aceleradores - uniovi · 15m de longitud y pesa 35 tm. •existen 20 km de estos imanes...
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La energía almacenada por los todos los imanes del LHC a 14 TeV es de 10.4 GJ (g ~ 7000)• 3.1 m/s más despacio que la luz, 11000 vueltas/s!!! Comparando con los aceleradores previos:
• Campo magnético: x 2 (~8T)• Energía del haz: x 7 (7+7= 14TeV)• Energía almacenada: x 200 (b = 0.999999 99 ·c )
10 GJ A380 @ 700 km/h
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Ejemplo, visto en las
técnicas III en la práctica
de la cámara de Niebla:
Speed (units of c) Lorentz factor (g)
0.000 1.000
0.250 1.033
0.300 1.048
0.400 1.091
0.500 1.155
0.600 1.250
0.700 1.400
0.750 1.512
0.800 1.667
0.866 2.000
0.900 2.294
0.990 7.089
0.999 22.366
0.99995 100.000
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Cathode Ray Tube (CRT) has the basic
ingredients of a scientific accelerator:
Particle source
Acceleration scheme
Focusing scheme
Beam steering
Beam observation
( )dp
F q E v Bdt
= = + ´
rr r rrParticle momentum p given by Lorentz Force:
Particle momentump =r
Electric fieldE =r
Magnetic fieldB =r
Particle chargeq =Particle velocityp =r
dp / dt =
3838
High Beam Energy with Super-Conducting
Magnets: Handle High Currents and Large Stored Energy
24.9.09 38
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•Se usan electroimanes dipolares para acelerar los
protones y mantener su trayectoria. Cada uno tiene
15m de longitud y pesa 35 Tm.
•Existen 20 km de estos imanes superconductores y
para enfriarlos a 1.9 K se usan 96 Tm de He
superfluido
•Se requieren campos magnéticos de 8.3 T para
mantener la trayectoria de los protones, cada uno con
una corriente de 11,700 A. En una casa familiar
medio se usan menos de 70 A.
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LHC: Super-Conducting RF
Cavities
R. Assmann 41
time
RMS bunch length 11.2 cm 7.6 cmRMS energy spread 0.031% 0.011%
450 GeV 7 TeV2.5 ns
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1232 main
dipoles +
3700
multipole
corrector
magnets
392 main
quadrupoles +
2500 corrector
magnets
Regular arc:
Magnets
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Regular arc:
Cryogenics
Supply and recovery of
helium with 26 km long
cryogenic distribution
line
Static bath of superfluid
helium at 1.9 K in cooling
loops of 110 m length
Connection via service
module and jumper
R. Schmidt
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El espacio más vacío del Sistema Solar
10-13 atmósferas, ¡diez veces menos que la presión de la Luna!
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Insulation vacuum for
the cryogenic
distribution line
Regular arc:
Vacuum
Insulation vacuum for the
magnet cryostats
Beam vacuum for
Beam 1 + Beam 2
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Examples of damage from beams
Lead block
accidentally put into
a p beam
Entry and exit holes of an electron beam
impacting on a spoiler
Crossing angle ≳ ± 140 μrad
Quadrupoles start at L* = 23 m from IP
Two beam pipes, horizontally separated by 19.4 cm
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5555
To get to 7 TeV: Synchrotron – circular
accelerator and many passages in RF cavitiesLINAC (planned for several hundred GeV - but not above 1 TeV, e.g ILC)
LHC circular machine with energy gain per turn ~0.5 MeV
acceleration from 450 GeV to 7 TeV takes about 20 minutes
....requires deflecting magnets (dipoles)
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The Charged Particle Beam• The accelerator generates, accelerates, transports and
delivers beams to the user (e.g. HEP exp).
• Beam are transported in ultra-high vacuum.
• A beam can consist of individual bunches.
• Each “bunch” is an ensemble of charged particles that are
grouped together in space and carry the same (very similar)
energy (±0.1%).
• Radio-frequency fields are used to accelerate particles
coherently and to group them together longitudinally.
• Magnetic fields are used to guide the beam particles on well
defined paths and to focus them into a small transverse area.
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LHC: Longer Term Future
• 2010 – 2011: Physics Run1@3.5 TeV (7 TeV Ecm)
• 2012: Physics Run1@4 TeV (8 TeV Ecm)
• 2013 – 2014: Shutdown: Repair of interconnects
• 2015 – 2018: Physics Run2@6.5 TeV (13 TeV Ecm)
• 2019 – 2020: Shutdown. Upgrades and repairs
• 2021 – 2023: Physics Run3@7 TeV (14 TeV Ecm)
• Long term:
– HL-LHC upgrade >2024? 5-10 times higher luminosity
same beam energy
– HE-LHC upgrade higher beam energy
magnets do not exist yet…57
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The choice of particle type•Hadron colliders
(p-pbar or pp or ions)
“Discovery” machines
Tevatron 1983-2011
p-p: 2 x 1TeV
LHC 2021
p-p: 2 x 7 TeV
VLHC study (?)
p-p: 2 × 20 TeV
2 ×100 TeV
•Lepton colliders
(e-e+)
LEP ECM~210GeV
“Precision” studies
Linear collider study
e+e-: 0.5-1.5 TeV
(eg, gg, e-e- options)
mm collider study
2 × 0.15/4.0 TeV
Plasma accelerators
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International Linear ColliderILC Facts
• Cavity temperature: 2 K
• Detectors: 2, based on complementary technologies
• Site:To be determined
• ILC Community:Nearly 300 laboratories and universities around the world are involved in the ILC: more than 700 people are working on the accelerator design, and another 900 people on detector development. The accelerator design work is coordinated by the Global Design Effort, and the physics and detector work by the World Wide Study.
• Collisions:Between electrons and their antiparticles, positrons, in bunches of 5 nanometres (5 billionths of a metre) in height each containing 20 billion particles and colliding 14,000 times per second
• Energy:Up to 500 GeV
with an option to upgrade to 1 TeV
• Acceleration Technology:16,000 superconducting accelerating cavities made of pure niobium
• Length:Approximately 31 kilometres, plus two damping rings each with a circumference of 6.7 kilometres
• Accelerating Gradient: 31.5 megavolts per metre
http://www.linearcollider.org/
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Luminosidad
Triplet
aperture
and
collimation
setup
accuracy
Loss limits:
collimation,
(UFO’s), …
Beam-
beam,
brightness
& robust-
ness limits
http://lpc.web.cern.ch/lpc/lumi.html
The design luminosity of the LHC is
1034 cm−2s−1=10nb-1s-1 providing a
bunch collision rate of 40 MHz
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