The Collider Detector at Fermilab (aka CDF) Jennifer Pursley Intermediate Seminar Oct. 28, 2003

Goal of this Talk: • To give an overview of the general characteristics of a modern particle detector Goal of CDF: •Accurately measure Standard Model parameters, especially for heavy bosons and the top quark •Look for new physics (beyond SM) •Best high energy detector until LHC comes online (~2007)

Accelerating p-pbar

CDF – Run 2

Artist’s rendition of the Detector: •Silicon •COT •Calorimeters •Muon detectors

Silicon Detector • Heart of any modern particle detector • Purpose: to accurately measure decay vertices of short-lived particles • CDF uses 3 levels of Si: – L00 (Layer 00) – SVX II (Silicon Vertex – Layers 0-4) – ISL (Intermediate Silicon Layer) • Comprises most of the channels in CDF: ~800,000 out of about 1.5 million

Schematic of Si Detector

• Placed directly on top of beamline to provide better vertexing capabilities • Made of single sided silicon wafers • Readout electronics mounted on top of silicon Layer 00

SVX II • SVX I proved essential in CDF Run I • Primary component of Si detector • Provides the most vertex information • Made up of: – 12 triangular wedges (ladders) – Each with 5 layers, numbered 0-4 • Uses double sided Si wafers, alternating 3 stereo 0-90 ° with 2 small angle stereo 1.2° • Same electronics setup as L00

One Completed SVX Barrel Length: 29.0 cm Inner Radius: 2.44 cm Outer Radius: 10.6 cm

ISL • Outermost layer of Si; lies between Si detector and rest of detector • Purpose: extends farther out than SVX and L00 to make measurements at higher η (pseudorapidity) • Has 3 layers • Single sided Si • Same electronics setup as L00 and SVX

ISL From the Inside

ISL with SVX and L00 Length: 174 cm Inner Radius: ~20 cm Outer Radius: ~28 cm

Silicon Insertion into CDF

COT – Central Outer Tracker • Open cell drift chamber • Chamber filled with gas (Ar-Et-CF

4

) • Wires strung the length of the chamber are charged • Particles passing through drift chamber ionize gas, producing electrons which are collected by the charged wires • Has 8 Superlayers, each with 12 layers • 4 Superlayers are axial, 4 at stereo ± 3°

Stringing Wires in the COT Channels ~30,000 Inner Radius: ~44 cm Outer Radius: ~132 cm

Inserting COT into CDF

Central Calorimeters • 2 kinds of calorimeters: – EM: alternating slabs of lead and scintillating material (plastic) to stop electrons – Hadron: alternating slabs of steel and scintillating material to stop the heavier particles • Scintillation light collected by PMTs (photomultiplier tubes) • Endplugs also contain EM and hadron calorimeters

• Outer layers of CDF • Made up of drift chambers and scintillation counters Muon Detectors

The Finished Product