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

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

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

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

The Finished Product