters


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CASTOR Design

(a)Quarts plates of 4 mm thickness (b) tungsten plate(c) air-core light guides of the CASTOR prototype.

In a heavy ion collisionsSearch for the exotic particles

In a heavy ion collisionsSearch for the exotic particles

The calorimeter is located behind the hadronic forward calorimeter The detector will contribute mainly to forward QCD studies (diffractive, low-x) andcosmic-rays-related physics in both proton-proton and heavy-ion collisions at LHC energies.

More details in:CMS NOTE-2008/022


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Zero Degree Calorimetry(ZDC)

Beam pipe splits~140 m from IR

Beams

EMEMQuartz fiber/tungsten platesImproves resolution at large bReadout through HF electronics signals available for L1 trigger

Neutral particle absorber (TAN)

The detector slot will house the pp machine Luminosity Monitor (LM).

It will have a length of 10cm and will need to have an absorber in front of it.

This absorber will be the Electromagnetic Section (EM) of the ZDC with length of 10cm.

The ~75cm behind the luminosity monitor will be used for the Hadron Section of ZDC (HAD)

HADHAD


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ZDC Construction

Structure of Quartz/Quartz fiber: 0.6 mm – diameter of core;

0.63 mm – diameter of doped silica clad; 0.05 mm - thickness of polyamide buffer


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What can CMS do with ZDC

Some Results From the Test Beam and

cosmic data


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Mithat KAYA 37

Muon signal at the HB from the HCAL and ECAL combined

Test Beam-2006

The HB signal distribution for 150 GeV/c μ− from tower 4(η = 0.3). The solid curve represents a fit using combined Gaussian and Landau distributions

Using the 50 GeV/c electron calibration, the mean energy deposited by a 150 GeV/c muon is 2.4 ± 0.1 GeV. If the pion calibration correction is applied, the mean energy deposited is at 2.8 ± 0.2 GeV.

IPM09: 1st IPM Meeting On LHC Physics, 20-24 Apr 2009, Isfahan

the response of 150 GeV/c muons in theHB using 3 × 3 HB tower structure.


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Ratio of calibration constant for ring 1 HO tiles in the test beam set up with the HPD’s being operated at 10 kV and at 8 kV.

Energy resolution for pions as a function of beamenergy measured with EB + HB and with EB + HB + HO for the beam being shot at (a) η = 0.22 and (b) η = 0.56

Energy distribution for a 300 GeV pion beam measured with EB + HB and with EB + HB + HO.

Pedestal peak and muon signal for a ring 2 tile operated with a voltage of (a) 8 kV, (b) 10 kV on the HO HPD.

Design, performance, and calibration of the CMS hadron-outer calorimeterVolume 57, Number 3 / October, 2008 653-663 Springer Berlin / Heidelberg

HO Test Beam Results

http://www.springerlink.com/content/u8575wtm8uw7/?p=89d77beae4b64816b627624d217ca488&pi=0


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Energy distribution for 150 GeV muons where all HE layers in a single tower are summed.

Mean=3.53 GeV

A/√E B where E is in GeV, with ⊕stochastic term A = 1.02 GeV1/2and constant term B = 0.027

300 GeV/c Pion Beam

Fractional energy resolution of HE as a function of beam energy.

HE Test Beam Results


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One of the unique features of the HF response is its speed.

The peak position of pulses from 100 GeV electrons is 1 ns later ∼compared to that of pions at the same energy. The average distance between electromagnetic and hadronic shower maxima is 17 cm.∼

The deeper shower signals do reach the PMTs earlier because of the fact that the generated light travels shorter (fiber) distance. The di erence ffbetween the electromagnetic (tEM max ≈ 15 cm) and the hadronic (tHAD max ≈ 32 cm) shower maxima is about 17 cm, which corresponds to 1 ns time ∼di erence between the arrivals of electron and pion ffsignals to the PMTs

HF Performance2004 Test Beam Results

More Details in: CMS NOTE 2006/044


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(a)High energy muons impacting the PMT glass generate spuriously large energies. (b) The zero-supressed energy loss distribution clearly shows the single p.e. peak at 4 GeV, as expected.

150 GeV Muon signal at HF 2004 Test Beam Results

More Details in: CMS NOTE 2006/044


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CASTOR Aug-Sep 2007Test Beam Results


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Shower profile for 80 GeV (a) electrons and (b) pions

Energy resolution for (a)electrons and (b) pions

Energy resolution

More Details on:CMS CR -2008/090

CASTOR Test Beam ResultsPosition Sensitivity

The energy resolution is around 6% and 20% for 100 GeV electrons andpions respectively


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HCAL ENERGYHCAL ENERGY ECAL ENERGYECAL ENERGYHO EnergyHO EnergyHB ENERGYHB ENERGYHF ENERGYHF ENERGY

Beam DirectionBeam Direction

2.109 Proton Beam (clockwise) “shots” onto a collimator 150 meters upstream of CMS (also called “splash” events)

Hadronic Barel(HB)First Event sept-2008

Collimator Closed


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HCAL

ECALTracker

DT

COSMIC Event SamplesAt Global Runs B=3.8 T

CMS ran for 4 continuous weeks 24/7 and collected nearly 300M cosmic events with B=3.8T

• The HCAL and Very-Forward calorimetry detector systems and some Test Beam results are described here,

• These detectors are the essential part of the CMS experiment, without these detectors it is impossible to study new physics.

• The construction and the structure of these detectors are the perfection of both technology and engineering.


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Conclusion

Hadron Calorimetry and Very-Forward Calorimetry in CMS Hadron Calorimetry and Very-Forward...

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