PowerPoint Presentation

Gamma-400 new calorimeter status Oscar AdrianiINFN and University of Florence

Trieste, May 5th, 2013

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013Starting pointThe starting point is the presentation at the Moscow meeting in FebruaryNo change in the proposed structureNew results from:Simulation (Rejection factor)Test beam data analysisMeanwhile we have provided to Russian colleagues the description of the pre-prototype, that will be sent in RussiaThe electrical interface document is under preparation by Trieste peoplesThe calorimeter proposal should be updated according to the discussion under way in Russia:increase the weight of the payloadIncrease the top surface of the calorimeter to increase the gamma acceptanceScaling of the calorimeter is feasible and should be studiedO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013The proposed configuration: CsI(Tl) ~ 1680 kgCubesNNN202020 L of small cube (cm)3.6*Crystal volume (cm3)46.7Gap (cm)0.3Mass (Kg)1683N.Crystals8000Size (cm3)78.078.078.0Depth (R.L.) (I.L.)3939391.81.81.8Planar GF (m2sr) **1.91(* one Moliere radius)(** GF for only one face)Very deep!!!!O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013The readout sensorsMinimum 2 Photo Diodes are necessary to cover the whole huge dynamic range 1 MIP107 MIPS, since Emax in one crystal ~ 0.1 Etot

Large Area Excelitas VTH2090 9.2 x 9.2 mm2 for small signals Inserted in the simulation!Small area 0.5 x 0.5 mm2 for large signals

Two independent readout channels will be usedDetails later on!

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013Mechanical idea

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 20135Simulation FLUKA based simulationPlanar generation surface on one of the 5 facesResults valid also for the other faces!Carbon fiber in between crystals (3 mm gaps)Large photodiode is inserted on the crystal in the simulationWe take into account also the energy release in the Photodiode itself!Results are valid for every face since scintillation light is isotropically emittedElectrons:100 GeV 1 TeV rangeProtons:100 GeV 100 TeV range~ 100 10.000 events for each energyNo mis-calibration effects are included in the simulationLight collection efficiency and PD quantum efficiency are included in the simulationFor the moment we have very low statistics for high energy particles (huge computing time is necessary.)

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Selection efficiency: ~ 36%

GFeff ~ 3.4 m2srElectronsElectrons 100 1000 GeV(Measured Energy Real Energy) / Real EnergyCrystals onlyCrystals + photodiodesNon-gaussian tails due to leakages and to energy losses in carbon fiber material RMS~2%Ionization effect on PD: 1.7%O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 20137ProtonsEnergy resolutionSelection efficiencies: 0.1-1TeV ~ 35% 1TeV ~ 41% 10TeV ~ 47%

GFeff0.1-1TeV ~ 3.3 m2srGFeff1TeV ~ 3.9 m2srGFeff10TeV ~ 4.5 m2sr

100 TeV40%(Measured Energy Real Energy) / Real Energy

10 TeV39%(Measured Energy Real Energy) / Real Energy

100 1000 GeV32%(Measured Energy Real Energy) / Real Energy

1 TeV35%(Measured Energy Real Energy) / Real EnergyO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 20138Proton rejection factorMontecarlo study of proton contaminationusing CALORIMETER INFORMATIONS ONLYPARTICLES propagation & detector response simulated with FLUKAGeometrical cuts for shower containmentCuts based on longitudinal and lateral development

LatRMS4protonselectronsLONGITUDINALLATERAL155.000 protons simulated at 1 TeV : only 1 survive the cuts

The corresponding electron efficiency is 37% and almost constant with energy above 500gev

Mc study of energy dependence of selection efficiency and calo energy distribution of misreconstructed events

10TeV1TeVl1O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

E(GeV)E3dN/dE(GeV2 ,s-1 )Protons in acceptance(9,55m2sr)/dEElectrons in acceptance(9,55m2sr)/dEvelaElectrons detected/dEcalProtons detected as electrons /dEcalContamination :0,5% at 1TeV2% at 4 TeVAn upper limit90% CL is obtainedusing a factor X 3,89Proton rejection factorO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 201310The prototypes and the test beamsTwo prototypes have been built at INFN Florence, with the help of INFN Trieste, INFN Pisa and University of Siena.

A small, so called pre-prototype, made of 4 layers with 3 crystals each12 CsI(Tl) crystals, 2.5x2.5x2.5 cm3

A bigger, properly called prototype, made of 14 layers with 9 crystals each126 CsI(Tl) crystals, 3.6x3.6x3.6 cm3

Both devices have been tested at CERN SPS (pre-prototype in October 2012 and prototype in January-February 2013)O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 201311The prototype

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013The prototype

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 201313Noise

CN evaluated with disconnected channels and 4-sigma cut

WITH and WITHOUT CN subtractionO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013Noise studiesThe noise of the 16 CASIS channels is correlated, but not in a clear way (for example the correlation coefficient for the disconnected channels is not very high)When we have a shower it is not so clear how to compute the CMNDisconnected channels do not give a good estimateIt is not so clear how to identify the signals without signals (if there are.)Result The CMN subtraction does not give clear advantages, mainly if showers are presentO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013Hit definition

S=ADC-PED-CN S=ADC-PED Hit defined by 4-sigma cut on SO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

First layer used to select Z=1 and Z=2 nuclei. Z=1Z=230GVO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Layer with MAX hitShower START First layer with a hit > 15 MIP30GVZ=1

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Layer with MAX hitShower START First layer with a hit > 15 MIP30GVZ=2

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Z=2Z=130GVTotal energy deposit VS shower-starting layerMaximal containment when starting-layer == 2O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Z=2Z=130GVAverage longitudinal profile(Starting layer == 2)O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013Energy resolution30 GVStarting-layer ==2

Z=2Z=158% (fit)37% (fit)O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013Calibation of the crystals

Before calibrationAfter calibrationO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013Response uniformity of the crystals

~14% UniformityO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013A strange effect.

To be checked!!!Particles hitting the PD?Effect seen by Ferm????O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013A glance at prototype's TB data

H: Z=1 =330He: Z=2=1300Li: Z=3 =3000Be: Z=4=5300B: Z=5=8250C: Z=6=12000NZ=7=16000HeLiBeBCNPlease remind that this is a calorimeter!!!!Not a Z measuring device!!!!O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 201327Energy deposit for various nuclei

Charge is selected with the placed-in-front tracking system

Good Linearity even with the large area PD!PreliminaryCourtesy of Pi-Si groupO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Courtesy of Pi-Si groupO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013How to improve the calorimeter performances?We could try to see the Cherenkov light produced in the crystals by the electromagnetic component of the showerImprovement of the e/p rejection factorImprovement of the hadronic energy resolution (DREAM project)

Problem: different response to electromagnetic and hadronic particles (e/h>1)Effect: worsening of energy resolutionSolution: try to compensate the hadronic response to make it equal to electromagnetic oneSoftware compensation developed in the last few yearsHardware compensation (~late 1980)

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013Some ideas for the Cherenkov lightUse of SiPM to detect Cherenkov lightDiscrimination btw Fast Cherenkov light and Slow Scintillation light possible with dedicated fast sampling electronicsUse of SiPM highly sensitive in the UV regionUse of UV transmitting filters on the SiPM faceto block the largely dominant scintillation lightPossible use of 3 SiPM for each crystal on orthogonal facesto have a good uniformity in the response for particles hitting the different calorimeters facesDedicated test beam at INFN-Frascati in October700 MeV electron beamsFew crystals equipped with UV-transmitting filters and SiPM

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013Which Calorimeter can we put in Gamma-400?Basic idea: remove CC1, use only CC2Few layers of silicon in between the first few layers of crystals to obtain the desired angular resolution are possibleRemind: Basic CCUBE: 0.78m x 0.78m x 0.78m=0.475 m3, 8000 crystals, 1683 kgStarting russian design (from Sergey design):9400 crystals + 2 X0 CC1=9400+784 equivalent crystals=10180 crystals, 2140 kgPossible proposal: A Dream.: 1m x 1m x 0.8 m: 13.300 crystals, 2790 kgStill a Dream: 1m x 1m x 0.7 m: 11.600 crystals, 2440 kgA Realistic Dream: 1m x 1m x 0.65 m: 10.800 crystals, 2260 kgA very good det.: 1m x 1m x 0.6 m: 9.975 crystals, 2090 kg

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013ConclusionAn homogeneous, isotropic calorimeter looks to be an optimal tool for Gamma-400-NThe status of the project is quite advanced:SimulationPrototypesTest beamsNext steps:R&D on the Cherenkov light during 2013 and 2014Possibly enlarge the prototypes dimensionsLow energy electron test beam in INFN Frascati in autumn 2013Test at Serpukhov with high energy protons and electrons in 2014R&D for the Calibration system of every crystal is certainly necessary!Possible synergy and help from the russian colleagues for this item?

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013BackupO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

= 1.15 cmShower starting point resolutionO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Shower Length (cm)Signal / EnergyProton 1 TeVO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Shower Length (cm)Signal / EnergyProton 10 TeVO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Calibration curves Shower Length (cm)100 1000 GeV1 TeV10 TeVSignal / EnergyO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013Counts estimation, electronsG400 configuration: CsI(Tl), 20x20x20 crystals Size: 78.0x78.0x78.0 cm3 gap 0.3 cmTaking into account: geometrical factor and exp. duration + selection efficiency 80%

ExperimentDurationPlanar GF (m2 sr)Calo s(E)/ECalo depthe/p rejection factorE > 0.5 TeVE > 1 TeVE > 2 TeVE > 4 TeVCALET5 y0,12~2%30 X010531936119510AMS0210 y0,5**~2%16 X0103 **26606509179484ATIC30 d0,25~2%18 X0

104

1092130FERMI10 y1,6@300 GeV * 0,6@800 GeV *~15%8,6 X010459864254500G40010 y8,5~0,9%39 X010645230386540135021436* efficiencies included** calorimeter standaloneO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013ExperimentDurationPlanar GF (m2 sr)e selCalo s(E)/ECalo depthE > 0.1 PeVE > 0.5 PeVE > 1 PeVE > 2 PeVE > 4 PeVe convpHepHepHepHepHeCALET5 y0,120,8~40%30 X0 1,3 l01461389102311000,5CREAM180 d0,430,8~45%20 X0 1,2 l04139331100000,4 CT*ATIC30 d0,250,8~37%18 X0 1,6 l055000000000,5 CT*G40010 y8,50,8~17%39 X0 1,8 l016521156249791083261326609210210,4 ~ kneeCounts estimation, protons and helium nuclei* carbon targetPolygonato modelG400 configuration: CsI(Tl), 20x20x20 crystals Size: 78.0x78.0x78.0 cm3 gap 0.3 cmTaking into account: geometrical factor and exp. duration + selection efficiency 80%O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Total silicon signals / Total crystal signals ElectronsO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Emax ~ 0.1 EtotO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

E = 17%Energy resolutionO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013ElectronsVery simple geometrical cuts:The track should point to a fiducial surface (two crystals on the side are eliminated)The maximum of the shower should be well contained in the fiducial volumeThe length of the shower should be at least 40 cm (~21 X0)

Efficiency of these cuts~ 36% Effective geometrical factor ~ (0.78*0.78*p)*5*e m2 sr= 9.55*e m2 sr

Gfeff~3.4 m2sr (including the efficiency)calorimeterO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Electron #1O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Electron #1cmcmLongitudinal profileSignalIntegral SignalO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

( Measured Energy Real Energy ) / Real EnergyElectrons 100 1000 GeVEnergy resolutionNon gaussian tails due to leakages and to the carbon fiber material RMS~2%O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

( Measured Energy Real Energy ) / Real EnergyElectrons 100 1000 GeVCrystals onlyCrystals + Photodiodes1.7% differenceO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013ProtonsVery simple geometrical cuts:A good reconstruction of the shower axisAt least 50 crystals with >25 MIP signal

Energy is reconstructed by using the shower length measured in the calorimeter, since leakage are important (1.8 lI for perpendicular incidence)

calorimeterO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Proton #1O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Proton #1cmcmLongitudinal profileSignalIntegral SignalShower starting point is identified with ~1 cm resolutionO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Shower Length (cm)Signal / EnergyProton 100 1000 GeVShower length can be used to reconstruct the correct energyRed points: profile histogramFitted with exponential functionsTo get the correct energy measurementO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Proton energy resolution100 1000 GeV

1 TeV10 TeV32%35%39%

100 TeV40%( Measured Energy Real Energy ) / Real Energy

O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013Efficiencies and Geometrical factorsGF(1 face) = 0.78*0.78*p m2 sr= 1.91 m2 sr GF(5 faces)= 1.91*5 m2 sr = 9.55 m2 sr

EnergyeEnergy resolutionGfeff (m2sr)100-1000 GeV35%32%3.31 TeV41%34%3.910 TeV47%38%4.5Selection cuts can be tuned to optimize the parametersRoughly speaking: GF>3 m2sr with good energy resolution!!!!O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013Some caveats.Please note:The theoretical previsions for the knee region are really very much spread out!Pre-PAMELA-ATIC-CREAM scenarium: simple single power low up tp the knee regionPost-PAMELA_ATIC_CREAM scenarium: the models have to exaplain the change in slope around 200 GV/c, and the different slopes btw protons and heliumDifferents sources, different injectiuon spectra, closeby sources,,non standard propagation scenarium.

Many works have been published in the last few years:Thoudam and HorandelZatsepin, Panov, Sokolskaya. Bernard, Delahaye, Keum, Liu, Salati, TailletYuan, Zhang, BiTomassetti Blasi, Amato, Donato, Serpico

As a results, the expected spectrum around knee is unclear, and probably higher than the one expected up to few years agoPossible structures may arise?Direct measurementes are really essential!With the propsed calorimeter, we could measure well above the knee

I can give you references if you are interestedO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

A spot on the pre-prototype test beam (m beam)PD OnlyPD OnlyPD OnlyPD OnlyO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013A spot on the pre-prototype test beam (m- beam)

PD OnlyPD OnlyPD OnlyPD OnlyO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

A spot on the pre-prototype test beam (e- beam)PD OnlyPD OnlyPD OnlyPD OnlyO. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Energy resolution12.8 GVStarting-layer ==2Z=2Z=182% (RMS)39% (RMS)O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013

Energy resolution12.8 GVStarting-layer ==2Z=2Z=160% (fit)34% (fit)O. Adriani Gamma-400 New calorimeter status Trieste, May 5h, 2013