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83-546: Ichinoseki is located inland in the south of Iwate Prefecture, a little over two hours north of Tokyo by the Tōhoku Shinkansen . A large volume of extremely stable granite rock runs beneath the city, and is the center of a site being promoted as a suitable location for construction of the International Linear Collider (ILC). Akita Prefecture Iwate Prefecture Miyagi Prefecture Ichinoseki has

166-491: A Radio-frequency quadrupole (RFQ) stage from injection at 50kVdC to ~5MeV bunches, a Side Coupled Drift Tube Linac (SCDTL) to accelerate from 5Mev to ~ 40MeV and a Cell Coupled Linac (CCL) stage final, taking the output to 200-230MeV. Each stage is optimised to allow close coupling and synchronous operation during the beam energy build-up. The project aim is to make proton therapy a more accessible mainstream medicine as an alternative to existing radio therapy. The higher

249-586: A humid climate ( Köppen climate classification Cfa ) with warm summers and cold winters. The average annual temperature in Ichinoseki is 10.9 °C. The average annual rainfall is 1248 mm with September as the wettest month and January as the driest month. The temperatures are highest on average in August, at around 24.3 °C, and lowest in January, at around -1.5 °C. The agricultural makeup of

332-461: A $ 20 billion total. Upon completion of the 2013 ILC Design Report, Barish said the cost of building the ILC was the equivalent of 7.78 billion 2012 U.S. dollars; it will require "22.6 million hours of labor and location-specific costs including site preparation, scientific detectors and facility operations." Linear particle accelerator A linear particle accelerator (often shortened to linac )

415-433: A 370-meter linac stage. Synchrotron radiation from high energy electrons will produce electron-positron pairs on a titanium-alloy target, with as much as 60% polarization; the positrons from these collisions will be collected and accelerated to 5 GeV in a separate linac. To compact the 5 GeV electron and positron bunches to a sufficiently small size to be usefully collided, they will circulate for 0.1–0.2 seconds in

498-550: A Little Linac model kit, containing 82 building blocks, was developed for children undergoing radiotherapy treatment for cancer. The hope is that building the model will alleviate some of the stress experienced by the child before undergoing treatment by helping them to understand what the treatment entails. The kit was developed by Professor David Brettle, Institute of Physics and Engineering in Medicine (IPEM) in collaboration with manufacturers Best-Lock Ltd. The model can be seen at

581-432: A beam line length reduction from some tens of metres to a few cm is quite possible. The LIGHT program (Linac for Image-Guided Hadron Therapy) hopes to create a design capable of accelerating protons to 200MeV or so for medical use over a distance of a few tens of metres, by optimising and nesting existing accelerator techniques The current design (2020) uses the highest practical bunch frequency (currently ~ 3 GHz) for

664-534: A circular design, particles can be effectively accelerated over longer distances. Also, only a fraction of the particles brought onto a collision course actually collide. In a linear accelerator, the remaining particles are lost; in a ring accelerator, they keep circulating and are available for future collisions. The disadvantage of circular accelerators is that charged particles moving along bent paths will necessarily emit electromagnetic radiation known as synchrotron radiation . Energy loss through synchrotron radiation

747-457: A faster speed each time they pass between electrodes; there is little electric field inside the electrodes so the particles travel at a constant speed within each electrode. The particles are injected at the right time so that the oscillating voltage differential between electrodes is maximum as the particles cross each gap. If the peak voltage applied between the electrodes is V p {\displaystyle V_{p}} volts, and

830-419: A few MeV. An advantageous alternative here, however, is a progressive wave, a traveling wave. The phase velocity the traveling wave must be roughly equal to the particle speed. Therefore, this technique is only suitable when the particles are almost at the speed of light, so that their speed only increases very little. The development of high-frequency oscillators and power amplifiers from the 1940s, especially

913-465: A force given by the Lorentz force law: where q {\displaystyle q} is the charge on the particle, E → {\displaystyle {\vec {E}}} is the electric field, v → {\displaystyle {\vec {v}}} is the particle velocity, and B → {\displaystyle {\vec {B}}}

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996-415: A group of particles into the first electrode once each cycle of the voltage, when the charge on the electrode is opposite to the charge on the particles. Each time the particle bunch passes through an electrode, the oscillating voltage changes polarity, so when the particles reach the gap between electrodes the electric field is in the correct direction to accelerate them. Therefore, the particles accelerate to

1079-502: A horizontal waveguide loaded by a series of discs. The 1947 accelerator had an energy of 6 MeV. Over time, electron acceleration at the SLAC National Accelerator Laboratory would extend to a size of 2 miles (3.2 km) and an output energy of 50 GeV. As linear accelerators were developed with higher beam currents, using magnetic fields to focus proton and heavy ion beams presented difficulties for

1162-542: A pair of damping rings, 3.24 km in circumference, in which they will be reduced in size to 6 mm in length and a vertical and horizontal emittance of 2 pm and 0.6 nm, respectively. From the damping rings the particle bunches will be sent to the superconducting radio frequency main linacs, each 11 km long, where they will be accelerated to 250 GeV. At this energy each beam will have an average power of about 5.3 megawatts . Five bunch trains will be produced and accelerated per second. To maintain

1245-439: A precise alignment of their components through the use of servo systems guided by a laser beam. Various new concepts are in development as of 2021. The primary goal is to make linear accelerators cheaper, with better focused beams, higher energy or higher beam current. Induction linear accelerators use the electric field induced by a time-varying magnetic field for acceleration—like the betatron . The particle beam passes through

1328-401: A resonant cavity to produce complex electric fields. These fields provide simultaneous acceleration and focusing to injected particle beams. Beginning in the 1960s, scientists at Stanford and elsewhere began to explore the use of superconducting radio frequency cavities for particle acceleration. Superconducting cavities made of niobium alloys allow for much more efficient acceleration, as

1411-469: A result. The development of the strong focusing principle in the early 1950s led to the installation of focusing quadrupole magnets inside the drift tubes, allowing for longer and thus more powerful linacs. Two of the earliest examples of Alvarez linacs with strong focusing magnets were built at CERN and Brookhaven National Laboratory . In 1947, at about the same time that Alvarez was developing his linac concept for protons, William Hansen constructed

1494-410: A series of ring-shaped ferrite cores standing one behind the other, which are magnetized by high-current pulses, and in turn each generate an electrical field strength pulse along the axis of the beam direction. Induction linear accelerators are considered for short high current pulses from electrons but also from heavy ions. The concept goes back to the work of Nicholas Christofilos . Its realization

1577-613: A substantially higher fraction of the input power could be applied to the beam rather than lost to heat. Some of the earliest superconducting linacs included the Superconducting Linear Accelerator (for electrons) at Stanford and the Argonne Tandem Linear Accelerator System (for protons and heavy ions) at Argonne National Laboratory . When a charged particle is placed in an electromagnetic field it experiences

1660-631: A sufficient luminosity to produce results in a reasonable time frame after acceleration the bunches will be focused to a few nanometers in height and a few hundred nanometers in width. The focused bunches then will be collided inside one of two large particle detectors . Originally, three sites for the International Linear Collider were leading contenders at established High Energy Physics centers in Europe. At CERN in Geneva

1743-591: Is a proposed linear particle accelerator . It is planned to have a collision energy of 500  GeV initially, with the possibility for a later upgrade to 1000 GeV (1 TeV). Although early proposed locations for the ILC were Japan, Europe ( CERN ) and the USA ( Fermilab ), the Kitakami highland in the Iwate prefecture of northern Japan has been the focus of ILC design efforts since 2013. The Japanese government

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1826-690: Is a type of particle accelerator that accelerates charged subatomic particles or ions to a high speed by subjecting them to a series of oscillating electric potentials along a linear beamline . The principles for such machines were proposed by Gustav Ising in 1924, while the first machine that worked was constructed by Rolf Widerøe in 1928 at the RWTH Aachen University . Linacs have many applications: they generate X-rays and high energy electrons for medicinal purposes in radiation therapy , serve as particle injectors for higher-energy accelerators, and are used directly to achieve

1909-501: Is accelerated. A linear particle accelerator consists of the following parts: As shown in the animation, the oscillating voltage applied to alternate cylindrical electrodes has opposite polarity (180° out of phase ), so adjacent electrodes have opposite voltages. This creates an oscillating electric field (E) in the gap between each pair of electrodes, which exerts force on the particles when they pass through, imparting energy to them by accelerating them. The particle source injects

1992-402: Is converted into heat. In an energy recovery linac (ERL), the accelerated in resonators and, for example, in undulators . The electrons used are fed back through the accelerator, out of phase by 180 degrees. They therefore pass through the resonators in the decelerating phase and thus return their remaining energy to the field. The concept is comparable to the hybrid drive of motor vehicles, where

2075-402: Is highly dependent on progress in the development of more suitable ferrite materials. With electrons, pulse currents of up to 5 kiloamps at energies up to 5 MeV and pulse durations in the range of 20 to 300 nanoseconds were achieved. In previous electron linear accelerators, the accelerated particles are used only once and then fed into an absorber (beam dump) , in which their residual energy

2158-509: Is inversely proportional to the fourth power of the mass of the particles in question. That is why it makes sense to build circular accelerators for heavy particles—hadron colliders such as the LHC for protons or, alternatively, for lead nuclei . An electron–positron collider of the same size would never be able to achieve the same collision energies. In fact, energies at the LEP which used to occupy

2241-425: Is necessary to use groups of magnets to provide an overall focusing effect in both directions. Focusing along the direction of travel, also known as phase stability , is an inherent property of RF acceleration. If the particles in a bunch all reach the accelerating region during the rising phase of the oscillating field, then particles which arrive early will see slightly less voltage than the "reference" particle at

2324-427: Is the magnetic field. The cross product in the magnetic field term means that static magnetic fields cannot be used for particle acceleration, as the magnetic force acts perpendicularly to the direction of particle motion. As electrostatic breakdown limits the maximum constant voltage which can be applied across a gap to produce an electric field, most accelerators use some form of RF acceleration. In RF acceleration,

2407-481: Is used to drive a series of gaps, those gaps must be placed increasingly far apart as the speed of the particle increases. This is to ensure that the particle "sees" the same phase of the oscillator's cycle as it reaches each gap. As particles asymptotically approach the speed of light, the gap separation becomes constant: additional applied force increases the energy of the particles but does not significantly alter their speed. In order to ensure particles do not escape

2490-416: Is willing to contribute half of the costs, according to the coordinator of study for detectors at the ILC. The ILC would collide electrons with positrons . It will be between 30 km and 50 km (19–31 mi) long, more than 10 times as long as the 50 GeV Stanford Linear Accelerator , the longest existing linear particle accelerator. The proposal is based on previous similar proposals from Europe,

2573-627: The Date clan during the Edo period , who ruled Sendai Domain under the Tokugawa shogunate . A portion of the present city was part of Ichinoseki Domain , a sub-domain of Sendai Domain. The town of Ichinoseki was established within Nishiiwai District, Iwate on April 1, 1889 with the establishment of the modern municipality system. It was raised to city status on April 1, 1948 by the merger of

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2656-975: The Diet of Japan . Ichinoseki has 29 public elementary schools and 16 public junior high schools operated by the city government and one junior high school and eight public elementary schools operated by the Iwate Prefectural Board of Education. There is also one private high school and one private junior college. The Prefecture also operates one special education school for the handicapped. [REDACTED] East Japan Railway Company (JR East) - Tōhoku Shinkansen [REDACTED] East Japan Railway Company (JR East) - Tōhoku Main Line [REDACTED] East Japan Railway Company (JR East) - Ōfunato Line [REDACTED] Media related to Ichinoseki, Iwate at Wikimedia Commons International Linear Collider The International Linear Collider ( ILC )

2739-498: The Future Circular Collider , which has overlapping physics goals with the ILC. In March 2024, the "Federation of Diet Members for the ILC" met to receive "Reports on the ILC project's progress and initiatives by relevant organizations". Fifty participants, including Diet members and other government agencies, as well as researchers and businesses, received reports on the project's progress. Participants discussed

2822-745: The Japanese Paleolithic period. The area was inhabited by the Emishi people, and came under the control of the imperial dynasty during the early Heian period . During the Heian period , it was controlled by the Abe clan , followed by the Northern Fujiwara clan of Hiraizumi . During the Sengoku period , the area was dominated by various samurai clans before coming under the control of

2905-705: The Jefferson Lab (US), in the Budker Institute of Nuclear Physics (Russia) and at JAEA (Japan). At the University of Mainz , an ERL called MESA is expected to begin operation in 2024. The concept of the Compact Linear Collider (CLIC) (original name CERN Linear Collider, with the same abbreviation) for electrons and positrons provides a traveling wave accelerator for energies of the order of 1 tera-electron volt (TeV). Instead of

2988-464: The Science Museum, London . The expected shortages of Mo-99 , and the technetium-99m medical isotope obtained from it, have also shed light onto linear accelerator technology to produce Mo-99 from non-enriched Uranium through neutron bombardment. This would enable the medical isotope industry to manufacture this crucial isotope by a sub-critical process. The aging facilities, for example

3071-674: The T2K experiment , a factor not in its favor, although 20 huge caverns with access tunnels have already been constructed in Japan for hydroelectric power plants (e.g. the Kannagawa Hydropower Plant ). Following the closure of the Tevatron some groups within the USA had expressed interest, with Fermilab being a favored site because of the facilities and experts already present. Much of the speculated interest from other countries

3154-477: The ILC's future. The meeting resulted in three recommendations: 1. The ILC project will be further promoted by the research community, industry, organizations promoting the candidate sites, relevant ministries and agencies, the Diet members and other political organizations within an all-Japan framework. 2. For the ILC project, international collaboration will be further strengthened as a global initiative involving

3237-638: The ILC, have been unified under the Linear Collider Collaboration . There are two basic shapes of accelerators. Linear accelerators ("linacs") accelerate elementary particles along a straight path. Circular accelerators ("synchrotrons"), such as the Tevatron , the LEP , and the Large Hadron Collider (LHC), use circular paths. Circular geometry has significant advantages at energies up to and including tens of GeV : With

3320-602: The International Linear Collider. On August 23, 2013, the Japanese high-energy physics community's site evaluation committee proposed it should be located in the Kitakami Mountains of the Iwate and Miyagi Prefectures . As of March 7, 2019, the Japanese government has stated that it is not ready to support the construction of the Collider due to its high proposed cost of approximately $ 7 billion. This decision

3403-897: The Next Linear Collider (NLC), the Global Linear Collider (GLC) and Teraelectronvolt Energy Superconducting Linear Accelerator (TESLA) – joined their efforts into one single project (the ILC). In March 2005, the International Committee for Future Accelerators (ICFA) announced Prof. Barry Barish , director of the LIGO Laboratory at Caltech from 1997 to 2005, as the Director of the Global Design Effort (GDE). In August 2007,

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3486-468: The Promotion of Regional Revitalization ( Kishida Cabinet Secretariat ), which promotes the development of new technologies to combat depopulation, for meeting a "high standard" of digital transformation / telework infrastructure. Related projects have been awarded over ¥80M in government grants. The area of present-day Ichinoseki was part of ancient Mutsu Province , and has been settled since at least

3569-456: The RF power creates a standing wave . Some linacs have short, vertically mounted waveguides, while higher energy machines tend to have a horizontal, longer waveguide and a bending magnet to turn the beam vertically towards the patient. Medical linacs use monoenergetic electron beams between 4 and 25 MeV, giving an X-ray output with a spectrum of energies up to and including the electron energy when

3652-575: The Reference Design Report for the ILC was released. Physicists working on the GDE completed a detailed ILC design report, publishing it in June 2013. The electron source for the ILC will use 2-nanosecond laser light pulses to eject electrons from a photocathode , a technique allowing for up to 80% of the electrons to be polarized; the electrons then will be accelerated to 5 GeV in

3735-570: The Standard Model are expected to be discovered and measured. At the ILC physicists hope to be able to: To achieve these goals, new generation particle detectors are necessary. In August 2004, the International Technology Recommendation Panel (ITRP) recommended a superconducting radio frequency technology for the accelerator. After this decision the three existing linear collider projects –

3818-405: The U.S., and Japan. In a staged approach, the ILC could initially be constructed at 250 GeV, for use as a Higgs factory . Such a design would be approximately 20 km in length. Studies for an alternative project, the Compact Linear Collider (CLIC) are also underway, which would operate at higher energies (up to 3 TeV) in a machine of length similar to the ILC. These two projects, CLIC and

3901-432: The accelerator complex and detectors is expected to require seven years. The host country would be required to pay $ 1.8 billion for site-specific costs like digging tunnels and shafts and supplying water and electricity. Former U.S. Secretary of Energy Steven Chu estimated the total cost to be US$ 25 billion. ILC Director Barish said this is likely to be an overestimate. Other Department of Energy officials have estimated

3984-411: The accelerator, it is necessary to provide some form of focusing to redirect particles moving away from the central trajectory back towards the intended path. With the discovery of strong focusing , quadrupole magnets are used to actively redirect particles moving away from the reference path. As quadrupole magnets are focusing in one transverse direction and defocusing in the perpendicular direction, it

4067-577: The average output current is still limited.) The high density of the output makes the linac particularly attractive for use in loading storage ring facilities with particles in preparation for particle to particle collisions. The high mass output also makes the device practical for the production of antimatter particles, which are generally difficult to obtain, being only a small fraction of a target's collision products. These may then be stored and further used to study matter-antimatter annihilation. Linac-based radiation therapy for cancer treatment began with

4150-427: The center of the bunch. Those particles will therefore receive slightly less acceleration and eventually fall behind the reference particle. Correspondingly, particles which arrive after the reference particle will receive slightly more acceleration, and will catch up to the reference as a result. This automatic correction occurs at each accelerating gap, so the bunch is refocused along the direction of travel each time it

4233-427: The charge on each particle is q {\displaystyle q} elementary charges , the particle gains an equal increment of energy of q V p {\displaystyle qV_{p}} electron volts when passing through each gap. Thus the output energy of the particles is electron volts, where N {\displaystyle N} is the number of accelerating electrodes in

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4316-412: The city outside the centre is mostly composed of farmers, leading to an influx of Chinese and Filipino immigrants due to marriage. As a result, Ichinoseki has a varied ethnic makeup, although the newcomers still remain a small minority. Per Japanese census data, the population of Ichinoseki peaked in the 1950s and has declined over the past 70 years. Ichinoseki has been recognized by Japan's Office for

4399-433: The device. Where Ising had proposed a spark gap as the voltage source, Wideroe used a 25kV vacuum tube oscillator. He successfully demonstrated that he had accelerated sodium and potassium ions to an energy of 50,000 electron volts (50 keV), twice the energy they would have received if accelerated only once by the tube. By successfully accelerating a particle multiple times using the same voltage source, Wideroe demonstrated

4482-603: The dielectric strength limits the maximum acceleration that can be achieved within a certain distance. This limit can be circumvented using accelerated waves in plasma to generate the accelerating field in Kielfeld accelerators : A laser or particle beam excites an oscillation in a plasma , which is associated with very strong electric field strengths. This means that significantly (factors of 100s to 1000s ) more compact linear accelerators can possibly be built. Experiments involving high power lasers in metal vapour plasmas suggest that

4565-438: The electrons are directed at a high-density (such as tungsten ) target. The electrons or X-rays can be used to treat both benign and malignant disease. The LINAC produces a reliable, flexible and accurate radiation beam. The versatility of LINAC is a potential advantage over cobalt therapy as a treatment tool. In addition, the device can simply be powered off when not in use; there is no source requiring heavy shielding – although

4648-447: The energy is distributed among the constituent quarks , antiquarks and gluons of baryonic particles. As such, one of the roles of the ILC would be making precision measurements of the properties of particles discovered at the LHC. It is widely expected that effects of physics beyond that described in the current Standard Model will be detected by experiments at the proposed ILC. In addition, particles and interactions described by

4731-603: The first description of a linear particle accelerator using a series of accelerating gaps. Particles would proceed down a series of tubes. At a regular frequency, an accelerating voltage would be applied across each gap. As the particles gained speed while the frequency remained constant, the gaps would be spaced farther and farther apart, in order to ensure the particle would see a voltage applied as it reached each gap. Ising never successfully implemented this design. Rolf Wideroe discovered Ising's paper in 1927, and as part of his PhD thesis he built an 88-inch long, two gap version of

4814-584: The first patient treated in 1953 in London, UK, at the Hammersmith Hospital , with an 8 MV machine built by Metropolitan-Vickers and installed in 1952, as the first dedicated medical linac. A short while later in 1954, a 6 MV linac was installed in Stanford, USA, which began treatments in 1956. Medical linear accelerators accelerate electrons using a tuned-cavity waveguide, in which

4897-421: The first travelling-wave electron accelerator at Stanford University. Electrons are sufficiently lighter than protons that they achieve speeds close to the speed of light early in the acceleration process. As a result, "accelerating" electrons increase in energy but can be treated as having a constant velocity from an accelerator design standpoint. This allowed Hansen to use an accelerating structure consisting of

4980-489: The frequency of the acceleration voltage selected, the more individual acceleration thrusts per path length a particle of a given speed experiences, and the shorter the accelerator can therefore be overall. That is why accelerator technology developed in the pursuit of higher particle energies, especially towards higher frequencies. The linear accelerator concepts (often called accelerator structures in technical terms) that have been used since around 1950 work with frequencies in

5063-641: The global accelerator program. This collaboration should utilize the framework of the Liaison Committee on Future High-Performance Accelerators, in partnership with the Cabinet Office, as well as other relevant ministries and agencies. The Reference Design Report estimated the cost of building the ILC, excluding R&D, prototyping, land acquisition, underground easement costs, detectors, contingencies, and inflation, at US$ 6.75 billion (in 2007 prices). From formal project approval, completion of

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5146-500: The highest kinetic energy for light particles (electrons and positrons) for particle physics . The design of a linac depends on the type of particle that is being accelerated: electrons , protons or ions. Linacs range in size from a cathode-ray tube (which is a type of linac) to the 3.2-kilometre-long (2.0 mi) linac at the SLAC National Accelerator Laboratory in Menlo Park, California . In 1924, Gustav Ising published

5229-437: The initial stages of the accelerator. Because the magnetic force is dependent on the particle velocity, it was desirable to create a type of accelerator which could simultaneously accelerate and focus low-to-mid energy hadrons . In 1970, Soviet physicists I. M. Kapchinsky and Vladimir Teplyakov proposed the radio-frequency quadrupole (RFQ) type of accelerating structure. RFQs use vanes or rods with precisely designed shapes in

5312-500: The kinetic energy released during braking is made available for the next acceleration by charging a battery. The Brookhaven National Laboratory and the Helmholtz-Zentrum Berlin with the project "bERLinPro" reported on corresponding development work. The Berlin experimental accelerator uses superconducting niobium cavity resonators. In 2014, three free-electron lasers based on ERLs were in operation worldwide: in

5395-553: The klystron, was essential for these two acceleration techniques . The first larger linear accelerator with standing waves - for protons - was built in 1945/46 in the Lawrence Berkeley National Laboratory under the direction of Luis W. Alvarez . The frequency used was 200 MHz .  The first electron accelerator with traveling waves of around 2 GHz was developed a little later at Stanford University by W.W. Hansen and colleagues. In

5478-455: The machine. At speeds near the speed of light, the incremental velocity increase will be small, with the energy appearing as an increase in the mass of the particles. In portions of the accelerator where this occurs, the tubular electrode lengths will be almost constant. Additional magnetic or electrostatic lens elements may be included to ensure that the beam remains in the center of the pipe and its electrodes. Very long accelerators may maintain

5561-409: The maximum power that can be imparted to electrons in a synchrotron of given size. Linacs are also capable of prodigious output, producing a nearly continuous stream of particles, whereas a synchrotron will only periodically raise the particles to sufficient energy to merit a "shot" at the target. (The burst can be held or stored in the ring at energy to give the experimental electronics time to work, but

5644-485: The other hand, with ions of this energy range, the speed also increases significantly due to further acceleration. The acceleration concepts used today for ions are always based on electromagnetic standing waves that are formed in suitable resonators . Depending on the type of particle, energy range and other parameters, very different types of resonators are used; the following sections only cover some of them. Electrons can also be accelerated with standing waves above

5727-461: The otherwise necessary numerous klystron amplifiers to generate the acceleration power, a second parallel electron linear accelerator of lower energy is to be used, which works with superconducting cavities in which standing waves are formed. High-frequency power is extracted from it at regular intervals and transmitted to the main accelerator. In this way, the very high acceleration field strength of 80 MV / m should be achieved. In cavity resonators,

5810-447: The particle travels, and the central tubes are only used to shield the particles during the decelerating portion of the oscillator's phase. Using this approach to acceleration meant that Alvarez's first linac was able to achieve proton energies of 31.5 MeV in 1947, the highest that had ever been reached at the time. The initial Alvarez type linacs had no strong mechanism for keeping the beam focused and were limited in length and energy as

5893-426: The particle traverses a series of accelerating regions, driven by a source of voltage in such a way that the particle sees an accelerating field as it crosses each region. In this type of acceleration, particles must necessarily travel in "bunches" corresponding to the portion of the oscillator's cycle where the electric field is pointing in the intended direction of acceleration. If a single oscillating voltage source

5976-523: The range from around 100 MHz to a few gigahertz (GHz) and use the electric field component of electromagnetic waves. When it comes to energies of more than a few MeV, accelerators for ions are different from those for electrons. The reason for this is the large mass difference between the particles. Electrons are already close to the speed of light , the absolute speed limit, at a few MeV; with further acceleration, as described by relativistic mechanics , almost only their energy and momentum increase. On

6059-495: The research community. This will be achieved through close cooperation between the ILC International Development Team (IDT), an international promotion organization established under ICFA, and the domestic research community. 3. The Ministry of Education, Culture, Sports, Science and Technology (MEXT) should play an active role in collaborating with the international research community to achieve

6142-409: The surface in non-permeable soil. Dubna has a pre-accelerator complex which could have been easily adapted for the needs for the ILC. But all three were more or less well suited for housing a Linear Collider and one had ample choice for a site selection process in Europe. Outside Europe a number of countries expressed interest. Japan receives a large amount of funding for neutrino activities, such as

6225-481: The towns of Ichinoseki and Yamame with the villages of Mataki and Nakasato. Ichinoseki has a mayor-council form of government with a directly elected mayor and a unicameral city council of 25 members. Ichinoseki and the town of Hiraizumi collectively contribute five seats to the Iwate Prefectural legislature. In terms of national politics, the city is part of Iwate 3rd district of the lower house of

6308-423: The treatment room itself requires considerable shielding of the walls, doors, ceiling etc. to prevent escape of scattered radiation. Prolonged use of high powered (>18 MeV) machines can induce a significant amount of radiation within the metal parts of the head of the machine after power to the machine has been removed (i.e. they become an active source and the necessary precautions must be observed). In 2019

6391-561: The tunnel is located deep underground in non-permeable bedrock. This site was considered favorable for a number of practical reasons but due to the LHC the site was disfavored. At DESY in Hamburg the tunnel is close to the surface in water saturated soil. Germany leads Europe for scientific funding and was therefore considered reliable in terms of funding. At JINR in Dubna the tunnel is close to

6474-417: The tunnel now given over to the LHC, were limited to 209 GeV by energy loss via synchrotron radiation. Even though the nominal collision energy at the LHC will be higher than the ILC collision energy (14,000  GeV for the LHC vs. ~500 GeV for the ILC), measurements could be made more accurately at the ILC. Collisions between electrons and positrons are much simpler to analyze than collisions in which

6557-576: The two diagrams, the curve and arrows indicate the force acting on the particles. Only at the points with the correct direction of the electric field vector, i.e. the correct direction of force, can particles absorb energy from the wave. (An increase in speed cannot be seen in the scale of these images.) The linear accelerator could produce higher particle energies than the previous electrostatic particle accelerators (the Cockcroft–Walton accelerator and Van de Graaff generator ) that were in use when it

6640-497: The utility of radio frequency (RF) acceleration. This type of linac was limited by the voltage sources that were available at the time, and it was not until after World War II that Luis Alvarez was able to use newly developed high frequency oscillators to design the first resonant cavity drift tube linac. An Alvarez linac differs from the Wideroe type in that the RF power is applied to the entire resonant chamber through which

6723-554: Was hearsay from within the scientific community, and very few facts were published officially. The information presented above is a summary of that contained in the International Workshop on Linear Colliders 2010 (ECFA-CLIC-ILC Joint Meeting) at CERN. The 2008 economic crisis led the United States and United Kingdom to cut funds to the collider project, leading to Japan's position as the most likely host for

6806-527: Was informed partly by the Science Council of Japan . The Japanese government sought monetary support from other countries to help fund this project. In 2022, the Japanese plan for the ILC was "shelved" by a panel for Japan’s Ministry of Education, Culture, Sports, Science and Technology (MEXT) Several reasons were given, including potentially insufficient international support and the CERN proposal for

6889-620: Was invented. In these machines, the particles were only accelerated once by the applied voltage, so the particle energy in electron volts was equal to the accelerating voltage on the machine, which was limited to a few million volts by insulation breakdown. In the linac, the particles are accelerated multiple times by the applied voltage, so the particle energy is not limited by the accelerating voltage. High power linacs are also being developed for production of electrons at relativistic speeds, required since fast electrons traveling in an arc will lose energy through synchrotron radiation ; this limits

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