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87-458: The CLIC accelerator would use a novel two-beam acceleration technique at an acceleration gradient of 100 M V /m, and its staged construction would provide collisions at three centre-of-mass energies up to 3 TeV for optimal physics reach. Research and development (R&D) are being carried out to achieve the high precision physics goals under challenging beam and background conditions. CLIC aims to discover new physics beyond

174-420: A ⟹ a = F m , {\displaystyle \mathbf {F} =m\mathbf {a} \quad \implies \quad \mathbf {a} ={\frac {\mathbf {F} }{m}},} where F is the net force acting on the body, m is the mass of the body, and a is the center-of-mass acceleration. As speeds approach the speed of light , relativistic effects become increasingly large. The velocity of

261-433: A d t . {\displaystyle \mathbf {\Delta v} =\int \mathbf {a} \,dt.} Likewise, the integral of the jerk function j ( t ) , the derivative of the acceleration function, can be used to find the change of acceleration at a certain time: Δ a = ∫ j d t . {\displaystyle \mathbf {\Delta a} =\int \mathbf {j} \,dt.} Acceleration has

348-428: A ¯ = Δ v Δ t . {\displaystyle {\bar {\mathbf {a} }}={\frac {\Delta \mathbf {v} }{\Delta t}}.} Instantaneous acceleration, meanwhile, is the limit of the average acceleration over an infinitesimal interval of time. In the terms of calculus , instantaneous acceleration is the derivative of the velocity vector with respect to time:

435-408: A = lim Δ t → 0 Δ v Δ t = d v d t . {\displaystyle \mathbf {a} =\lim _{{\Delta t}\to 0}{\frac {\Delta \mathbf {v} }{\Delta t}}={\frac {d\mathbf {v} }{dt}}.} As acceleration is defined as the derivative of velocity, v , with respect to time t and velocity

522-606: A t v 2 ( t ) = v 0 2 + 2 a ⋅ [ s ( t ) − s 0 ] , {\displaystyle {\begin{aligned}\mathbf {s} (t)&=\mathbf {s} _{0}+\mathbf {v} _{0}t+{\tfrac {1}{2}}\mathbf {a} t^{2}=\mathbf {s} _{0}+{\tfrac {1}{2}}\left(\mathbf {v} _{0}+\mathbf {v} (t)\right)t\\\mathbf {v} (t)&=\mathbf {v} _{0}+\mathbf {a} t\\{v^{2}}(t)&={v_{0}}^{2}+2\mathbf {a\cdot } [\mathbf {s} (t)-\mathbf {s} _{0}],\end{aligned}}} where In particular,

609-406: A t = r α . {\displaystyle a_{t}=r\alpha .} The sign of the tangential component of the acceleration is determined by the sign of the angular acceleration ( α {\displaystyle \alpha } ), and the tangent is always directed at right angles to the radius vector. In multi-dimensional Cartesian coordinate systems , acceleration

696-418: A y = d v y / d t = d 2 y / d t 2 . {\displaystyle a_{y}=dv_{y}/dt=d^{2}y/dt^{2}.} The two-dimensional acceleration vector is then defined as a =< a x , a y > {\displaystyle {\textbf {a}}=<a_{x},a_{y}>} . The magnitude of this vector

783-479: A negative , if the movement is unidimensional and the velocity is positive), sometimes called deceleration or retardation , and passengers experience the reaction to deceleration as an inertial force pushing them forward. Such negative accelerations are often achieved by retrorocket burning in spacecraft . Both acceleration and deceleration are treated the same, as they are both changes in velocity. Each of these accelerations (tangential, radial, deceleration)

870-411: A standstill (zero velocity, in an inertial frame of reference ) and travels in a straight line at increasing speeds, it is accelerating in the direction of travel. If the vehicle turns, an acceleration occurs toward the new direction and changes its motion vector. The acceleration of the vehicle in its current direction of motion is called a linear (or tangential during circular motions ) acceleration,

957-429: A 12 GHz sequence and a local beam current as high as 100 A . Each 2.5 km-long Drive Beam linac is powered by 1 GHz klystron s . This produces a 148 μs-long beam (for the 1.5 TeV energy stage scenario) with a bunching frequency of 0.5 GHz. Every 244 ns the bunching phase is switched by 180 degrees, i.e. odd and even buckets at 1 GHz are filled alternately. This phase-coding allows

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1044-407: A given force decreases, becoming infinitesimally small as light speed is approached; an object with mass can approach this speed asymptotically , but never reach it. Unless the state of motion of an object is known, it is impossible to distinguish whether an observed force is due to gravity or to acceleration—gravity and inertial acceleration have identical effects. Albert Einstein called this

1131-458: A mass of 3 TeV is possible at CLIC. Due to the clean environment of electron-positron colliders, CLIC would be able to measure the properties of these potential new particles to a very high precision. Examples of particles CLIC could directly observe at 3 TeV are some of those proposed by the supersymmetry theory : charginos , neutralinos (both ~≤ 1.5 TeV), and sleptons (≤ 1.5 TeV). However, research from experimental data on

1218-450: A nucleus with an electric field gradient . While the barn never was an SI unit, the SI standards body acknowledged it in the 8th SI Brochure (superseded in 2019) due to its use in particle physics . During Manhattan Project research on the atomic bomb during World War II , American physicists Marshall Holloway and Charles P. Baker were working at Purdue University on a project using

1305-462: A particle accelerator to measure the cross sections of certain nuclear reactions. According to an account of theirs from a couple years later, they were dining in a cafeteria in December 1942 and discussing their work. They "lamented" that there was no name for the unit of cross section and challenged themselves to develop one. They initially tried to find the name of "some great man closely associated with

1392-443: A particle may be expressed as an angular speed with respect to a point at the distance r {\displaystyle r} as ω = v r . {\displaystyle \omega ={\frac {v}{r}}.} Thus a c = − ω 2 r . {\displaystyle \mathbf {a_{c}} =-\omega ^{2}\mathbf {r} \,.} This acceleration and

1479-408: A particle moving on a curved path as a function of time can be written as: v ( t ) = v ( t ) v ( t ) v ( t ) = v ( t ) u t ( t ) , {\displaystyle \mathbf {v} (t)=v(t){\frac {\mathbf {v} (t)}{v(t)}}=v(t)\mathbf {u} _{\mathrm {t} }(t),} with v ( t ) equal to

1566-531: A period of time. The total number of collisions will be directly proportional to the luminosity of the collisions measured over this time. Therefore, the collision count can be calculated by multiplying the integrated luminosity by the sum of the cross-section for those collision processes. This count is then expressed as inverse femtobarns for the time period (e.g., 100 fb in nine months). Inverse femtobarns are often quoted as an indication of particle collider productivity. Fermilab produced 10 fb in

1653-484: A rather unconventional design to reach the high linear accelerations required. CLIC is foreseen to be built and operated in three stages with different centre-of-mass energies: 380 GeV, 1.5 TeV, and 3 TeV. The integrated luminosities at each stage are expected to be 1  ab , 2.5 ab, and 5 ab respectively, providing a broad physics programme over a 27-year period. These centre-of-mass energies have been motivated by current LHC data and studies of

1740-535: A simple gauge extension beyond the Standard Model ; using vector boson scattering for giving insight into the mechanism of electroweak symmetry breaking; and exploiting the combination of several final states to determine the elementary or composite nature of the Higgs boson (reach of compositeness scale up to ~50 TeV). Direct pair production of particles up to a mass of 1.5 TeV, and single particle production up to

1827-420: A superconducting solenoid magnet with a field strength of 4 T . This magnetic field bends charged particles, allowing for momentum and charge measurements. The magnet is then surrounded by an iron yoke which would contain large area detectors for muon identification. The detector also has a luminosity calorimeter (LumiCal) to measure the products of Bhabha scattering events, a beam calorimeter to complete

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1914-471: A threshold scan around the top quark pair-production threshold (~350 GeV) to precisely determine the mass and other significant properties of the top quark. For this scan, CLIC currently plans to devote 10% of the running time of the first stage, collecting 100 fb. This study would allow the top quark mass to be ascertained in a theoretically well-defined manner and at a higher precision than possible with hadron colliders. CLIC would also aim to measure

2001-427: A vector tangent to the circle of motion. In a nonuniform circular motion, i.e., the speed along the curved path is changing, the acceleration has a non-zero component tangential to the curve, and is not confined to the principal normal , which directs to the center of the osculating circle, that determines the radius r {\displaystyle r} for the centripetal acceleration. The tangential component

2088-415: Is also used in all fields of high-energy physics to express the cross sections of any scattering process , and is best understood as a measure of the probability of interaction between small particles. A barn is approximately the cross-sectional area of a uranium nucleus. The barn is also the unit of area used in nuclear quadrupole resonance and nuclear magnetic resonance to quantify the interaction of

2175-410: Is broken up into components that correspond with each dimensional axis of the coordinate system. In a two-dimensional system, where there is an x-axis and a y-axis, corresponding acceleration components are defined as a x = d v x / d t = d 2 x / d t 2 , {\displaystyle a_{x}=dv_{x}/dt=d^{2}x/dt^{2},}

2262-485: Is defined as a =< a x , a y , a z > {\displaystyle {\textbf {a}}=<a_{x},a_{y},a_{z}>} with its magnitude being determined by | a | = a x 2 + a y 2 + a z 2 . {\displaystyle |a|={\sqrt {a_{x}^{2}+a_{y}^{2}+a_{z}^{2}}}.} The special theory of relativity describes

2349-438: Is defined as the derivative of position, x , with respect to time, acceleration can be thought of as the second derivative of x with respect to t : a = d v d t = d 2 x d t 2 . {\displaystyle \mathbf {a} ={\frac {d\mathbf {v} }{dt}}={\frac {d^{2}\mathbf {x} }{dt^{2}}}.} (Here and elsewhere, if motion

2436-472: Is described by the Frenet–Serret formulas . Uniform or constant acceleration is a type of motion in which the velocity of an object changes by an equal amount in every equal time period. A frequently cited example of uniform acceleration is that of an object in free fall in a uniform gravitational field. The acceleration of a falling body in the absence of resistances to motion is dependent only on

2523-647: Is essential to profit from the complete physics potential of CLIC. The current detector design, named CLICdet, has been optimised via full simulation studies and R&D activities. The detector follows the standard design of grand particle detectors at high energy colliders: a cylindrical detector volume with a layered configuration, surrounding the beam axis. CLICdet would have dimensions of ~13 × 12 m (height × length) and weigh ~8000 tonnes. CLICdet consists of four main layers of increasing radius: vertex and tracking system, calorimeters , solenoid magnet , and muon detector. The vertex and tracking system

2610-433: Is felt by passengers until their relative (differential) velocity are neutralized in reference to the acceleration due to change in speed. An object's average acceleration over a period of time is its change in velocity , Δ v {\displaystyle \Delta \mathbf {v} } , divided by the duration of the period, Δ t {\displaystyle \Delta t} . Mathematically,

2697-570: Is found by the distance formula as | a | = a x 2 + a y 2 . {\displaystyle |a|={\sqrt {a_{x}^{2}+a_{y}^{2}}}.} In three-dimensional systems where there is an additional z-axis, the corresponding acceleration component is defined as a z = d v z / d t = d 2 z / d t 2 . {\displaystyle a_{z}=dv_{z}/dt=d^{2}z/dt^{2}.} The three-dimensional acceleration vector

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2784-396: Is given by the angular acceleration α {\displaystyle \alpha } , i.e., the rate of change α = ω ˙ {\displaystyle \alpha ={\dot {\omega }}} of the angular speed ω {\displaystyle \omega } times the radius r {\displaystyle r} . That is,

2871-413: Is given by the orientation of the net force acting on that object. The magnitude of an object's acceleration, as described by Newton's Second Law , is the combined effect of two causes: The SI unit for acceleration is metre per second squared ( m⋅s , m s 2 {\displaystyle \mathrm {\tfrac {m}{s^{2}}} } ). For example, when a vehicle starts from

2958-419: Is in a straight line , vector quantities can be substituted by scalars in the equations.) By the fundamental theorem of calculus , it can be seen that the integral of the acceleration function a ( t ) is the velocity function v ( t ) ; that is, the area under the curve of an acceleration vs. time ( a vs. t ) graph corresponds to the change of velocity. Δ v = ∫

3045-447: Is located at the innermost region of CLICdet and aims to detect the position and momenta of particles with minimum adverse impact on their energy and trajectory . The vertex detector is cylindrical with three double layers of detector materials at increasing radii and has three segmented disks at each end in a spiral configuration to aid air flow cooling. These are assumed to be made of 25x25 μm2 silicon pixels of thickness 50 μm, and

3132-472: Is said to be undergoing centripetal (directed towards the center) acceleration. Proper acceleration , the acceleration of a body relative to a free-fall condition, is measured by an instrument called an accelerometer . In classical mechanics , for a body with constant mass, the (vector) acceleration of the body's center of mass is proportional to the net force vector (i.e. sum of all forces) acting on it ( Newton's second law ): F = m

3219-532: Is the unit (inward) normal vector to the particle's trajectory (also called the principal normal ), and r is its instantaneous radius of curvature based upon the osculating circle at time t . The components are called the tangential acceleration and the normal or radial acceleration (or centripetal acceleration in circular motion, see also circular motion and centripetal force ), respectively. Geometrical analysis of three-dimensional space curves, which explains tangent, (principal) normal and binormal,

3306-488: Is the unit typically used to measure the number of particle collision events per femtobarn of target cross-section , and is the conventional unit for time-integrated luminosity . Thus if a detector has accumulated 100 fb of integrated luminosity, one expects to find 100 events per femtobarn of cross-section within these data. Consider a particle accelerator where two streams of particles, with cross-sectional areas measured in femtobarns, are directed to collide over

3393-1048: The ISR , the SPS and the LHC at CERN, and the Tevatron in the US. Examples of lepton colliders are the SuperKEKB in Japan, the BEPC II in China, DAFNE in Italy, the VEPP in Russia, SLAC in the US, and the Large Electron–Positron Collider at CERN. Some of these lepton colliders are still running. Hadrons are compound objects, which lead to more complicated collision events and limit

3480-529: The Standard Model of particle physics, through precision measurements of Standard Model properties as well as direct detection of new particles. The collider would offer high sensitivity to electroweak states, exceeding the predicted precision of the full LHC programme. The current CLIC design includes the possibility for electron beam polarisation . The CLIC collaboration produced a Conceptual Design Report (CDR) in 2012, complemented by an updated energy staging scenario in 2016. Additional detailed studies of

3567-412: The Standard Model prediction would indirectly signal the presence of new physics. Such indirect methods give access to energy scales far beyond the available collision energy, reaching sensitivities of up to tens of TeV. Examples of indirect measurements CLIC would be capable of at 3 TeV are: using the production of muon pairs to provide evidence of a Z ′ boson (reach up to ~30 TeV) indicating

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3654-405: The cosmological constant , LIGO noise , and pulsar timing , suggests it's very unlikely that there are any new particles with masses much higher than those which can be found in the standard model or the LHC. On the other hand, this research has also indicated that quantum gravity or perturbative quantum field theory will become strongly coupled before 1 PeV, leading to other new physics in

3741-498: The dimensions of velocity (L/T) divided by time, i.e. L T . The SI unit of acceleration is the metre per second squared (m s ); or "metre per second per second", as the velocity in metres per second changes by the acceleration value, every second. An object moving in a circular motion—such as a satellite orbiting the Earth—is accelerating due to the change of direction of motion, although its speed may be constant. In this case it

3828-461: The displacement , initial and time-dependent velocities , and acceleration to the time elapsed : s ( t ) = s 0 + v 0 t + 1 2 a t 2 = s 0 + 1 2 ( v 0 + v ( t ) ) t v ( t ) = v 0 +

3915-472: The empirical law B D R ∝ E 30 τ 5 {\displaystyle BDR\propto E^{30}\tau ^{5}} , where E {\displaystyle E} is the accelerating gradient and τ {\displaystyle \tau } is the RF pulse length. The high accelerating gradient and the target BDR value (3 × 10 pulsem) drive most of

4002-415: The equivalence principle , and said that only observers who feel no force at all—including the force of gravity—are justified in concluding that they are not accelerating. Barn (unit) A barn (symbol: b ) is a metric unit of area equal to 10  m (100  fm ). Originally used in nuclear physics for expressing the cross sectional area of nuclei and nuclear reactions , today it

4089-463: The gravitational field strength g (also called acceleration due to gravity ). By Newton's Second Law the force F g {\displaystyle \mathbf {F_{g}} } acting on a body is given by: F g = m g . {\displaystyle \mathbf {F_{g}} =m\mathbf {g} .} Because of the simple analytic properties of the case of constant acceleration, there are simple formulas relating

4176-431: The reaction to which the passengers on board experience as a force pushing them back into their seats. When changing direction, the effecting acceleration is called radial (or centripetal during circular motions) acceleration, the reaction to which the passengers experience as a centrifugal force . If the speed of the vehicle decreases, this is an acceleration in the opposite direction of the velocity vector (mathematically

4263-606: The "rural background" of one of the scientists, suggested to them the term " barn ", which also worked because the unit was "really as big as a barn." According to the authors, the first published use of the term was in a (secret) Los Alamos report from late June 1943, on which the two originators were co-authors. The unit symbol for the barn (b) is also the IEEE standard symbol for bit . In other words, 1 Mb can mean one megabarn or one megabit. Calculated cross sections are often given in terms of inverse squared gigaelectronvolts ( GeV ), via

4350-452: The 50 Hz bunch train crossing rate. As of 2017, approximately two percent of the CERN annual budget is invested in the development of CLIC technologies. The first stage of CLIC with a length of around 11 km (7 mi) is currently estimated at a cost of six billion CHF. CLIC is a global project involving more than 70 institutes in more than 30 countries. It consists of two collaborations:

4437-510: The Beam Delivery System (BDS), which squeezes and brings the beams into collision. The two beams collide at the IP with 20 m rad crossing angle in the horizontal plane. Each Drive Beam complex is composed of a 2.5 km-long linac, followed by a Drive Beam Recombination Complex: a system of delay lines and combiner rings where the incoming beam pulses are interleaved to ultimately form

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4524-490: The CLIC detector and physics collaboration (CLICdp), and the CLIC accelerator study. CLIC is currently in the development stage, conducting performance studies for accelerator parts and systems, detector technology and optimisation studies, and physics analysis. In parallel, the collaborations are working with the theory community to evaluate the physics potential of CLIC. The CLIC project has submitted two concise documents as input to

4611-571: The CLIC potential for New Physics, the CLIC project implementation plan and the Detector technologies for CLIC. An overview is provided in the 2018 CLIC Summary Report. Acceleration In mechanics , acceleration is the rate of change of the velocity of an object with respect to time. Acceleration is one of several components of kinematics , the study of motion . Accelerations are vector quantities (in that they have magnitude and direction ). The orientation of an object's acceleration

4698-627: The Drive Beam and the beam recombination makes it more convenient than using klystrons to directly accelerate the Main Beam. The main technology challenges of the CLIC accelerator design have been successfully addressed in various test facilities. The Drive Beam production and recombination, and the two-beam acceleration concept were demonstrated at the CLIC Test Facility 3 (CTF3) . X-band high-power klystron -based RF sources were built in stages at

4785-474: The ECAL coverage down to 10 mrads polar angle, and an intra-train feedback system to counteract luminosity loss due to relative beam-beam offsets. Strict requirements on the material budget for the vertex and tracking system do not allow the use of conventional liquid cooling systems for CLICdet. Therefore, it is proposed that a dry gas cooling system will be used for this inner region. Air gaps have been factored into

4872-502: The Higgsstrahlung and WW-fusion production processes. The second and third stages give access to phenomena such as the top-Yukawa coupling , rare Higgs decays and the Higgs self-coupling. The top quark, the heaviest of all known fundamental particles, has currently never been studied in electron - positron collisions. The CLIC linear collider plans to have an extensive top quark physics programme. A major aim of this programme would be

4959-487: The TeVs. To reach the desired 3 TeV beam energy, while keeping the length of the accelerator compact, CLIC targets an accelerating gradient up to 100 MV/m. CLIC is based on normal- conducting acceleration cavities operated at room temperature , as they allow for higher acceleration gradients than superconducting cavities. With this technology, the main limitation is the high-voltage breakdown rate (BDR), which follows

5046-508: The achievable precision of physics measurements. This is for instance why the Large Hadron Collider was designed to operate at such a high energy even while it was already known the Higgs particle ought to be found at around the energies it eventually was: the lesser accuracy of a hadron collider necessitated more numerous and higher energy impacts to compensate. Lepton colliders on the other hand collide fundamental particles , therefore

5133-534: The aim is to have a single point resolution of 3 μm. The tracking system is made of silicon sensor modules expected to be 200 μm thick. The calorimeters surround the vertex and tracking system and aim to measure the energy of particles via absorption. The electromagnetic calorimeter (ECAL) consists of ~40 layers of silicon/tungsten in a sandwich structure; the hadronic calorimeter (HCAL) has 60 steel absorber plates with scintillating material inserted in between. These inner CLICdet layers are enclosed in

5220-462: The beam parameter s and machine design. In order to reach these high accelerating gradients while keeping the power consumption affordable, CLIC makes use of a novel two-beam-acceleration scheme: a so-called Drive Beam runs parallel to the colliding Main Beam. The Drive Beam is decelerated in special devices called Power Extraction and Transfer Structures (PETS) that extract energy from the Drive Beam in

5307-400: The behavior of objects traveling relative to other objects at speeds approaching that of light in vacuum. Newtonian mechanics is exactly revealed to be an approximation to reality, valid to great accuracy at lower speeds. As the relevant speeds increase toward the speed of light, acceleration no longer follows classical equations. As speeds approach that of light, the acceleration produced by

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5394-433: The center of the circle. This acceleration constantly changes the direction of the velocity to be tangent in the neighboring point, thereby rotating the velocity vector along the circle. Expressing centripetal acceleration vector in polar components, where r {\displaystyle \mathbf {r} } is a vector from the centre of the circle to the particle with magnitude equal to this distance, and considering

5481-432: The change of the direction of the velocity vector, while its magnitude remains constant. The derivative of the location of a point on a curve with respect to time, i.e. its velocity, turns out to be always exactly tangential to the curve, respectively orthogonal to the radius in this point. Since in uniform motion the velocity in the tangential direction does not change, the acceleration must be in radial direction, pointing to

5568-935: The changing direction of u t , the acceleration of a particle moving on a curved path can be written using the chain rule of differentiation for the product of two functions of time as: a = d v d t = d v d t u t + v ( t ) d u t d t = d v d t u t + v 2 r u n   , {\displaystyle {\begin{alignedat}{3}\mathbf {a} &={\frac {d\mathbf {v} }{dt}}\\&={\frac {dv}{dt}}\mathbf {u} _{\mathrm {t} }+v(t){\frac {d\mathbf {u} _{\mathrm {t} }}{dt}}\\&={\frac {dv}{dt}}\mathbf {u} _{\mathrm {t} }+{\frac {v^{2}}{r}}\mathbf {u} _{\mathrm {n} }\ ,\end{alignedat}}} where u n

5655-501: The conversion ħ c / GeV = 0.3894 mb = 38 940  am . In natural units (where ħ = c = 1), this simplifies to GeV = 0.3894 mb = 38 940  am . In SI, one can use units such as square femtometers (fm ). The most common SI prefixed unit for the barn is the femtobarn, which is equal to a tenth of a square zeptometer. Many scientific papers discussing high-energy physics mention quantities of fractions of femtobarn level. The inverse femtobarn (fb )

5742-455: The design of the detector to allow the flow of the gas , which will be air or Nitrogen . To allow for effective air cooling, the average power consumption of the Silicon sensors in the vertex detector needs to be lowered. Therefore, these sensors will operate via a current-based power pulsing scheme: switching the sensors from a high to low power consumption state whenever possible, corresponding to

5829-530: The field" that they could name the unit after, but struggled to find one that was appropriate. They considered " Oppenheimer " too long (in retrospect, they considered an "Oppy" to perhaps have been allowable), and considered " Bethe " to be too easily confused with the commonly-used Greek letter beta . They then considered naming it after John Manley , another scientist associated with their work, but considered "Manley" too long and "John" too closely associated with toilets . But this latter association, combined with

5916-497: The first decade of the 21st century. Fermilab's Tevatron took about 4 years to reach 1 fb in 2005, while two of CERN 's LHC experiments, ATLAS and CMS , reached over 5 fb of proton–proton data in 2011 alone. In April 2012 the LHC achieved the collision energy of 8 TeV with a luminosity peak of 6760 inverse microbarns per second; by May 2012 the LHC delivered 1 inverse femtobarn of data per week to each detector collaboration. A record of over 23 fb

6003-499: The first factor two recombination: the odd bunches are delayed in a Delay Loop (DL), while the even bunches bypass it. The time of flight of the DL is about 244 ns and tuned at the picosecond level such that the two trains of bunches can merge, forming several 244 ns-long trains with bunching frequency at 1 GHz, separated by 244 ns of empty space. This new time-structure allows for further factor 3 and factor 4 recombination in

6090-466: The following combiner rings with a similar mechanism as in the DL. The final time structure of the beam is made of several (up to 25) 244 ns-long trains of bunches at 12 GHz, spaced by gaps of about 5.5 μs. The recombination is timed such that each combined train arrives in its own decelerator sector, synchronized with the arrival of the Main Beam. The use of low-frequency (1 GHz), long-pulse-length (148 μs) klystrons for accelerating

6177-406: The form of powerful Radio Frequency (RF) waves, which is then used to accelerate the Main Beam. Up to 90% of the energy of the Drive Beam is extracted and efficiently transferred to the Main Beam. The electrons needed for the main beam are produced by illuminating a GaAs -type cathode with a Q-switched polarised laser , and are longitudinally polarised at the level of 80%. The positron s for

6264-631: The high-gradient X-band test facility (XBOX), CERN. These facilities provide the RF power and infrastructure required for the conditioning and verification of the performance of CLIC accelerating structures, and other X-band based projects. Additional X-band high-gradient tests are being carried out at the NEXTEF facility at KEK and at SLAC , a new test stand is being commissioned at Tsinghua University and further test stands are being constructed at INFN Frascati and SINAP in Shanghai. A state-of-the-art detector

6351-434: The initial state of each event is known and higher precision measurements can be achieved. Another means of categorizing colliders is by their physical geometry: either linear or circular. Circular colliders benefit from being able to accelerate particles over and over to reach very high energies, and from being able to repeatedly intersect their beams, to reach very high numbers of collisions between individual particles. On

6438-465: The main beam are produced by sending a 5 GeV electron beam on a tungsten target. After an initial acceleration up to 2.86 GeV, both electrons and positrons enter damping rings for emittance reduction by radiation damping . Both beams are then further accelerated to 9 GeV in a common booster linac. Long transfer lines transport the two beams to the beginning of the main linacs where they are accelerated up to 1.5 TeV before going into

6525-412: The mass of the particle determine the necessary centripetal force , directed toward the centre of the circle, as the net force acting on this particle to keep it in this uniform circular motion. The so-called ' centrifugal force ', appearing to act outward on the body, is a so-called pseudo force experienced in the frame of reference of the body in circular motion, due to the body's linear momentum ,

6612-422: The motion can be resolved into two orthogonal parts, one of constant velocity and the other according to the above equations. As Galileo showed, the net result is parabolic motion, which describes, e.g., the trajectory of a projectile in vacuum near the surface of Earth. In uniform circular motion , that is moving with constant speed along a circular path, a particle experiences an acceleration resulting from

6699-617: The next update of the European Strategy for Particle Physics (ESPP) summarising the physics potential of CLIC as well as the status of the CLIC accelerator and detector projects. The update of the ESPP is a community-wide process, which is expected to conclude in May 2020 with the publication of a strategy document. Detailed information on the CLIC project is available in CERN Yellow Reports, on

6786-489: The only stable leptons around (electrons and positrons) are, as the name says, very light. They will have to be accelerated to much higher speeds than heavier particles (baryons) in order to gain the same energy, and suddenly synchrotron loss becomes the limiting factor. As a linear collider, CLIC will not have this problem. It still has to tackle the problems of not being able to recirculate its beams, though, which despite it being called "compact", necessitates massive scale and

6873-446: The orientation of the acceleration towards the center, yields a c = − v 2 | r | ⋅ r | r | . {\displaystyle \mathbf {a_{c}} =-{\frac {v^{2}}{|\mathbf {r} |}}\cdot {\frac {\mathbf {r} }{|\mathbf {r} |}}\,.} As usual in rotations, the speed v {\displaystyle v} of

6960-413: The other hand they are limited by the fact that keeping the particles circulating means constantly accelerating them inwards. This makes charged particles emit synchrotron radiation , eventually leading to a significant energy loss and a limit on achievable collision energy. This so called synchrotron loss is especially harmful to lepton colliders, because it scales as the fourth power of particle speed, and

7047-476: The physics case for CLIC, an advanced design of the accelerator complex and the detector, as well as numerous R&D results are summarised in a recent series of CERN Yellow Reports. There are two main types of particle colliders, which differ in the types of particles they collide: lepton colliders and hadron colliders. Each type of collider can produce different final states of particles and can study different physics phenomena. Examples of hadron colliders are

7134-405: The physics potential carried out by the CLIC study. Already at 380 GeV, CLIC has good coverage of Standard Model physics; the energy stages beyond this allow for the discovery of new physics as well as increased precision measurements of Standard Model processes. Additionally, CLIC will operate at the top quark pair-production threshold around 350 GeV with the aim of precisely measuring

7221-460: The properties of the top quark. CLIC would allow the exploration of new energy ranges, provide possible solutions to unanswered problems, and enable the discovery of phenomena beyond our current understanding. The current LHC data suggest that the particle found in 2012 is the Higgs boson as predicted by the Standard Model of particle physics. However, the LHC can only partially answer questions about

7308-399: The speed of travel along the path, and u t = v ( t ) v ( t ) , {\displaystyle \mathbf {u} _{\mathrm {t} }={\frac {\mathbf {v} (t)}{v(t)}}\,,} a unit vector tangent to the path pointing in the direction of motion at the chosen moment in time. Taking into account both the changing speed v ( t ) and

7395-608: The top quark electroweak couplings to the Z boson and the photon, as deviations of these values from those predicted by the Standard Model could be evidence of new physics phenomena, such as extra dimensions. Further observation of top quark decays with flavour -changing neutral currents at CLIC would be an indirect indication of new physics, as these should not be seen by CLIC under current Standard Model predictions. CLIC could discover new physics phenomena either through indirect measurements or by direct observation. Large deviations in precision measurements of particle properties from

7482-420: The true nature of this particle, such as its composite/fundamental nature, coupling strengths , and possible role in an extended electroweak sector. CLIC could examine these questions in more depth by measuring the Higgs couplings to a precision not achieved before. The 380 GeV stage of CLIC allows, for example, accurate model-independent measurements of Higgs boson couplings to fermions and bosons through

7569-596: Was achieved during 2012. As of November 2016, the LHC had achieved 40 fb over that year, significantly exceeding the stated goal of 25 fb . In total, the second run of the LHC has delivered around 150 fb to both ATLAS and CMS in 2015–2018. As a simplified example, if a beamline runs for 8 hours (28 800 seconds) at an instantaneous luminosity of 300 × 10  cm ⋅s  = 300 μb ⋅s , then it will gather data totaling an integrated luminosity of 8 640 000  μb  = 8.64 pb  = 0.008 64  fb during this period. If this

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