calorimetry cornell-alcpg

NLC – The Next Linear Collider Project

Colorado Univ. - Boulder

Calorimetry Cornell-ALCPG

Calorimetry Detector Study

Plans at Colorado

Uriel Nauenberg

for

The Colorado Group

The Cornell ALCPG Meeting

July , 2003



Calorimetry Purpose

What Drives the Calorimetry Quality in SUSY

In the measurement of 2nd Chargino and

Heavy Neutralinos we need to measure

low energy edge of the Z and higgs.

Need excellent energy resolution for the

ence excellent em energy resolution.



SUSY 2nd Chargino

l l combined mass+ -



SUSY 2nd Chargino

Z Energy Mass Cut Z Correct Z

0

Z h



Scintillator Geometry

x-y view z view



Fiber Placement

Light Correction

Light Correction



Photon Shower

Energy Leakage

30 Layers 35 Layers



Photon Shower

Energy Leakage

40 Layers 45 Layers



Photon Shower

Variations in Energy leakage

30 Layers 45 layers



Calorimeter Simulation

Calorimeter Energy Resolution2 mm scint., 1.75 mm W, 1 mm space

30 Layers 35 Layers




Calorimeter Energy Resolution2 mm scint., 1.75 mm W, 1 mm space

40 Layers 45Layers




Calorimeter Energy Resolution1.75 mm W, 1 mm space

1mm scint. 2 mm scint.45 LAYERS



Photon Showers

Photon Shower Radii 5 GeV 15 GeV



Photon Shower

Photon Shower Radii 50 GeV 75 GeV



Photon Shower Radius



Photon Showers

Method of Obtaining Space Point

Generate Showers with GEANT 4.0

Calculate Position =

x E Ei i

i



Photon Showers

Reconstruction of Position from Energy Sharing



Photon Shower

Position Resolution when Tiles are Offset



Photon Showers

Tiles not offset Tiles offset

About 1.5 cm from edge



Photon Showers

Spatial Resolution Near Center of Tile

Tiles not offset Tiles offset



Photon Shower

Position Resolution Using Forty Layers

5 cm tiles



Photon Showers

Resolution in the track slope near center of tile

Tiles Not Offset Tiles Offset



Photon Shower

Tile Areas of Simulation



Photon Showers

Resolution

3 layers read together 5 layers read together40 layers total



Particle Separation

Standard Model SUSY



Particle Separation

Betweeen s Betweeen and Charged

Particles



Calorimeter-ALCPG

We have built a cosmic ray telescope 15x15 cm

Plan to use 1.3 GeV Muons

Plan to Study

Light Collection Efficiency for a straight fiber

versus a curved fiber using Tyvek and using

3M Super Reflector as a function of the distance

from the fiber.

2



Calorimeter-ALCPG

Plan to Study

Fiber Readout with Avalanche PhotoDiodes;study voltage stability, temperature stability;light loss versus fiber length.

Study uniformity of response of variousphotodiodes.



Calorimeter-ALCPG

Cosmic Ray rate observed in Boulder is 2

per cm per minute which is twice the expected rate at sea level.

We are building a calorimeter module to study the content of the cosmic rays at Boulder’s altitude while testing our concept of spatial resolution and while waiting for beam availability.

2



Calorimeter Test Stand




5 cm scintillator pieces with fiber




5 cm scintillator pieces with fibers epoxied




Computer Readout

Camac crate and ADC from SLAC

Investigating getting Crate Controller

PCI card interface from Fermilab or

purchase from Kinetic Systems.




Planned Measurements

We get ~ 30 cts /h in 5x5 mm

Measure light collection uniformity across 5x5 cm scintillator piece for the 2 kinds of fiber insert

geometry.

2



Calorimeter Design

Good Resolution (11%/E) Needs 45 layers 770 K 5x5 cm pieces Needs to be Optimized with SIMULATION

7 x 7 cm may be O.K.

2

2



Calorimeter Pieces Measurements

Measured 13 ordered pieces

x = 50.007 0.020 mm

y = 49.984 0.039 mm

excellent size uniformity



Calorimeter R&D

Going to work with a company to determine whether we can meltscintillator grooves with wire

currents.

We did this very well with lead platesand thin aluminum sheets. Then imprint thin grooves 5 cm apart




Avalanche Photodiodes Characterize Pulse Height Stability vs Voltage Temperature Rate Uniformity, Linearity, etc.

calorimetry cornell-alcpg

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