cms hcal r&d

Andris Skuja – CMS HCAL Meeting at JINR, Dubna on December 5, 2003

CMS HCAL R&DCMS HCAL R&DCMS HCAL R&DCMS HCAL R&D

R&D for Hadron Calorimeter Upgrades

Andris Skuja

University of Maryland

December 5, 2003


HCAL Upgrades for SLHCHCAL Upgrades for SLHCHCAL Upgrades for SLHCHCAL Upgrades for SLHC

The Super LHC will have a design luminosity of 1035 cm-2/sec

This will be achieved by doubling the number of bunches as well as increasing the amount of particles per bunch

The result will be an increase of radiation levels everywhere. The problematic regions are HE above an η of 2 and all of HF

The US groups are investigating possible upgrades of both regions

Initially, readout electronics will remain as presently designed running at 40 MHz. It is felt that off-line software can sort out the correct beam crossing time to 12.5 nsec


Mass Reach vs energy and LMass Reach vs energy and LMass Reach vs energy and LMass Reach vs energy and L

1032

1033

1034

1035

103

104

Luminosity(/cm2sec)

MZ'

(GeV

)

N=100 Events, Z' Coupling

2 TeV 14 TeV 28 TeV 100 TeV

VLHC

LHC

Tevatron


SLHC Detector EnvironmentSLHC Detector EnvironmentSLHC Detector EnvironmentSLHC Detector Environment

LHC SLHC

s 14 TeV 14 TeVL 1034 1035

100 1000

Bunch spacing dt 25 ns 12.5 ns

N. interactions/x-ing ~ 20 ~ 100 dNch/d per x-ing ~ 100 ~ 500

Tracker occupancy 1 5Pile-up noise 1 ~2.2Dose central region 1 10

Bunch spacing reduced 2x. Interactions/crossing increased 5 x. Pileup noise increased by 2.2x if crossings are time resolvable.

2/( sec)cm 2/( sec)cm 1 /fb yr 1 /fb yr

Ldt


VLHC Detector EnvironmentVLHC Detector EnvironmentVLHC Detector EnvironmentVLHC Detector Environment

LHC VLHC

s 14 TeV 100 TeVL 1034 1034

100 100

Bunch spacing dt 25 ns 19 ns

N. interactions/x-ing ~ 20 ~ 25** dNch/d per x-ing ~ 100 ~ 250**

Tracker occupancy 1 2.5**Pile-up noise 1 2.5**Dose central region 1 5**

** 130 mB inelastic cross section, <Nch> ~ 10, <Et> = 1GeV

2/( sec)cm 2/( sec)cm 1 /fb yr 1 /fb yr

Ldt


CMS HCALsCMS HCALsCMS HCALsCMS HCALsHad Barrel: HB

Had Endcaps:HE

Had Forward: HF

HB

HE

HF

HO


HCAL : HE and HBHCAL : HE and HBHCAL : HE and HBHCAL : HE and HB

HE HB


Optical Design for CMS HCALsOptical Design for CMS HCALsOptical Design for CMS HCALsOptical Design for CMS HCALs

Common Technology for HB, HE, HO


HF detectorHF detectorHF detectorHF detector

HAD (143 cm)

EM (165 cm)

5mmTo cope with high radiation levels (>1 Grad accumulated in 10 years) the active part is Quartz fibers: the energy measured through the Cerenkov light generated by shower particles.

Iron calorimeter Covers 5 > > 3 Total of 1728 towers, i.e.2 x 432 towers for EM and HAD x segmentation (0.175 x 0.175)


HF Fiber stuffing at CERNHF Fiber stuffing at CERNHF Fiber stuffing at CERNHF Fiber stuffing at CERN


Issues for SLHCIssues for SLHCIssues for SLHCIssues for SLHC

Radiation Damage

Rate Effects

Bunch ID determination

Activation/access


Scintillator - Dose/DamageScintillator - Dose/DamageScintillator - Dose/DamageScintillator - Dose/Damage

Scintillator under irradiation forms Color centers which reduce the Collected light output (transmission loss). LY ~ exp[-D/Do], Do ~ 4 Mrad

Current operational limit ~ 5 Mrad


Radiation damage to scintillatorsRadiation damage to scintillatorsRadiation damage to scintillatorsRadiation damage to scintillators

0 1 2 3 4 510

-2

10-1

100

101

102

103 Dose in ECAL and HCAL for L = 1035 and One Year

Dos

e(M

rad)

Barrel doses are not a problem. For the endcaps a technology change may be needed for 2 < |y| < 3 for the CMS HCAL.

Dose per year at SLHV

ECAL

HCAL


Bunch ID: CMS HB Pulse Shape Bunch ID: CMS HB Pulse Shape Bunch ID: CMS HB Pulse Shape Bunch ID: CMS HB Pulse Shape

100 GeV electrons. 25ns bins. Each histo is average pulse shape, phased +1ns to LHC clock

12 ns difference between circled histo’s no problem with bunch ID


Timing using calorimeter pulse shapeTiming using calorimeter pulse shapeTiming using calorimeter pulse shapeTiming using calorimeter pulse shapeC

alcu

late

d ev

ent

tim

e (i

n cl

ock

cyc

les)

CMS HE

Calculated event time (vertical scale) vs actual event time. CMS HE, 100GeV pions. Watch pile-up though. The faster the calorimeter, the less important pile-up will be.

2003 Test Beam


HF Cerenkov Calorimeter Pulse ShapeHF Cerenkov Calorimeter Pulse ShapeHF Cerenkov Calorimeter Pulse ShapeHF Cerenkov Calorimeter Pulse Shape

25 ns

CMS HF Calorimeter 2003 Test Beam

Intrinsically very fast


Activation and Radiation Exposure LimitsActivation and Radiation Exposure LimitsActivation and Radiation Exposure LimitsActivation and Radiation Exposure Limits


Activation in “forward” RegionActivation in “forward” RegionActivation in “forward” RegionActivation in “forward” Region


Activation in “endcap” RegionActivation in “endcap” RegionActivation in “endcap” RegionActivation in “endcap” Region


Profitable R&D Directions?Profitable R&D Directions?Profitable R&D Directions?Profitable R&D Directions?

Cerenkov calorimeters are rad-hard and fast good candidates for future colliders• Quartz fiber or plate

• Gas cerenkov

New photon detectors low cost, small, rad-hard• Red-sensitive HPDs

• Geiger-mode photodiodes

New scintillator materials rad-hard

New directions: • A number of new calorimeter concepts, some more

realistic for a CMS calorimetry upgrade than others


A• Blue Tiles

• Current materials

• Em 408-425nm

• Blue Green WLS

• WLS faster than Y11

• EM 490-520nm

• Use in muon system and for triggering

• Areas of low/moderate radiation

B/C• Blue/Green – Green

Tiles

• Em 490-510nm

• Green/Yellow WLS

• EM 550-560nm

• Benefits:

• Stays short of the “crevasse” in the transmission curve.

• In a region of “better” HPD QE.

• Potentially good system response.

Scintillator R&D ApproachesScintillator R&D ApproachesScintillator R&D ApproachesScintillator R&D Approaches


Optical Attenuation in FiberOptical Attenuation in FiberOptical Attenuation in FiberOptical Attenuation in Fiber


Example of excitation and emission measurement: Example of excitation and emission measurement: Standard vs New MaterialsStandard vs New Materials

Example of excitation and emission measurement: Example of excitation and emission measurement: Standard vs New MaterialsStandard vs New Materials

204T-1 ex, em K27

050

100150200

250300350

400450

300 400 500 600

wavelength nm

int emission

excitation

201T-1 ex, em

0

100

200

300

400

500

600

700

300 400 500 600

wavelength nm

int emission

excitation

309A-1 ex, em DSB1 wls

0

50100

150200

250

300350

400

350 400 450 500 550 600

wavelength nm

int emission

excitation

305A-1 ex, em DSB2 wls

0

50100

150

200250

300

350400

450

350 400 450 500 550 600

wavelength nm

int emission

excitation


Averaged PMT pulses for a standard scintillation tile Averaged PMT pulses for a standard scintillation tile read out with multiclad WLS fibersread out with multiclad WLS fibers

Averaged PMT pulses for a standard scintillation tile Averaged PMT pulses for a standard scintillation tile read out with multiclad WLS fibersread out with multiclad WLS fibers


DEP HPD with red photocathode ECAL Avalanche Photodiode

Advantages

Fits into existing RBX and Electronics Same power supply and control Small development costs

optimize AR coatingreduce dark count?

Disadvantages

Only 7% quantum efficiency in red Cost per tube is high ($150/ch)

Advantages

85% quantum efficiency in the red Understood and in use in CMS Cost is only $30/ch No HV, bias is 200-500 V

Disadvantages

New fiber attachment system Modified RBX design Interface to QIE Need bias and temperature control

Two Reasonable Choices

Readout for Red ScintillatorReadout for Red ScintillatorReadout for Red ScintillatorReadout for Red Scintillator


ECAL electronics?

QIE with modifications?

Off-Axis detector may use Pixelated APD (Ray Yarema)

Comparison of HPD vs APD must be in the context of the preamplifier (noise and gain) as well as details of the APD operation: Gain, temperature, capacitance, etc…

Prisca Cushman has made a number of numerical studies to compare APDs and HPDs

APD & Choice of electronicsAPD & Choice of electronicsAPD & Choice of electronicsAPD & Choice of electronics


• Compare red sensitive HPD to APD

• Design and build fiber interface to APD

• Design and build interface of APD to QIE

• Optimize APD operating conditions to HCAL

RadHard Scintillator RadHard Scintillator Readout UpgradeReadout Upgrade

RadHard Scintillator RadHard Scintillator Readout UpgradeReadout Upgrade

A Number of investigations will be carried out in 2004


New Photodetector: SiPMsNew Photodetector: SiPMsNew Photodetector: SiPMsNew Photodetector: SiPMs

The Silicon Photomultiplier is a Russian invention, reported by Boris Dolgoshein and colleagues at Moscow Engineering and Physics Institute, Lebedev Physical Institute, and Pulsar Enterprise (Moscow).

Ref: NIM A 504 (2003) 48 - 52; NIM A 442 (2000) 187-192

SiPM consists of ~10**3 micropixels, size ~30microns, with very thin (0.75 micron) high field depletion layer.

Pixels are resistively isolated, each working in limited Geiger mode as “binary” devices. The pixels signals are ganged together by aluminum strips and the summed signal is effectively analog, with dynamic range limited by the number of pixels (<~ 60% occupancy for good linearity).

Gain ~10**6 Bias voltage ~25V Broad spectral sensitivity

Sees single pe, and resolves adjacent many-pe peaks with low noise

Works In high magnetic fields Time resolution ~30ps for 10 pe

Size ~few mm Cost $10 in large lots ($50 in small lots)

5000 are at DESY for TESLA tile-fiber hadron calorimter


SiPMsSiPMsSiPMsSiPMs

Where might we use (or have used) SiPMs?

CMS HCAL, except possibly for dynamic range. Present SiPM: ~100. If possible to increase pixel density to 2500 mm-2 and area to (1 cm)**2 ==> 6 x 10**4 dynamic range. Ease FE electronics (?). No HV cables or supply. Cheap phototransducer.

Use with RadHard Green/Red tile-fiber calorimeter for High eta HE S-CMS for SLHC

TOF for particle ID (a bit far-out)

I will try to use them (with small blocks of scintillator) for source-garaged verifiers for all the installed CMS drivers. A nice minor use of the high-gain, low-voltage and low cost. But hand-held survey meters can do this job adequately, as we do at CDF!

Use our imaginations…..


SiPMsSiPMsSiPMsSiPMs

Issues:

How Rad tolerant? (and how much would that matter?)

Are pixel / device recovery times adequate for LHC (and SLHC) crossing rates? [higher pixel density ==> smaller C and Q per pixel, shorter RC. So probably worth pursuing.]

Availability, delivery times. I’m still waiting after nearly 2 months for a few samples @$50 per device from Elena Popova, to whom Dolgoshein referred me. Dolgoshein says PULSAR will do another large production run in April. I might be able to piggyback a certain number on that order. Boris did not say what micropixel count and density.

Will PULSAR develop larger area SiPM? higher micropixel density?


HE: Quartz plate and and HE: Quartz plate and and Matching WLS FiberMatching WLS Fiber

HE: Quartz plate and and HE: Quartz plate and and Matching WLS FiberMatching WLS Fiber

HE: Replace HE scintillaor in layers closest to IP with quartz plate for η > 1.5. We will also need to match the quartz light output to a WLS fiber.

Iowa, Fairfield and Mississippi will do a number of trials in 2004 to see if this proposal is viable.


• The HF detector at LHC has high-OH core, high NA, hard plastic cladding, QP fibers (quartz core plastic cladding)

• Iowa group has tested fibers at LIL CERN 500 MeV electrons NIM A490 (2002) 444

• The HF detector will receive about 100 Mrad/year at eta=5 with accumulated dose 1-2 Grad/10 years

HF CalorimetryHF CalorimetryHF CalorimetryHF Calorimetry


• The HF region will have much higher doses than LHC environment (1-2 Grad/year and about 20 Grad/10 years)

• For high radiation doses must use no organic materials

• We will test special quartz fibers with quartz cladding. These fibers are Silica/Silica, High-OH, UV enhanced, QQ (Quartz core/ Quartz cladding) with different type of buffer materials (Acrylic, Polymide, Aluminum) with different diameters (300, 600, and 800 micron)

• Fibers will be given 5 x 1017 n/cm2, about 20 Grad(neutrons with energy > 0.1 MeV)in IPNS (Intense Pulsed Neutron Source)at Argonne National Laboratory

• The range of 10-50 Grad will also be available at this facility.

• We will test the induced attenuation vs wavelength, transmission of Xe light in the 350-800 nm range after irradiation. Also measure the tensile strength before and after the irradiation.

• These measurements will be important for SLHC R&D for HCAL, HE, HF, ZDC, & CASTOR forward detectors.

HF CalorimetryHF CalorimetryHF CalorimetryHF Calorimetry


Iowa Polymicro New Rad-hard Quartz Iowa Polymicro New Rad-hard Quartz fiber/plate projectfiber/plate project


Goals:

Determine if optical fibers are capable of functioning in a radiation environment 10 times the present CMS detector levels.

If yes, then explore what fiber designs would be best for the CMS detector upgrade.

Test candidate fiber materials –core, clad and buffer to determine suitable materials.

Fabricate/Purchase test fibers with materials from step 3.

Test candidate fibers for radiation hardness, mechanical and optical performance before and after irradiation.

Develop preliminary fiber specifications




Fiber Designs – conduct review of the fiber designs suitable for the CMS application. From this review, select the focus of the design and testing activities. Focus should be on the fiber design offering the most chances of success. There are way too many fiber designs to test all.


Gas Cerenkov S/V LHC Forward Gas Cerenkov S/V LHC Forward CalorimeterCalorimeter

Gas Cerenkov S/V LHC Forward Gas Cerenkov S/V LHC Forward CalorimeterCalorimeter

O. Atramentov, J.Hauptman, N. Akchurin

•CMS Note-00-007 “Velocity-of-light gas …”

•Jim Virdee suggested we design calorimeter for SLHC

•This work funded by LC R&D consortium

Oleksiy Atramentov, John Hauptman, Nural Akchurin, Oesa Walker, Rohit Nabyar

•CMS Note-00-007 “Velocity-of-light Gas …”

•Jim Virdee suggested that we design a calorimeter for the SLHC

•This work funded by LC R&D consortium (Luminosity monitor, 1.4 ns, 1MGy/y, large e/gamma backgrounds)

•For SLHC, think of tungsten, hex rods, 1 meter depth, beta butylene,


Calorimeter designCalorimeter designCalorimeter designCalorimeter design

The Cerenkov light is generated by shower particles that cross gas gaps between absorber elements.

e-

• Shower particles co-move with the Cherenkov light as two overlapped pancakes. The width of these pancakes is about 12 ps.

• Inside surfaces must be highly reflective at grazing incidence.


Gas Cherenkov Calorimeter:Gas Cherenkov Calorimeter:Gas Cherenkov Calorimeter:Gas Cherenkov Calorimeter:

Gas has index of refraction n = 1+, ( 10-3), therefore Cherenkov angle is small

and energy threshold for electrons is high

MeV2.112

e

th

mE

• The Cherenkov photon signal exits the calorimeter volume at the velocity of light

• Decay products from radioactivation of the calorimeter mass are below Eth and therefore invisible

• A calorimeter made wholly of gas and metal cannot be damaged by any dose of radiation.

05.2θsinC


Production of Cherenkov photons by 10 GeV electron transversing 2mm gas conduits in Pb (a simulation)

Photon ProductionPhoton ProductionPhoton ProductionPhoton Production


Geometries: now being simulated Geometries: now being simulated – G3 and G4 – G3 and G4

Geometries: now being simulated Geometries: now being simulated – G3 and G4 – G3 and G4

•Tubes – reflecting on inside

•Hex rods – reflecting on outside

•“Lasagna” separated functions of absorber material and reflecting surface

•Other geometries …


DREAM Calorimetry:DREAM Calorimetry:DREAM Prototype (Upstream)DREAM Prototype (Upstream)

DREAM Calorimetry:DREAM Calorimetry:DREAM Prototype (Upstream)DREAM Prototype (Upstream)

The detector is made from 4 mm X 4mm copper tubes with a 2.5 mm dia hole in them. There are 19 hexagonal towers (38 Readout channels). There are 5580 copper tubes total.

The detector weighs 1030 kg.

2 m deep copper is ~10 interaction lengths.

Effective rad.length is 20.10 mm and the Moliere rad is 20.35 mm

16.2 cm


DualReadout = Scintillator + DualReadout = Scintillator + QuartzQuartz

DualReadout = Scintillator + DualReadout = Scintillator + QuartzQuartz

69.3% Cu, scintillating fiber 9.4%, Cherenkov 12.6% and air is 8.7%

3 scintillating and 4 clear fibers per hole.

Scintillator and the quartz fiber bundles are readout separately with R580 PMTs.

There are 270 tubes per tower.

Flat-to-flat measures 72 mm and contains >93% EM shower.

38 PMTs are housed in a readout box behind the detector. Wratten 3 filter on scintillators.

Scintillating fiber

Quartz fiber

SCSF-81J Kuraray, QP Polymicro, PJR-FB750 Toray.


100 GeV Pions100 GeV Pions100 GeV Pions100 GeV Pions

Scintillator(rms/mean)=12.3%

Quartz(rms/mean)=19.0%

S(e/pi)=1.22

Q(e/pi)=1.56

Q(e/h) ~5S(e/h) ~1.4


Energy Resolution (100 GeV Energy Resolution (100 GeV pions)pions)

Energy Resolution (100 GeV Energy Resolution (100 GeV pions)pions)

The scintillating section of the detector measures 100 GeV pions with 12.3% resolution before correction.

Once the fluctuations in the EM energy deposition is removed using the information from the quartz section, the hadronic energy resolution improves.

After this correction, the energy resolution improves dramatically to 2.6%.

Preliminary


RemarksRemarksRemarksRemarks

The combination of scintillator and clear fibers gives a good handle to measure the electromagnetic fraction for each event which can be used to improve hadronic energy resolutions significantly.

If the beam energy is known, like test beams, the energy resolution can be improved by a factor of ~4-5. But this assumes the particle energy is already known. Beware.

If, on the other hand, Ebeam is treated as unknown, the improvement is ~2-3. Still a big factor.

At the limit, the energy resolution for electrons and the pions need to be the same once this source of fluctuation is removed.

Analysis continues. Interesting but probably not applicable for a CMS

upgrade


Hadron

The light color is solid metal. Detectors that sample the shower

are shown in darker color.Detector near front end is for EM shower

Some forward-angle calorimeters for the LHC will receive huge amounts of radiation, ~100 Grad.

Need detector to be fast, simple, and radiation hard.

PPAC – a Rad Hard DetectorPPAC – a Rad Hard DetectorPPAC – a Rad Hard DetectorPPAC – a Rad Hard Detector


Iowa PPAC - a radiation hard Iowa PPAC - a radiation hard detectordetector


Three flat plates, separated by 2 mmMiddle plate at high voltageOuter plates hold atmospheric pressure Filled with 10-40 torr of a suitable gas

Timing resolution better than 300 ps

Will test energy and time resolution at the Advanced Photon Source (APS) at Argonne

A simple and reliable device for samplingshowers from hadrons and photons.

For highest radiation levels must be made with no organic materials


This PPAC detector concept can be developed as a candidate for luminosity monitor, HF and ZDC at SLHC.




Planned tests with double PPAC•Test with EM showers using 80 ps

bunches of 7 GeV electrons from the Advanced Photon Source, at Argonne National Laboratory

•Test with low energy hadron showers using the 120 GeV proton test beam at Fermilab




PPAC vs. Scintillating tilePPAC vs. Scintillating tilePPAC vs. Scintillating tilePPAC vs. Scintillating tile

A radiation hard PPAC could be made as a drop in replacement for a scintillating tile in HE.

It would fit in the same space and produce a similar (but faster) signal

Front End electronics would have to be redesigned


Iowa/Fairfield Iowa/Fairfield Secondary Emission Sensor Modules for Secondary Emission Sensor Modules for

CalorimetersCalorimeters



Basic Idea:A Dynode Stack is an Efficient High Gain Radiation Sensor

High Gain & Efficient (yield ~1 e/mip for CsSb coating)Compact (micromachined metal<1mm thick/stage)Rad-Hard (PMT dynodes>100 GRads)FastSimple SEM monitors proven at accelerators Rugged/Could be structural elements (see below)Easily integrated compactly into large calorimeters

low dead areas or services needed.

SE Detector Modules Are Applicable to:- Energy-Flow Calorimeters- Polarimeters- Forward Calorimeters






Basic SEM Calorimeter Sensor Module Form:

“A Flat PMT without a Photocathode”:

- The photocathode is replaced by an SEM film on Metal.

Stack of 5-10 metal sheet dynodes in a metal “window”-ceramic wall vacuum package about 5-10 mm thick x 10-25 cm square, adjustable in shape/area to the transverse shower size.

Sheet dynodes/insulators made with MEMS/micromachining techniques are newly available, in thicknesses as fine as ~0.1 mm/dynode

Ceramic wall thickness can be ~2mm, moulded and fired from commonly available greenforms (Coors, etc.)

Outer electrodes (SEM cathode, anode) can be thick metal, serving as absorber and structural elements.





CalorimetersCalorimetersSchematic of SEM Calorimeter Sensor Module

brazed ceramic insulators

10 mil HV insulator (polymer)

signal (male)

signal (female) -optional for stacking

film bias resistor chain

1.8 mm thick Cu

HV connector

HV female socket (optional for stacking)

stackable

-2kV

signal out6 dynodes (200 µm thick @ 0.8mm spacing) 50ž

2 silicon micro channel plates

Cs3Sb SEM Surface

1cm

15 cm

top view

ceramic

Cu plate


AcknowledgementsAcknowledgementsAcknowledgementsAcknowledgements

Thanks to Tiziano Camporesi, Jim Freeman and Dan Green

Slides were contributed by many of our US CMS Collaborators

• Prisca Cushman• Virgil Barnes• Yasar Onel• Dave Winn• Lucien Crimaldi• John Hauptman• Nural Akchurin• Randy Ruchti and Dan Karmgard

I invite all members of CMS HCAL to contribute to the upgrade of our calorimeter for SLHC

cms hcal r&d

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