Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States...

36
Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals Indiana University/Baton Rouge 6 – 17 January 2003 Elvin Harms Beams Division/Fermilab Harms@fnal. gov

Transcript of Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States...

Page 1: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

Real Accelerators: a facility overviewthe nuts and bolts…and gaskets and resistors

United States Particle Accelerator School – Accelerator FundamentalsIndiana University/Baton Rouge6 – 17 January 2003Elvin HarmsBeams Division/[email protected]

Page 2: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 2

Introduction

‘Scratch the surface’ overviewWhat goes into making a real working acceleratorPerspective of ‘big’ machinesPrinciples applicable to all types of acceleratorsInteractive

Page 3: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 3

Scale

Table topE. O. Lawrence

early cyclotron ‘dees’

Berkley, California USA

Page 4: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 4

Scale

Big machine

LHC – 27 kilometers

(under construction)

CERNGeneva,

Switzerland

Page 5: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 5

What makes up an Accelerator?

Two primary components– Magnet system

• Keep the beam focused• Keep the beam on course

– Radiofrequency system• Impart energy to the particle beam

AccelerationMaintain beam’s energy

(synchrotron light)Maintain structure (colliding beams)

Page 6: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 6

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• Ramp slowly• Coil placement critical to field

Permanent

Page 7: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 7

Magnets

Gradient or ‘Combined function’– Steering and focusing by a single element

Page 8: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 8

Magnets

Separated function– Focusing and bending are done by separate

magnets• Quadrupole for focusing• Dipole for bending

Page 9: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 9

Magnets

Flavors– Dipoles– Quadrupoles– Correctors

• ‘trim’ dipoles• (skew) quadrupoles• sextupoles• even higher order• Special purpose

– Injection/Extraction– Light sources

Page 10: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 10

Magnets

Flavors

Quadrupole Sextupole

Page 11: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 11

Magnets

Flavors– Undulator/Wiggler

Page 12: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 12

Magnets

Superconducting

Page 13: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 13

Radiofrequency systems

Low level– Frequency– Amplitude (voltage)– feedback

Page 14: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 14

Radiofrequency systems

High level– Amplification– Accelerating cavities

Page 15: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 15

Piecing the machine together

A true complex, not just a machine

Page 16: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 16

Piecing the machine together

Cascade of accelerators– Different technologies are more efficient in different

energy regimes• Ion sources• Injectors• Collectors• Transfer lines• End accelerator

Page 17: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 17

Piecing the machine together

Page 18: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 18

Piecing the machine together

Power– Accelerators require

lots of it!– Stable and reliable

source

Page 19: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 19

Piecing the machine together

Power– Magnets connected in series

• Distribution• Regulation/feedback loops• Current changes through a component leads to changes

in beam behavior (never better…)

Page 20: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 20

Piecing the machine together

Contain the beam in a pipeVacuum– Particles travel a long way while being accelerated/in

storage– Scattering by air can lead to reduced beam quality

• emittance growth• energy loss

Page 21: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 21

Piecing the machine together

Vacuum– Quality: 10-7 mbar and lower for

circular machines– Distributed pumping– Ion pumps, TSP’s, cryo

pumping– Pick the correct materials and

seals– Meticulous cleaning beforehand– UHV: bake the chamber in

place

Page 22: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 22

Piecing the machine together

Cooling– Virtually every component requires some sort of

external cooling, electronics, too– Water is most common medium– Superconducting components require cryogens– Coolant should be in as direct contact with heat load

as possible (best thermal transfer)

Page 23: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 23

Piecing the machine together

Water Cooling– Conventional magnet coils

typically have a coolant hole through middle of conductor

– Control the chemistry• Water must be low conductivity

(deionized) since water & current flow together

• Remove the dissolved oxygen• Minimize particulates – small

orifices– Regulate the temperature

Page 24: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 24

Piecing the machine together

Cryogenic Cooling– Superconducting

coils bathed in liquid helium at 4.6K or less

– Lots of refrigeration (significant power use)

– Low heat loss– Magnets are super

“thermos” bottles

Page 25: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 25

Piecing the machine together

Enclosure– Electrical and Radiation

hazards when operating– Personnel protection

Page 26: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 26

Piecing the machine together

Equipment housing– Want power supplies and other interface equipment

as close as possible, but accessible

Page 27: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 27

Keeping it all together / Making it work

Alignment– Keep it in line!

– Tevatron 150 to 800 GeV in 30 seconds

– 0 = 21s– C ~4 miles– > 1.4 million miles traveled

during acceleration alone

Page 28: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 28

Keeping it all together / Making it work

Alignment– Where is it?

• Position of components with respect to each other

• Macro-positioning

Page 29: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 29

Keeping it all together / Making it work

Alignment– Move it

• Reference system• Fixturing• Component stands• Remote positioning

Page 30: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 30

Keeping it all together / Making it work

Diagnostics– Where’s the beam, what does it look like, how many

particles?• Beam Position Monitor• Beam Loss Monitor• Profile Monitor/Wire scanner• Schottky detector• Toroid• Resistive Wall Monitor• Damper• …

Page 31: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 31

Keeping it all together / Making it work

Diagnostics

Page 32: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 32

Keeping it all together / Making it work

Diagnostics

Page 33: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 33

Keeping it all together / Making it work

Controls system– Monitor and Control– Timing– Fast response– Beam removal– Coordination– Human interface

Page 34: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 34

Where does the beam go?

Experiments / End Users– Internal to machine

• Interaction regions• Beam quality/size

Page 35: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 35

Where does the beam go?

Experiments / End Users– External

• Rate, energy, size, and location to deliver beam

– Single-turn– Resonant extraction– Synchrotron light

Page 36: Real Accelerators: a facility overview the nuts and bolts…and gaskets and resistors United States Particle Accelerator School – Accelerator Fundamentals.

USPAS - Winter 2003 36

Resources

People are the most important componentOther resources– Books– Schools, Workshops, conferences– Web