NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Presentation at the ALCPG-SLAC

Meeting

Progress Report of Work at Colorado

January, 2004

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

LCD-ALCPGLCD-ALCPG

THE GROUP

Shirley Choi, Bradford Dobos, Tyler Dorland, Eric Erdos,

Jeremiah Goodson, Jack Gill, Jason Gray

Andrew Hahn, Eric Kuhn, Alfonso Martinez

Kyle Miller, Uriel Nauenberg, Joseph Proulx,

Jesse Smock

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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ACTIVITIES

Develop a new geometrical structure in calorimetry that is cost effective and will have the energy and time resolution required in a Linear Collider environment.

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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The Calorimeter Scintillator tile layers 5 x 5 cm2, 2mm thick. Alternate layers are offset. See next slide. Effective 2.5 x 2.5 cm2 spatial resolution. Reduces by 25 the number of channels when

compared to 1 cm2 tile structures.

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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The Basic Geometrical Structure

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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The Tile Arrangement

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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The Calorimeter test unit we have built Cosmic Ray Trigger

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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New Readout Equipment We have LabView Installed. University money. We have purchased readout from National Instruments. We are calibrating the ADCs. Learning the power of LabView. We already know we have problems with calorimeter; low pulse height

from cosmic muons. It is time to have fun investigating. A lot of work in the near future.

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Test Calorimeter in Box Test Pulse Digitized LabView

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Labview Pulse Height Analyzer for a Pulser

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Moliere RadiusComparison of Photons Spatial Resolution

with no offset case Resultant Spatial Resolution Comparison Net Mass and Jet Directional Resolution Can we Separate Hadrons from the Shower Energy Flow Resolution of 2.5 x 2.5 cm2

versus 1 cm2 tile structures.

Issues on Spatial Resolution

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Standard Dev. of the Shower Energy Distribution

5 Gev Photon 75 GeV Photon Shower of Dist. vs P

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Moliere Radius

The Moliere Radius is defines as containing 90% of the

Energy. This is roughly equivalent to 1.63 x = 1.63 x 1.5

Moliere Radius = 2.5 cm.

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Spatial Resolution 1 dimension(z)

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Mass of the Z0 e e No Offset Offset

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Directional Biases in the Shower Fit red = 00 dip angle blue = 450 dip angle

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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After 1st order Corrections

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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direction

Understanding the Fit Bias

fitted direction

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Z0 Mass Fit after Bias Correction no offset offset

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Photon Energy Spectra from Reactions at 1 TeV

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Low Energy End of the Photon Energy Spectrum from Reactions

at 1 TeV

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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100 GeV Shower Deposition Resolution

No Conditions 2% of shower in few layers

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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More on Resolution

Some evidence that resolution deteriorates as dip angle

increases. Being investigated.

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Distance Between Particles at Calorimeter

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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What have we learned so far

Loosing light from curved (2.5 cm. radius) fibers. Our colleagues from Italy have indicated fibers need to be annealed. We have an oven. Will study this problem next.

We can gang 3 or 5 layers together without much loss in resolution. We need to study this more carefully for 1-2 GeV photons.

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Issues in Resolution

Dynamic Range 0.5-250 GeV. Can we achieve

good energy resolution over this spectrum in the electromagnetic calorimeter device. Number of readout bits needed.

Can we achieve good spatial directional resolution in the low energy end of the spectrum.

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

LCD-ALCPGLCD-ALCPG

• We need to study the resolution effectiveness via We need to study the resolution effectiveness via simulation. Need to understand our present simulation. Need to understand our present resolution.resolution.

• We need to study the light collection efficiency, We need to study the light collection efficiency, uniformity. This will be done with cosmic rays. uniformity. This will be done with cosmic rays. Tyvek versus Radiant Mirror paper. Tyvek versus Radiant Mirror paper.

• We need to study how to construct these in a simple We need to study how to construct these in a simple manner to maintain cost effectiveness while manner to maintain cost effectiveness while maintaining accuracy. maintaining accuracy.

What Needs to be StudiedWhat Needs to be Studied

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Continue, What Needs to be Studied• We need to develop Extruded Scintillator techniques

with the Fermilab folks to determine whether we can maintain thickness dimensions to within a fraction of a mm.

• Can we inscribe grooves 5 cm apart in Extruded Scintillator and can we maintain lateral dimensions to a mm.

• We need to develop Pattern Recognition and Energy Flow algorithms that use our different geometrical arrangement. We are now starting this effort.

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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Continue, What Needs to be Studied

• We need to compare our algorithms with those of the silicon based study to determine cost benefit alternatives.

• Study electronics readout; APDs, HPDs,VLPCs. We have started a collaboration with Fermilab’s electronics group.

• This requires cryogenic techniques we do not have. Are investigating collaborative arrangements with Fermilab to provide cryogenics help.

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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A LOT OF WORK IN NEAR FUTURE

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

LCD-ALCPGLCD-ALCPG

NLC – The Next Linear Collider Project

Colorado Univ. – Boulder, Jan., 2004

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