7c95a4850af784843c0cc02bc370ae86.ppt
- Количество слайдов: 75
Particle Accelerators or Making subatomic particles go very fast! Philip Burrows John Adams Institute, Oxford University Visiting Oxford Fellow, Canterbury University
Large Hadron Collider (LHC) Largest, highest-energy particle collider CERN, Geneva Philip Burrows Otago University, Dunedin 13/10/08
In case you missed it … All eyes on collider as it comes to life Will atom smasher signal end of the world? Le LHC, un succès européen à célébrer Large Hadron Collider e International Linear Collider a caccia del bosone di Higgs Wir stoßen die Tür zum dunklen Universum auf Philip Burrows Otago University, Dunedin 13/10/08
Large Hadron Collider (LHC) Largest, highest-energy particle collider CERN, Geneva Philip Burrows Fi rs tp ro to ns Se pt em be r 10 th Otago University, Dunedin 13/10/08
Philip Burrows Otago University, Dunedin 13/10/08
Large Hadron Collider (LHC) Largest, highest-energy particle collider CERN, Geneva Philip Burrows Otago University, Dunedin 13/10/08
The fastest racetrack on the planet The protons will reach 99. 9999991% speed of light, and go round the 27 km ring 11, 000 times per second Philip Burrows Otago University, Dunedin 13/10/08
The emptiest vacuum in the solar system Ten times more atmosphere on the Moon than inside LHC beam pipes Philip Burrows Otago University, Dunedin 13/10/08
The coldest places in the galaxy The LHC operates at -271 C (1. 9 K), colder than outer space. A total of 36, 800 tonnes are cooled to this temperature. The largest refrigerator ever Philip Burrows Otago University, Dunedin 13/10/08
The hottest spots in the galaxy When the two beams of protons collide, they will generate temperatures 1000 million times hotter than the heart of the sun, but in a minuscule space Philip Burrows Otago University, Dunedin 13/10/08
The biggest detectors ever built Philip Burrows Otago University, Dunedin 13/10/08
The biggest detectors ever built To sample and record the debris from up to 600 million proton collisions per second, we are building gargantuan devices to measure particles with micron precision. Philip Burrows Otago University, Dunedin 13/10/08
The most extensive computer system To analyse the data tens of thousands of computers around the world are being harnessed in the Grid Philip Burrows Otago University, Dunedin 13/10/08
First event 10 September 2008 Philip Burrows Otago University, Dunedin 13/10/08
Why build accelerators?
Uncovering the origin of the universe Big Bang now Older …. . larger … colder …. less energetic Philip Burrows Otago University, Dunedin 13/10/08
Telescopes to the early universe Big Bang now Older …. . larger … colder …. less energetic Philip Burrows Otago University, Dunedin 13/10/08
Composition of the universe Philip Burrows Otago University, Dunedin 13/10/08
Why build accelerators? • Want to see what matter is made of • Smash matter apart and look for the building blocks • Take small pieces of matter: accelerate them to very high energy crash them into one another • LHC: protons crashing into protons head-on Philip Burrows Otago University, Dunedin 13/10/08
Why colliders? The higher the energy, the smaller the pieces we can reveal in the collisions Philip Burrows Otago University, Dunedin 13/10/08
Why colliders? The higher the energy, the smaller the pieces we can reveal in the collisions 60 mph Philip Burrows stationary Otago University, Dunedin 13/10/08
Why colliders? The higher the energy, the smaller the pieces we can reveal in the collisions 60 mph 30 mph Philip Burrows stationary 30 mph Otago University, Dunedin 13/10/08
Why colliders? The higher the energy, the smaller the pieces we can reveal in the collisions For speeds well below 60 mph stationary 30 mph light speed: same damage! Philip Burrows Otago University, Dunedin 13/10/08
Why colliders? Philip Burrows Otago University, Dunedin 13/10/08
Why colliders? Now try this with protons moving near light speed stationary Philip Burrows Otago University, Dunedin 13/10/08
Why colliders? Now try this with protons moving near light speed stationary Philip Burrows Otago University, Dunedin 13/10/08
Why colliders? For the same physics, 14, 000 times the energy stationary of each proton in the LHC Philip Burrows Otago University, Dunedin 13/10/08
Why colliders? Most of the energy goes into carrying the momentum forward Philip Burrows Otago University, Dunedin 13/10/08
Why colliders? All the energy available for smashing up the protons Philip Burrows Otago University, Dunedin 13/10/08
High energy is critical Size of structure we can probe with a collider like LHC = h/p (de Broglie, 1924) h = Planck’s constant = 6. 63 x 10**-34 Js p = momentum of protons The larger the momentum (energy), the smaller the size Philip Burrows Otago University, Dunedin 13/10/08
How to accelerate protons to high energies? protons carry electric CHARGE feel electric force Philip Burrows Otago University, Dunedin 13/10/08
Accelerating protons Apply an electric field accelerate! Philip Burrows Otago University, Dunedin 13/10/08
Accelerating protons Apply an electric field accelerate! Philip Burrows Otago University, Dunedin 13/10/08
Accelerating protons Apply an electric field accelerate! - + V Philip Burrows Otago University, Dunedin 13/10/08
Accelerating protons Apply an electric field accelerate! - + V Philip Burrows Otago University, Dunedin 13/10/08
Accelerating protons Apply an electric field accelerate! - + V Philip Burrows Otago University, Dunedin 13/10/08
Accelerating electrons - + V Philip Burrows Otago University, Dunedin 13/10/08
Accelerating electrons - + V Philip Burrows Otago University, Dunedin 13/10/08
Accelerating electrons Energy ~ voltage - + V Philip Burrows Otago University, Dunedin 13/10/08
The early days Philip Burrows Otago University, Dunedin 13/10/08
The early days - Philip Burrows + Otago University, Dunedin 13/10/08
The early days X-rays Philip Burrows Otago University, Dunedin 13/10/08
First use of an accelerator in medicine! Mrs. Roentgen’s hand Philip Burrows Otago University, Dunedin 13/10/08
Cockcroft – Walton Accelerator 800, 000 Volts Philip Burrows Otago University, Dunedin 13/10/08
Van de Graaff Accelerator 1500, 000 Volts Philip Burrows Otago University, Dunedin 13/10/08
How many Volts? ? ? Voltage [Volts] Philip Burrows Size probed [metres] Otago University, Dunedin 13/10/08
How many Volts? ? ? Voltage [Volts] Size probed [metres] 1000, 000 000 1 Philip Burrows (Mega) Otago University, Dunedin 13/10/08
How many Volts? ? ? Voltage [Volts] Size probed [metres] 1000, 000 000 1 (Mega) 1000, 000 Philip Burrows (Giga) 0. 000 000 000 1 Otago University, Dunedin 13/10/08
How many Volts? ? ? Voltage [Volts] Size probed [metres] 1000, 000 000 1 (Mega) 1000, 000 (Giga) 1000, 000 (Tera) Philip Burrows 0. 000 000 000 1 Otago University, Dunedin 13/10/08
How many Volts? ? ? Voltage [Volts] Size probed [metres] 1000, 000 000 1 (Mega) 1000, 000 (Giga) 1000, 000 (Tera) 0. 000 000 000 1 LHC: 7000, 000 000 000 01 7 trillion Volts 10**-20 metres Philip Burrows Otago University, Dunedin 13/10/08
How to reach LHC energies? • We need 7000, 000 Volts /proton beam How to do this? ? Philip Burrows Otago University, Dunedin 13/10/08
How to reach LHC energies? • We need 7000, 000 Volts /proton beam How to do this? ? ? Philip Burrows Otago University, Dunedin 13/10/08
How to reach LHC energies? • We need 7000, 000 Volts /proton beam How to do this? ? ? • Would need 10, 000, 000 AA batteries Philip Burrows Otago University, Dunedin 13/10/08
How to reach LHC energies? • We need 7000, 000 Volts How to do this? ? ? • Would need 10, 000, 000 AA batteries • 5 x 10**11 m = 3 x Earth’s orbit radius around Sun Philip Burrows Otago University, Dunedin 13/10/08
How to reach LHC energies? • We need 7000, 000 Volts How to do this? ? ? • Would need 10, 000, 000 AA batteries • 5 x 10**11 m = 3 x Earth’s orbit radius around Sun • $30, 000, 000 – discount for bulk buy? ! Philip Burrows Otago University, Dunedin 13/10/08
Accelerating Technology • Batteries have too low voltage per metre: 1. 5 Volts per 5 cm = 30 Volts / m (‘gradient’) Philip Burrows Otago University, Dunedin 13/10/08
Accelerating Technology • Batteries have too low voltage per metre: 1. 5 Volts per 5 cm = 30 Volts / m (‘gradient’) • Forefront accelerating gradients ~ 30 MILLION Volts / m • Hence largest accelerator (LHC) is **ONLY** 27 km long! Philip Burrows Otago University, Dunedin 13/10/08
Accelerating Technology • Batteries have too low voltage per metre: 1. 5 Volts per 5 cm = 30 Volts / m (‘gradient’) • Forefront accelerating gradients ~ 30 MILLION Volts / m • Hence largest accelerator (LHC) is **ONLY** 27 km long! • Accelerate using radio-frequency EM waves launched into metal cavities … • Protons gain energy by ‘surfing’ the waves Philip Burrows Otago University, Dunedin 13/10/08
Niobium Accelerating Structures Philip Burrows 59 Otago University, Dunedin 13/10/08
Human surfer Philip Burrows Otago University, Dunedin 13/10/08
Subatomic surfer E + + Electromagnetic wave Philip Burrows Otago University, Dunedin 13/10/08
Large Hadron Collider (LHC) Philip Burrows Otago University, Dunedin 13/10/08
More about LHC • 27 km tunnel is 50 – 150 m below ground Philip Burrows Otago University, Dunedin 13/10/08
More about LHC • 27 km tunnel is 50 – 150 m below ground • Two beams of protons circulating in opposite directions • Beams controlled by 1800 superconducting magnets (8 T) Philip Burrows Otago University, Dunedin 13/10/08
More about LHC • 27 km tunnel is 50 – 150 m below ground • Two beams of protons circulating in opposite directions • Beams controlled by 1800 superconducting magnets (8 T) • Each beam contains 3000 ‘bunches’ of protons • Each bunch contains 200 billion protons Philip Burrows Otago University, Dunedin 13/10/08
More about LHC • 27 km tunnel is 50 – 150 m below ground • Two beams of protons circulating in opposite directions • Beams controlled by 1800 superconducting magnets (8 T) • Each beam contains 3000 ‘bunches’ of protons • Each bunch contains 200 billion protons • 600 million proton-proton collisions per second Philip Burrows Otago University, Dunedin 13/10/08
Large Hadron Collider (LHC) Will give us a first look at new physics landscape. Panoramic view, but with low resolution: ‘broad-band’ survey: A precision microscope (‘narrow-band’ instrument) is needed to illuminate the features in the new landscape … Philip Burrows Otago University, Dunedin 13/10/08
International Linear Collider 31 km Philip Burrows 68 Otago University, Dunedin 13/10/08
Linear Colliders for electrons + positrons Stanford Linear Accelerator Center (California) Philip Burrows Otago University, Dunedin 13/10/08
Accelerators Worldwide • High-energy accelerators 120 • Synchrotron radiation X-ray sources 100 Philip Burrows Otago University, Dunedin 13/10/08
Diamond: synchrotron source of X-rays Philip Burrows 71 Otago University, Dunedin 13/10/08
Accelerators Worldwide • High-energy accelerators 120 • Synchrotron radiation X-ray sources 100 • Radiotherapy 7700 • Biomedical research 1000 Philip Burrows Otago University, Dunedin 13/10/08
Clatterbridge: cancer treatment w protons Philip Burrows Otago University, Dunedin 13/10/08
Accelerators Worldwide • High-energy accelerators 120 • Synchrotron radiation X-ray sources 100 • Radiotherapy 7700 • Biomedical research 1000 • Industrial processing 1500 • Ion implanters, surface modification 7000 Total Philip Burrows 17, 500 Otago University, Dunedin 13/10/08
Large Hadron Collider (LHC) Philip Burrows Otago University, Dunedin 13/10/08
7c95a4850af784843c0cc02bc370ae86.ppt