# Presentation: 324907

## Overview of theTevatron Collider

- Elvin Harms
- Fermilab Antiproton Source
- _[Harms@fnal.gov](mailto:Harms@fnal.gov)__   X4387_

## Thank You!

## Accelerator Complex Overview

*Accelerator Complex Overview*

**Tevatron**

**NuMI**

**Main Injector**
**Recycler**

**Antiproton source**

**Proton source**

**Switchyard 120**

**MiniBooNe**

## Accelerator Complex Overview

*Accelerator Complex Overview*

**Proton source**

**Antiproton source**

- AP3

- P2

- P1

- AP1

- A1

- MI-8

**SY120**

**MiniBooNe**

**NuMI**

**Main Injector**
**Recycler**

**Tevatron**

## Piecing the machine together

*Piecing the machine together*

- Cascade of accelerators
- Different technologies are more efficient in different energy regimes
- Ion sources
- Injectors
- Collectors
- Transfer lines
- End accelerator

## Piecing the machine together

## Accelerator Complex Overview

- Proton source
- Cockroft-Walton preaccelerator 750 keV

## Accelerator Complex Overview

- Proton source
- Drift tube Linac 116 MeV

- Proton source
- Side-coupled cavity Linac 400 MeV

## Accelerator Complex Overview

- Proton source
- Rapid-cycling Booster synchrotron 8 GeV

## Accelerator Complex Overview

- Main Injector/Recycler 8 to 150 GeV

## Accelerator Complex Overview

- Antiproton source
- Antiproton production target station 120 GeV
- Debuncher 8 GeV
- Accumulator 8 GeV

## Accelerator Complex Overview

- Tevatron
- Superconducting synchrotron 980 GeV

## What makes up a synchrotron?

- Two primary components
- Radiofrequency system
- Impart energy to the particle beam
- Acceleration
- Maintain beam’s energy (synchrotron light)
- Maintain structure (Colliding beams)
- Magnet system
- Keep the beam focused
- Keep the beam on course

## Magnets

- Electromagnets
- Conventional
- Water or air-cooled
- Copper or aluminum coils
- Iron shapes and contains the field
- Superconducting
- Liquid helium cooled
- Higher fields > higher energies
- Coil placement critical to field
- Permanent

## Magnets

- Gradient
- “Combined” function

## Magnets

- Separated function
- Focusing and bending are done by separate magnets

## Magnets

- Flavors
- Dipoles
- Quadrupoles
- Correctors
- ‘trim’ dipoles
- (skew) quadrupoles
- Sextupoles
- even higher order
- Special purpose
- Injection/Extraction
- Light sources

## Magnets

- Flavors

- Quadrupole

- Sextupole

## Radiofrequency systems

- Low level
- Frequency
- Amplitude (voltage)
- feedback
- High level
- Accelerating cavities
- Amplification

## What we’re doing right now

- Collider Run II
- Tevatron operating at 980 GeV
- 36 X 36
- 36 ‘bunches’ of protons
- 36 ‘bunches’ of antiprotons
- The only game on the planet
- LHC at CERN ~2007

## Shot set-up – a 3-ring circus

*Shot set-up – a 3-ring circus*

| Tevatron | Main Injector | Pbar source |
| --- | --- | --- |
| Set at 150 GeV | Check/correct closed orbit | Cool Pbars into core & maintain stability |
| Verify/correct A150 line tune | Check/correct extraction positions | Accept reverse protons, maximize transmission from MI, minimize injection oscillations |
| Load protons | Provide protons for tuneup of beam lines | Redistribute core longitudinally for unstacking |

## Shot set-up - Tevatron

- Back to 150 GeV
- Reverse injection to MI

## Shot set-up – Main Injector

- Orbit/tunes set
- Reverse protons to Pbar
- Protons to Tevatron

## Shot set-up – Antiproton source

- ‘cool’ the core
- maintain stability
- tranverse emittances
- longitudinally
- tools
- Stochastic cooling
- Stabilizing RF
- dampers

## Shot set-up – Antiproton source 

- Reverse Proton tune up

## Shot set-up – Antiproton source 

- Minimize Accumulator Turn-by-Turn 		oscillations

## Doing Shots

- Load protons one bunch at a time
- 3 trains of 12 bunches
-  Unstack from core
- Pbars to MI
- Accelerate to 150 GeV & Coalesce
- Transfer to Tevatron/cog

## Doing Shots

- Unstacking
- 2.5 MHz (h=4) RF system
- 4 bunches at a time
- low initial voltage
- increase voltage to narrow bunches
-  lock to MI RF
- bunch at 53 MHz (h=84)
- extract
- ~30 seconds per transfer

## Doing Shots

- Unstacking & Extraction
- Re-bunch at 53 MHz on extraction orbit
- Shuttered fast kicker magnet (1.6s)

## Doing Shots

- Transfer to MI
- Acceleration to 150 GeV
- Coalescing

## Doing Shots

- Coalescing
- 4-53 MHz bunch _trains_ into 4-2.5 MHz _bunches_

## Tevatron Loading scheme

- Protons are loaded first - 1 bunch at a time and spaced in 3 groups of 12
- Antiprotons are loaded four bunches at a time for a total of 9 transfers from the Accumulator to MI to the Tevatron
- The 36 bunches of Pbars are equally spaced in 3 groups of 12 around the Tevatron

## What is Luminosity?

- Collider performance is measured by the *Luminosity*
*Intensities*
*Emittances*
*Beta function*
*Frequency of bunches crossing*
*Units of cm**-2**s**-1*

## How are we doing?

- Best store to date: 2.64 E31 cm-2s-1
- Goal: 4 E31 by 30 September

## How are we doing?

## What is Integrated Luminosity?

- Luminosity delivered over time
- Peak instantaneous luminosity – cm-2s-1
- Store duration - seconds
- Measured in inverse nano, pico, femto barns
- 1 barn 10-24 cm2

## What is Integrated Luminosity?

## Luminosity

## Other terms/topics

- Bunches, buckets, and batches
- Cell
- Emittance
- House
- Lattice
- ‘Shot’ lattice
- Low beta
- Channel 13
- ???